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In Vitro Cytotoxicity of Peritoneal Macrophages Activated with Mycobacterium smegmatis
Author(s) -
Yamamoto Saburo,
Tokunaga Tohru
Publication year - 1978
Publication title -
microbiology and immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.664
H-Index - 70
eISSN - 1348-0421
pISSN - 0385-5600
DOI - 10.1111/j.1348-0421.1978.tb00345.x
Subject(s) - fibrosarcoma , trypan blue , biology , cytotoxicity , population , in vitro , microbiology and biotechnology , mastocytoma , peritoneal cavity , macrophage , in vivo , immunology , biochemistry , medicine , environmental health , anatomy , genetics
Incorporation of 3 H‐TdR into EL4 leukemic cells in vitro was inhibited by peritoneal exudate cells (PEC) harvested from syngeneic C57BL/6J mice given an intraperitoneal (i.p.) injection of 1 × 10 7 viable Mycobacterium smegmatis ATCC 607 (Smeg) 4 days before. This phenomenon was also observed in the following five systems of PEC from animals and syngeneic tumor cells: C57BL/6J mice and B16 melanoma; DBA/2 mice and P815 mastocytoma; SWM/Ms mice and K5 fibrosarcoma; BALB/c, nu/nu mice and KKN‐1 fibrosarcoma; and strain 2 guinea pigs and line‐10 hepatoma. The in vitro cytotoxicity of the PEC activated by viable Smeg was much higher than those activated by dead‐Smeg, viable BCG or proteose peptone. The activity of the adherent fraction of the PEC was stronger than that of the nonadherent one, and not influenced by either anti‐θ or anti‐mouse lymphocyte rabbit sera. The PEC induced with Smeg 4 days before contained a large population of mononuclear cells (88.9%) and a significant level of polymorphonuclear cells (PMN) (3.2%), and showed a much higher cytotoxicity than the PEC induced with Smeg 3 hr before, which contained a much larger population of PMN (71.9%), suggesting that PMN were not the effector cells in this system. In vitro and in vivo treatment with macrophage‐inhibitors such as carrageenan, trypan blue and cytochalacin B, reduced the activity of the PEC. All of these facts suggested macrophages as the effector. Viable macrophages were required for the growth inhibition of EL4 in vitro : gamma‐ray irradiated or freeze‐thawed macrophages were ineffective. Kinetic studies revealed that inhibition of 3 H‐TdR incorporation into EL4 cells started within 3 hr of incubation together with the activated macrophages at an effector to target (E/T) ratio of 5, and the incorporation decreased gradually with the lapse of incubation time. On the other hand, 51 Cr release from labelled EL4 was undetected when the E/T ratio was 5 but detected at on E/T of 10 or more. Even at the higher E/T ratio, at least 10 hr were needed until the release of 51 Cr, suggesting that the activated macrophages produced growth inhibition of tumor cells followed by cell destruction.