B cell selection in germinal centers (GCs) is important for the success of antibody responses against influenza, HIV-1 and many other pathogens. However, the full set of signals involved in mounting GC responses is not understood. Recent work highlights the importance of signals from T follicular helper (Tfh) cells in driving preferential outgrowth of higher affinity B cells. The factors determining the strength and quality of signaling between Tfh cells and B cells are incompletely defined and are a focus of this proposal. The surface receptor HVEM (TNFRSF14) is frequently mutated in human GC-derived lymphomas (follicular lymphoma and GCB-diffuse large B cell lymphoma). This finding suggests HVEM has an important role in normal GC function but this role has not been defined. We have found that HVEM deficiency gives B cells a competitive advantage over wild-type B cells during GC responses. Our preliminary data suggest that this advantage only occurs when T cells are capable of sensing HVEM through expression of BTLA. We therefore propose a model where HVEM engagement of BTLA on Tfh cells restrains the amount of T cell help delivered to the B cell.
The first Aim will define how HVEM restrains the competitiveness of B cells for representation in the GC. Adoptive transfer and conditional deletion approaches will be used to determine the stage(s) of the B cell response at which HVEM acts. The function of the HVEM intracellular domain will be tested using retroviral gene transduction approaches and the effects of HVEM deficiency on plasma cell formation, affinity maturation and recall responses will be determined.
The second Aim will define how BTLA within CD4 T cells determines the quality of help received by the B cell. We will use retroviral gene transduction to test the role of the BTLA cytoplasmic domain in Tfh cell function. Analysis of T cells lacking the tyrosine phosphatases, SHP1 and SHP2, will define their roles in BTLA function. The influence of HVEM-BTLA engagement on cell-cell contact and T cell signaling will be studied using intravital 2-photon microscopy combined with the Salsa6f calcium reporter. Erk signaling will be followed using a new nuclear-cytoplasmic translocation reporter mouse line.
The final Aim will examine how loss of the HVEM-BTLA interaction contributes to GC-derived lymphomagenesis. We will test whether BTLA functions as an extrinsic tumor suppressor by testing for accelerated outgrowth of Bcl2-overexpressing GC B cells in mice lacking BTLA in T cells. We will test for possible co-oncogenic effects of combined HVEM- and Gna13-deficiency. By defining how HVEM and BTLA act to control T cell help of B cell responses, this work may point to new approaches for augmenting B cell diversification and affinity maturation in GCs. An understanding of how HVEM constrains GC B cell accumulation, including cells over-expressing Bcl2, will provide insights that may lead to new approaches for treatment of FL and GCB-DLBCL.

Public Health Relevance

This work will define how HVEM and BTLA regulate T cell-dependent B cell responses. The impact of these surface receptors on constraining germinal center and plasma cell responses will be determined. The work will establish the signals transmitted by BTLA that regulate follicular helper T cell respones. Real time intravital imaging with a calcium reporter and a newly developed Erk reporter will test how BTLA controls T cell helper functions. Studies in mice over-expressing Bcl2 in B cells will test whether T cell BTLA acts as a cell-extrinsic tumor suppressor.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
2R01AI045073-21
Application #
9739133
Study Section
Cellular and Molecular Immunology - B Study Section (CMIB)
Program Officer
Ferguson, Stacy E
Project Start
1999-04-01
Project End
2024-08-31
Budget Start
2019-09-01
Budget End
2020-08-31
Support Year
21
Fiscal Year
2019
Total Cost
Indirect Cost
Name
University of California San Francisco
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
094878337
City
San Francisco
State
CA
Country
United States
Zip Code
94118
Wu, Jiaxi; Wu, Huaizhu; An, Jinping et al. (2018) Critical role of integrin CD11c in splenic dendritic cell capture of missing-self CD47 cells to induce adaptive immunity. Proc Natl Acad Sci U S A 115:6786-6791
Barnes, Michael J; Cyster, Jason G (2018) Lysophosphatidylserine suppression of T-cell activation via GPR174 requires G?s proteins. Immunol Cell Biol 96:439-445
Rodda, Lauren B; Lu, Erick; Bennett, Mariko L et al. (2018) Single-Cell RNA Sequencing of Lymph Node Stromal Cells Reveals Niche-Associated Heterogeneity. Immunity 48:1014-1028.e6
Laidlaw, Brian J; Schmidt, Timothy H; Green, Jesse A et al. (2017) The Eph-related tyrosine kinase ligand Ephrin-B1 marks germinal center and memory precursor B cells. J Exp Med 214:639-649
Sumida, Hayakazu; Lu, Erick; Chen, Hsin et al. (2017) GPR55 regulates intraepithelial lymphocyte migration dynamics and susceptibility to intestinal damage. Sci Immunol 2:
Wu, Shuang; Majeed, Sophia R; Evans, Timothy M et al. (2016) Clathrin light chains' role in selective endocytosis influences antibody isotype switching. Proc Natl Acad Sci U S A 113:9816-21
Reboldi, Andrea; Cyster, Jason G (2016) Peyer's patches: organizing B-cell responses at the intestinal frontier. Immunol Rev 271:230-45
Bannard, Oliver; McGowan, Simon J; Ersching, Jonatan et al. (2016) Ubiquitin-mediated fluctuations in MHC class II facilitate efficient germinal center B cell responses. J Exp Med 213:993-1009
Reboldi, Andrea; Arnon, Tal I; Rodda, Lauren B et al. (2016) IgA production requires B cell interaction with subepithelial dendritic cells in Peyer's patches. Science 352:aaf4822
Muppidi, Jagan R; Lu, Erick; Cyster, Jason G (2015) The G protein-coupled receptor P2RY8 and follicular dendritic cells promote germinal center confinement of B cells, whereas S1PR3 can contribute to their dissemination. J Exp Med 212:2213-22

Showing the most recent 10 out of 57 publications