Mycoplasma-dependent Activation of Normal Lymphocytes: Role of Arginine and Nonviable Mycoplasma Antigen in the Induction of Lymphocyte-mediated Cytotoxicity for Syngeneic Mouse Target Cells

The ability of arginine supplementation to abrogate or potentiate Mycoplasma arthritidis-mediated cytotoxicity induction by normal CBA mouse lymphocytes was investigated. Also, nonviable antigens of M. arthritidis were assayed for their ability to induce a cytotoxic response. The presence of additional arginine in the culture medium had no significant effect on the amount of cytotoxicity produced. In some cases, an increase in cytotoxicity was seen in the presence of additional arginine. Amino acid analysis of the culture supernatants showed that the arginine in the nonsupplemented medium was exhausted during the assay, whereas ample amounts of arginine were present in the supplemented medium. However in both cases the amount of cytotoxicity was comparable. Nonviable antigens of M. arthritidis were unable to induce a significant cytotoxic response in the presence of normal lymphocytes. The same antigens exhibited a suppressive response when tested for blastogenesis in the presence of normal lymphocytes. A discussion of lymphocyte involvement is presented.