Researchers correct genetic mutation

UCLA researchers led by Dr. Donald Kohn have created a method for modifying blood stem cells to reverse the genetic mutation that causes a life-threatening autoimmune syndrome called IPEX. The gene therapy, which was tested in mice, is similar to the technique Kohn has used to cure patients with another immune disease, severe combined immune deficiency, or SCID, also known as bubble baby disease.

The work is described in a study published in the journal Cell Stem Cell.

IPEX is caused by a mutation that prevents a gene called FoxP3 from making a protein needed for blood stem cells to produce immune cells called regulatory T cells. Regulatory T cells keep the body’s immune system in check; without them, the immune system attacks the body’s own tissues and organs, which is known as autoimmunity.

The approach adds a normal copy of the FoxP3 gene to blood stem cells, which can produce all types of blood cells. In the study, the approach corrected the genetic mutation in mice with a version of IPEX that’s similar to the human version of the disease, and it restored proper immune regulation.

To get the normal copy of the FoxP3 gene to the proper place within the blood stem cells, the researchers used a tool called a viral vector — a specially modified virus that can carry genetic information to a cell’s nucleus without causing a viral infection. The UCLA team engineered the viral vector used in the study so that the gene is turned on only in regulatory T cells, but not in other types of cells.

“It’s exciting to see how our gene therapy techniques can be used for multiple immune conditions,” said Kohn, a professor of pediatrics and microbiology, immunology and molecular genetics at the David Geffen School of Medicine at UCLA and member of the Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research at UCLA. “This is the first time we’ve tested a technique that targets an autoimmune disorder, and the findings could help us better understand or lead to novel treatments for other autoimmune conditions such as multiple sclerosis or lupus.”

The name IPEX stands for immune dysregulation, polyendocrinopathy, enteropathy, X-linked. The syndrome can affect the intestines, skin and hormone-producing glands such as the pancreas and thyroid, as well as other parts of the body. It is typically diagnosed within the first year of life and can be life-threatening in early childhood. IPEX can be treated with a bone marrow transplant, but finding a matched bone marrow donor can be difficult, and the transplant procedure is often risky because people with IPEX can be very sick.

In the new study, the UCLA researchers used viral vectors to deliver normal copies of the FoxP3 gene to the genome of the mice’s blood stem cells so that they produced functional regulatory T cells. All of the mice in the study were virtually free of IPEX symptoms shortly after the treatment.

“It’s incredibly important that we only create regulatory T cells that have the non-mutated FoxP3 gene,” said Katelyn Masiuk, a student in the ULCA physician-scientist degree program and the study’s first author. “We found that if the FoxP3 protein is turned on in blood stem cells, the whole blood system functions abnormally. We realized that we needed a vector that only made FoxP3 in the regulatory T cells made from the blood stem cells, but not in the blood stem cells themselves or other types of blood cells they make.”

The researchers also put their IPEX-targeting vector into human blood stem cells and then transfused those cells into mice without immune systems. The human blood stem cells were able to produce regulatory T cells that turned on the vector.

Kohn, who also is a member of the UCLA Children’s Discovery and Innovation Institute and the UCLA Jonsson Comprehensive Cancer Center, said the results are promising and the researchers hope to test the approach in human patients.

Kohn said that to treat humans with IPEX, blood stem cells would be removed from the bone marrow of patients with IPEX. Then, the FoxP3 mutation would be corrected in a lab using the IPEX-targeting vector. The patients would receive a transplant of their own corrected blood stem cells, which would produce a continuous life-long supply of regulatory T cells.

Kohn is also the principal investigator in a clinical trial that is testing the use of patients’ own genetically corrected blood stem cells to treat sickle cell disease, the most common inherited blood disorder in the U.S. And in another study led by Kohn, a similar technique has cured 40 babies with SCID.

Kohn, Masiuk, Dr. Roger Hollis (a study co-author and member of Kohn’s lab) and Dr. Maria Grazia Roncarolo of Stanford University are inventors of the FoxP3 vector, for which a patent application has been filed by the UCLA Technology Development Group on behalf of the Regents of the University of California.

The FoxP3 vector for IPEX is not yet available in clinical trials and has not been approved by the FDA for use in humans.

The research was funded by the UCLA Molecular Biology Institute’s Whitcome Predoctoral Training Program and the T32 Medical Scientist Training Program, a program of the National Institute of General Medical Sciences. provide custom protein services in the biological sciences, enabling access to the latest tools, techniques, and expertise with competitive pricing and rapid turnaround time. We serve a broad spectrum of industrial and academic clients with a commitment to delivering high-quality data and customer services. Here are some our products: SPRCo-ImmunoprecipitationPull-DownsCLIP-seq, etc.

Introduction to a protein engineering technique—mutation

Positional mutation is a protein engineering technique that substitutes, inserts or deletes specific nucleotides in known DNA sequences based on the known structure and function of proteins to produce mutant protein (enzyme) molecules with novel traits. The technology is widely used in the biological and medical fields. Position mutation technology has the characteristics of high mutation rate, simple and easy to perform, and good repeatability. As a research method, localization mutation technology is also widely used to study the relationship between protein structure and function, so as to elucidate the regulation mechanism of genes, the etiology and mechanism of diseases.




The “small change” of protein molecules based on natural protein structure refers to the modification, substitution or deletion of a few residues of proteins of known structure. This is the most widely used method in protein engineering, and can be mainly divided into proteins. Two types of modification and gene location mutation. Gene-localized mutation refers to the transformation of protein molecules at the genetic level, that is, the method of site-directed mutagenesis, the insertion, deletion, substitution and reorganization of nucleotide codons of genes encoding proteins, and then the mutated genes are carried out. The protein expresses and analyzes the functional activity of the expressed protein, and the result provides a new design for protein molecular engineering.


