T cell transformation with Herpesvirus saimiri: a tool for neuroimmunological research

The finite life span of human T lymphocytes and their requirement of regula r restimulation frequently limit human T cell studies. Once infected with H . saimiri, however, human and monkey T cells are transformed to stable grow th without the need for further restimulation. H. saimiri persists in human growth-transformed T cells episomally and only a few viral genes are expre ssed. The release of infectious virus from transformed human T cells has no t been observed. H. saimiri-transformed T cells have the phenotype of matur e activated CD4(+) or CD8(+) T cells. Transformed T cells retain a structur ally and functionally intact T cell receptor and respond specifically to re cognition of their antigen. They produce Th1-like cytokines, provide B cell help, can be triggered to become cytotoxic, and are sensitive to a variety of apoptosis-inducing treatments. While H. saimiri-transformed T cells res emble native T cells in numerous aspects, their reactivity to CD2 is striki ngly different: Native T cells are activated via CD2 by certain pairs of mA bs, but not by the mere binding of CD2 to its ligand CD58. In contrast, H. saimiri-transformed T cells are activated by a single crosslinked anti-CD2 mAb and also by interaction with CD58-bearing cells. (C) 2000 Elsevier Scie nce B.V. All rights reserved.