BURN INJURY PRIMES NAIVE CD4-CELLS FOR AN AUGMENTED T-HELPER-1 RESPONSE( T)

Background. The mechanisms responsible for altered T-cell responses an d cytokine production after injury are not well understood We used T-c ell receptor (TCR) transgenic mice to study burn injury effects on nai ve versus antigen-activated CD4+ T cells in vivo. Methods, One week af ter sham or Burn injury, lymph node cells were prepared from TCR trans genic mice and stimulated with TCR transgene-specific antigens. T-cell proliferation was measured and culture supernatants were tested for i nterleukin-2 (IL-2), interferon-gamma (IFni-gamma), IL-4, and IL-10 by enzyme-linked immunosorent assay (ELISA). Burn injury effects on anti gen-activated T cells were studied by immunizing TCR transgenic or wil d-type mice at the time of injury. Results. The antigen-stimulated pro liferation of naive CD4+ T cells was unaffected by burn injury and no increase in T-helper 2 (Th2)-type cytokine production Was observed. In stead, burn injury augmented IFN-gamma production by naive CD4+ transg enic T cells, and IL-2 production was marginally reduced. Thus, burn i njury primed naive T cells for an enhanced Th1-type response. In contr ast, antigen-specific proliferation, IL-2, and IFN-gamma production by T cells ha harvested from immunized wildtype mice were suppressed. Un expectedly, high mortality was observed when burn-injured TCR transgen ic mice were immunized. Conclusion. Our results show that burn injury has differential effects on naive and antigen-activated CD4+ T cells a nd can prime naive CD4+ T cells.