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Polymerase Chain Reaction (PCR) relies on thermocycling, consisting of repeated cycles of heating and cooling allowing for DNA-primer annealing and enzymatic synthesis of thousands to billions of copies of a target DNA sequence. Since its invention in 1983, PCR has evolved into an assemblage of methodologies widely used in Life Sciences, Biotechnology, Clinical Diagnostics, Forensics and many other fields.
Thermostable DNA Polymerase
PCR employs a thermostable DNA polymerase that is heat resistant and capable of generating new strands of DNA using a template and primers. The first described thermostable DNA polymerase is Taq DNA polymerase isolated from bacterium Thermis aquaticus. However, the lack in 3’ to 5’ exonuclease proofreading activity of Taq results in a high error rate when replicating DNA by PCR. High fidelity PCR is required for many applications, including cloning and sequencing, where sequence accuracy is crucial. It is recommended that low error rate enzymes, such as Pfu DNA polymerase from Pyrococcus furiosus, should be used in order to reduce spurious mutations introduced during PCR. Although it possesses 3’ to 5’ proofreading activity, Pfu exhibits only moderately 5 to 10-fold lower error rate than Taq. To eliminate spurious mutations in particular for long amplicons, a thermostable DNA polymerase with higher fidelity is required.
G&P HiFi™ PCR DNA Polymerase
G&P HiFi™ is a Thermococcus proofreading DNA polymerase engineered for superior fidelity and performance. The engineered PCR enzyme contains amino acid modifications conferring dramatic improvements through screening a large library of enzyme variants. G&P HiFi™ is the most accurate thermostable DNA polymerase, featuring an error rate over 100-fold lower than Taq, making it a superior choice for applications requiring high fidelity. Combined with the proprietary reaction buffers that facilitate specific primer annealing and accurate DNA replication, successful amplification of a wide range of template types and sizes (up to 15 kb) can be achieved using a single enzyme. G&P HiFi™ requires only 10-20 sec per kb extension time per cycle, making it possible to perform PCR with extreme speed. It also produces higher yields with lower enzyme amounts than other common high fidelity enzymes. Overall G&P HiFi™ delivers industry-leading performance with following unique features that no other system can match:
1. HIGHEST FIDELITY
The improved thermostability, proofreading activity and optimized buffer systems of G&P HiFi™ result in superior accuracy for high fidelity PCR applications. The mutation frequency (%) of G&P HiFi™ DNA polymerase is over 100-fold lower than that of Taq, ~15-fold lower than that of Pfu, 4-5-fold lower than that of KOD+, 2-3-fold lower than that of Phusion (see Figure 1 below), making G&P HiFi™ the most accurate PCR enzyme available for high fidelity PCR.
Figure 1. Fidelity Comparison of Thermostable DNA Polymerases.
The fidelity in DNA replication by commonly used DNA polymerases, Taq, Pfu, KOD+, Phusion, and G&P HiFi™ was measured as the mutation frequency (%) in PCR products using a LacI-based fidelity assay.
2. SUPERIOR ROBUSTNESS
Using as a single enzyme, G&P HiFi™ delivers robust performance across a wide range of amplicons from 0.4 to 12.5 kb in size when using only 0.1 to 1 ng of template DNA per reaction. It outperforms two other commonly used high fidelity enzymes, which are engineered by fusion or other technologies (supplier N and supplier T), when amplifying the large target DNA of 12.5 kb (Figure 2). Supplier N’s enzyme generates predominantly non-specific, smaller PCR products, while supplier T’s product works much less efficiently (compare lane #8 with lanes #9 & #10 in Figure 2). All G&P HiFi™ PCR reactions are performed with a consolidated PCR protocol using a single enzyme, eliminating the need for hot-start in most cases (refer to the product details and protocols for more information). G&P HiFi™ is capable of amplifying extremely long amplicons (up to 15 kb), enabling truly high fidelity PCR-based DNA cloning, assembly and mutagenesis by directly amplifying large vectors and DNA inserts.
