Early expansion of secondary B cells after primary immunization with antigen complexed with IgE.
IgE antibodies have potent immunoregulatory effects in vivo, and mice immunized with IgE-antigen (IgE/ Ag) complexes exhibit a several hundred-fold higher humoral Ag-specific response than mice immunized with non-complexed Ag. In vitro studies indicate that this is a result of efficient endocytosis of the IgE/Ag complexes via the low-affinity receptor for IgE (CD23) on B cells, leading to efficient antigen presentation to T cells. Previous studies of IgE-induced Ab responses in vivo have only measured serum responses. The authors have now studied the up-regulated response as the number of IgG-, IgA-, IgE- and IgM-secreting single B cells in spleen, lymph nodes and bone marrow of mice immunized with IgE-anti-TNF+BSA-TNP (2,4,6-trinitrophenylated bovine serum albumin). IgE and Ag induced a greater than 500-fold increase of specific IgG-secreting spleen cells with the peak of the response 6 days after primary immunization. The response of other Ab isotypes and the response in other lymphoid organs was marginal. The rapid increase in the number of IgG-secreting cells in the spleen suggests that IgE/Ag complexes induce a secondary type of antibody response without requirement for conventional priming.
Westman
S
S
Department of Pathology, Uppsala University, Sweden.
Gustavsson
S
S
Heyman
B
B
D000367:Age Factors; D000818:Animals; D000917:Antibody Formation; D000936:Antigen-Antibody Complex / Q000276:immunology*; D000941:Antigens / Q000008:administration & dosage; D001402:B-Lymphocytes / Q000276:immunology*; D000939:Epitopes; D005260:Female; D007073:Immunoglobulin E / Q000008:administration & dosage / Q000276:immunology*; D007156:Immunologic Memory; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D008811:Mice, Inbred DBA; D012737:Sex Factors; D013154:Spleen / Q000166:cytology; D013997:Time Factors; D015854:Up-Regulation
D000936:Antigen-Antibody Complex; D000941:Antigens; D000939:Epitopes; D007073:Immunoglobulin E