Distribution of in vitro-stimulated immune lymphocytes in mice bearing Moloney murine sarcoma virus-induced primary tumor.

The distribution of in vitro-stimulated immune lymphocytes in tumor-bearing mice was studied. Spleen cells from BALB/c mice which had regressed Moloney murine sarcoma virus (M-MSV)-induced primary tumors, were sensitized in vitro by using Moloney murine leukemia virus-induced BALB/c lymphoma (LSTRA). Lymphocytes obtained 6 days after stimulation were examined for cytotoxic activity against LSTRA cells, labeled with 51 Cr or 99mTc, and inoculated into mice bearing MSv-induced primary tumors. The distribution of 52Cr-labeled lymphocytes was determined by counting the radioactivity of each organ. Compared to normal lymphocytes, in vitro-stimulated lymphocytes accumulated significantly in tumor tissues and lymphatic organs. The accumulation of MSV-immune lymphocytes in tumor tissues was not evident in 3-methylcholanthrene-induced BALB/c fibrosarcoma, suggesting the operation of specific mechanisms of accumulation of immune lymphocytes. Scintigraphy was performed by inoculating the 99mTc-labeled lymphocytes via the tail vein the tumor-bearing mice. Visualization of the tumor was possible in mice given in vitro-stimulated lymphocytes.