Enrichment of memory cells carrying receptors for a protein antigen (HSA). II. Improved enrichment technique, using BSA density gradient separation.
Mice primed to human serum albumin (HSA) by means of an HSA--sheep red cell conjugate, developed a high level of memory to HSA, with little concomitant antibody production ('pure priming'). The proportion of HSA-specific antigen-binding cells was determined in the spleens of the primed mice by means of a rosette technique, using an HSA-donkey red cell conjugate. The specificity of the rosette-forming cells (RFC) was confirmed by the ability of soluble HSA to inhibit rosette formation. Highly enriched rosette suspensions (up to 40-fold enrichment) were prepared by bovine serum albumin density gradient centrifugation. The enriched suspensions could transfer adoptively memory to HSA, whereas the rosette-depleted fractions were totally inactive. It was thus confirmed that memory cells are included in the antigen-binding cells. A detectable level of memory could be transferred with 3000 rosettes. RFC similarly isolated from spleens of non-primed mice could also transfer a low level of responsiveness to HSA, but only when large numbers (70,000) were injected, together with primed, RFC-depleted spleen cells.
D000818:Animals; D000917:Antibody Formation; D001666:Binding Sites, Antibody; D002469:Cell Separation / Q000379:methods; D002499:Centrifugation, Density Gradient; D006801:Humans; D007104:Immune Adherence Reaction; D007111:Immunity, Cellular; D007156:Immunologic Memory; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010527:Perissodactyla / Q000276:immunology; D012709:Serum Albumin / Q000276:immunology*; D012710:Serum Albumin, Bovine / Q000276:immunology; D012756:Sheep / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000276:immunology
D012709:Serum Albumin; D012710:Serum Albumin, Bovine