TY - JOUR T1 - Comparison of Macrophage Activation Using γ-Globulin and Serum-derived Macrophage Activating Factor JF - Anticancer Research JO - Anticancer Res SP - 4707 LP - 4710 DO - 10.21873/anticanres.14471 VL - 40 IS - 8 AU - MINORI AKAMATSU AU - RIHO MASHIBA AU - KUMPEI KAWAKATSU AU - MAMI ISHIKAWA AU - TAKAHITO NISHIKATA Y1 - 2020/08/01 UR - http://ar.iiarjournals.org/content/40/8/4707.abstract N2 - Background/Aim: Serum-derived macrophage activating factor (serum-MAF) can rapidly activate macrophage phagocytic activity by inducing characteristic membrane ruffles designated as Frill-like structures. Serum-MAF contains γ-globulin, an activator of phagocytosis. This study examined whether serum-MAF and γ-globulin activate macrophages similarly. Materials and Methods: Morphological changes in macrophages were observed by time-lapse imaging and the efficiency of engulfment was analysed quantitatively. Immunological staining of talin-1 and a calpain inhibitor were performed. Results: The engulfment efficiency of serum-MAF- and γ-globulin-activated macrophages was significantly different. Talin-1 showed weak co-localisation with the Frill-like structures. Treatment with a calpain inhibitor similarly down-regulated phagocytosis irrespective of the activation factor. Conclusion: There was a difference between macrophage activation mechanisms by γ-globulin and serum-MAF. Talin may slightly contribute to serum-MAF activation. It is possible to distinguish between the calpain-dependent fundamental ‘mechanism of phagocytosis’ and the activating factor-dependent rapid ‘activation mechanism’. ER -