IgM / Ag Complexes Induced by IgG / Ag and IgE / Ag , But Not Complement Receptors 1 and 2 Can Be Antibody Production in Mice Deficient for Molina and Birgitta Heyman

IgM / Ag Complexes Induced by IgG / Ag and IgE / Ag , But Not Complement Receptors 1 and 2 Can Be Antibody Production in Mice Deficient for Molina and Birgitta

Antibody production in mice deficient for complement receptors 1 and 2 can be induced by IgG/Ag and IgE/Ag, but not IgM/Ag complexes.

Deficiencies in C factors C2, C3, or C4 as well as lack of C receptors 1 and 2 (CR1/2) lead to impaired Ab production. Classical pathway activation plays a major role, as mice deficient in factor B, a key factor in the alternative pathway, have normal Ab production. Abs in complex with their specific Ag are known to feedback regulate the Ab response, and enhanced responses are initiated by IgM,...

Marginal zone B cells transport IgG3-immune complexes to splenic follicles.

Ag administered together with specific IgG3 induces a higher Ab response than Ag administered alone, an effect requiring the presence of complement receptors 1 and 2 (CR1/2). In this study, we have investigated the fate of Ag, the development of germinal centers (GCs), and the Ab response after i.v. administration of IgG3 anti-trinitrophenyl (TNP) in complex with OVA-TNP. After 2 h, OVA-TNP was...

Feedback Enhancement of Antibody Responses via Complement and Fc Receptors

Dahlström, J. 2001. Feedback Enhancement of Antibody Responses via Complement and Fc Receptors. Acta Universitatis Upsaliensis. Comprehensive Summaries of Uppsala Dissertations from the Faculty of Medicine 1000. 53 pp. Uppsala. ISBN 91-554-4943-3. IgG, IgM and IgE in complex with antigen have the capacity to regulate specific immune responses. In this investigation, the role of Fc receptors for...

Restoration of the antibody response to IgE/antigen complexes in CD23-deficient mice by CD23+ spleen or bone marrow cells.

Mice immunized with IgE/Ag complexes produce significantly more Ag-specific Abs than mice immunized with Ag alone. The enhancement is mediated via the low-affinity receptor for IgE (FcepsilonRII or CD23), as shown by its complete absence in mice pretreated with mAbs specific for CD23 and in CD23-deficient mice. Because the constitutive expression of murine CD23 is limited to B cells and follicu...