Comparative immunological studies on cryosurgery and surgical operation using Moloney murine sarcoma virus-induced primary tumors in BALB/c mice.

The effect of cryosurgery and surgical operation on Moloney murine sarcoma virus-induced primary tumors in the treated and untreated groups of BALB/c mice was compared in terms of tumor growth, cumulative mortality, lymphocyte-mediated cytotoxicity, proliferative response of lymphocytes, and humoral antibody formation. The results indicate that cryosurgical treatment showed both in vivo and in vitro effects; (i) tumor growth and cumulative mortality in mice treated by cryosurgery were significantly lower than those in untreated groups, and (ii) their cellular immune response was enhanced, as manifested by increase in a proliferative response and in lymphocyte-mediated cytotoxic activity against Moloney murine leukemia virus-induced lymphoma. The proliferative response of spleen cells and the cytotoxic activity of lymphocytes were not parallel; the proliferative response detected by 3H-thymidine incoroporation manifested peak activity 3 days after cryosurgery, but the cytotoxic activity detected by 125I-iododeoxyuridine-releasing tests was considerably decreased at this stage. Two weeks after cryosurgery and thereafter, however, the cytotoxic activity of this group increased to a level higher than that of untreated or surgically treated groups. On the contrary, surgical operation abrogated the proliferative response of spleen cells. Immunofluorescence tests revealed, however, that humoral antibody formation was higher in surgically operated groups than in other groups.