Figure 2. Superior Amplification Robustness by G&P HiFi™.
G&P HiFi™ was capable of amplifying of a wide range of amplicons from 0.4 to 12.5 kb in size using only a single enzyme. Each PCR product was amplified from a concentration of template DNA of 0.1 to 1 ng per reaction. G&P HiFi™ PCR reactions were performed using a standard 3-step cycling profile (30 cycles): 5-second denaturation, 15-second annealing, and 10-second per kb extension time. Total reaction time for the 12.5 kb amplicon was less than 2 hours. PCR reactions with supplier N’s and supplier T’s DNA polymerases were conducted using the buffers and protocols provided by the manufacturers. 5 µl of each PCR reaction (50 µl total) was loaded on the agarose gel and molecular size markers in kb were indicated left.
3. EXTREME SENSITIVITY
The engineered G&P HiFi™ DNA Polymerase exhibits dramatic improvements in sensitivity and specificity, outperforming two other commercial DNA polymerase from supplier N and T (Figure 3). G&P HiFi™ shows superior performance in amplifying of a template DNA with concentrations as low as 0.1 pg per reaction using two different reaction buffers (HS and HD buffers) supplied with the enzyme. In contrast, one of commercial DNA polymerases (supplier N) yields much less 3.4-kb PCR product and supplier T’s enzyme fails to generate any 3.4-kb PCR product when using 0.1 pg of the template DNA in the PCR reactions according to the manufacturers’ procedures (compare lane #11 with lanes #12 & #13 in Figure 3).
Figure 3. Extrem Sensitivity by G&P HiFi™.
The 3.4-kb target DNA sequences were amplified from a 10-fold dilution series of plasmid DNA template starting from 1 ng down to only 0.1 pg per reaction using G&P HiFi™ DNA polymerase or two commercial enzymes, supplier N and T. All reactions were performed using G&P HiFi standard protocols or manufacturers’ protocols from supplier N and T, consisting of standard 3-step cycling profiles (30 cycles). 5 µl of each PCR reaction (50 µl total) was loaded on the gel and molecular size markers in kb were indicated left.
G&P HiFi™ also delivers superior product yields with minimal enzyme amounts needed. As shown in Figure 4, it is capable of amplifying a DNA template (7.5 kb in size comprising an entire plasmid vector) using only 1/8 amount of G&P HiFi™ that is used in a standard PCR reaction. In contrast, two commercial PCR enzymes (supplier N’s and T’s) perform very poorly, exhibiting either inefficient amplification or failure to produce any 7.5-kb PCR product with predominantly non-specific, smaller products (compare lane #5 with lanes #6 & #7 in Figure 4). The unique condition and formulation of G&P HiFi™ greatly increases PCR amplification sensitivity and specificity, eliminating spurious amplification resulting from non-specific annealing.
Figure 4. High Specificity Amplification with Minimal Amounts of G&P HiFi™.
The 7.5-kb target DNA sequences (i.e., entire plasmid vector) were amplified using a 2-fold dilution series of G&P HiFi™ DNA polymerase from 1 unit (the amount used in a standard reaction) down to 0.125 unit or using two commercial enzymes (supplier N’s and T’s) at 0.125 unit per reaction. All reactions (50 µl each) were performed using G&P HiFi™ standard protocols or manufacturers’ protocols with standard 3-step cycling profiles (30 cycles). 5 µl of each PCR reaction was loaded on the gel and molecular size markers in kb were indicated left.
Featured Products:
G&P HiFi™ PCR Enzyme, Kit and Master Mix
G&P HiFi™ DNA polymerase is supplied with two proprietary buffers (one standard and another one detergent free) for optimal performance and compatibility with downstream applications (SKU#P01301 & #P01302). Both buffers contain magnesium with PCR conditions optimized, consistently delivering excellent efficiency, specificity and sensitivity for high fidelity PCR. We also offer G&P HiFi PCR kit and ready-to-use 2x master mix. G&P HiFi™ PCR kit (SKU#K01301) contains all reagents for high fidelity PCR and optimization by the user. The master mix (SKU#M01303) contains all ingredients for high fidelity PCR, including G&P HiFi™ DNA polymerase, salts, magnesium, dNTPs, stabilizers, and enhancers in an optimized reaction buffer.
