Increased macrophage activity in protein A treated tumor regressed animals

Male swiss albino mice transplanted with 1 x 10(6) viable fibrosarcoma tumor cells were treated with Protein A (60 micrograms/kg) right from the day of transplantation for 4 weeks, twice weekly. The therapy resulted in lesser tumor incidence, significant inhibition of tumor growth and enhanced percent survival in treated animals as compared to untreated controls. Treated animals also showed gains in body weight, an increase in peripheral blood leucocyte count, significant increase in macrophage function and number. Stimulation of macrophage number and macrophage function by Protein A may be related to its antitumor.