F 344 rats were given vitamin A for four consecutive days and then their alveolar macrophages (AM Ø) were obtained by bronchopulmonary lavage of the lung. Compared with unstimulated AM Ø, AM Ø from rats given vitamin A had more numerous and longer cytoplasmic projections, and these projections had many knobs on their sides and tip.
The AM Ø became attached to syngeneic mammary adenocarcinoma cells at many focal points and the tumor cells then lost surface microvilli around the contact zones. Detachment of the knobs from the projections on AM Ø was often observed in areas of close association between AM Ø and tumor cells. The detached knobs were 250 nm in diameter, gave a positive reaction for acid phosphatase, and frequently became attached to the surface of tumor cells. Then, many of the tumor cells in the vicinity of AM Ø exhibited cytolytic changes.
It is concluded that the cytotoxicity of stimulated AM Ø is due to their attachment to the surface of tumor cells and their release of particles with acid phosphatase activity into the narrow space between the cells, and then to uptake of these particles by susceptible tumor cells.
Alveolar macrophage Cytoplasmic projection Knobs
This is a preview of subscription content, log in to check access.
Bucana C, Hoyer HB, Breesman S, McDaniel M, Hanna MGJr (1976) Morphological evidence for the translocation of lysosomal organelles from cytotoxic macrophages into the cytoplasm of tumor target cells. Cancer Res 36:4444–4458PubMedGoogle Scholar
Cohn ZA, Benson B (1965) Thein vitro differentiation of mononuclear phagocytes. II. The influence of serum on granule formation, hydrolase production, and pinocytosis. J Exp Med 121:835–848PubMedCrossRefGoogle Scholar
Currie GA (1978) Activated macrophages kill tumour cells by releasing arginase. Nature [Lond] 273:758–759CrossRefGoogle Scholar
Currie GA, Basham C (1975) Activated macrophages release a factor which lyses malignant cells but not normal cells. J Exp Med 142:1600–1603PubMedCrossRefGoogle Scholar
Hibbs JBJr (1974) Heterocytolysis by macrophages activated by Bacillus Calmette-Guérin: lysosome exocytosis into tumor cells. Science 184:468–471PubMedCrossRefGoogle Scholar
Nathan CF, Silverstein SC, Bruckner LH, Cohn ZA (1979) Extracellular cytolysis by activated macrophages and granulocytes. II. Hydrogen peroxide as a mediator of cytotoxicity. J Exp Med 149:100–113PubMedCrossRefGoogle Scholar
Novikoff PM, Novikoff AB, Quintana N, Hauw JJ (1971) Golgi apparatus, GERL, and lysosomes of neurons in rat dorsal root ganglia, studied by thick section and thin section cytochemistry. J Cell Biol 50:859–886PubMedCrossRefGoogle Scholar
Papadimitriou JM (1973) Detection of macrophage receptors for heterologous IgG by scanning and transmission electron microscopy. J Pathol 110:213–220PubMedCrossRefGoogle Scholar
Rhodes J, Oliver S (1980) Retinoids as regulators of macrophage function. Immunology 40:467–472PubMedGoogle Scholar
Rosenau W, Burke GC, Anderson R (1981) Effects of lymphotoxin on target-cell plasmamembrane lipids. Cell Immunol 60:144–154PubMedCrossRefGoogle Scholar
Sone S, Fidler IJ (1980) Tumor cytotoxicity of rat alveolar macrophages activatedin vitro by endotoxin. J Reticuloendothel Soc 27:269–279PubMedGoogle Scholar
Stimpel M, Proksch A, Wagner H, Lohmann-Pathes ML (1984) Macrophage activation and induction of macrophage cytotoxicity by purified polysaccharide fractions from the plantEchinacea purpurea. Infect Immun 46:845–849PubMedGoogle Scholar
Tachibana K, Sone S, Tsubura E, Kishino Y (1984) Stimulatory effect of vitamin A on tumoricidal activity of rat alveolar macrophages. Br J Cancer 49:343–348PubMedGoogle Scholar
Unkeless JC, Gordon S, Reich E (1974) Secretion of plasminogen activator by stimulated macrophages. J Exp Med 139:834–850PubMedCrossRefGoogle Scholar