Cognate T-cell help in the induction of IgA responses in vivo.
Evidence from in vitro studies indicates that immunoglobulin A (IgA) responses are highly T dependent, yet investigations of the requirement for cognate help for IgA responses in vivo have not previously been undertaken. Experiments reported in this paper employ hapten-carrier immunization of individual Peyer's patches (PP), the site of generation of IgA antibody-containing cells (ACC) responding to lumenal antigenic challenge in the intestine, to determine the requirements for T-cell and B-cell priming under normal physiological conditions in vivo. These experiments demonstrate that both hapten-specific B-cell priming and carrier-specific T-cell priming in PP are required for an IgA-specific anti-hapten ACC response in the intestinal lamina propria to subsequent lumenal challenge with hapten-carrier conjugate. These results confirm that IgA B-cell induction in PP requires cognate T-cell help. An IgA ACC response can also be obtained when hapten and carrier priming occur in different PP, providing functional significance for our previous observations that PP-derived T-helper cells are able to migrate between PP after priming.
Dunkley
M L
ML
Faculty of Medicine, University of Newcastle, NSW, Australia.
Husband
A J
AJ
Underdown
B J
BJ
D000818:Animals; D006241:Haptens; D006433:Hemocyanins / Q000276:immunology; D007070:Immunoglobulin A / Q000096:biosynthesis*; D007583:Jejunum / Q000276:immunology; D008211:Lymphocyte Cooperation / Q000276:immunology; D008297:Male; D010581:Peyer's Patches / Q000276:immunology; D051381:Rats; D011919:Rats, Inbred Strains; D006377:T-Lymphocytes, Helper-Inducer / Q000276:immunology*; D005719:gamma-Globulins / Q000276:immunology
D006241:Haptens; D007070:Immunoglobulin A; C030730:dinitrophenyl gamma globulin; D005719:gamma-Globulins; C054401:trinitrophenyl keyhole limpet hemocyanin; D006433:Hemocyanins; C032808:keyhole-limpet hemocyanin