Description
The MR1 monoclonal antibody specifically binds to CD154 (CD40 Ligand, gp39), an accessory molecule expressed on activated T helper (CD4+) lymphocytes. CD154 has also been detected on other types of leukocytes, including CD8+ T cells, medullary thymocytes, activated CD4+ NK-T cells, and human NK cells. CD154 plays an important role in costimulatory interactions between T and B lymphocytes and between antigen-presenting cells and lymphocytes, regulating the immune response at multiple levels. MR1 mAb inhibits in vitro activation of B lymphocytes by T helper cells by blocking interaction of gp39 with CD40. In vitro interactions of T cells and antigen-presenting cells can also be blocked by the MR1 antibody. In vivo treatment with MR1 antibody blocks the development of experimental autoimmune disease, inhibits formation of germinal centers and generation of memory B cells, reduces T-lymphocyte responses to allogeneic cells and allografts, prevents intrathymic deletion of self-reactive T lymphocytes, and disrupts antigen-specific T-cell responses.
Flow cytometry: For the detection of mouse CD154 on activated peripheral T cells, it is strongly recommended that T cells be purified before activation. Mouse CD154 is transiently expressed on the surfaces of activated normal T cells and certain T cell clones with a maximal level detected 6-8 hours post-activation. Activation with immobilized anti-CD3e mAb (e.g., 145-2C11, Cat. No. 557306/553058, or 500A2, Cat. No. 553238) is sufficient to induce CD154 expression on CD4+ cells. It has been reported that CD8+ cells express CD154 only in response to PMA/Ionomycin treatment. Therefore, for detection of CD154, it is crucial to utilize the proper activation stimuli and to stain cells at the optimal time for CD154 expression. We recommend the use of biotinylated mouse anti-hamster IgG cocktail (Cat. No. 554010) followed by a "bright" second-step reagent, such as Streptavidin-PE (Cat. No. 554061), for optimal detection of CD154.
Store undiluted at 4°C. The monoclonal antibody was purified from tissue culture supernatant or ascites by affinity chromatography. This preparation contains no preservatives, thus it should be handled under aseptic conditions.
1. Since applications vary, each investigator should titrate the reagent to obtain optimal results.
2. Although hamster immunoglobulin isotypes have not been well defined, BD Biosciences Pharmingen has grouped Armenian and Syrian hamster IgG monoclonal antibodies according to their reactivity with a panel of mouse anti-hamster IgG mAbs. A table of the hamster IgG groups, Reactivity of Mouse Anti-Hamster Ig mAbs, may be viewed at http://www.bdbiosciences.com/documents/hamster_chart_11x17.pdf.
3. Please refer to www.bdbiosciences.com/us/s/resources for technical protocols.
