Clonal analysis of the T-cell response of mice to herpes simplex virus: correlation between lymphokine production in vitro and the induction of delayed-type hypersensitivity and antiviral activity in vivo.

The properties of two morphologically distinct L3T4+, Lyt2- "helper" T-cell clones specific for herpes simplex virus were investigated. Both of the clones produced IL-3 and interferon, but neither produced IL-2. Clone D6.6 produced macrophage agglutinating factor, a fibronectin-like lymphokine, and also a delayed hypersensitivity (DH) response when injected locally into syngeneic mice. Despite the presence of a DH producing clone and a non-DH producing clone, both were able to reduce the local virus titre to an equivalent degree. It is suggested that this protective activity is associated with the production of interferon-gamma. The significance of these results to mechanisms of protection against herpes simplex virus in vivo is discussed.