title: Effect of rabbit anti-asialo GM1 treatment in vivo or with anti-asialo GM1 plus complement in vitro on cytotoxic T cell activities.
abstract: The susceptibility of cytotoxic effector lymphocytes and their induction to in vivo or in vitro treatment with rabbit anti-neutral glycolipid ganglio-N-tetraosylceramide (anti-ASGM1) antiserum was investigated. Intravenous injection of anti-ASGM1 antiserum eliminated measurable natural killer (NK) cell activity in spleen cells of mice infected for 5 days with Vaccinia virus, or for 8 days with lymphocytic choriomeningitis virus (LCMV) if injected 24 hr prior to testing. In addition, this treatment lowered measurable virus-specific cytotoxic T cell activity by 60 to 95%. Virus-specific cytotoxic T cell and NK cell activity generated during a primary infection in vivo was also sensitive to treatment in vitro with anti-ASGM1 antiserum (1/300 to 1/600 dilution) plus rabbit complement at a dilution of 1/15 (20 to 50% cell death, more than 30-fold decrease of cytotoxic activity); in vitro treatment with rabbit complement alone often enhanced NK and cytotoxic T cell activity slightly. In vivo treatment with anti-ASGM1 before primary immunization decreased generation of primary CTL only if high doses of anti-ASGM1 antiserum were injected twice. Antiviral T cells generated during secondary stimulation in vitro and alloreactive cytotoxic T cells from a mixed lymphocyte culture were resistant to treatment in vitro with anti-ASGM1 plus complement at the end of the culture period. Treatment in vitro of in vivo-primed responder spleen cells with anti-ASGM1 plus complement before their addition to a secondary restimulation culture resulted in complete inhibition of a secondary antiviral cytotoxic T cell response. In vivo treatment with anti-ASGM1 24 hr before their spleen cells were harvested and restimulated in vitro significantly reduced the virus-specific T cell activity of mice that had been immunized with virus several weeks previously. A cloned T cell line exclusively exerting NK-like activity was resistant, and two cloned virus-specific cytotoxic T cell lines were susceptible to treatment with anti-ASGM1 plus complement in vitro. These results caution the general use of rabbit anti-ASGM1 as a marker to distinguish NK from CTL cells; they indicate a possible relationship between NK and CTL cells and suggest that in vitro culture of lymphocytes may alter or select the cell surface expression or availability of the ASGM1 marker(s).
mesh_terms: D000818:Animals; D003165:Complement System Proteins / Q000502:physiology*; D003602:Cytotoxicity, Immunologic; D004306:Dose-Response Relationship, Immunologic; D004334:Drug Administration Schedule; D005677:G(M1) Ganglioside; D006028:Glycosphingolipids / Q000276:immunology*; D007106:Immune Sera / Q000008:administration & dosage* / Q000494:pharmacology; D007117:Immunization, Secondary; D008213:Lymphocyte Activation; D051379:Mice; D008810:Mice, Inbred C57BL; D013602:T-Lymphocytes, Cytotoxic / Q000145:classification / Q000276:immunology*; D014616:Vaccinia virus / Q000276:immunology
chemical_list: D006028:Glycosphingolipids; D007106:Immune Sera; D005677:G(M1) Ganglioside; C018835:asialo GM1 ganglioside; D003165:Complement System Proteins