English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

Complement activation plays a critical role in the immune response to T-cell-dependent and T-cell-independent antigens. However, the effect of conjugation of T-cell-dependent protein carriers to T-cell-independent type 2 antigens on the requirement for complement in the humoral immune response to such antigens remains unknown. We studied the role of complement activation on the antibody response of BALB/c mice immunized with the T-cell-independent type 2 antigen serotype 14 pneumococcal capsular polysaccharide (PPS14), either in unmodified form or conjugated to ovalbumin (OVA). In mice immunized with either PPS14 or PPS14-OVA, depletion of endogenous complement at the time of primary immunization by treatment with cobra venom factor (CVF) diminished serum anti-PPS14 concentrations after primary immunization but enhanced antibody responses after secondary immunization. The secondary immunoglobulin G (IgG) anti-PPS14 antibody response after immunization with PPS14-OVA was especially enhanced by complement depletion, was observed at doses as low as 0.2 mug of antigen, and was maximal when CVF was administered within 2 days of immunization. The avidity and opsonophagocytic functions of IgG anti-PPS14 antibodies were comparable in mice immunized with PPS14-OVA with or without complement depletion. Serum anti-PPS14 antibody concentrations were near normal, and the enhancing effects of CVF treatment on the secondary anti-PPS14 antibody response were also apparent in splenectomized mice immunized with PPS14-OVA. These results demonstrate that complement activation can have distinct effects on the primary and secondary antibody responses to a T-cell-independent type 2 antigen, either unmodified or conjugated to a T-cell-dependent protein carrier. These differences should be taken into consideration when using complement to modulate the immune response to vaccines.

infection and immunity

Depletion of Complement Has Distinct Effects on the Primary and Secondary Antibody Responses to a Conjugate of Pneumococcal Serotype 14 Capsular Polysaccharide and a T-Cell-Dependent Protein Carrier