The Mechanism Underlying T Cell Help for Induction of an Antigen-Specific In Vivo Humoral Immune Response to Intact Streptococcus pneumoniae Is Dependent on the Type of Antigen
Abstract
Little is known concerning the role of T cells in regulating an anti-polysaccharide Ig response to an intact pathogen. We previously reported that the in vivo Ig responses to Streptococcus pneumoniae (strain R36A), specific for pneumococcal surface protein A (PspA) and for the phosphorylcholine (PC) determinant of C-polysaccharide, were both dependent on TCR-alpha beta T cells and B7-dependent costimulation, although only PspA-specific memory was generated. In this report, we show that the T cell help underlying these two Ag-specific Ig responses is distinct. Using H-Y-specific T cell transgenic mice made "nonleaky" by crossing with mice genetically deficient for TCR-a, we demonstrate that the T cell help for the anti-PC, in contrast to the anti-PspA, response is TCR-nonspecific and occurs normally in the absence of germinal center formation, although it is still dependent on B7-dependent costimulation. Consistent with these data, we demonstrate, using cathepsin S-/- mice, that although the anti-PC response is largely dependent on CD4+ T cells, there is a reduced (or lack of) dependence, relative to the anti-PspA response, on the generation of new peptide-MHC class II complexes. In this regard, the T cell help for an optimal anti-PC response is delivered more rapidly than that required for an optimal anti-PspA response. Collectively, these data demonstrate a novel accelerated TCR-nonspecific B7-dependent form of T cell help for augmenting a polysaccharide-specific Ig response to an intact bacterium without the generation of memory.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2002
- Accession Number
- ADA534639
Entities
People
- Abdul Q. Khan
- Ching-liang Chu
- Clifford M Snapper
- Harold A. Chapman
- Osami Kanagawa
- Richard Riese
- Yi Shen
- Zheng-qi Wu
Organizations
- Uniformed Services University of the Health Sciences