Immune Checkpoints

Working in the field of Immune checkpoints? Bio-Connect offers products related to immuneckpoints from several suppliers such as antibodies, assays, proteins, primers, cDNA ORF, siRNA/ShRNA and more. On this page you will find popular target links to products and background information. If you have any questions or if you are looking for certain products you can contact our techsupport.

Regulation of immunity by immune checkpoints

T-cell activation is an important part of effectuating the immune system. A three signal hypothesis has been constructed to explain the mechanism of activation. A first signal is antigen-specific  and is provided through the interaction of the T-Cell receptor with the peptide MHC molecules on the dendritic cell (DC)/ antigen presenting cell (APC) or tumor cell. T cell receptor (TCR) signaling intensity is determined by several factors as antigen load, duration of interaction, MHC molecules, etc.
T cells require also a second signal to become fully activated, the co-stimulatory signal, is antigen nonspecific and is provided by the interaction between co-stimulatory molecules expressed on the membrane of the presenting cell (dendritic-, antigen-presenting-, tumor-cell, etc.) and the T cell., in the absence of this co-stimulatory signal T cells show an absence or diminished reaction when presented with signal 1.
A balanced immune system (maintaining homeostasis) depends on these co-stimulatory signals and is critical for good health. Uncontrolled reactions to antigens or self-antigens could result in auto-immune diseases, or (chronic) inflammation leading to damage in many body tissues. The balance in the immune system is regulated by an equilibrium between co-activating and co-inhibitory stimulatory signals.
These signals that are essential for a homeostasis and good health are also referred to as immune checkpoints. These immune checkpoints and the downstream signaling routes are researched and investigated as a target for the treatment of cancer and other diseases. Small molecules and other biological products that modulate these pathways can help influence the immune response in a manner that alleviates disease.

The last signal also influencing the activation of the T Cells are cytokines. Cytokines produced in the environment of the T cell also influence the genetic programming and the transcription factors. The first 2 described signals are also having an influence on the receptiveness to specific cytokines.

Coming back to the immune checkpoints and the second signal to activate T cells. This is one of the most promising routes to influence antitumor immunity.  Tumors use certain immune checkpoint pathways as a mechanism of immune resistance, particularly against T cells that possess specificity for tumor antigens. The immune checkpoint pathways are activated by ligand–receptor interactions, and can be blocked/neutralized  by antibodies or influenced by adding recombinant ligands or receptors.

The immune checkpoints can be grouped in several families: One of the most intense studied families is the B7-CD28 superfamily​. The B7-family consists of structurally related cell-surface protein ligands, which bind to receptors on lymphocytes that regulate immune responses. The co-activating or co-inhibitory signals are delivered through the CD28 family of receptors present on lymphocytes. The binding also influences the production of interleukins. Interaction of B7-family members with co-activating receptors increases immune responses and interaction with co-inhibitory receptors attenuates immune responses.
There are currently several known members of the B7 family: B7-1 (CD80), B7-2 (CD86), inducible costimulator ligand (ICOS-L, B7-H2), programmed death-1 ligand (PD-L1, B7-H1), programmed death-2 ligand (PD-L2, B7-DC), B7-H3, B7-H4, VISTA (B7-H5), B7-H6 and B7-H7. The CD28-superfamily consists of the corresponding receptors to the B7-group of products. The following members are known in this family:CD28, CTLA-4 (CD152), ICOS, PD-1, NKp30, CD28H and BTLA.
Other known immune checkpoint families are the TNF-superfamily and the Immunoglobulin superfamily. There is also a group of receptors and ligands that show immune checkpoint activity but are not part of one of the described families.

Below you will find highlights of the products that we offer for research in Immune Checkpoints. For additional Immune Checkpoint Reagents with the focus on T Cells, visit the AdipoGen Immune Checkpoints page.

B7-CD28 superfamily 


Immunoglobulin superfamily

PD-1CD279PD-L1B7-H1, CD274inhibition
PD-1CD279PD-L2B7-DC, CD273inhibition
ICOSCD278ICOSLGB7-H2, CD275inhibition
TIGITVstm3, WUCAMCD155PVRinhibition
TIGITVstm3, WUCAMCD112Nectin-2inhibition
HVEM*TNFRSF14*CD160BY55, NK1, NK28inhibition
CD2442B4CD48BCM1, BLAST, BLAST1activation
   *part of TNF-Superfamily




Receptor. Ligand Regulation
4-1BBTNFRSF9, CD1374-1BBLTNFSF9, CD137LGactivation
CD27TNFRSF7CD70TNFSF7, CD27LGactivation
CD40TNFRSF5CD40LTNFSF5, CD40LG, CD154inhibition
ADORA2Aadenosine A2a receptor



*part of CD28-Superfamily
Click and select your product category and other filter options to downsize your result.

