Isotypes of antibodies induced by plain dextran or a dextran-protein conjugate.
Mice were immunized with alpha (1----6) dextran or its protein conjugate with monthly intervals, and their antibodies were quantitated with an isotype-resolved radioimmunoassay. Plain dextran (molecular weight = 5-40 million) induced antibody concentrations varying from 20 to 80 micrograms/ml (primary response). The response to a booster injection was weaker than the response to the first injection. More than 90% of anti-dextran antibodies were IgM but IgG and IgA responses could be unequivocally demonstrated. IgG1 and IgG3 were the predominant subclasses of IgG. Dextran antibody responses to a conjugate of dextran (molecular weight approximately equal to 10000) and chicken serum albumin (CSA) were stronger (80-300 micrograms/ml) than responses to plain dextran, and anti-CSA responses to the conjugate were even stronger (up to 900 micrograms/ml). Three distinctly different isotype patterns were observed. A pattern IgM much greater than IgG1 = IgG3 greater than IgG2a prevailed in responses to the plain dextran and in primary anti-dextran responses to dextran-CSA. Another pattern IgG1 greater than IgG3 greater than IgM greater than IgG2a was observed in late anti-dextran responses to dextran-CSA. The third pattern IgG1 much greater than IgG2a greater than IgG3 approximately equal to IgM was characteristic of anti-CSA antibodies. Little IgG2b or IgA antibodies were found. Different isotype patterns can best be explained on the basis of secondary factors such as T cell help.
Seppälä
I
I
Pelkonen
J
J
Mäkelä
O
O
D000818:Animals; D000917:Antibody Formation / Q000187:drug effects*; D002645:Chickens / Q000276:immunology; D003911:Dextrans / Q000276:immunology / Q000494:pharmacology*; D005260:Female; D007126:Immunoglobulin Allotypes / Q000276:immunology*; D051379:Mice; D010081:Oxazolone / Q000276:immunology; D011863:Radioimmunoassay; D012709:Serum Albumin / Q000276:immunology / Q000494:pharmacology*; D012710:Serum Albumin, Bovine
D003911:Dextrans; D007126:Immunoglobulin Allotypes; D012709:Serum Albumin; C043578:bovine serum albumin-dextran conjugate; D010081:Oxazolone; D012710:Serum Albumin, Bovine