DETECTION OF ANTIGEN-SPECIFIC T-CELL CYTOKINE EXPRESSION IN WHOLE-BLOOD BY FLOW-CYTOMETRY

We have recently described a highly sensitive flow cytometric techniqu e, based on the ability to detect single cell expression of cytokines, to simultaneously quantitate and phenotypically characterize antigen- specific memory/effector T cells in PBMC cultures. In this report, we describe a simplified procedural modification which enables the rapid detection of low frequency memory CD4 + and CD8 + T cells expressing c ytokines in response to soluble antigen in whole blood. When compared with T cell responses in PBMC cultures, whole blood cultures demonstra ted similar but slightly higher percentages of T cells responsive to s pecific antigen. In addition, T cell responses to cytomegalovirus in w hole blood were observed only in sensitized (seropositive) individuals , and CD4 + T cell responses could be blocked by anti-class II MHC ant ibodies. This procedure may provide a means to examine direct effects of pharmacological drug concentrations on T cell immunity in clinical samples. (C) 1998 Elsevier Science B.V.