More detailed information on the different members of the B7-CD28 superfamily

Name Information
CD80 (B7-1)CD80 is expressed by activated B cells and by monocytes and dendritic cells. This ligand binds to CD28 to provide a co-stimulatory signal necessary for T cell activation and survival, and cytokine production. Additionally, CD80 binds to CTLA-4 which inhibits T cells.
CD86 (B7-2)CD86 is expressed by activated T and B cells, macrophages, and dendritic cells. This ligand binds to CD28 to provide a co-stimulatory signal necessary for T cell activation and survival, and cytokine production. Additionally, CD80 binds to CTLA-4 which inhibits T cells.
CD28This molecule is constitutively expressed on almost all human CD4+ T-cells and about half of all CD8 T-cells. CD28 binding with two ligands CD80 and CD86, expressed on dendritic cells, the binding results in T cell expansion.
CTLA-4 (CD152)CTLA-4 is expressed on activated T and B lymphocytes. CTLA-4 is structurally similar to the T-cell co-stimulatory protein, CD28, and both molecules bind to the B7 family members B7-1 (CD80) and B7-2 (CD86). Upon ligand binding, CTLA-4 inhibits cell-mediated immune responses. CTLA-4 plays roles in induction and/or maintenance of immunological tolerance, thymocyte development, and regulation of protective immunity. CTLA-4 is part of a group of inhibitory receptors that are explored as cancer treatment targets through immune checkpoint blockade.
PD-L2 (B7-DC)PD-L2 is a transmembrane protein expressed on monocytes, macrophages, and subsets of dendritic cells. PD-L2 binds to its receptor, PD-1, found on CD4 and CD8 thymocytes as well as activated T and B lymphocytes and myeloid cells. Engagement of PD-L2 with PD-1 leads to inhibition of TCR-mediated T cell proliferation and cytokine production.
PD-L1 (B7-H1)PD-L1 is expressed on T lymphocytes, B lymphocytes, NK cells, dendritic cells, as well as IFNγ stimulated monocytes, epithelial cells, and endothelial cells. PD-L1 binds to its receptor, PD-1, found on CD4 and CD8 thymocytes as well as activated T and B lymphocytes and myeloid cells. Engagement of PD-L1 with PD-1 leads to inhibition of TCR-mediated T cell proliferation and cytokine production. PD-L1 is thought to play an important role in circumventing the immune system. Induced PD-L1 expression is common in many tumors and results in increased resistance of tumor cells to CD8 T cell-mediated lysis.
PD-1 (CD279)PD-1 is temporary expressed on CD4 and CD8 thymocytes as well as activated T and B lymphocytes and myeloid cells. PD-1 expression declines after successful elimination of an antigen. PD-1 signals after binding to one of the two ligands, PD-L1 and PD-L2 both members of the B7 family. Upon ligand binding, PD-1 signaling inhibits T-cell activation, leading to reduced proliferation, cytokine production, and T-cell death. Additionally, PD-1 is known to play key roles in tolerance and prevention of autoimmune disease in mice. Induced PD-L1 expression is common in many tumors including squamous cell carcinoma, colon adenocarcinoma, and breast adenocarcinoma. PD-L1 overexpression results in increased resistance of tumor cells to CD8 T cell-mediated lysis. In mouse models of melanoma, tumor growth can be temporarily arrested via treatment with antibodies which block the interaction between PD-L1 and its receptor PD-1. For these reasons anti-PD-1 mediated immunotherapies are currently being explored as cancer treatments.
ICOSLG (CD275,B7-H2)Expressed mainly on B cells and dendritic cells
ICOS (CD278)This molecule, short for Inducible T-cell costimulator, and also called CD278, is expressed on activated T cells. Its ligand is ICOSL, expressed mainly on B cells and dendritic cells. The molecule seems to be important in T cell effector function.
CD276 (B7-H3)CD276 is expressed weakly on activated lymphocytes, macrophages, dendritic cells, nasal and airway epithelial cells, osteoblasts, and some tumor cell lines. A soluble form of CD276 is also secreted by monocytes, dendritic cells, and activated T cells. The biological role of CD276 is still under investigation however, recent studies suggest a negative regulatory role for CD276 in T cell responses.
B7-H4 (VTCN1)B7-H4 is expressed by tumor cells and tumor-associated macrophages and plays a role in tumor escape.
BTLA (CD272)BTLA , short for B and T Lymphocyte Attenuator , has HVEM (Herpesvirus Entry Mediator) as its ligand. Surface expression of BTLA is gradually down regulated during differentiation of human CD8+ T cells from the naive to the effector cell phenotype, however tumor-specific human CD8+ T cells express high levels of BTLA.
VISTA (B7-H5)VISTA - Short for V-domain Ig suppressor of T cell activation, VISTA is primarily expressed on hematopoietic cells. Therefore a consistent expression of VISTA on leukocytes within tumors may allow VISTA blockade to be effective across a broad range of solid tumors.
B7-H6B7-H6 belongs to the B7 family and is selectively expressed on tumor cells. Interaction of B7-H6 with NKp30 (CD337) results in natural killer (NK) cell activation and cytotoxicity.
NKp30 (CD337)Cytotoxicity-activating receptor that contributes to the increased efficiency of activated NK cells to mediate tumor cell lysis
B7-H7B7-H7 is a protein ligand found on the surface of monocytes. The encoded protein is thought to regulate cell-mediated immunity by binding to a receptor on T lymphocytes and inhibiting the proliferation of these cells.
CD28H (TMIGD2)Broad expression in lymph node, spleen, appendix and small intestine also present in 12 other tissues. TMIGD2 is widely expressed on naïve T cells as well as dendritic cells, monocytes, and B cells.

