HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Citation Map Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Chung, J. B. Articles by Monroe, J. G. Search for Related Content PubMed PubMed Citation Articles by Chung, J. B. Articles by Monroe, J. G.

Incomplete Activation of CD4 T Cells by Antigen-Presenting Transitional Immature B Cells: Implications for Peripheral B and T Cell Responsiveness¹

James B. Chung^*, Andrew D. Wells, Scott Adler, Anand Jacob, Laurence A. Turka and John G. Monroe^2,

Divisions of ^* Rheumatology and Nephrology, Department of Medicine, and Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104

B cells leave the bone marrow as transitional B cells. Transitional B cells represent a target of negative selection and peripheral tolerance, both of which are abrogated in vitro by mediators of T cell help. In vitro, transitional and mature B cells differ in their responses to B cell receptor ligation. Whereas mature B cells up-regulate the T cell costimulatory molecule CD86 (B7.2) and are activated, transitional B cells do not and undergo apoptosis. The ability of transitional B cells to process and present Ag to CD4 T cells and to elicit protective signals in the absence of CD86 up-regulation was investigated. We report that transitional B cells can process and present Ag as peptide:MHC class II complexes. However, their ability to activate T cells and elicit help signals from CD4-expressing Th cells was compromised compared with mature B cells, unless exogenous T cell costimulation was provided. A stringent requirement for CD28 costimulation was not evident in interactions between transitional B cells and preactivated CD4-expressing T cells, indicating that T cells involved in vivo in an ongoing immune response might rescue Ag-specific transitional B cells from negative selection. These data suggest that during an immune response, immature B cells may be able to sustain the responses of preactivated CD4⁺ T cells, while being unable to initiate activation of naive T cells. Furthermore, the ability of preactivated, but not naive T cells to provide survival signals to B cell receptor-engaged transitional immature B cells argues that these B cells may be directed toward activation rather than negative selection when encountering Ag in the context of a pre-existing immune response.

This article has been cited by other articles:

				R. J. Brezski and J. G. Monroe B Cell Antigen Receptor-Induced Rac1 Activation and Rac1-Dependent Spreading Are Impaired in Transitional Immature B Cells Due to Levels of Membrane Cholesterol J. Immunol., October 1, 2007; 179(7): 4464 - 4472. [Abstract] [Full Text] [PDF]

				J. G. Evans, K. A. Chavez-Rueda, A. Eddaoudi, A. Meyer-Bahlburg, D. J. Rawlings, M. R. Ehrenstein, and C. Mauri Novel Suppressive Function of Transitional 2 B Cells in Experimental Arthritis J. Immunol., June 15, 2007; 178(12): 7868 - 7878. [Abstract] [Full Text] [PDF]

				J. L. Fallas, W. Yi, N. A. Draghi, H. M. O'Rourke, and L. K. Denzin Expression Patterns of H2-O in Mouse B Cells and Dendritic Cells Correlate with Cell Function J. Immunol., February 1, 2007; 178(3): 1488 - 1497. [Abstract] [Full Text] [PDF]

				V. Roy, N.-H. Chang, Y. Cai, G. Bonventi, and J. Wither Aberrant IgM Signaling Promotes Survival of Transitional T1 B Cells and Prevents Tolerance Induction in Lupus-Prone New Zealand Black Mice J. Immunol., December 1, 2005; 175(11): 7363 - 7371. [Abstract] [Full Text] [PDF]

				L.-A. M. Pozzi, J. W. Maciaszek, and K. L. Rock Both Dendritic Cells and Macrophages Can Stimulate Naive CD8 T Cells In Vivo to Proliferate, Develop Effector Function, and Differentiate into Memory Cells J. Immunol., August 15, 2005; 175(4): 2071 - 2081. [Abstract] [Full Text] [PDF]

				F. G. Karnell, R. J. Brezski, L. B. King, M. A. Silverman, and J. G. Monroe Membrane Cholesterol Content Accounts for Developmental Differences in Surface B Cell Receptor Compartmentalization and Signaling J. Biol. Chem., July 8, 2005; 280(27): 25621 - 25628. [Abstract] [Full Text] [PDF]

				D. Mielenz, C. Vettermann, M. Hampel, C. Lang, A. Avramidou, M. Karas, and H.-M. Jack Lipid Rafts Associate with Intracellular B Cell Receptors and Exhibit a B Cell Stage-Specific Protein Composition J. Immunol., March 15, 2005; 174(6): 3508 - 3517. [Abstract] [Full Text] [PDF]

				M. R. Pranzatelli, E. D. Tate, A. L. Travelstead, and D. Longee Immunologic and Clinical Responses to Rituximab in a Child With Opsoclonus-Myoclonus Syndrome Pediatrics, January 1, 2005; 115(1): e115 - e119. [Abstract] [Full Text] [PDF]