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G&P HiFi™ PCR Products
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Product Information
Immune Checkpoints and Costimulatory Pathways
T cell-mediated immunity is initiated by recognition of antigenic peptide-MHC I/II complexes on antigen presenting cells (APC) through the T cell receptor (TCR). This transduces an activating signal into the T cells leading to the clonal selection of antigen-specific T cells, subsequently their activation and proliferation in secondary lymphoid organs, their migration to the sites of inflammation, and ultimately the execution of immune effector functions directly or indirectly through other effector cells or factors (e.g., cytokines). T cell responses are regulated by a balance between co-stimulatory and inhibitory signaling pathways elicited by different membrane-bound receptors and ligands (see the diagram below).
Above these inhibitory pathways are often referred to as immune checkpoints that are crucial for maintaining self-tolerance (or preventing autoimmunity) as well as modulating the duration and amplitude of immune responses. Interestingly many immune checkpoint ligands or receptors are overexpressed on tumor cells or on non-transformed cells within the tumor microenvironment. The blockade of immune checkpoints has been clinically proven to be one of most promising approaches to inducing therapeutic anti-tumor immunity. For example, anti-CTLA4 monoclonal antibody, Ipilimumab (Yervoy®), and anti-PD1 monoclonal antibodies, Nivolumab (Opdivo®) and Pembrolizumab (Keytruda®), have been approved as a new class of immunotherapy for cancer patients, including those with melanoma and lung cancer (click here to see a list of antibodies in clinical use/development).
Another category of immune-inhibitory molecules or checkpoints include certain metabolic enzymes, such as indoleamine 2,3-dioxygenases (IDO-1, IDO-2), which are expressed by both tumor cells and infiltrating myeloid cells, and arginase (ARG1), which is produced primarily by myeloid-derived suppressing cells. These enzymes inhibit immune responses through local depletion of amino acids that are essential for anabolic functions in lymphocytes (in particular T cells) or through the synthesis of specific natural ligands for cytosolic receptors that can alter lymphocyte functions. The molecular analogs of the substrates for above these enzymes can act as competitive inhibitors or suicide substrates that are capable of enhancing intratumoral inflammation and anti-tumor immunity.
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Immune Checkpoints & Costimulators Related Genes, Proteins and Antibodies
G&P Biosciences provide a comprehensive list of products and services for immune checkpoints and co-stimulatory pathways' R&D. We offer 100% sequence verified full-length cDNA clones for all immune checkpoints and co-stimulators related genes as well as pre-packaged high-titer lentiviral particles for most of them. The pre-packaged lentiviral particles are ready to transduce any mammalian cell types to generate stable expressing cell lines with the choice of multiple antibiotics selection markers available. We also offer highly purified recombinant proteins (either as a Fc-fusion or with a His-tag) for most immune checkpoints and co-stimulators related gene products. Additionally we offer recombinant monoclonal antibodies that target immune checkpoint and co-stimulatory molecules with high affinity and specificity. Many of these antibodies efficiently block immune checkpoint-mediated inhibitory pathways or activate co-stimulatory pathways, therefore potently enhancing anti-tumor immunity in vitro and in vivo.
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Immune Costimulators: Gene, Lentivirus, Protein & Antibody Products
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Immune Checkpoints: Gene, Lentivirus, Protein & Antibody Products
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» For more details, please go to our "Gene" "Lentivirus" "Protein" and "Antibody" product pages
» To request a quotation for any custom-made gene, protein or antibody, visit our "Services" pages.
