Immunosuppression by Antilymphocyte Serum and Its Effect on Tumors Induced by 3-Methylcholanthrene in Mice

Summary

Heterologous antilymphocyte serum (ALS) was prepared in rabbits and a pony. The ALS was titrated in vivo in terms of its ability to suppress the rejection of allografted tumors. From this titration, a dosage schedule was devised, adequate to suppress allograft rejection for longer than 84 days. A standard dose of 3-methylcholanthrene injected intramuscularly induced the same frequency of tumors after an identical latency in mice, whether or not they had been treated with an immunosuppressive regimen of ALS.