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Two Human IgM Myeloma Proteins with Unusual Specificities for Streptococcal Carbohydrate‐Associated Epitopes
Author(s) -
EMMRICH F.,
BUNDLE D.,
ZEE J.,
OUT T.,
ZENKE G.,
EICHMANN K.
Publication year - 1985
Publication title -
scandinavian journal of immunology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.934
H-Index - 88
eISSN - 1365-3083
pISSN - 0300-9475
DOI - 10.1111/j.1365-3083.1985.tb01410.x
Subject(s) - antibody , myeloma protein , rhamnose , epitope , chemistry , microbiology and biotechnology , biochemistry , biology , immunology , polysaccharide
Five hundred and fifty human sera from patients with IgM myeloma or Waldenström's macroglobulinaemia were screened by a solid‐phase enzyme‐linked immunoassay for binding to the carbohydrate of group A streptococci (A‐CHO). Two of them (AC8 and AC 179) contained immunoglobulin. which bound specifically to A‐CHO even at serum dilutions of 1:10 7 . Using synthetic oligosaccharides coupled to protein for inhibition studies, the fine specificities of AC8 and AC179 were determined. AC179 is directed to α‐linked rhamnose oligosaccharides, AC8 appears to be specific for N ‐acetyl‐D‐glucosamine (GlcNAc) side chains β(1→2)‐linked to rhamnose, whereas GlcNAc side chains in A‐CHO are reported to be β(1→3)‐linked to the rhamnose backbone. Naturally occurring anti‐A‐CHO antibodies consist mainly of low‐affinity antibodies to such β(1→3)‐linked GlcNAc. In contrast, both myeloma antibodies show more than 10 times higher relative affinities to A‐CHO than antibodies prepared from normal human serum (anti‐GlcNAc and anti‐A‐CHO, respectively) by selection for high affinity in the elution procedure. AC179 induced complement activation in the presence of A‐CHO.