Design goals and solutions for location mutation

The common design goals of localization mutations are to improve the heat and acid stability of proteins, increase activity, reduce side effects, improve specificity, and conduct structural-functional studies through protein engineering. Hartley is equal to 1986 to complete a design goal and solution that we want, and still has important reference value. The stability of protein is an important prerequisite for the normal biological activity of proteins. Therefore, improving the stability of proteins has become one of the important goals of protein design and transformation.


Type of mutation

There are many ways to change the nucleotide sequence of a gene, such as chemical synthesis of genes, direct modification of genes, and cassette mutation technology. Depending on the manner in which the gene is mutated, it can also be classified into three categories: insertion of one or more amino acid residues; deletion of one or more amino acid residues; replacement or substitution of one or more amino acid residues. In order to achieve the purpose of gene location mutation, in vitro recombinant DNA technology or PCR method is often used.


Site-directed mutation

The amino acids in a protein are determined by the triplet codon in the gene. By changing one or two bases, the amino acid species can be changed to produce a new protein. It is usually the amino acid that changes a position in the functional region to study the structure, stability or catalytic properties of the protein. The work of point mutation is the main body of current protein engineering research. So far, many kinds of proteins such as subtilisin, T4 lysozyme, dihydrofolate reductase, trypsin and ribonuclease have been modified. For example, replacing Asn117 of a tissue-type plasminogen activator (t-PA) with Glu117, thereby removing an original glycosylation site; since the original sugar chain can promote t -PA is cleared from plasma, so point mutations can reduce plasma clearance of t-PA and prolong plasma half-life.


Box mutation

In 1985, Wells proposed a genetic modification technique for a box-type mutation that can produce 20 different amino acid mutants at one site, and can perform “saturation” analysis of important amino acids in protein molecules. Using the localization mutation, two original vectors and endonuclease cleavage points not present on the gene are added on both sides of the amino acid code to be modified, and the endonuclease is used to digest the gene, and then the synthesized double-stranded DNA fragment with different changes is substituted for digestion. part. A variety of mutant genes can be obtained in such a single treatment.


Procedure for locating mutations

The protein molecular design program for gene localization mutation follows the procedure in the design principle, but the gene location mutation has its own particularity, and its specific procedure is as follows.

  1. Establish a structural model of the protein under study

Establishing a three-dimensional structural model of a protein is critical to establishing a mutation site or region and predicting the structure and function of the mutated protein. The structure can be determined by X-ray crystallography, two-dimensional nuclear magnetic resonance, or the like, or a structural model can be established based on the structure of the analog or other structural prediction methods.

  1. Identify locations that have a significant impact on the required properties
  2. Predict the structure of the mutant
  3. Construct mutants. Mutant protein
  4. Examination of mutant proteins


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Introduction to plant tissue culture

Tissue culture techniques of higher plants refer to techniques for isolating one or several individual cells or a part of a plant body for cultivation.

Generally speaking, we refer to a generalized tissue culture in which a part of a plant body (i.e., an explant) is isolated by aseptic processing, inoculated on a medium, and cultured under artificially controlled conditions to produce a complete plant.

Image: plant cell culture

Physiological basis of plant cell culture

Cell totipotency: Each cell of a plant carries a complete set of genomes and has the potential to develop into a full plant.

Plant growth regulating substances play a key role in the differentiation and determination of plant cell tissues. It includes: auxins, cytokinins, gibberellins, abscisic acid, ethylene, and the like.

Auxins are mainly used for the formation of callus, the production of somatic embryos and the rooting of test-tube seedlings. Commonly used auxins are 2,4-D, NAA (naphthaleneacetic acid), IBA (indolebutyric acid), IAA (indole acetic acid) and the like. Its effect is 2,4-D>NAA>IBA>IAA.

Cytokinins promote cell division and differentiation, delay tissue aging, and promote bud production. Commonly used cytokinins are Zip, KT (clopidogrel), 6-BA (6-benzylaminoadenine), ZT (zeatin) and others. The order from strong to weak is Zip>KT>6-BA>ZT.

Gibberellin promotes the growth of differentiated shoots and breaks the dormancy of seeds. Commonly used gibberellin is GA3.

Types of plant cell culture

Tissue culture can be divided into tissue or callus culture, organ culture, plant culture, cell and protoplast culture according to the culture target.

  1. Tissue or callus culture is a tissue culture in a narrow sense, which is to cultivate various parts of the plant, such as shoot tip meristem, formation layer, xylem, phloem, epidermal tissue, endosperm tissue and thin wall tissue, etc.; or culture of callus produced by plant organ culture, both of which are induced to form plants by re-differentiation.
  2. Organ culture, namely the culture of isolated organs, depend on the crop and needs, may include isolation of shoot tips, stem segments, root tips, leaves, leaf primordia, cotyledons, petals, stamens, pistils, ovules, embryos, ovary, or fruits culture of explants.
  3. Plant culture is the cultivation of intact plant material, such as seedlings and larger plants.
  4. Cell culture is a culture of ex vivo single cells or pollen single cells or small cell clusters which can maintain good dispersibility by liquid shaking culture of callus or the like.
  5. Protoplast culture is the cultivation of protoplasts that remove cell walls by

enzymatic and physical methods.

Characteristics of plant cell culture

Tissue culture is a new technology developed in this century. Due to the advancement of science and technology, especially the application of exogenous hormones, tissue culture not only provides theoretically reliable experimental evidence for related disciplines, but also becomes a kind of a new method for large-scale, batch-scale production of seedlings.

