Impaired T cell functions preceding lymphoproliferative disorders in mice neonatally tolerized to transplantation antigens.

In A/J (H-2a) (A) mice, the neonatal i.v. injection of (B10 x A)F1 spleen cells (SC) induces partial transplantation tolerance (TT) to C57BL/10ScSn (H-2b) (B10) skin allografts, chronic host-versus-graft disease (HVGD) and lethal lymphoproliferative disorders (LPD). They produce anti-T-cell autoantibodies (ATA), and the proliferative responses of their SC to the T cell mitogen Con A are decreased. We found that, similar to ATA, the hyporeactivity of T cells developed earlier (at 1-2 weeks of age) than splenomegaly. The proportions of both CD4+ and CD8+ T cells were not reduced in the spleens of tolerized mice without manifest LPD. The supernatants (SN) of Con A-stimulated tolerized SC contained no, or only small amounts of interleukin-2 (IL-2). Thus, in the tolerized mice, ATA and T cell deficiency preceded the development of LPD. ATA and the decreased amount of the T cell growth factor IL-2 might play a role in the defective T cell activation.