LARGE CLONAL EXPANSIONS OF CD8(-CELLS IN ACUTE INFECTIOUS-MONONUCLEOSIS() T)

Primary infection with Epstein-Barr virus often results in the clinica l syndrome of acute infectious mononucleosis (glandular fever). This i llness is characterized by a striking lymphocytosis, the nature of whi ch has been controversial. We show that large monoclonal or oligoclona l populations of CD8(+) T cells account for a significant proportion o f the lymphocytosis and provide molecular evidence that these populati ons have been driven by antigen. The results suggest that the selectiv e and massive expansion of a few dominant clones of CD8(+) T cells is an important feature of the primary response to this virus.