Differential cytokine profiles in CD4⁺ and CD8⁺ T cells during acute murine GVHD. Mesenteric lymph nodes were collected on day +9 after BMT from irradiated BALB/c (H2^d) recipients of 15 million B6 (H2^b) bone marrow cells (BMCs) and 5 million splenocytes (SCs). Cells were assessed for intracellular TNFα or IFNγ expression in CD4⁺ cells and CD8⁺ cells. Significantly higher frequency of mesenteric lymph node (MLN) CD4⁺ T cells than CD8⁺ T cells (P < .01) expresses TNFα after nonspecific activation in vitro. The absolute number of TNFα⁺CD4⁺ and TNFα⁺CD8⁺ cells were not significantly different in the MLNs. Representative data from 1 of 3 independent experiments are presented as means plus or minus SEM (error bars).