FlowMAb FITC anti-mouse PD-L1 (B7-H1)
Product Details
The 10F.9G2ā¢ monoclonal antibody reacts with mouse PD-L1 (programmed death ligand 1), also known as B7-H1 or CD274. PD-L1 is a 40 kDa type I transmembrane protein that belongs to the B7 family of the Ig superfamily. PD-L1 is expressed on T lymphocytes, B lymphocytes, NK cells, and dendritic cells, as well as IFNĪ³-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 tumor immune evasion. Induced PD-L1 expression is common in many tumors and results in increased resistance of tumor cells to CD8 T cell-mediated lysis. In mouse models of melanoma, tumor growth can be transiently arrested via treatment with antibodies that block the interaction between PD-L1 and PD-1. This fluorescein isothiocyanate (FITC)-conjugated version of the antibody is useful for flow cytometry, immunofluorescence, and immunohistochemistry (frozen) applications.Specifications
| Isotype | Rat IgG2b,Ā Īŗ |
|---|---|
| Recommended Isotype Control(s) | FlowMAb FITC rat IgG2b isotype control, anti-keyhole limpet hemocyanin |
| Conjugation | FITC |
| Excitation Source | Blue 488 nm |
| Excitation Max | 494 nm |
| Emission Max | 518 nm |
| Immunogen | Mouse CD274 |
| Reported Applications |
Immunofluorescence Immunohistochemistry (frozen) Flow cytometry |
| Formulation |
PBS, pH 6.5 Contains 0.09% Sodium Azide |
| Production | Purified from cell culture supernatant in an animal-free facility |
| Purification | Protein G. Conjugated with fluorescein isothiocyanate under optimal conditions. |
| Storage | The antibody solution should be stored at the stock concentration at 4Ā°C and protected from prolonged exposure to light. Do not freeze. |
Additional Formats
Recommended Products
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Recommended Isotype Control(s)
FlowMAb FITC rat IgG2b isotype control, anti-keyhole limpet hemocyanin
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Recommended Dilution Buffer
InVivoPure pH 6.5 Dilution Buffer
Flow Cytometry
Aloulou, M., et al. (2016). "Follicular regulatory T cells can be specific for the immunizing antigen and derive from naive T cells" Nat Commun 7: 10579. PubMed
T follicular regulatory (Tfr) cells are a subset of Foxp3(+) regulatory T (Treg) cells that form in response to immunization or infection, which localize to the germinal centre where they control the magnitude of the response. Despite an increased interest in the role of Tfr cells in humoral immunity, many fundamental aspects of their biology remain unknown, including whether they recognize self- or foreign antigen. Here we show that Tfr cells can be specific for the immunizing antigen, irrespective of whether it is a self- or foreign antigen. We show that, in addition to developing from thymic derived Treg cells, Tfr cells can also arise from Foxp3(-) precursors in a PD-L1-dependent manner, if the adjuvant used is one that supports T-cell plasticity. These findings have important implications for Tfr cell biology and for improving vaccine efficacy by formulating vaccines that modify the Tfr:Tfh cell ratio.
Flow Cytometry
Ngiow, S. F., et al. (2015). "A Threshold Level of Intratumor CD8+ T-cell PD1 Expression Dictates Therapeutic Response to Anti-PD1" Cancer Res 75(18): 3800-3811. PubMed
Despite successes, thus far, a significant proportion of the patients treated with anti-PD1 antibodies have failed to respond. We use mouse tumor models of anti-PD1 sensitivity and resistance and flow cytometry to assess tumor-infiltrating immune cells immediately after therapy. We demonstrate that the expression levels of T-cell PD1 (PD1(lo)), myeloid, and T-cell PDL1 (PDL1(hi)) in the tumor microenvironment inversely correlate and dictate the efficacy of anti-PD1 mAb and function of intratumor CD8(+) T cells. In sensitive tumors, we reveal a threshold for PD1 downregulation on tumor-infiltrating CD8(+) T cells below which the release of adaptive immune resistance is achieved. In contrast, PD1(hi) T cells in resistant tumors fail to be rescued by anti-PD1 therapy and remain dysfunctional unless intratumor PDL1(lo) immune cells are targeted. Intratumor Tregs are partly responsible for the development of anti-PD1-resistant tumors and PD1(hi) CD8(+) T cells. Our analyses provide a framework to interrogate intratumor CD8(+) T-cell PD1 and immune PDL1 levels and response in human cancer. Cancer Res; 75(18); 3800-11. (c)2015 AACR.