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Product Information
Transforming Growth Factor β Receptor (TGFBR) Family
The transforming growth factor β (TGFβ) superfamily of ligands are pleiotropic cytokines that regulate a diverse range of cellular processes, including cell proliferation, differentiation, migration, adhesion and death. The superfamily of ligands include: Activin, Nodal, TGFβ, BMP (bone morphogenetic protein), GDF (growth and differentiation factor), and AMH (anti-müllerian hormone). They elicit signaling pathways that are evolutionarily conserved and involved in the cellular processes in both adult organisms and developing embryos. The signaling begins with the engagement of a ligand with a type II TGFβ receptor (TGFBR), which in turn recruits and activates a type I receptor. Both type receptors contain a cysteine-rich extracellular domain (ECD), a transmembrane (TM) domain and a cytoplasmic serine/threonine kinase (STK) domain. The TGFBR family is the only receptor family with such a STK activity. The type I receptors differ from the type II receptors by the presence of a conserved 30-amino acid stretch of glycine-serine (GS) repeats before the kinase domain (see the schematic diagram below). The binding of a ligand causes the conformational change in a type II receptor so that its cytoplasmic kinase domain is in a catalytically favorable orientation. The type II receptor then phosphorylates and activates a type I receptor, which eventually phosphorylates the downstream SMAD family transcription factors for the regulation of target gene expression.
In mammals there are 5 type II receptors and 7 known type I receptors (see the diagram above). Each class of TGFβ ligands appears to bind to a specific type II receptor (see the summary table below). For example, the TGFβ family ligands, including TGFβ1, TGFβ2, and TGFβ3, bind TGFBR2 and are involved in embryogenesis, cell differentiation, apoptosis and many other functions. The Activin family ligands, including Activin A, Activin B and Activin AB, bind ACVR2A (activin A receptor type IIA) and are involved in embryogenesis and osteogenesis. Activins also regulate many hormones including pituitary, gonadal and hypothalamic hormones as well as insulin. In addition they may serve as nerve cell survival factors. Nodal binds to ACVR2B and can then either form a receptor complex with ACVR1B or ACVR1C. Nodal is involved in left and right axis specification, as well as mesoderm and endoderm induction. AMH binds AMHR2 and inhibits the development of the Müllerian ducts (paramesonephric ducts) in the male embryo. Unlike other ligands, the BMP family ligands recognize both type I and type II receptors with high affinity only when both type receptors are present. They are involved in osteogenesis, cell growth & differentiation, anterior-posterior axis specification, and homeostasis.
| Ligand Family | Type II Receptor | Type I Receptor | Binding Proteins |
| Activin | ACVR2A | ACVR1B/ALK4 | Follistatin, BAMBI |
| AMH | AMHR2 | TGFBR1/ALK5, ACVR1/ALK2 | |
| BMP | BMPR2 | BMPR1A/ALK3, BMPR1B/ALK6 | Follistatin, Noggin, Chordin, DAN, BAMBI |
| GDF | ACVR2A, ACVR2B | TGFBR1/ALK5, ACVR1B/ALK4 | DAN |
| Nodal | ACVR2B | ACVR1B/ALK4, ACVR1C/ALK7 | Lefty |
| TGFβ | TGFBR2 | TGFBR1/ALK5 | TGFBR3 |
A unique feature of TGFBR signaling is the existence of diverse binding proteins that are not related by sequence but can act as functional antagonists or agonists. There are several classes of binding proteins, including Follistatin, Chordin, Noggin, and DAN. They differ in their ligand affinity as well as their mode of regulation. For example, Follistatin acts as a binding protein to BMP4 without competing with type I receptor binding whereas Noggin and Chordin directly compete for receptor binding. Follistatin also binds and inhibits Activin. Members of the DAN family, Cerberus, DAN, and Gremlin, also antagonize TGFβ family ligands. They contain 9 conserved cysteines, which can form disulfide bridges. DAN also antagonizes GDF family members, such as GDF5, GDF6 and GDF7. Lefty is a regulator of TGFβ ligands and is involved in the axis patterning during embryogenesis. BMP and Activin membrane bound inhibitor (BAMBI), has a similar extracellular domain as a type I receptor but lacks a serine/threonine protein kinase domain. It binds to the type I receptor preventing it from being activated, therefore serving as a negative regulator for the signaling. An additional TGFβ receptor type III (TGFBR3) that lacks catalytic activity or signaling domain can form a complex with TGFBR1 and TGFBR2 to enhance their binding to TGFβ ligands.
