title: Immune status of mice tolerant of living cells. II. Continuous presence and nature of facilitation-enhancing antibodies in tolerant animals.
abstract: CBA mice were rendered highly tolerant to A/Jax cells by neonatal intravenous injections of (CBA x A)F(1) spleen cells. The high degree of tolerance was ascertained by the absence of circulating antibodies detected in the sera by the usual tests and by the perfect state of A skin grafts during all the experiments. Tolerant sera (sera from tolerant animals) were studied at three periods of tolerance: before skin test grafting, from 2 to 11 wk after grafting, and at time of sacrifice at almost 6 months of age. The tolerant sera were shown to have specific facilitation-enhancing properties promoting the take and growth of A/Jax sarcoma (SaI and /Sa 15091a grafted on normal CBA mice. These properties were present throughout the duration of the experiments, showing that they were not the result of a beginning interruption of tolerance. The tolerant sera, although lacking the usual serological properties (hemagglutination, hemolysis, cytotoxicity, passive cutaneous anaphylaxis) had, however, specific synergistic hemagglutinating properties (increasing the hemagglutinating titer of a reference immune serum). Antibodies giving direct specific hemagglutination could be extracted from spleens of 20% of highly tolerant mice. The tolerant sera were also found to contain more IgG1 and more IgA than normal sera while they contained normal quantities of the complement-fixing immunoglobulins IgG2 and IgM. Fractionation of tolerant sera on DEAE chromatography column confirmed the data concerning immunoglobulin classes and demonstrated direct specific serological activities undetected in unfractionated sera: a weak hemolysis in the most cationic fractions and a weak hemagglutination in the middle fractions. Synergistic hemagglutination, detected in unfractionated serum, was localized in fast anionic fractions containing high IgA concentration, along with facilitation-enhancing activity, thus confirming a link suggested previously between these three properties. The relation between immunological tolerance and facilitating antibodies was discussed in the light of the fact that antibodies, possibly of a particular class continuously present at low dose in the sera of highly tolerant animals, are able to transfer (at least partly) this state of tolerance provided a sensitive test system is utilized.
mesh_terms: D000818:Animals; D000906:Antibodies / Q000032:analysis*; D002848:Chromatography, DEAE-Cellulose; D005260:Female; D006084:Graft Rejection; D006386:Hemagglutination Tests; D007106:Immune Sera / Q000032:analysis; D007108:Immune Tolerance; D005779:Immunodiffusion; D007070:Immunoglobulin A / Q000032:analysis; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D007165:Immunosuppression Therapy; D008297:Male; D051379:Mice; D008815:Mice, Inbred Strains; D009368:Neoplasm Transplantation; D010323:Passive Cutaneous Anaphylaxis; D012513:Sarcoma, Experimental / Q000276:immunology; D016038:Skin Transplantation; D013154:Spleen / Q000276:immunology; D014184:Transplantation, Homologous
chemical_list: D000906:Antibodies; D007106:Immune Sera; D007070:Immunoglobulin A; D007074:Immunoglobulin G; D007075:Immunoglobulin M