A novel factor which augments the expression of major histocompatibility complex I (MHC augmenting factor or MHC-AF) antigens on tumor cell lines, has been isolated from the culture supernatants of human peripheral blood mononuclear cells activated by concanavalin-A. A mouse equivalent of this factor has also been isolated from the culture supernatants of mouse spleen cells activated by mitogens or in a mixed lymphocyte reaction. Mouse MHC-AF enhances the expression of class I MHC antigens on murine tumor cell lines (EL-4 and BW5147) but not on human tumor cell lines (K562 and HR-7). Human MHC-AF on the other hand enhances the MHC I expression on both human as well as murine cell lines. Interferon gamma (IFN-gamma), a cytokine also known to enhance the expression of MHC I antigens, acts in a highly species specific manner with mouse IFN-gamma augmenting the MHC I on murine tumor cell lines and human IFN-gamma augmenting the MHC I on human tumor cell lines only. These results indicate important differences in the cross species biological activities of MHC-AF and IFN-gamma, and provide additional evidence for MHC-AF being distinct from IFN-gamma.
Animals ; Cell Line ; Cell Line, Tumor* ; Hand ; Histocompatibility Antigens Class I* ; Humans ; Interferons ; Lymphocyte Culture Test, Mixed ; Lymphocytes ; Lymphokines ; Major Histocompatibility Complex ; Mice ; Mitogens ; Species Specificity* ; Spleen

Sensitivity of Fas expressing tumor cells (high levels in Hut78 & Jurkat; low levels in P815) toward the cytotoxic Con-A (5 microg/ml) activated spleen cells from young (12 to 16 week old males) and old (2 year old males) mice were studied. The spleen cells from young mice activated for a day showed high levels of cytotoxic activity against Hut78 and Jurkat cell lines but not against P815 cells. The cytotoxic activity against P815 cells were detected in the spleen cells from old but not young mice following a longer period of Con-A activation (three days). Comparable levels of cytotoxic activity against Hut78 and Jurkat cells were observed in the spleen cells from both young and old mice following three days of activation. Treatment of Hut78 cells with anti-Fas antibody affected the tumor cells become resistant against the cytotoxic activity of the spleen cells from young mice in a dose dependent manner however P815 cells were not affect by the anti-Fas antibody treatment. These results show that there are differences in the sensitivity of target tumor cells toward Con-A induced cytotoxic spleen cells from young and old mouse. Mitogen-induced cytotoxic lymphocytes from young mouse spleen appear to kill targets through mechanisms involving Fas antigen, specially, in early stage (1 day) of activation. Old mouse spleen cells generated high levels of cytotoxic cells in later phase (3 days), which appear to kill through Fas-unrelated mechanisms.
Age Factors ; Animal ; Antigens, CD95/immunology* ; Cell Death/immunology ; Cells, Cultured ; Concanavalin A ; Cytotoxicity Tests, Immunologic ; Flow Cytometry ; Gene Expression Regulation/immunology ; Human ; Jurkat Cells ; Mice ; Mice, Inbred Strains ; Mitogens ; Spleen/immunology* ; T-Lymphocytes/immunology*

Effect of M. tuberculosis infection was studied on the expression of intercellular adhesion molocule-1 (ICAM-1) and Mac-1 markers on murine peritoneal macrophages. Intraperitoneal administration of M. tuberculosis resulted in a marked increase in the proportion of Mac-1+ cells whereas the proportion of ICAM-1+ cells declined sharply 4 h post infection. Absolute numbers of Mac-1+ and ICAM-1+ cells however increased at all time points after the infection. Comparison of kinetics of changes observed in Mac-1+ and ICAM-1+ cell populations with differential leukocyte counts in peritoneal cells indicated that these alterations could be due to cellular influx, especially that of neutrophils, or up regulation of these markers on macrophages and other peritoneal cells. In adherent peritoneal macrophages infected in vitro with M. tuberculosis, proportion of Mac-1+ and ICAM-1+ cells increased markedly within 24 h of infection. Mean expression of these markers on per cell basis also increased significantly. Similar results were obtained by using RAW 264.7 mouse macrophage cell line, suggesting that the enhanced expression of Mac-1 and ICAM-1 markers was a direct effect of M. tuberculosis infection and not mediated by contaminating cell types present in adherent macrophage preparations. Mac- 1 and ICAM-1 expression was further studied on macrophages that had actually engulfed M. tuberculosis and compared with bystander macrophages without intracellular M. tuberculosis. For this purpose M. tuberculosis pre-stained with DilC18 fluorescent dye were used for infecting adherent peritoneal macrophages. Mac-1 and ICAM-1 expression on gated DilC18 positive and negative cell populations was analyzed. Our results indicate that the expression of Mac-1 and ICAM- 1 markers was significantly enhanced on all macrophages incubated with M. tuberculosis but was more pronounced on macrophages with internalized mycobacteria. Taken together, our results suggest that the expression of Mac-1 and ICAM-1 markers is significantly up regulated
Animals ; Biological Markers/analysis/metabolism ; Cells, Cultured ; Intercellular Adhesion Molecule-1/analysis/*biosynthesis ; Macrophage-1 Antigen/analysis/*biosynthesis ; Macrophages, Peritoneal/*immunology/*microbiology ; Mice ; Mice, Inbred C57BL ; *Mycobacterium tuberculosis ; Peritoneum/microbiology ; Phagocytosis/physiology ; Research Support, Non-U.S. Gov't ; Tuberculosis/*immunology ; Up-Regulation