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TGFBR Family Related Genes, Proteins and Antibodies
G&P Biosciences provide a comprehensive list of products and services for TGFβ family ligands and receptors R&D. We offer 100% sequence verified full-length cDNA clones for all known TGFBR related genes as well as pre-packaged high-titer lentiviral particles. The pre-packaged lentiviral particles are ready to transduce any mammalian cell types to generate stable expressing cell lines with the choice of multiple antibiotics selection markers available. We also offer highly purified recombinant proteins (either as a Fc-fusion or with a His-tag) for all TGFBR family members. Additionally we offer recombinant monoclonal antibodies that target TGFBRs with high affinity and specificity. Many of these antibodies efficiently block or activate TGFBR-mediated signaling pathways.
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TGFBR Family: Gene, Lentivirus, Protein & Antibody Products
| Type I Receptor |
Type II Receptor |
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» For more details, please go to our "Gene" "Lentivirus" "Protein" and "Antibody" product pages
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Product Information
B7 Family Ligands and CD28 Family Receptors
The B7 family ligands and the CD28 family receptors belonging to the immunoglobulin superfamily (IgSF) are essential in modulating immune responses. Most B7 ligands contain both Ig-like variable (V)-type and Ig-like constant (C)-type domains, whereas most CD28 receptor has only one Ig-like V-type domain ("IgV" and "IgC" as shown in the schematic diagram below). The IgV-type domains are usually responsible for interacting with their corresponding ligands or receptors. Interactions between B7 ligands and CD28 receptors play a central role in regulating T cell response by eliciting both positive co-stimulatory and negative inhibitory signals. B7 ligands are expressed on the surface of many cell types including antigen-presenting cells (APC), where they interact with CD28 family receptors on T cells to provide activating or inhibitory signals to regulate T cell activation and tolerance. Some inhibitory B7 ligands such as PD-L1 and PD-L2 are also expressed on tumor cells, resulting in the suppression of immune response. Therefore stimulating or neutralizing the interactions between B7 ligands and CD28 receptors hold great therapeutic potential. They constitute an important class of molecular targets for the development of novel therapeutic agents for human diseases, including autoimmune disorders and cancers.
Among above these pathways, B7-1 (CD80) and B7-2 (CD86) ligands acting through their receptors, CD28 and CTLA4 (CD152), are the most extensively characterized. Ligands B7-1 and B7-2 on antigen-presenting cells (APC) bind CD28 on resting T cells and transduce a major co-stimulatory signal to activate T cells. After the initial activation, CTLA4 expression is induced on T cells and it engages the same B7-1 and B7-2 ligands to restrain CD28-mediated activating signals. During the past decade, several new pathways have been discovered, including PD-L1/PD-L2/PD-1, ICOSL/ICOS, and B7-H4/BTLA. PD-L1 and PD-L2 are two ligands for the receptor PD1, which mediates inhibitory pathways critical for maintaining self-tolerance and modulating the duration and amplitude of T cell-mediated immune responses. In contrast, ICOSL binds its receptor ICOS to activate a co-stimulatory pathway important for helper T cell differentiation and memory B cell development. Interestingly some B7 family ligands show promiscuous binding behavior, e.g., ICOSL can also bind both CD28 and CTLA4 receptors, while PD-L1 can bind B7-1 ligand (see the diagram above).
