Identification of the mouse IgG3 receptor: implications for antibody effector function at the interface between innate and adaptive immunity.

摘要: Mouse IgG3 appears early in immune responses independently of T cell help and, as such, is an effector molecule the system. Yet, a specific cellular receptor remains undefined. In transfection experiments, mouse FcγRI was clearly able to bind complexes IgG3, whereas FcγRII could not. Furthermore, macrophages from mice expressing and FcγRIII but lacking were unable phagocytose complexes, thus identifying sole for complexes. Competition studies demonstrated that monomeric inhibit IgG2a binding with ID50 ≈10−7 M (fivefold lower than IgG2a). The identification establishes participant events at interface between innate adaptive immunity, implying greater role this development normal pathologic previously recognized.