Clinical and Diagnostic Laboratory Immunology, 03 1995, 125-131, Vol 2, No. 2
RM Hamadeh, U Galili, P Zhou and JM Griffiss
Anti-alpha-galactosyl (anti-Gal) is a natural human serum antibody that
binds to the carbohydrate Gal alpha 1,3Gal beta 1,4GlcNAc-R (alpha-
galactosyl epitope) and is synthesized by 1% of circulating B lymphocytes
in response to immune stimulation by enteric bacteria. We were able to
purify secretory anti-Gal from human colostrum and bile by affinity
chromatography on silica-linked Gal alpha 1,3Gal beta 1,4GlcNAc. We found
similar secretory anti-Gal antibodies in human milk, saliva, and vaginal
washings. Secretory anti-Gal from milk and saliva was exclusively
immunoglobulin A (IgA); that from colostrum and bile also contained IgG and
IgM isotypes. Serum was also found to contain anti-Gal IgM and IgA in
addition to the previously reported IgG. Anti-Gal IgA purified from
colostrum and bile had both IgA1 and IgA2. Secretory anti-Gal from saliva,
milk, colostrum, and bile agglutinated rabbit erythrocytes (RRBC) and bound
to bovine thyroglobulin, both of which have abundant alpha-galactosyl
epitopes. The RRBC-hemagglutinating capacity of human saliva, milk, bile,
and serum was specifically adsorbed by immobilized Gal alpha 1,3Gal beta
1,4GlcNAc but not by Gal alpha 1,4Gal beta 1,4GlcNAc, Gal beta 1,3GalNAc,
Gal beta 1,4GlcNAc, Gal beta 1,4GlcNAc alpha 1,2Man, or Fuc alpha 1,2Gal
beta 1,4GlcNAc. No RRBC-hemagglutinating activity could be detected in rat
milk, rat bile, cow milk, or rabbit bile, suggesting a restricted species
distribution for secretory anti-Gal similar to that found for serum
anti-Gal.(ABSTRACT TRUNCATED AT 250 WORDS)
Copyright © 1995 by the American Society for Microbiology. All rights reserved.
Anti-alpha-galactosyl immunoglobulin A (IgA), IgG, and IgM in human secretions
Department of Laboratory Medicine, University of California San Francisco 94143.
| Antimicrob. Agents Chemother. | Clin. Microbiol. Rev. | Infect. Immun. |
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