SURFACE MARKER PATTERNS OF T-CELLS AND EXPRESSION OF INTERLEUKIN-2 RECEPTOR IN MEASLES INFECTION

The surface marker patterns of T cells of Ghanaian children during mea sles infection were studied and an attempt was made to demonstrate T c ell activation and viability in vitro after activation in vivo by meas les virus. The frequencies of CD4(+) and CD8(+) naive T cells in measl es patients were high while their memory T cells were remarkably reduc ed with no sign of proliferation even at the acute phase of the illnes s. The reduction of memory T cells was prolonged during the convalesce nt phase (2 months after onset). The anti-CD3 monoclonal antibody-indu ced expression of interleukin-2 receptor alpha chain (IL-2R/CD25) was significantly suppressed; however, the addition of phorbol 12-myristat e 13-acetate or ionomycin caused a remarkable recovery of CD25 express ion. On simple culture, an appreciable proportion of T cells from meas les patients died rapidly in contrast with only a few T cells from hea lthy controls doing so. The suppression of CD25 expression was still d emonstrated during the convalescent phase of the disease. Taken togeth er these results suggest unresponsiveness and activation-induced cell death of T cells during severe measles infection in Ghanaian children. Furthermore the prolonged abnormalities of T cells (i.e. decreased me mory T cells and inhibition of CD25 expression during the convalescent phase) might be related to post-measles infection immunosuppressive s tatus.