H-2 Dependence of Co-Operation Between T and B Cells in Vivo

Abstract

In nude mice from a stock which has been backcrossed several times to BALB/c (H-2d), a lasting restoration of immune competence could be induced by H-2 compatible (BALB/c, DBA, B10.D2) thymus cells but not by H-2 incompatible thymus cells. Heterozygous, H-2bH-2d, thymus cells from BALB/c × C57, F1 or from a BALB/c × (BALB/c × C57) backcross produce variable effects; only sometimes was a lasting restoration achieved. This cannot be accounted for by rejection of the injected thymus cells since nude mice do not reject tissue grafts. Therefore the H-2 complex must play an active role in an enduring co-operation between bone marrow-derived (B) cells and thymus-derived (T) cells.