Nonspecific augmentation of lymph node T cells and I‐E‐independent selective deletion of VβbTl4+ T cells by Mtv‐2 in the DDD mouse

DDD/1 (DDD) mice were characterized by marked paucity of T cells in lymph nodes (LN). In DDD-Mtv-2/Mtv-2 (DDD-Mtv-2) congenics, T cells were 4- to 18-fold increased depending on ages but B cells doubled at the most. Thymus weight also increased. In DDDfDDD-Mtv-2, DDD neonatally infected with Mtv-2-derived exogenous MMTV (MMTV-2), neither LN cells nor thymus weight increased. The V beta 5+ and V beta 8+ T cell contents in LN were practically the same among three strains. The Mtv-2-induced expansion of LN T cells was polyclonal and appeared indigenous to DDD mice. Both Mtv-2 and MMTV-2 induced progressive age-dependent deletion of V beta 14+CD4+ LN cells. Mtv-2 but not MMTV-2 caused deletion of V beta 14+CD8+ LN cells and mature V beta 14+CD4+ thymocytes. Thus, Mtv-2- and MMTV-2-induced V beta 14+ T cell deletion may reflect intrathymic and peripheral elimination, respectively. The absence of I-E gene expression in DDD indicates that V beta 14+ T cell deletion advances independently of I-E molecules in this experimental system.