The reason why plant tissue culture has developed so rapidly is that it has such a wide range of applications due to the following characteristics:

  1. Culture conditions can be artificially controlled.

The plant material used in tissue culture is completely grown under artificially supplied culture medium and microclimate environment. It is free from the adverse effects of four seasons, day and night changes and severe weather in nature, and the conditions are uniform, which is very beneficial to plant growth. It is convenient for stable annual production.

  1. Short growth cycle and high reproductive rate.

Due to artificially controlled culture conditions of plant tissue culture, it provides different culture conditions according to various requirements of parts of plants, so the growth is faster. In addition, the plants are also relatively small, often 20-30d for a cycle. Therefore, although plant tissue culture requires certain equipment and energy consumption, since plant materials can be produced in a geometrical order, the overall cost is low, and high-quality seedlings or virus-free seedlings of uniform specifications can be provided in time.

  1. Convenient management, which is conducive to factory production and automation control

Plant tissue culture is conducted under certain conditions of temperature, light, humidity, nutrition, hormones, etc. in a certain place and environment, which is highly conducive to high intensification and high-density factory production, and is also conducive to automatic control of production.

It is the development direction of future agricultural factory cultivation. Compared with pot cultivation and field cultivation, it saves a series of complicated labors such as cultivating and weeding, watering and fertilizing, and controlling pests and diseases, which can greatly save manpower, material resources and land needed for field planting.

Lifeasible offers a complete range of high-quality plant tissue culture products that facilitate the development of new plant traits and large-scale production, including Amino Acids, Antibiotics, Auxins etc.

Detailed introduction of protein structure

Protein is mainly composed of chemical elements such as carbon, hydrogen, oxygen and nitrogen. It is an important biological macromolecule. All proteins are multimers formed by the connection of 20 different amino acids. After Forming proteins, these amino acids are also called as a residue.


The boundaries between proteins and peptides are not very clear. Some people believe that the number of residues required for a functionally acting domain is called a polypeptide or peptide if the number of residues is less than 40. To function biologically, proteins need to be properly folded into a specific configuration, mainly through a large number of non-covalent interactions (such as hydrogen bonds, ionic bonds, van der Waals forces and hydrophobic interactions); in addition, in some proteins (especially in the case of secreted proteins), disulfide bonds also play a key role. In order to understand the mechanism of action of proteins at the molecular level, it is often necessary to determine the three-dimensional structure of a protein. Structural biology has been developed by studying protein structure, using techniques including X-ray crystallography, nuclear magnetic resonance, etc. to resolve protein structures.


A certain number of residues are necessary to exert a certain biochemical function; 40-50 residues are usually the lower limit of the size of a functional domain. Protein size can range from such a lower limit up to thousands of residues. The current estimated average length of proteins differs between different species, typically about 200-380 residues, while eukaryotes have an average protein length of about 55% longer than prokaryotes. Larger protein aggregates can be formed by many protein subunits; for example, by the polymerization of thousands of actin molecules to form protein fibers.


Discovery history

In 1959, Perutz and Kendrew analyzed the structure of hemoglobin and myoglobin, solved the three-dimensional structure, and won the 1962 Nobel Prize in Chemistry.

Pauling discovered the basic structure of the protein. Based on the X-ray diffraction data, Crick and Watson proposed a model of the three-dimensional structure of DNA. Received the 1962 Nobel Prize in Physiology or Medicine. After the 1950s, Hauptmann and Karle established a purely mathematical theory for the direct determination of crystal structures using X-ray analysis, which has epoch-making significance in crystal research, especially in the study of macromolecular biological substances such as hormones, antibiotics, and proteins. And the molecular structure of new drugs played an important role. They were awarded the 1985 Nobel Prize in Chemistry.


Structure type

Protein molecules are covalent polypeptide chains formed by the condensation of amino acids end-to-end, but natural protein molecules are not loose random polypeptide chains. Each natural protein has its own unique spatial structure or three-dimensional structure, which is often referred to as the conformation of the protein, ie the structure of the protein.

The molecular structure of a protein can be divided into four levels to describe its different aspects:

Primary structure: A linear amino acid sequence that makes up a protein polypeptide chain.

Secondary structure: a stable structure formed by hydrogen bonds between C=O and N-H groups between different amino acids, mainly α-helix and β-sheet.

Tertiary structure: The three-dimensional structure of a protein molecule formed by the arrangement of multiple secondary structural elements in three dimensions.

Quaternary structure: used to describe a protein complex molecule that is functionally formed by interactions between different polypeptide chains (subunits).

In addition to these structural levels, proteins can be transformed in multiple similar structures to perform their biological functions. For functional structural changes, these tertiary or quaternary structures are usually described in a chemical conformation, and the corresponding structural transformation is referred to as a conformational change.



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What is Adjuvant Selection?

Adjuvant Selection is the main method for finding molecular genetic markers, vaccines like bacterial vaccines, cancer vaccines, RNA vaccines, MAS breeding and so on.

Major methods for finding molecular genetic markers

DNA markers are divided into two types: type Ⅰ markers, mainly are some single genes, and used to compare the homologous loci varieties of relative distance and chain and linear correlation; Ⅱ type markers, mainly high polymorphism, information content rich DNA fragments, is one of the most commonly used microsatellite marker. Through Adjuvant Optimization, more and more kinds of molecular markers were introduced, including restricted fragment length polymorphism (RFLP), random amplified polymorphic DNA (RAPD), amplified fragment length polymorphism (AFLP), and Microsatellites. At present, there are 2,505 markers in the world’s pig research, including 1,391 microsatellite markers. Ⅰ type 873, type Ⅱ mark 1632.

