CD3− Bone Marrow Cells Augment the Generation of Cytotoxic T Lymphocytes Showing a Preference for the X-Chromosome Linked Gene Product of Stimulator Cells

Responder cells, composed of both a limited number of nylon wool‐passed lymph node (NW‐LN) cells and an excess number of CD3+ cell‐depleted bone marrow (CD3− BM) cells from the same strain of mice, were stimulated with allogeneic spleen cells in vitro. The CD3− BM cells augmented the generation of allogeneic major histocompatibility complex (MHC) class I specific cytotoxic T lymphocytes (CTL) from NW‐LN cells. C3H/He (H‐2k, C3H background) responder cells were stimulated with either B10.D2 (H‐2d, B10 background) or BALB/c (H‐2d, BALB background) spleen cells. In the former stimulation, the CTL induced lysed B10.D2 target cells more efficiently than the BALB/c cells. Furthermore, these CTL lysed more (B10.D2 × BALB/c) F1 male target cells than (BALB/c × B10.D2) F1 male. In the latter stimulation, the CTL lysed more BALB/c than B10.D2 cells, and more (BALB/c × B10.D2) F1 male than (B10.D2 × BALB/c) F1 male. The reciprocal mixed lymphocyte cultures (MLC) were carried out, in which BALB/c responder cells were stimulated with either C3H/He or B10.BR (H‐2k, B10 background) spleen cells. In the former stimulation, the CTL induced lysed more C3H/He or (C3H/He × B10.BR) F1 male target cells than B10.BR or (B10.BR × C3H/He) F1 male, and in the latter, the reciprocal results were obtained. These results suggested that the CTL induced had a preference for the X‐chromosome linked gene products (Xlgp), besides the specificity for the allogeneic MHC class I, of the mice used as stimulator.