The cytotoxic T lymphocyte response against a protein antigen does not decrease the antibody response to that antigen although antigen-pulsed B cells can be targets.
The role of activated CD8+ T cells in shaping the dynamics of in vivo antigen presentation and immune responses is a subject receiving more attention. We studied whether cytotoxic T lymphocyte (CTL) would limit antibody responses by targeting antigen-specific B cells. A modified in vivo CTL assay was developed and used herein to demonstrate cytotoxicity in vivo, and to show that antigen-specific B cells that process exogenous antigen and present peptide in association with MHC class I can be the targets of CD8+ T cells. B cells from C57BL/6 mice immunized with ovalbumin (OVA)/alum were pulsed with OVA in vitro, and transferred into C57BL/6 recipient mice that had been immunized with vaccinia virus expressing SIINFEKL minigene to generate CD8+ CTL against K(b)/SIINFEKL. OVA-pulsed B220+ B cells from OVA-immunized mice were killed to a greater extent than B220+ B cells from naïve mice (28+/-20% versus 12+/-16%, p=0.0042). However, mice receiving vaccinia-SIINFEKL and generating CTL, did not appear to target endogenous B cells, since both primary and secondary antibody responses to OVA were unaffected. Our findings indicate that CTL responses to the protein antigen do not interfere with endogenous B cell responses, even though exogenous B cells expressing the CTL epitope can be efficiently lysed.
Wang
Weila
W
Laboratory of Plasma Derivatives, Division of Hematology, Office of Blood Research and Review, Center for Biologics Evaluation and Research, Food and Drug Administration, 29 Lincoln Drive, Bethesda, MD 20892, USA. wangw@cber.fda.gov
Golding
Basil
B
D000818:Animals; D017951:Antigen Presentation; D001402:B-Lymphocytes / Q000276:immunology*; D017690:Cell Transplantation; D002478:Cells, Cultured; D003602:Cytotoxicity, Immunologic; D005260:Female; D051379:Mice; D008810:Mice, Inbred C57BL; D010047:Ovalbumin / Q000276:immunology; D010446:Peptide Fragments / Q000276:immunology; D013154:Spleen / Q000166:cytology / Q000276:immunology; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*
D010446:Peptide Fragments; D010047:Ovalbumin