The main methods to search for molecular genetic markers are candidate gene method and genome scanning method.

  1. Candidate gene method as a candidate gene for a trait, it is usually some genes whose biological functions and nucleic acid sequences are known, and they are involved in the growth and development process of the trait. These genes may be structural genes, regulatory genes or genes that affect the expression of traits in biochemical metabolic pathways. Candidate gene method research should follow certain steps, such as candidate gene selection primer design, gene specific fragment amplification, polymorphic locus search and so on. Candidate gene search USES genes that are thought to have a direct physiological function for a trait to find QTLS. In addition, genes found in other species that control some traits can be studied as candidate genes for pigs. For example, the h-fabp gene affects the backfat thickness and intramuscular fat content of pigs (Gerbens et al., 1999). 2000; 2001); The melanocorticoid receptor 4 (MC4R) gene was significantly correlated with the intake, backfat thickness and growth rate of pigs (Kim et al., 1999; 2000).
  2. Genome scanning: all genetic information is stored on the 19 pairs of chromosomes of the pig. Reference families were established, such as meishan European and American pig species, wild boar big white pig, and their hybrid offspring were used to find QTL through genetic markers. The most effective design is the genotype analysis of F2 generation isolation population. Figure 4-2 is a simple schematic diagram of single genetic marker and linkage QTL analysis. Alleles of genetic markers and their linkage QTL in F1 generation were heterozygous. In the F2 generation isolation population, the ratio of the three possible genotypes per seat should be 1:2:1, when the average performance of marker genotypes is compared, the existence of linkage QTL can be analyzed.

Anderson (1994), such as reported with a wild boar by the results of the large white building reference group, using the 105 DNA markers in the genetic map, the separation of F2 generation 200 pigs linkage analysis research found that on chromosome 4 seat back fat and control the growth rate, the average genetic effect 24 g/d and 5 mm, respectively, the equivalent of F2 DaiQun total phenotypic variation of 12% and 18%. Daily weight gain can differ by more than 50g between two extreme homozygous genotypes, resulting in a 10kg weight difference at market time in pigs.

(iii) MAS breeding

In pig breeding selection, it is difficult to determine the sex efficiency of low heritability (e.g., reproductive traits), high cost of measurement (e.g., disease resistance), phenotypic values (e.g., lean meat rate) or limited sexual performance (e.g., milk production) early in development. It is estimated that the selection of the marker before the determination of the offspring can increase the selectivity response by 10%~15%. The MAS of compatriots who choose to combine can be increased by about 40%. Combining multiple genetic markers and trait information, the selectivity response can be increased by 50%~200%. Using marker selection in cross breeding can predict and make full use of heterosis. Molecular genetic markers can also be applied to early selection and screening and detection of large populations to select populations with desired genotypes.

For example, there is little progress in the improvement of pig litter, a low genetic trait, by traditional methods. Rothschild et al. found in 1994 that the estrogen receptor (ESR) gene was one of the main genes responsible for the litter size of pigs, which could control the total litter size of 1.5 pigs and the live litter size of 1 pig in the meishan synthetic line of China. In the Chinese two-flower face hybrid population, the agricultural university of China not only confirmed the results of Rothschild et al., but also found another main gene locus controlling the number of piglets – FSH, which can control the total number of piglets and the number of live piglets by 2.0.

Although MAS can improve the effectiveness of selection and the annual amount of genetic improvement, its effectiveness is also affected by many factors. In addition to the heritability of traits, the intensity of selection, and the size of the selected population, the determinants are the linkage between genetic markers and QTLS. Zhang (1992) pointed out that each QTL could be specifically detected by using genetic markers closely linked to QTL, and the final selection of genetic markers would be equivalent to the selection of QTL itself. Therefore, genetic markers closely related to QTL must be obtained in order to improve MAS efficiency. Resources at present, through the establishment of the pig family, has some related to the growth, reproduction and carcass, meat quality of QTL mapping in some microsatellite nearby, such as on chromosome 3 microsatellite Sw2427 – Sw251 area and daily gain of pigs, on chromosome 4 S0101 – S0107 area and back fat belly fat, 7 chromosome S0064 S0066 regional composition and has a strong correlation between birth weight and body. It can be predicted that with the discovery of more genetic markers closely linked to QTL, MAS will be applied more effectively in practical breeding.

Cancer vaccine types and delivery systems (part Two)

3 Cancer vaccine adjuvant selection

The initial aim of formulating vaccines in adjuvants was to deliver the antigen in a poorly metabolizing and slowly degrading substance. The intention was to favor the slow and sustained release of the antigen to be captured by antigen-presenting cells (APCs) and be subsequently presented to T cells. Aluminum salts are widely used to favor T helper cell 2 (Th2)-mediated humoral immunity, but they are less efficient for promoting Th1-dependent immunity. To this aim, water-in-oil adjuvants have been developed to create a depot of the antigen at the site of the injection. The next generation of vaccine delivery agents includes nanoparticles such as silica or liposomes or synthetic polymers, which are ideal vehicles to be taken up by dendritic cells (DCs) patrolling within the subcutaneous tissues. However, the challenge with such supports is to selectively promote DC uptake while eluding the systemic reticuloendothelial network of macrophages, which routinely clear circulating particles. In addition to these substances designed to favor delivery of the antigen to APCs, today’s therapeutic vaccines also contain another class of adjuvants aimed to deliver danger signals to activate the immune system, as antigen alone may fail to prime effective T cell responses or even induce tolerance.

