Quantitative determination of in vitro immunoglobulin secretion with protein A from Staphylococcus aureus.
A micromethod for the quantitative determination of Ig secreted in vitro by mice lymphocytes isolated from the spleen of normal animals is described. The indicator system consists in sheep erythrocytes radiolabelled with sodium chromate (51Cr) and coated with protein A of Staphylococcus aureus (51Cr-labelled ES). When splenocytes were incubated in fluid phase at 37 degrees C for 3 1/2 h with rabbit antisera to mouse Ig (IgM and IgG) and with guinea pig complement, the immune complexes formed between the secreted Ig and its specific IgG antibody are bound to protein A on the erythrocyte surface allowing the complement-mediated lysis of 51Cr-labelled ES. The degree of haemolysis produced in this experimental system, which reflects the amount of in vitro secreted Ig, was quantitatively measured by radioactive determination of 51Cr release. In combination with the ES plaque assay the method also gives information as immunoglobulin secretion per plaque forming cell.
D000818:Animals; D000921:Antibody-Producing Cells / Q000276:immunology; D006168:Guinea Pigs; D006462:Hemolytic Plaque Technique; D007074:Immunoglobulin G / Q000032:analysis / Q000096:biosynthesis*; D007075:Immunoglobulin M / Q000032:analysis / Q000096:biosynthesis*; D051379:Mice; D008808:Mice, Inbred CBA; D011817:Rabbits; D012756:Sheep; D013205:Staphylococcal Protein A / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000276:immunology
D007074:Immunoglobulin G; D007075:Immunoglobulin M; D013205:Staphylococcal Protein A