TY - JOUR
T1 - Fc region-dependence of IgG3 anti-streptococcal group A carbohydrate antibody functional affinity. I. The effect of temperature
AU - Greenspan, N. S.
AU - Dacek, D. A.
AU - Cooper, L. J.N.
N1 - Copyright:
Copyright 2004 Elsevier B.V., All rights reserved.
PY - 1988
Y1 - 1988
N2 - Previous studies have demonstrated that IgG3 anti-streptococcal group A carbohydrate (GAC) mAb bind to the surfaces of heat-killed, pepsin-digested group A streptococcal cells in an Fc region-dependent cooperative manner. This form of positive cooperative binding of antibody to Ag was hypothesized to result from noncovalent assocation of Fc regions of antibodies bound close to one another on the Ag surface. Because IgG3 Fc regions are self-aggregating and IgG3 molecules are frequently cryoprecipitable, we have now investigated the effect of temperature on the binding, and cooperative binding, of IgG3 anti-GAC mAb to solid-phase (sp) Ag. The Ag used was a covalent conjugate of N-acetyl-D-glucosamine (GlcNAc; the epitopes on GAC) and BSA. The main findings were: 1) IgG3 anti-GAC mAb bind to sp GlcNAc-BSA to greater extents at lower temperatures, 2) IgM anti-GAC mAb and Fab and F(ab')2 fragments, derived from an IgG3 anti-GAC mAb, bind to sp GlcNAc-BSA to comparable extents at different temperatures, 3) idiotope-expressing IgG3 anti-GAC mAb bind to sp anti-idiotope to comparable extents at different temperatures, and 4) unlabeled IgG3 anti-GAC mAb enhance the binding of radiolabeled IgG3 anti-GAC mAb to sp GlcNAc-BSA, and the degree of this enhancement is greater at lower temperature. These, and additional results, support the conclusion that for some sp Ag the functional affinities of IgG3 antibodies, are influenced by the Fc region in a temperature-dependent manner.
AB - Previous studies have demonstrated that IgG3 anti-streptococcal group A carbohydrate (GAC) mAb bind to the surfaces of heat-killed, pepsin-digested group A streptococcal cells in an Fc region-dependent cooperative manner. This form of positive cooperative binding of antibody to Ag was hypothesized to result from noncovalent assocation of Fc regions of antibodies bound close to one another on the Ag surface. Because IgG3 Fc regions are self-aggregating and IgG3 molecules are frequently cryoprecipitable, we have now investigated the effect of temperature on the binding, and cooperative binding, of IgG3 anti-GAC mAb to solid-phase (sp) Ag. The Ag used was a covalent conjugate of N-acetyl-D-glucosamine (GlcNAc; the epitopes on GAC) and BSA. The main findings were: 1) IgG3 anti-GAC mAb bind to sp GlcNAc-BSA to greater extents at lower temperatures, 2) IgM anti-GAC mAb and Fab and F(ab')2 fragments, derived from an IgG3 anti-GAC mAb, bind to sp GlcNAc-BSA to comparable extents at different temperatures, 3) idiotope-expressing IgG3 anti-GAC mAb bind to sp anti-idiotope to comparable extents at different temperatures, and 4) unlabeled IgG3 anti-GAC mAb enhance the binding of radiolabeled IgG3 anti-GAC mAb to sp GlcNAc-BSA, and the degree of this enhancement is greater at lower temperature. These, and additional results, support the conclusion that for some sp Ag the functional affinities of IgG3 antibodies, are influenced by the Fc region in a temperature-dependent manner.
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M3 - Article
C2 - 3058803
AN - SCOPUS:0024270849
SN - 0022-1767
VL - 141
SP - 4276
EP - 4282
JO - Journal of Immunology
JF - Journal of Immunology
IS - 12
ER -