4 The choice of cancer vaccine delivery system

The choice of delivery systems and route of immunization depends on the end use of the vaccine. For practical reasons and minimal side effects, most prophylactic vaccines are administered via the skin, usually by subcutaneous injections in the epidermis or the dermis. These two locations are ideal, as they are enriched respectively in Langerhans DCs and dermal DCs, both cell populations being very efficient in capturing and processing antigens. The oral route is also very convenient and is used by vaccines against polio, typhoid fever, cholera, and rotavirus. The oral route is, however, more challenging in view of the extreme conditions in the gastrointestinal tract, including the low pH in the stomach and the presence of microbiota, which may degrade the antigen before it reaches the lymphoid organs. Moreover, the usually tolerogenic gut environment may not be ideal to generate a strong systemic immune response.

With regard to therapeutic vaccines used to treat chronic noncontagious diseases such as cancer, atopy, or diabetes, both immediate cellular effector responses and long-term immunity are desired to guarantee the continuous immune-surveillance of the disease. Although prophylactic vaccines for global immunization programs must be simple, inexpensive, and given via a noninvasive route, therapeutic cancer vaccines can benefit from more complicated technologies and use more invasive routes of delivery if beneficial for the patient. There is a very large array of cancer vaccines under development which use various delivery systems, and which are being tested in clinical trials. Other delivery routes tested in therapeutic cancer vaccines range from subcutaneous and intradermal to more invasive intraperitoneal and intranodal injections, to optimize antigen uptake by APCs and favor a local potent immune response. For instance, particulate therapeutic vaccines such as virosomes or nanoparticles can be injected in LNs using an ultrasound-guided imaging procedure. Although most of these strategies are still in the development stage, the potential to achieve strong and long-lasting antitumor responses is high, owing to new delivery systems and better understanding of T cell memory development.


[1] FUTURE II Study Group. Quadrivalent vaccine against HumanPapillomavirns to prevent high-grade cervical lessions. N Engl J Med, 2007, 356(19): 1915

[2] Olsson SE, Villa LL, Costa RLR, et a1. Induction of inmmne memory following administration of a prophylactic quadrivalent human papillomavirus (HPV) types 6/1 1/16/18 LI virus-like particle (VLP) vaccine. Vaccine, 2007 (25): 4931

[3] Harris JE, Ryan L, Hoover Jr HC, et a1. Adjuvant active specific immunotherapy for stage II and III colon cancer with an autologous tumor cell vaccine: Eastern Cooperative Oncology Group Study E5283. J Clin Orwol, 2000, 18(1): 148

[4] Berd D, Maguire Jr HC, Mastrangelo MJ, et a1. Treatment of human melanoma with a hapten — modified antologous vaccine. Ann NY Acad Sci, 1993, 690(8): 7

[5] Remann R, Goldschmidt AJ, Richter A. Adjuvant therapy of renal cell carcinoma patients with an autologous tumor cell lysate vaccine: a-year—follow—up analysis AnticancerRes, 2003, 23(2A): 969

[6] Mitchell MS, Kan — Mitchell J, Kempf RA, et a1. Active specific im-munotherapy for melanoma: phase I trial of allogeneic lysates and a novel adjuvant. Cancer Res, 1988, 48(20): 5883

Current status of clinical diagnosis and treatment of pemphigus (part two)

3 Benign Mucous Membrane Pemphigoid

3.1 Clinical manifestations

Conjunctival and oral mucosal damage accounted for 60% to 90%, patients with nasal, pharyngeal, genital and anal mucosa accounted for about 25%, skin involvement is rare, skin damage is very similar to the lesions of bullous pemphigoid, but the time is short, and the stenosis or adhesion caused by scar healing and scar formation is characteristic.

3.1.1 Eye damage

The eye is the only affected part, and the damage usually occurs asymmetrically. After 1 to 2 years, the contralateral eye mucosa is involved. There are symptoms of catarrhal conjunctivitis. Transparent blisters can be found and quickly ruptured. Subsequently, scar atrophy, conjunctival and bulbar conjunctiva adhesions, eye movement involvement, tendon varus leading to secondary corneal changes, corneal opacity, scar formation of the tarsal plate with mucosa, atrophy of the gland and blockage of the lacrimal duct, thus corneal dryness, discoloration and blinding ulcers are formed.

3.1.2 Mucosal damage

Multiple blisters quickly form painful erosions and the scars heal. If the damage occurs in the tongue ligament, the contracted scar can limit the movement of the tongue. Damage that occurs in soft palate, tonsil, and buccal mucosa may limit food intake. The genital area of ​​the vulva can form a head adhesion, a vaginal stenosis, and the like.

3.1.3 Skin damage

The incidence of skin damage is only about 25%, the damage is a tension blisters, the blister wall is not easy to rupture, occurs on erythematous skin, one or more parts. Healed with atrophic scars. If bullae occur in the head, scarring hair loss may occur. Generalized lesions are extremely rare, and even if there are secondary scar formation.

Benign mucosal pemphigoid can occur repeatedly for several years without significant effect on general health. The faster the disease progresses, the worse the prognosis. Due to eating difficulties, malnutrition and cachexia may occur, and the incidence of blindness is approximately 20% to 60%. Although extremely rare, there have been reports of cancerous changes in the scars of the oral mucosa.

3.2 Laboratory examination

3.2.1Histopathology: typical epidermis blister, no spine release. Infiltration of inflammatory cells composed of lymphocytes, plasma cells, and eosinophils can be seen in the upper dermis. Subsequently, there were a large number of fibroblasts with superficial dermal fibrosis and vascular hyperplasia and scar contracture.

