T-cell receptor heterogeneity among epstein-barr virus-stimulated t-cell populations

The mechanism by which Epstein-Barr Virus (EBV) escapes T-cell activity during latency in immunocompetent individuals has long been debated. In order to identify potential weaknesses in the EBV-specific immune response, a study of T-cell receptors (TCR) within virus stimulated T-cell populations was performed. Membrane staining techniques and the polymerase chain reaction were used to address two questions: (1) Does EBV behave as a superantigen, thus stimulating, and possibly eliminating, T-cell subsets based on TCR Vβ expression?, and (2) Are T-cells dependent on a predominant TCR Vβ segment for effective cytotoxic function towards EBV? In search for superantigen effects, Vβ repertoires among PBL from seropositive and seronegative individuals were compared both before and after short term in vitro exposure to EBV. In order to characterize functional TCR, the Vβ usage among CD8⁺ EBV-specific cytotoxic T-cell clones was determined. Taken together, results illustrated the strengths rather than weaknesses of the EBV-specific T-cell immune response. T-cells did not respond to EBV in a manner typifying potent superantigen activity, nor did T-cells rely on the expression of a single Vβ gene segment for efficient, EBV-specific cytotoxic function.