The receptors for the B7 family members, B7-H3 and B7-H5, have not been identified. B7-H3 can bind activated T cells and produces both stimulatory and inhibitory effects. B7-H4 also binds activate T cells but is thought to inhibit T cell function through the newly identified receptor, BTLA (CD272). Myeloid-derived suppressor cells (MDSC) also express a receptor for B7-H4 and aberrant expression of B7-H4 is seen in many cancer types and often associates with poor prognosis. Recently two new B7 family members, B7-H6 and B7-H7, have also been described. B7-H6 binds the activating natural killer receptor NKp30 (CD337). However the physiological function of B7-H6 remain elusive. B7-H7 can co-stimulate or inhibit T cell growth and cytokine production. CD28H has been identified as a receptor for B7-H7 to transduce a co-stimulatory signal for T cell activation. Collectively the spatially and temporally regulated expression of co-stimulatory and inhibitory B7 ligands provides the controls underlying T cell-mediated immune responses.
Featured Products:
B7 Family Ligands and CD28 Family Receptors Related Genes, Proteins and Antibodies
G&P Biosciences provide a comprehensive list of products and services for B7 family ligands and CD28 family receptors R&D. We offer 100% sequence verified full-length cDNA clones for all known B7 ligands and CD28 receptors related genes as well as pre-packaged high-titer lentiviral particles. The pre-packaged lentiviral particles are ready to transduce any mammalian cell types to generate stable expressing cell lines with the choice of multiple antibiotics selection markers available. We also offer highly purified recombinant proteins (either as a Fc-fusion or with a His-tag) for most B7 family ligands and CD28 family receptors. Additionally we offer recombinant monoclonal antibodies that target B7 family ligands and CD28 family receptors with high affinity and specificity. Many of these antibodies efficiently block B7 ligand/CD28 receptor-mediated inhibitory pathways or activate co-stimulatory pathways, therefore potently enhancing anti-tumor immunity in vitro and in vivo.
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B7 Ligands & CD28 Receptors: Gene, Lentivirus, Protein & Antibody Products
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Product Information
Immunoglobulin Superfamily (IgSF)
The immunoglobulin superfamily (IgSF) is the most abundant gene/protein family in the human genome with 765 members identified. All IgSF members share a structural domain known as the immunoglobulin (Ig)-like domain, which is named after the immunoglobulin or antibody molecules. Antibodies are specialized proteins that recognize foreign antigens, such as bacteria and viruses, as part of the body's immune response. Antibodies contain a variable (V) region and a constant (C) region. Ig-like domains can resemble either the variable (V) region or the constant (C) region; these domains are referred to as Ig V-set/-type (IgV) and C-set/-type (IgC), respectively (see the structure below). Some Ig-like domains have characteristics of both IgV and IgC; these domains are described as Ig I-set/-type (IgI), meaning intermediate.
The Ig-like domains normally contain 70-110 amino acids and are characterized by an Ig fold, a sandwich-like structure formed by two sheets of antiparallel β-strands (see the structure above). Interactions between hydrophobic amino acids on the inner side of the sandwich and highly conserved disulfide bonds between two sheets stabilize the Ig-fold. The Ig-like domains can be further classified according to their size and function. For example, the IgV domains (right) typically contain 9 β-strands that are longer than IgC domains that have only 7 β-strands (left). On one side of the IgV domain, there is a section termed the complementarity determining regions (CDR1-3) that are critical for the specificity of an antibody or IgV domain binding to the ligand. Some Ig-like domains resemble IgV in the amino acid sequence, but are similar in size to IgC domains. They are termed IgC2 domains, whereas standard IgC domains are referred to as IgC1 domains.
Much like the role of antibodies to recognize particular antigens, the Ig-like domains allow proteins to interact with other molecules (see the diagram and examples below). Many IgSF members are cell surface or soluble proteins that are involved in the recognition, binding, or adhesion processes of cells. They include cell surface antigen receptors, co-receptors, co-inhibitory and co-stimulatory molecules for the immune system. Some IgSF members are molecules involved in antigen presentation to lymphocytes, cell adhesion molecules (CAMs), and cytokine receptors. They are commonly associated with functional roles in our immune system. Interestingly many IgI domain containing proteins act as receptors for growth factors, stimulating signaling inside the cell that helps respond to its environment. Other IgI domain containing proteins are also found in muscle cells; their ability to bind other muscle proteins aid in muscle contraction. Due to the diverse functions, changes in many IgSF members at genetic or proteomic levels can cause a variety of disorders that affect different body systems.