3.2.2 Immunofluorescence: direct immunofluorescence of skin mucosa to detect IgG and C3 deposition in the basement membrane zone, and IgA and C3 deposition were also observed. The homogenous linear deposition was almost the same as that in bullous pemphigoid. The positive rate of indirect immunofluorescence detection of anti-basal membrane circulating antibodies was <10%, and the titer was low. If the DIF is negative, the fresh tissue should be removed from the erythema around the lesion for repeated testing.

4 Pathogenesis of Pemphigus

In the plasma of patients with pemphigus, there is anti-Dsg3 and/or anti-Dsg1 IgG, and no anti-Dsg2 antibody exists. This autoreactive antibody binds to its corresponding antigen, leading to a series of clinical pemphigus. The emergence of performance. In the active phase of pemphigus vulgaris, the serum is mainly pathogenic IgG4 subclass and IgG1, while in the serum of patients with long-term remission, there are low-valency IgG1 subclasses, IgG4 and Dsg1 and Dsg13 on keratinocytes. The combination causes the loss of adhesion between cells, leading to the release of intercellular cells and the formation of blisters in the epidermis.

The antigen Dsg produced in the MMP autoimmune disease belongs to the transmembrane component of desmos, belonging to the cadherin superfamily in the adhesion molecule, whose gene is located at 18q12.1. Dsg is divided into three categories: Dsg1, Dsg2, and Dsg3. Among them, Dsg2 is expressed in all tissues with desmosome, including monolayer epithelial cells and myocardial tissue. Dsg1 and Dsg3 are mainly restricted to stratified squamous cells. Current studies have shown that Dsg1 and Dsg3 are target antigens of pemphigus foliaceus (PF) and pemphigus vulgaris (PV), respectively. The relative molecular mass of Dsg3 is about 130 kD. which is mainly distributed on the surface of keratinocytes in the basal layer of the epidermis and the upper layer of the basal layer. The relative molecular mass of Dsg1 is about 160 kD, which is mainly distributed on the keratinocyte membrane in the upper layer of the epidermis, with the advantage of granular layer and subgranular layer expression. The Dsg3 and Dsg1 molecules, like other cadherin molecules, have five tandem repeats of approximately equal size extracellular domain (EC), each of which is approximately 100 amino acid residues in length, of which EC1 the region corresponds to the extracellular amino terminal residue and EC5 is at the carboxy terminus. The difference between Dsg1 and Dsg3 is mainly due to the homology of the 1 to 4 extracellular domains of Dsg1 and the homology of the 5 extracellular domains of Dsg3. Unlike classical cadherins, Dsg1 has a longer intracellular fragment, and the extracellular fragment of Dsg3 is slightly longer than Dsg1, but its intracellular domain is slightly shorter and has no glycine/serine-rich region.

In the five extracellular domains of the pemphigus antigen, EC1, EC2, and EC4 have relatively large homology and can be specifically recognized by the plasma of pemphigus patients. Therefore, these epitopes are called “an immune-dominant epitope, or a “pathogenic epitope,” an antibody that specifically recognizes an epitope is called a “pathogenic antibody.” The pemphigus antigen contains at least one “pathogenic epitope” in the EC1 -2 region, and antibodies against EC1 -2 are closely related to the pathogenesis of pemphigus. The recombinant protein expressed by the EC1 -2 and EC3 -4 gene sequences of Dsg3 only reacted with the plasma of pemphigus patients, and the response rates of the two were 57.9 % and 52.6%, respectively, and the bullous pemphigoid, system Lupus erythematosus and normal people do not respond. This indicates that EC1 -2 and EC3 -4 are antigen-specific and have a high affinity with pemphigus antibodies, thus providing a new approach for serological diagnosis and identification of pemphigus.

In Dsg1 and Dsg3, when either function is lost, the other can partially compensate for its function. This theory explains the tissue specificity of the loss of intercellular adhesion caused by autoantibodies in pemphigus patients. Because Dsg1 and Dsg3 have a certain distribution pattern, the difference in anti-Dsg antibodies also leads to differences in the clinical manifestations of pemphigus. By inserting the Dsg1 gene into Dsg3 knockout mice to form a transgenic mouse capable of expressing Dsg1, it was found that Dsg1 can compensate for partial Dsg3-mediated loss of intercellular adhesion function, which is confirmed genetically.

5 Treatment

Glucocorticoid is preferred for the treatment of pemphigus. Most scholars at home and abroad are empirical drugs. There are ethnic and regional differences in the choice of hormone dose. At present, the severity of the disease is not unified by using the scoring system. If the two are linked to the hormone dose and applied to the clinic, the treatment plan will be more reasonable. Determine the initial dose of hormone according to the ABSIS system: ABSIS skin severity score ≤10, give 30 ~ 40 mg / d, skin score of 10 ~ 50, 60 mg / d is appropriate, skin score > 50 points, give 80 mg /d. If the skin lesions are not controlled for 5 to 7 days, increase the dose by 50%. Reduced indications: Daily new blistering number <5, no new erythema; no obvious exudation of erosion surface; pemphigus antibody titer decreased earlier; ABSIS skin score decreased by more than 35%.

