An adoptive cell transfer system for the evaluation of immunity to Herpes simplex virus in mice.

Lymphocytes adoptively transferred from syngeneic immune donors protect mice against challenge with Herpes simplex virus type 1. Normal mice require transfer 3 x 10(7) spleen cells for protection. Sublethal irradiation (450 rad) decreases the number required five-fold. Lymphocytes from non-immune donors do not protect, and hyperimmunization does not enhance the protection efficiency of donors. The viral LD50 varies through a range 10(5)-fold during the period of recovery from this amount of radiation, but over the same period there is little variation in the number of cells required for protection. Nor is there much variation in this number between strains of mice naturally susceptible (CBA) and resistant (C57) to the virus. We conclude that natural resistance operates at a level of virus handling prior to operation of the lymphocyte system, perhaps at the generation of interferon. As few as 1.3 x 10(6) immune T lymphocytes can protect against challenge provided that they are transferred together with normal spleen cells. We conclude that primed lymphocytes act in co-operation with non-immune cells.