engleski

The role of macrophages in weakening of concomitant tumour immunity

Introduction: Concomitant immunity (CI) is a phenomenon of secondary tumour rejection during the primary tumour growth. Different tumours induce CI, but its mechanism and dynamic differ, depending on tumour type and experimental model. CI can be induced in model of artificial lung metastases of mammary carcinoma (MC) in CBA mice and attained its maximal intensity 9th day after primary tumour injection. The period of CI weakening is recorded 30th day after primary tumour injection and correlates with marked appearance of metastases. Objective: The experiments were designed to analyse the role of different spleen cell populations in weakening of CI and to test the effect of indomethacin (an inhibitor of prostaglandin E2 synthesis) on antimetastatic effect of various spleen cell populations. Materials and Methods: As experimental model we used adoptively transferred splenocytes, macrophages and/or lymphocytes from various periods after s.c. inoculation of 2x105 MC. A certain number of mice were treated by indomethacin. A day after adoptive transfer the 1x106 MC cells were intravenously injected and after 14 days the number of MC lung metastases were counted for evaluation of antimetastatic effect exhibited by various immunologic cells. Results and Conclusion: The results indicated that macrophages and lymphocytes from the period of weakening of CI have lost antimetastatic effect. Macrophages have acted immunosuppressively while lymphocytes were suppressed. We have obtained the inactivation of macrophages’ suppressor mechanisms as well as restoration of antimetastatic activity of lymphocytes and cytotoxic macrophages after inhibition of prostaglandin E2 synthesis. Thus the prolongation of CI period could delay the appearance of metastases.

macrophages; metastases; suppressor effect

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