The long-term use of large doses of hormones can easily lead to many drug reactions. Therefore, the combination of immunosuppressive agents, including azathioprine, cyclophosphamide, mycophenolate mofetil, etc., is generally used to reduce the number of hormones and shorten the treatment time. At the same time, it can be combined with an immune-modulator (Amlalazine, etc.), plasma exchange method and in vitro. Photochemotherapy, etc. Randomized controlled observation of prednisone combined with mycophenolate mofetil, azathioprine and prednisone alone in the treatment of 42 cases of pemphigus, combined with the ABSIS system to assess the severity of the disease before and after treatment, the results show that the three treatment days The short-term efficacy and safety of acne are similar, but prednisone combined with mycophenolate mofetil reduces the dose of hormones most significantly. In recent years, some biological agents and treatments have become new choices for the treatment of pemphigus, such as rituximab, high-dose intravenous immunoglobulin (IVIG), immunosorbent assay, TNF-α antagonist and hematopoietic stem cell transplantation therapy.

For the severe bullous disease such as pemphigus, detecting the Dsg ELISA index has certain guiding significance for judging its severity. However, if medical workers are to accurately grasp the changes in their condition, they also rely on an effective and widely recognized scoring system to provide a reliable clinical basis for the treatment and adjustment of pemphigus. At present, there are few clinical applications of ABSIS and PDAI. Both have their own advantages and disadvantages. If they can be combined, it is expected to improve the evaluation method. The correlation between the disease scoring system and antibody levels, and the number of hormones controlled by scoring will be important research topics. Many new drugs and treatments have emerged in recent years, and multi-center large-scale clinical trials are still needed to explore the best treatment options.



[1] Barnadas MA, Rubiales MV, Gich I, et al. Usefulness of specific anti-desmoglein 1 and 3 enzyme-linked immunoassay and indirect immunofluorescence in the evaluation of pemphigus activity [J]. Int J Dermatol, 2015, 54(11): 1261-1268.

[2] Daneshpazhooh M, Kamyab K, Kalantari MS, et al. Comparison of desmoglein 1 and 3 enzyme – linked immunosorbent assay and direct immunofluorescence for evaluation of immunological remission in pemphigus vulgaris [J]. Clinical & Experimental Dermatology, 2014, 39(1): 41-47.

[3] Nakahara T, Takagi A, Yamagami J, et al. High anti-desmoglein 3 antibody ELISA index and negative indirect immunofluorescence result in a patient with pemphigus vulgaris in remission: evaluation of the antibody profile by newly developed methods [J]. Jama Dermatology, 2014, 150(12): 1327-1330.

[4] Pfutze M, Niedermeier A, Eming R. Introducing a novel autoimmune bullous skin disorder intensity score ( ABSIS) in pemphigus [J]. Eur J Dermatol, 2007, 17(1): 4-11.

[5] Murrell DF, Dick S, Amagai M, et al. Consensus statement on definitions of disease, end points, and therapeutic response for pemphigus [J]. J Am Acad Dermatol, 2008, 58(6): 1043-1046.

[7] Chams-Davatchi C, Rahbar Z, Daneshpazhooh M, et al. Pemphigus vulgaris activity score and assessment of convergent validity [J]. Acta Med Iran, 2013, 51(51): 224-230.

[8] Sebaratnam DF, Frew JW, Davatchi F, et al. Quality -of-Life Measurement in Blistering Diseases [J]. Dermatol Clin, 2012, 30(2): 301-307.

[9] Mahajan VK, Sharma NL, Sharma RC, et al. Twelve-year clinicotherapeutic experience in pemphigus: a retrospective study of 54 cases [J]. Int J Dermatol, 2005, 44(10): 821-827.

[10] Agarwal M, Walia R, Kochhar AM, et al. Pemphigus Area and Activity Score (PAAS) –a novel clinical scoring method for monitoring of pemphigus vulgaris patients [J]. Int J Dermatol, 1998, 37(2): 158-160.

An overview of three-dimensional cell culture

What is 3D cell culture?

Three-dimensional cell culture is based on the common three-dimensional culture model of the scaffold, which can better simulate the natural environment in which the cells grow. Three-dimensional cell culture (TDCC) refers to the co-culture of vectors with different materials in three dimensions and various kinds of cells in vitro, so that cells can migrate and grow in the three-dimensional spatial structure of the carrier. Three-dimensional cell-carrier complex.

Frontier knowledge about 3D cell culture research

  1. Three-dimensional cell tissue plus tensile culture model of the United States flexcell company Tissue Train tensile stress stimulation three-dimensional hydrogel stent cell tissue culture system.

Functional highlights of the three-dimensional cell tissue augmentation culture model: after burning three-dimensional cell tissue culture and stretching three-dimensional cell tissue culture in the true sense of three-dimensional culture – the system with a variety of coated surfaces (Amino, Collagen (Type I Or IV), Elastin, ProNectin (RGD), Laminin (YIGSR) collagen hydrogels for extracellular matrix scaffolds in biomaterial scaffold studies, compared to traditional nanofiber scaffolds and porous scaffolds, hydrogel scaffolds The network contains a lot of water, which can supply cell nutrients well, and can also cross-link bioactive factors to regulate cell growth and differentiation. Therefore, hydrogel scaffolds can better simulate the tissue-like physics required for cell growth. The spatial structure has high plasticity, relatively simple manufacturing process and convenient clinical application.