Examples of IgSF Members
| Molecule Category | Examples | Description |
| Antigen receptors |
• Antibodies or IgM • T cell receptor chains |
Immunoglobulins or antibodies (the antigen receptors of B cells) are the founding members of the IgSF. In humans, there are 5 distinct types of Ig molecule all containing a heavy chain with 4-5 Ig domains and a light chain with 2 Ig domains. The antigen receptor of T cells is the T cell receptor (TCR), which is composed of two chains, either the TCRα and TCRβ chains, or the TCRδ γ and TCRγ chains. All TCR chains contain 2 Ig domains (IgV-IgC) in their extracellular regions. |
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Antigen presenting molecules |
• Class I MHC
• Class II MHC • β-2 microglobulin |
The ligands for TCRs are major histocompatibility complex (MHC) proteins. These come in two forms; MHC class I forms a dimer with β-2 microglobulin (β2M) and interacts with the TCR on cytotoxic T cells and MHC class II has two chains (α and β) that interact with the TCR on helper T cells. MHC class I, MHC class II and β2M molecules all possess one IgC domain, respectively. |
| Co-receptor |
• CD1 • CD4 • CD8 • CD19 |
Many molecules including those IgSF members on the surfaces of T cells also interact with MHC molecules during TCR engagement. These are known as co-receptors. The co-receptor CD4 is found on helper T cells and CD8 is found on cytotoxic T cells. Like CD1, CD8 has only 1 IgV domain but exists as a dimeric molecule (CD8α/32k and CD8β/37k). The co-receptor CD4 contains 4 IgV domains and exists as a monomeric molecule. A co-receptor complex is also used by the B cell receptor (BCR), including CD19 with 2 IgC2-domains. |
| Antigen receptor accessory molecules | • CD3-γ, -δ and -ε
• CD79a and CD79b |
CD3 is a molecule that helps to transmit a signal from the TCR following its interaction with MHC molecules. 3 different chains γ, -δ and -ε contain a single IgV domain. B cells also have cell surface accessory molecules, CD79a and CD79b. They contain a single IgV domain and assist with cell activation through BCR. |
| Co-stimulatory or inhibitory molecules | • CD28
• B7-1/CD80 and B7-2/CD86 • CTLA4 • PD1 • PD-L1 and PD-L2 |
One major group of co-stimulatory and inhibitory receptors are members of the CD28 family receptors, including CD28, CTLA4/CD152, program death-1 (PD-1), the B- and T-lymphocyte attenuator (BTLA, CD272), and the inducible T-cell co-stimulator (ICOS, CD278); and their IgSF ligands belong to the B7 family, including CD80 (B7-1), CD86 (B7-2), ICOS ligand, PD-L1 (B7-H1), PD-L2 (B7-DC), B7-H3, and B7-H4 (B7x). |
| Cell adhesion molecules (CAMs) | • NCAMs
• ICAMs • CD2 subset |
CD2 subset of IgSF represented a large group of homologous cell adhesion molecules (CAMs), includes CD2, CD58, CD48, CD150, CD229 and CD244. |
| Cytokine or growth factor receptors | • IL6R
• CSF1R • PDGFR • SCFR/c-Kit/CD117 |
Interleukin-6 receptorColony and stimulating factor 1 receptor; Platelet-derived growth factor receptor (PDGFR) and Mast/stem cell growth factor receptor precursor (SCFR, c-kit, CD117 antigen) |
| Receptor tyrosine kinases or phosphatases | • Tie1/Tie2
• RPTPs |
Tyrosine-protein kinase receptor Tie1/Tie2 precursor; Type IIa and Type IIb Receptor protein tyrosine phosphatases (RPTPs), including, but not limited to PTPRM, PTPRK, PTPRU, PTPRD, PTPRF |
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