Continuous proliferation of murine antigen-specific helper T lymphocytes in culture

Murine helper T cells activated to sheep or horse erythrocyte antigens in vivo have been established as continuous cell lines in culture. T cells require the presence of a T-cell growth factor (TCGF) for continuous proliferation. TCGF purified from murine, rat, or human sources all stimulate murine T-cell growth. The T-cell mitogens concanavalin A and phytohemagglutinin do not stimulate cell proliferation in continuous T-cell lines. All cells that grow in the presence of TCGF express Thy-1 antigens. Helper activity of T-cell lines is both antigen specific and effective for syngeneic or F1 B cells. Supernates from T-cell lines do not contain antigen-specific or nonspecific helper factors. Although several T-cell lines have shown stable helper activity for greater than 50 wk in culture, other cell lines have shown a gradual decline in effector function. The procedure used to establish and maintain proliferation of T cells in culture should be suitable for the selection and growth of antigen-specific effector T cells from each subclass.