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Locally Produced Antibody in Human Gastrointestinal Secretions

1969; American Association of Immunologists; Volume: 103; Issue: 6 Linguagem: Inglês

10.4049/jimmunol.103.6.1268

1550-6606

George W. Kriebel, Sumner C. Kraft, Richard M. Rothberg,

Blood groups and transfusion

Abstract The distribution of IgG, IgA, IgM and IgD was assessed in concentrates of parotid saliva, gastric juice and duodenal contents from 49 human subjects. Immunoglobulin A predominated in parotid saliva, and immunoglobulins were found inconstantly in unneutralized gastric juice. Thirty of 40 duodenal specimens contained IgA, IgM and IgD, and 25 contained all four immunoglobulins. To evaluate the source of the immunoglobulins found in these secretions, antibody against a dietary protein, bovine serum albumin (BSA), was employed as a specific marker. Evidence for local antibody production by lymphoid tissue of the gastrointestinal tract was provided by the following data. a) Anti-BSA was demonstrated in the gastrointestinal secretions of nine subjects without detectable serum anti-BSA. In these secretions anti-BSA was associated with IgA, IgM and IgD, but not IgG. b) This absence of anti-BSA associated with IgG is in contrast to its frequent association with the IgG of serum and external secretions from subjects with high amounts of circulating anti-BSA. c) Anti-BSA associated with IgM was demonstrated in gastrointestinal secretions but never in the serum. d) Among individuals with little or no serum anti-BSA, this antibody was detected in secretions from viscera exposed to BSA, but not in saliva from the parotid gland, which is not exposed to the antigen. The anti-BSA activity in gastrointestinal fluids was associated at least in part with secretory 11S IgA, but the finding of locally-produced antibody associated with IgM and IgD indicates that these immunoglobulins also may play an important role in external secretions.