What High-Quality Immune Checkpoint Antibodies Are Needed for Your Cancer Immunotherapy Research?

What are Immune Checkpoints?

Immune checkpoints are crucial regulatory molecules within the immune system. Their core function is to maintain immune balance and prevent excessive immune activation that could damage healthy tissues. While this mechanism is vital for preventing autoimmune diseases, it can also be exploited by tumor cells to evade immune surveillance. Cancer cells within the tumor microenvironment often upregulate specific immune checkpoint pathways to specifically suppress the function of T cells capable of recognizing tumor antigens. Since most of these immune checkpoints function via ligand-receptor interactions, they can be effectively blocked using specific antibodies. Currently, immune checkpoint blockade therapy has become one of the most promising directions in cancer immunotherapy, capable of reactivating anti-tumor immune responses.

Hangzhou Starter provides a variety of high-quality antibodies targeting mouse immune checkpoint proteins:

1.     CTLA-4 (CD152): Cytotoxic T-Lymphocyte Associated Protein 4 is an important inhibitory receptor primarily expressed on activated T and B lymphocytes. Structurally homologous to CD28, it competitively binds B7 family molecules (CD80/CD86) on antigen-presenting cells (APCs), delivering an inhibitory signal that negatively regulates T cell activation and proliferation, playing a key role in maintaining peripheral tolerance.

2.     4-1BB (CD137): A key co-stimulatory molecule of the TNFR superfamily expressed on activated T cells, NK cells, and DCs. Ligation with its ligand (4-1BBL) provides a potent co-stimulatory signal promoting T cell proliferation, survival, and cytokine production via NF-κB, c-Jun, and p38 pathways.

3.     4-1BBL (CD137L): The natural ligand for 4-1BB, belonging to the TNF superfamily, primarily expressed on activated APCs. The 4-1BB/4-1BBL interaction is crucial for T cell co-stimulation, promoting clonal expansion, enhancing effector function, and contributing to memory T cell formation.

4.     CD40: A member of the TNFR superfamily widely expressed on APCs. Engagement with its ligand (CD40L) promotes APC maturation/activation, enhancing antigen presentation and co-stimulatory molecule expression. Agonistic anti-CD40 antibodies can activate DCs to promote tumor-specific T cell responses.

5.     CD40L (CD154): Primarily expressed on activated CD4+ T cells. Interaction with CD40 is central to T cell-dependent B cell activation, antibody class switching, and germinal center formation. Blocking this pathway can suppress germinal center responses.

6.     CD47 (IAP): A widely expressed transmembrane protein acting as a "don't eat me" signal by engaging SIRPα on macrophages to inhibit phagocytosis. Many tumors overexpress CD47; blocking the CD47-SIRPα axis enhances macrophage-mediated tumor clearance.

7.     CD80 (B7-1): A B7 family co-stimulatory molecule expressed on activated B cells, DCs, and monocytes. It delivers a co-stimulatory signal via CD28 for naïve T cell activation and an inhibitory signal via CTLA-4, playing a dual role.

8.     CD86 (B7-2): Another key B7 family member with expression kinetics distinct from CD80. It also interacts with CD28 (co-stimulation) and CTLA-4 (inhibition), providing early co-stimulatory signals.

9.     CD276 (B7-H3): A B7 family member weakly expressed on APCs and often overexpressed on various tumor cells. It can inhibit T cell activation in the TME, making it a potential therapeutic target.

10.  LAG-3: Lymphocyte Activation Gene-3 is an inhibitory checkpoint expressed on activated T cells, NK cells, and Tregs. It binds MHC class II with high affinity, negatively regulating CD4+ T cell function and contributing to Treg suppression.

11.  OX40 (CD134): A TNFR superfamily member expressed on activated CD4+ and CD8+ T cells. OX40 signaling provides key co-stimulation, promoting T cell survival, proliferation, cytokine production, and inhibiting activation-induced cell death, crucial for effector and memory T cell generation.

12.  OX40L (CD134L): Expressed on activated APCs. The OX40L-OX40 interaction is critical for full T cell activation, enhancing proliferation, cytokine secretion, and memory formation.

13.  PD-1 (CD279): Programmed Death-1 is a deeply studied checkpoint on activated T cells, B cells, and myeloid cells. Binding to PD-L1/PD-L2 delivers inhibitory signals, leading to T cell exhaustion. Blocking PD-1/PD-L1 has shown remarkable clinical success.