  1. Three-dimensional cell tissue pressure-carrying culture system model of American three-dimensional cell tissue after-force culture model

Three-dimensional cell culture in three-dimensional cell culture

1) The system provides periodic or static pressure loading of various tissue, three-dimensional cell cultures;

2) based on the deformation of the flexible film substrate, uniform force;

3) Real-time observation of the reaction of cells and tissues under pressure;

4) can selectively block stress loading on cells;

5) Simultaneously have multi-channel cell pull force loading function;

6) Up to 4 channels, 4 different programs can be run simultaneously, and multiple different pressure deformation rate comparison experiments are performed;

7) Multiple frequencies (0.01-5 Hz), multiple amplitudes and multiple waveforms can be operated in the same program;

8) Better control of waveforms under ultra-low or ultra-high stress;

9) A variety of waveform types: static waveform, positive rotation waveform, cardiac waveform, triangular waveform, rectangle and various special waveforms;

10) computer system for pressure loading cycle, size, frequency, duration precise intelligent control typical application range: detection Biochemical reactions of various tissues and cells under pressure.

  1. Three-dimensional cell tissue augmentation culture model. Three-dimensional cell tissue stretchestensile force loading culture system model of American flexcell company Three-dimensional cell culture three-dimensional cell tension loading culture

1) The system provides axial and circumferential stress loading on two-dimensional, three-dimensional cells and tissues;

2) based on the deformation of the flexible film substrate, uniform force;

3) The reaction of cells and tissues under stress can be observed in real time;

4) can selectively block stress loading on cells;

5) Simultaneous multi-channel cell pressure loading function;

6) In combination with the Flex Flow parallel slab flow chamber, fluid shear stress can be applied while pulling the cells;

7) Up to 4 channels, 4 different programs can be run simultaneously, and multiple different tensile deformation rate comparison experiments are performed;

8) Multiple frequencies, multiple amplitudes and multiple waveforms can be operated in the same program;

9) Better control of waveforms under ultra-low or ultra-high stress;

10) Multiple waveform types: static waveform, positive rotation waveform, cardiac waveform, triangular waveform, rectangle, and various special waveforms;

3 Three-dimensional cell cultures in life applications:

Customized 3D cell culture services are common in our lives, and there are also 3D cell culture related products on the market.

  • Creative Bioarrayoffers 35 human cell systems with over 160 different cell types. Moreover, we also provide our customers primary cells from over 13 types of other animals.
  • These cells taken from living tissue are extremely accurate as they are literally coming from the source and are available from many sources on the human body. These living samples can give extremely accurate information about the cells in vivo and give relevant information regarding the living systems.
  • Not only canCreative Bioarray offer such a wide range of primary cells of humans, but we also have a selection of primary cells of animals for comparative testing.

Bone cells, which are found within the bone tissue, are responsible for bone production, maintenance and modeling. There are three different types of cells that found only in the bone. The osteoblasts are derived from mesenchymal stem cells and its function is bone matrix synthesis and its subsequent mineralization. The osteoclasts are large cells that dissolve the bone and osteocytes are cells inside the bone. At Creative Bioarray, we offer 6 types of human primary bone cells including: Human Bone marrow-derived endothelial Cells, Human Osteoblast Cells, Human Osteoblasts (HOB), Human Osteoblast Cells (Postnatal), Human Calvarial Osteoblasts (HCO) and Human Osteoblasts-femural (HO-f). The method we use to isolate endothelial cells was developed based on a combination of established and our proprietary methods. These cells are pre-coated with PECAM-1 antibody, following the application of magnetic beads pre-coated with secondary antibody. Human osteoblasts may be used for various types of in vitro, in vivo, or regenerative medicine studies in normal or diseased systems. In addition, they may be used in bone development studies.

What Types of Wholesale Shoes Can Be Found on Internet?

Wholesale shoes are available on the internet in a huge variety. There are many advantages other than money saving to buy these shoes from the internet. One can make the right choice by exploring the unlimited varieties in different categories. Moreover, it is a convenient way to obtain one’s favorite pair of shoes.

Shoes available in wholesale are purchased from the suppliers and manufacturers in bulk which result in lower price tags they bear. They are available at lower price doesn’t mean that they are less in terms of quality. All these things make wholesale footwear popular among people with different budgets and from different age groups. Here is a discussion on what types of wholesale shoes can be found at wholesale stores online.

Designer Shoes
Branded and designer shoes are often expensive and don’t fall in the budget of many people. However, designer shoes available at wholesale rates are available at various online stores. One can choose among shoes made by their favorite footwear brands and that too without worrying about the budget.

Shoes for Different Purposes
These on the internet can be found for different purposes. For instance, there are party shoes available in some of the most impressive designs. At the same time, one can find sports shoes and adventure shoes available at the wholesale footwear stores. Another popular category of shoes at such stores is that of office and workplace shoes.

Casual shoes too can be found at these stores to meet people’s requirements for everyday wear. There are shoes for special purposes like cycling, jogging and walking. Wedding shoes at wholesale prices too are available at excitingly affordable prices at these online stores.

Shoes for Different Age Groups
Shoes at wholesale stores can be found for different age groups. There are shoes for kids and school going children as well as those preferred by teenagers. Shoes for young adults as well as for elders too can be found in different styles at wholesale prices. There are different categories for men and women shoes to meet the tastes and preferences of people from both the gender groups.

Shoes in Different Styles
As mentioned before, one of the advantages of buying these online is that one get to explore a huge variety of shoes in different styles. For instance, it is easy to find boots, flip-flops, sandals, sneakers and all other types of shoes at decent price tags at wholesale footwear stores. Shoes in a variety of colors can also be found at these online destinations.

Different types of shoes are suitable for people with different personalities. For instance, height and dressing styles are among the important factors considered by people while purchasing a pair of shoes. It is easy for them to make the right choice while looking at these available in different styles and within different budgets.

Buyers usually ensure that they are not solely attracted by the lower price tags of wholesale shoes, but they also take account a number of factors while choosing the online destination for these. In any case, the popularity of shoes available at wholesale prices is rising with more and more people attracted towards them.

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