Macrophage Nonimmunologic Recognition: Target Cell Factors Related to Contact Inhibition

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Science  25 May 1973:
Vol. 180, Issue 4088, pp. 868-870
DOI: 10.1126/science.180.4088.868


Activated mouse macrophages were not cytotoxic to contact-inhibited nontumorigenic 3T3 fibroblasts, but caused marked destruction to non-contact-inhibited, tumorigenic 3T12 and simian virus 40-transformed fibroblasts. Nonimmunologic recognition and destruction of target cells by activated macrophages is independent of altered morphology, abnormal karyotype, and ability for continuous multiplication in vitro—all characteristics of 3T3 fibroblasts. A modification e f the target cell surface that results in a high in vitro saturation density, agglutinability by plant lectins, and tumorigenicity appears to evoke a cytotoxic response by activated macrophages.