14.  PD-L1 (B7-H1): The primary ligand for PD-1, widely expressed and often overexpressed on tumor cells, contributing to immune evasion. PD-L1 level is a key biomarker for predicting response to PD-1/PD-L1 blockade therapy.

15.  PD-L2 (B7-DC): Another PD-1 ligand, primarily expressed on DCs and macrophages. Its binding to PD-1 also effectively inhibits T cell activation.

16.  TIM-1 (CD365): T cell Immunoglobulin and Mucin domain containing protein 1, expressed on Th2 cells, involved in regulating T cell activation and differentiation, playing roles in allergy, asthma, and transplantation immunity.

17.  TIM-3 (CD366): Expressed on Th1 and cytotoxic T cells. Binding to its ligand Galectin-9 induces Th1 cell apoptosis, negatively regulating cellular immunity. TIM-3 contributes to T cell exhaustion alongside PD-1.

18.  VISTA: V-domain Ig suppressor of T cell activation is primarily expressed on myeloid cells and naïve T cells. It acts as an inhibitory receptor, suppressing T cell activation and cytokine production. Blocking VISTA can enhance anti-tumor immunity.

19.  ICOS: Inducible T cell CO-Stimulator, a CD28 family member on activated T cells. ICOS-ICOSL interaction provides co-stimulatory signals crucial for T follicular helper cell differentiation, germinal center reactions, and Treg function.

20.  GITR: Glucocorticoid-Induced TNFR-Related protein is highly expressed on Tregs and upregulated on conventional T cells upon activation. GITR signaling can counteract Treg suppression and enhance effector T cell function.

21.  Galectin-9: A soluble lectin, ligand for TIM-3. Galectin-9 binding induces Th1 cell apoptosis and is involved in Treg expansion/function, playing complex roles in immune regulation.

22.  CD27: A TNFR superfamily member on T cells, NK cells, and memory B cells. CD27-CD70 interaction provides co-stimulatory signals promoting T cell proliferation, survival, and memory formation.

23.  CD28: The classic co-stimulatory receptor constitutively expressed on naïve T cells. Binding to CD80/CD86 provides the second signal for T cell activation, promoting IL-2 production and proliferation.

24.  CD70: The ligand for CD27, expressed on activated immune cells. The CD70-CD27 pathway is important in T-B cell interactions, promoting B cell activation and antibody production.

25.  ICOSL (CD275): ICOS Ligand expressed on APCs. The ICOSL-ICOS interaction is vital for T cell-dependent immune responses, particularly in germinal center reactions and antibody affinity maturation.

26.  BTLA: B and T lymphocyte attenuator is an inhibitory checkpoint on lymphocytes. Binding to HVEM delivers inhibitory signals, negatively regulating T cell activation and maintaining immune homeostasis.

27.  FGL1: Fibrinogen-like protein 1 is a novel ligand for LAG-3, primarily expressed in the liver but often overexpressed in tumors. FGL1-LAG-3 interaction inhibits T cell function and is associated with resistance to PD-1/PD-L1 blockade.

28.  PSGL-1: P-Selectin Glycoprotein Ligand 1, expressed on leukocytes, primarily involved in leukocyte rolling. Recent studies indicate it also functions as an immune checkpoint, inhibiting T cell function via a VISTA-dependent mechanism.

29.  TIGIT: T cell immunoreceptor with Ig and ITIM domains, expressed on T and NK cells. It delivers inhibitory signals upon binding ligands like CD155, contributes to T cell exhaustion alongside PD-1, and is a hot target for clinical development.

Hangzhou Starter Bio-tech is committed to providing high-quality antibodies, proteins, kits, and R&D services for the global life sciences sector. The company possesses multiple advanced technology platforms, including recombinant rabbit monoclonal antibody, recombinant mouse monoclonal antibody, rapid mouse monoclonal antibody, and recombinant protein development platforms (covering E.coli, CHO, HEK293, and insect cell expression systems). It has officially passed EU 98/79/EC certification, ISO9001, and ISO13485 quality management system certifications. Leveraging 15 years of experience in monoclonal antibody and recombinant protein production and customization, Hangzhou Starter provides researchers in academia, pharmaceuticals, and diagnostics with a variety of high-quality, pre-clinical grade monoclonal antibodies and recombinant proteins.

The company employs large-scale tissue culture technology for antibody production and purifies them via affinity chromatography. The resulting antibodies feature high purity, low endotoxin levels, and are free from preservatives and stabilizers, making them suitable for in vivo preclinical studies. All antibody products are available in large-scale packaging from 100mg to 50g, offering excellent cost-effectiveness.

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