Immune Checkpoint Antibodies

Cat. No.Description
GTX1173554-1BBL / CD137L antibody [N2C3]
GTX109242Arginase 1 antibody - KO/KD Validated
GTX88996B7-H4 antibody, Internal
13482-T16B7-H5 / GI24 / VISTA Antibody, Rabbit PAb, Antigen Affinity Purified
GTX42439CD134 antibody [OX-40]
GTX74995CD134 antibody [OX86]
GTX42437CD137 antibody [17B5] (Low endotoxin, azide free)
10109-R114CD155 / PVR / NECL5 Antibody, Rabbit MAb
50259-R305CD155 / PVR Antibody, Rabbit MAb
GTX42201CD252 antibody [OX-89]
GTX42152CD276 antibody [MIH42]
GTX33959CD28 antibody
GTX80197CD28 antibody [CD28.2] (FITC)
GTX42131CD28 antibody [YTH913.12] (Low endotoxin, azide free)
GTX84720CD4 antibody [10B5]
GTX44531CD4 antibody [GK1.5]
GTX76318CD4 antibody [W3/25]
10774-MM03CD40 / TNFRSF5 Antibody, Mouse MAb
GTX101447CD40 antibody
GTX44541CD40 antibody [3/23] (Low endotoxin, azide free)
GTX13546CD40L / CD154 antibody [5F3]
10698-T56CD80 / B7-1 Antibody, Rabbit PAb, Antigen Affinity Purified
GTX84701CD80 antibody [2B11]
GTX41787CD86 antibody [24F]
GTX74650CD86 antibody [BU63]
10822-R103-PCEACAM1 / CD66a Antibody (PE), Rabbit MAb
50571-R030CEACAM1 / CD66a Antibody, Rabbit MAb
GTX75812CTLA4 antibody [WKH203] (Azide free)
GTX80283FOXP3 antibody [3G3]
GTX107737FOXP3 antibody [C3], C-term
GTX89934FOXP3 antibody, C-term
GTX127352Galectin 9 antibody
GTX130513IL10 antibody
GTX101138IL2 antibody
GTX108495IL2 Receptor beta antibody [C3], C-term
GTX130246iNOS antibody - Orthogonal Validated
GTX31185Interferon gamma antibody
GTX15624Interferon gamma antibody [2G1]
GTX42485Interferon gamma Receptor 1 antibody [BB1E2]
GTX53343Interferon gamma Receptor 2 antibody [7A25]
InVivoMAb anti-mouse VISTA
InVivoPlus anti-mouse VISTA
GTX76000KIR family antibody [NKVFS1]
GTX42244LAG3 antibody [C9B7W] (Low endotoxin, azide free)
GTX81605LAG3 antibody, Internal
50124-RP02PD1 / PDCD1 / CD279 Antibody, Rabbit PAb, Antigen Affinity Purified
10377-R002PD1 / PDCD1 Antibody, Rabbit MAb
GTX20256PD1 antibody [NAT105]
10084-R015PD-L1 / B7-H1 / CD274 Antibody, Rabbit MAb
50010-R401PD-L1 / B7-H1 / CD274 Antibody, Rabbit MAb
GTX104763PD-L1 antibody - KO/KD, Comparison, Orthogonal Validated
GTX85449PD-L2 antibody
GTX83552STAT1 antibody [4H9]
GTX110587STAT3 antibody [C2C3], C-term - KO/KD Validated
GTX104616STAT3 antibody [C3], C-term –- KO/KD Validated
GTX108701TBX21 antibody [N1C2]
GTX45121TGF beta 1 antibody
GTX130023TGF beta 1 antibody - Comparison, Overexpression Validated
50939-T24TIGIT / VSTM3 Antibody, Rabbit PAb, Antigen Affinity Purified
10390-R024TIM-3 / HAVCR2 Antibody, Rabbit MAb
GTX54117TIM-3 antibody
GTX110520TNF alpha antibody - Orthogonal Validated
GTX28349TNF alpha antibody [F6C5]

