caa a22 4500 465761879 CHVBK 20180323111901.0 cr unu---uuuuu 170327e19901201xx s 000 0 eng 10.1007/BF02987106 doi (NATIONALLICENCE)springer-10.1007/BF02987106 Inhibitors of lymphocyte activation secreted by human melanoma cell lines [Elektronische Daten] [Dario Giacomoni, Shlomo Ben-Efraim, Feridoon Najmabadi, Sheldon Dray] The concentrated supernatants of nine human melanoma cell line cultures were analyzed for the presence of factors that inhibitin vitro immunological reactions. All cell lines secreted a factor that inhibited LPS-induced proliferation of murine B cells; eight cell lines released a factor that inhibited PHA-induced proliferation of murine T cells; all of the three cell lines investigated secreted a factor that inhibited the allogeneic stimulation of BALB/c spleen cells by mitomycin-C-treated C57BL spleen cells. Further analysis of the M21 cell supernatant indicated that its continuous presence was required for the inhibition of the PHA but not of the LPS response suggesting a different mechanism of action. High levels of PHA, but not of LPS, could overcome the inhibitory effect of M21 supernatants. Fractionation of M21 supernatants by sucrose gradient centrifugation, DEAE chromatography and gel filtration suggested that the anti-PHA and the anti-LPS activities were due to different factors. These factors differed from a serine proteinase inhibitor that is also released by M21 cells. Since these inhibitory factors may have a role in protecting a melanoma tumor from attack by the immune system of the host, their consideration may be helpful in designing protocols for therapy which include methods to boost the antitumor responses of the host. Humana Press Inc., 1990 Human melanoma nationallicence Immunological inhibitions nationallicence Lymphocyte activation nationallicence Giacomoni Dario Department of Microbiology and Immunology, University of Illinois at Chicago, 60680, Chicago, IL, USA aut Ben-Efraim Shlomo Department of Microbiology and Immunology, University of Illinois at Chicago, 60680, Chicago, IL, USA aut Najmabadi Feridoon Department of Microbiology and Immunology, University of Illinois at Chicago, 60680, Chicago, IL, USA aut Dray Sheldon Department of Microbiology and Immunology, University of Illinois at Chicago, 60680, Chicago, IL, USA aut Medical Oncology and Tumor Pharmacotherapy Humana Press 7/4(1990-12-01), 273-280 0736-0118 7:4<273 1990 7 12032 https://doi.org/10.1007/BF02987106 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF02987106 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Giacomoni Dario Department of Microbiology and Immunology, University of Illinois at Chicago, 60680, Chicago, IL, USA aut NATIONALLICENCE 700 1- Ben-Efraim Shlomo Department of Microbiology and Immunology, University of Illinois at Chicago, 60680, Chicago, IL, USA aut NATIONALLICENCE 700 1- Najmabadi Feridoon Department of Microbiology and Immunology, University of Illinois at Chicago, 60680, Chicago, IL, USA aut NATIONALLICENCE 700 1- Dray Sheldon Department of Microbiology and Immunology, University of Illinois at Chicago, 60680, Chicago, IL, USA aut NATIONALLICENCE 773 0- Medical Oncology and Tumor Pharmacotherapy Humana Press 7/4(1990-12-01), 273-280 0736-0118 7:4<273 1990 7 12032 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer