Prolonged survival of skin homografts in adult mice following sub-lethal irradiation, injection of donor-strain spleen cells and administration of A-methopterin.

Abstract

Sixteen A-strain male mice were given 500 r wholebody irradiation, followed by an intravenous injection of 150 million nucleated spleen cells from male CBA mice twice daily for two days, startiag on the day of irradiation. Four mice received no further treatment; the remainder were given A-methopterin in a dosage of 1.5 mu g/g bodyweight every 2 days for six doses, starting 2, 6, or 10 days after irradiation. Four weeks after irradiation all surviving mice received a homograft of skin from a CBA male donor. The incidence of fatal graft- versus-host disease was greatly reduced by administration of A-methopterin starting on day 2, and reduced to a lesser extent by administration of the drug starting on day 6. (P.C.H.)