Origin and Differentiation of Lymphocytes Involved in the Secretory IgA Response

Selective induction of an immune response in human external secretions by ingestion of bacterial antigen.

“…An ingested antigeni could be absorbed from the gastrointestinal tract, enter the circulation, and after deposition in secretorx tissties, stimulate immunocompetent cells. This explanation is unlikely because circulatinig antigens should also induce a pronounced serum antibody response; this had not been observed in our experimenits or in investigations performed in other laboratories (6,17,19,29 (6,(17)(18)(19)(20)(29)(30)(31)(32) (32,(34)(35)(36)(37)(38)(39)(40). A conviiiciiig denionstration of the f'unctioin of Peyer's patclhes as sites for antigen stinmlilation of IgA prectirsor cells wvas provided FIGURE 1 Dynamics of the aggltitninii antib)ody respoinse to S. m71tutan.s ONIZ-176 in glaiidtilar seeretiolns aiter primairv (10) and secondary (20) Log2 agglutinin titer determined by microtitrations with 2 x 108 CFU/ml of formalin-killed S. mutatns a-e and g (20).…”

IgA Isotype Restriction in the Mucosal but Not in the Extramucosal Immune Response after Oral Immunizations with Cholera Toxin or Cholera B Subunit

“…Interestingly, in each of the above tissues, in contrast to the well-known IgA pre dominance in lamina propria [12], the antitoxin PFCs were more often of the IgGl than IgA class, and many IgM cells were present as well. This would sug gest the presence in Peyer's patches of precursor cells for IgG, IgA, and IgM cells [5] and the potential of each of those Igs to be expressed by those cells differ entiating to plasma cells in Peyer's patches, mesenter ic lymph nodes or spleen, in contrast to the popula tion of cells which differentiate to antibody-secreting plasma cells in lamina propria which predominantly secrete IgA antibody.…”

“…The immunogen is thought to make contact with immunocompetent B and T cells in Peyer's patches, and these cells, while differentiat ing, then migrate to the mesenteric lymph nodes and further via the thoracic duct lymph into the systemic circulation. Committed, migrating cells eventually re turn to the intestinal mucosa where the B-cell progeny secretes specific antibodies, predominantly of the di meric IgA type [5,12,18]. On repeated immunization the immunogen may also, to a lesser extent, directly stimulate antigen-specific memory cells in the gut lamina propria [13,19].…”

Subclass restriction of murine antibodies. II. The IgG plaque-forming cell response to thymus-independent type 1 and type 2 antigens in normal mice and mice expressing an X-linked immunodeficiency.

“…Although there is no doubt that single VH regions can pair with C#, Ca, C8, and Cy, only a few studies have examined whether VH regions can pair with multiple Cy subclasses. Single clones of cells secreting anti-DNP antibody frequently produce both IgG1 and IgG2 subclasses in splenic focus culture (39). Furthermore, the bulk of anti-poly-ie-glutamic acid 6°, Lalanine z°, e-tyrosine 1°) antibodies in mice are IgG1 (40) although minor levels of IgG2 and IgG3 antibodies have been detected (41).…”