The Nature of MHC Restrictions in T-B Cooperation

The I region of the mouse major histocompatibility complex plays an important role in controlling the interactions between T helper cells and B cells in response to antigen. For example, MHC incompatible T cells from BALB/c mice cooperate well with BALB/c B cells but poorly with CBA B cells in antibody formation. Data will be presented on helper T cell function in the PFC response to TNP-KLH in four sorts of mice, namely: a) double bone marrow chimeras (e.g. C3H + BALB/c stem cells → irradiated (C3H × BALB/c) F 1 recipients), b) single chimeras (e.g. C3H or BALB/c stem cells into (C3H × BALB/c) F 1 recipients), c) F 1 → Parental chimeras (e.g. (C3H × BALB/c) F 1 stem cells into C3H or BALB/c recipients), d) CBA mice rendered neonatally tolerant to BALB/c spleen cells. These studies suggest that the following factors determine optimal interaction between MHC incompatible T and B cells.