Use our advanced search engine to find your antibody. Search your target and fine-tune with the filters. You can filter on many features such as: application, species, host, conjugation, isotype, clonality, brand and more. If you still can’t find your antibody, request it here and we will locate it for you.

Immune Checkpoint Proteins

Cat. No.Description
10042-H02H2B4 / CD244 Protein, Human, Recombinant (Fc Tag)
15693-H01H4-1BBL Protein, Human, Recombinant (ECD, Fc Tag)
10698-H08HB7-1 Protein, Human, Recombinant (His Tag)
CHI-MF-110B7H4B7-H4 (mouse):Fc (mouse) (rec.)
11895-H02HBTLA Protein, Human, Recombinant (Fc Tag)
10041-H03HCD137 Protein, Human, Recombinant (His & Fc Tag)
10041-H08HCD137 Protein, Human, Recombinant (His Tag)
CHI-MF-110A4CD152 [CTLA-4] (mouse):Fc (mouse) (rec.)
CHI-MF-120A4CD152 [CTLA-4] (mouse):Fc (mouse) (rec.) (non-lytic)
10109-H02HCD155 / PVR Protein, Human, Recombinant (Fc Tag)
CHI-MF-110PDL1CD274 [B7-H1/PD-L1] (mouse):Fc (mouse) (rec.)
CHI-MF-120PDL1CD274 [B7-H1/PD-L1] (mouse):Fc (mouse) (rec.) (non-lytic)
CHI-MF-110PD1CD279 [PD-1] (mouse):Fc (mouse) (rec.)
10699-H08HCD86 Protein, Human, Recombinant (His Tag)
11159-H03HCTLA-4 Protein, Human, Recombinant (His & Fc Tag)
11159-H08HCTLA-4 Protein, Human, Recombinant (His Tag)
13643-H08HGITR Protein, Human, Recombinant (ECD, His Tag)
CHI-MF-11002IL-2 (mouse):Fc (mouse) (rec.)
CHI-MF-12002IL-2 (mouse):Fc (mouse) (rec.) (non-lytic)
CHI-MF-11021IL-21 (mouse):Fc (mouse) (rec.)
CHI-MF-12021IL-21 (mouse):Fc (mouse) (rec.) (non-lytic)
CHI-HF-21035IL-35 (human):Fc (human) (rec.)
CHI-MF-11135IL-35 (mouse):Fc (human) (rec.)
16498-H02HLAG3 Protein, Human, Recombinant (Fc Tag)
10481-H08HOX40 Protein, Human, Recombinant (His Tag)
10377-H08HPD-1 Protein, Human, Recombinant (His Tag)
50124-M03HPD-1 Protein, Mouse, Recombinant (His & Fc Tag)
10084-H08HPD-L1 Protein, Human, Recombinant (His Tag)
50010-M08HPD-L1 Protein, Mouse, Recombinant (His Tag)
10917-H08HTIGIT Protein, Human, Recombinant (His Tag)
10390-H08HTIM-3 Protein, Human, Recombinant (His Tag)
13482-H08HVISTA Protein, Human, Recombinant (His Tag)
51550-M08HVISTA Protein, Mouse, Recombinant (ECD, His Tag)

Subscribe to our newsletter here to receive interesting newsletter and offers related to immune checkpoints.

Related to:
News: Immune Checkpoint Proteins – The B7-CD28 SuperfamilyImmune Regulation Interleukins & CytokinesImmune Checkpoint Assays