| First Author | Heath AW | Year | 1994 |
| Journal | Eur J Immunol | Volume | 24 |
| Issue | 8 | Pages | 1828-34 |
| PubMed ID | 7519997 | Mgi Jnum | J:19906 |
| Mgi Id | MGI:68026 | Doi | 10.1002/eji.1830240816 |
| Citation | Heath AW, et al. (1994) Monoclonal antibodies to murine CD40 define two distinct functional epitopes. Eur J Immunol 24(8):1828-34 |
| abstractText | Two rat IgG2a antibodies which define distinct epitopes on murine CD40 have been generated. These antibodies specifically bind recombinant murine CD40 expressed on L cells, and the soluble extracellular domain of murine CD40 coated onto microtiter plates. Both antibodies bind B220+ but not B220 murine spleen cells, and immunoprecipitate a 45-kDa protein from the surface of purified murine splenic B cells. These antibodies exhibit separate functional properties, consistent with the notion that they define two distinct CD40 epitopes. One of the monoclonal antibodies (designated 1C10) directly induces a specific proliferative response from mature murine B cells, up-regulates several B cell surface antigens, and rescues immature B lymphoma cells from anti-IgM-induced growth arrest. The other monoclonal antibody (designated 4F11) exhibits none of these properties, but is capable of synergizing with suboptimal amounts of either anti-IgM antibodies or the 1C10 agonistic anti-CD40 antibody to produce an optimal proliferative response of purified small dense B cells. Furthermore, 4F11 antibody synergizes with suboptimal amounts of 1C10 antibody to rescue B lymphoma cells from anti-IgM-induced growth arrest. The 1C10 and 4F11 antibodies were unable to cross-block each other's binding to recombinant CD40 expressed in L cells, providing strong support for the notion that the antibodies recognize distinct epitopes on CD40. The potential implications of two functionally distinct CD40 epitopes are discussed. |