Flow Cytometry
Rutigliano, J. A., et al. (2014). "Highly pathological influenza A virus infection is associated with augmented expression of PD-1 by functionally compromised virus-specific CD8+ T cells" J Virol 88(3): 1636-1651. PubMed
One question that continues to challenge influenza A research is why some strains of virus are so devastating compared to their more mild counterparts. We approached this question from an immunological perspective, investigating the CD8(+) T cell response in a mouse model system comparing high- and low-pathological influenza virus infections. Our findings reveal that the early (day 0 to 5) viral titer was not the determining factor in the outcome of disease. Instead, increased numbers of antigen-specific CD8(+) T cells and elevated effector function on a per-cell basis were found in the low-pathological infection and correlated with reduced illness and later-time-point (day 6 to 10) viral titer. High-pathological infection was associated with increased PD-1 expression on influenza virus-specific CD8(+) T cells, and blockade of PD-L1 in vivo led to reduced virus titers and increased CD8(+) T cell numbers in high- but not low-pathological infection, though T cell functionality was not restored. These data show that high-pathological acute influenza virus infection is associated with a dysregulated CD8(+) T cell response, which is likely caused by the more highly inflamed airway microenvironment during the early days of infection. Therapeutic approaches specifically aimed at modulating innate airway inflammation may therefore promote efficient CD8(+) T cell activity. We show that during a severe influenza virus infection, one type of immune cell, the CD8 T cell, is less abundant and less functional than in a more mild infection. This dysregulated T cell phenotype correlates with a lower rate of virus clearance in the severe infection and is partially regulated by the expression of a suppressive coreceptor called PD-1. Treatment with an antibody that blocks PD-1 improves T cell functionality and increases virus clearance.
Immunofluorescence
Willimsky, G., et al. (2013). "Virus-induced hepatocellular carcinomas cause antigen-specific local tolerance" J Clin Invest 123(3): 1032-1043. PubMed
T cell surveillance is often effective against virus-associated tumors because of their high immunogenicity. It is not clear why surveillance occasionally fails, particularly against hepatitis B virus- or hepatitis C virus-associated hepatocellular carcinoma (HCC). We established a transgenic murine model of virus-induced HCC by hepatocyte-specific adenovirus-induced activation of the oncogenic SV40 large T antigen (TAg). Adenovirus infection induced cytotoxic T lymphocytes (CTLs) targeted against the virus and TAg, leading to clearance of the infected cells. Despite the presence of functional, antigen-specific T cells, a few virus-infected cells escaped immune clearance and progressed to HCC. These cells expressed TAg at levels similar to HCC isolated from neonatal TAg-tolerant mice, suggesting that CTL clearance does not select for cells with low immunogenicity. Virus-infected mice revealed significantly greater T cell infiltration in early-stage HCC compared with that in late-stage HCC, demonstrating progressive local immune suppression through inefficient T cell infiltration. Programmed cell death protein-1 (PD-1) and its ligand PD-L1 were expressed in all TAg-specific CD8+ T cells and HCC, respectively, which contributed to local tumor-antigen-specific tolerance. Thus, we have developed a model of virus-induced HCC that may allow for a better understanding of human HCC.
Immunohistochemistry (frozen), Immunofluorescence
Riella, L. V., et al. (2011). "Essential role of PDL1 expression on nonhematopoietic donor cells in acquired tolerance to vascularized cardiac allografts" Am J Transplant 11(4): 832-840. PubMed
The PD1:PDL1 pathway is an essential negative costimulatory pathway that plays a key role in regulating the alloimune response. PDL1 is expressed not only on antigen-presenting cells (APCs) but also cardiac endothelium. In this study, we investigated the importance of PDL1 expression on donor cardiac allograft in acquired transplantation tolerance in a fully MHC-mismatched model. We generated PDL1 chimeric mice on B6 background that expressed PDL1 on either hematopoietic cells or nonhematopoietic cells of the heart. Sham animals were used as controls. These hearts were then transplanted into BALB/c recipients and treated with CTLA4-Ig to induce tolerance. Cardiac endothelium showed significant expression of PDL1, which was upregulated upon transplantation. While the absence of PDL1 on hematopoietic cells of the heart resulted in delayed rejection and prevented long-term tolerance in most but not all recipients, we observed an accelerated and early graft rejection of all donor allografts that lacked PDL1 on the endothelium. Moreover, PDL1-deficient endothelium hearts had significant higher frequency of IFN-gamma-producing alloreactive cells as well as higher frequency of CD8(+) effector T cells. These findings demonstrate that PDL1 expression mainly on donor endothelium is functionally important in a fully allogeneic mismatched model for the induction of cardiac allograft tolerance