The long-term goal of this project is an understanding of how costimulatory signals provided by antigen-presenting cells (APC) contribute to the productive activation of CD4+ T-cells. In vitro approaches have shown that the maximal production of the growth factor IL-2 by CD4+ T-cells requires T-cell antigen receptor (TCR) recognition of antigenic peptide/MHC complexes, and a costimulatory signal transduced by CD28 following interaction with B7-1 and B7-2 molecules on the APC. Although this two signal model has provided an important framework for the study of T-cell activation, it does not account for the profound effects that inflammation and survival proteins have on T-cell immunity in vivo. Therefore, in the current application, T-cell costimulation will be studied with a novel system that allows in vivo tracking of the fate of a small population of adoptively transferred TCR transgenic T-cells in vivo. Results from this system have led to the hypothesis that at least three steps are required for the productive activation of naive antigen-specific T-cells in vivo: initial proliferation of the antigen-specific T-cells in response to antigen-presentation by dendritic cells; adjuvant-related sustenance of the expanded T-cell population; and differentiation of the T-cells into cells capable of producing effector cytokines such as IFN-gamma (IFN-g). This hypothesis will be tested by using confocal microscopy and in situ hybridization to visualize the interactions between adoptively transferred fluorescent dye-labeled antigen-specific T-cells, antigen- specific B-cells, and dendritic cells to determine whether CD28- and IL-2-dependent proliferation by naive T-cells is initiated by peptide/MHC complex-bearing dendritic cells. Flow cytometry will be used to determine whether this interaction causes CD40 ligand expression on the antigen- specific T-cells and whether CD40 ligand or lymphokines produced by the T-cells induce B7 molecules on antigen-specific B-cells or macrophages. These methods and RT-PCR will be used to determine whether adjuvants sustain the T-cell response by promoting T-cell proliferation and/or survival and whether these effects are mediated by CD28 or products of the TNF-a cascade through the action of IL-2 or bcl-2 family proteins. Finally, the spatial relationships between antigen-specific T-cells and IL-12 producing APC will be visualized by immunohistology and the in vivo mechanism by which IL-12 promotes T-cell differentiation in vivo will be studied by flow cytometric detection of cytoplasmic IFN-g within antigen-specific T-cells.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Research Project (R01)
Project #
5R01AI027998-12
Application #
6170210
Study Section
Immunobiology Study Section (IMB)
Program Officer
Quill, Helen R
Project Start
1989-04-01
Project End
2002-03-31
Budget Start
2000-04-01
Budget End
2001-03-31
Support Year
12
Fiscal Year
2000
Total Cost
$256,430
Indirect Cost
Name
University of Minnesota Twin Cities
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
168559177
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
Pape, Kathryn A; Maul, Robert W; Dileepan, Thamotharampillai et al. (2018) Naive B Cells with High-Avidity Germline-Encoded Antigen Receptors Produce Persistent IgM+ and Transient IgG+ Memory B Cells. Immunity 48:1135-1143.e4
Taylor, Justin J; Pape, Kathryn A; Steach, Holly R et al. (2015) Humoral immunity. Apoptosis and antigen affinity limit effector cell differentiation of a single naïve B cell. Science 347:784-7
Yang, Jessica A; Tubo, Noah J; Gearhart, Micah D et al. (2015) Cutting edge: Bcl6-interacting corepressor contributes to germinal center T follicular helper cell formation and B cell helper function. J Immunol 194:5604-8
Tubo, Noah J; Jenkins, Marc K (2014) TCR signal quantity and quality in CD4(+) T cell differentiation. Trends Immunol 35:591-596
Jenkins, Marc K; Moon, James J (2012) The role of naive T cell precursor frequency and recruitment in dictating immune response magnitude. J Immunol 188:4135-40
Pepper, Marion; Linehan, Jonathan L; Pagán, Antonio J et al. (2010) Different routes of bacterial infection induce long-lived TH1 memory cells and short-lived TH17 cells. Nat Immunol 11:83-9
McLachlan, James B; Catron, Drew M; Moon, James J et al. (2009) Dendritic cell antigen presentation drives simultaneous cytokine production by effector and regulatory T cells in inflamed skin. Immunity 30:277-88
Costalonga, Massimo; Zell, Traci (2007) Lipopolysaccharide enhances in vivo interleukin-2 production and proliferation by naive antigen-specific CD4 T cells via a Toll-like receptor 4-dependent mechanism. Immunology 122:124-30
McLachlan, James B; Jenkins, Marc K (2007) Migration and accumulation of effector CD4+ T cells in nonlymphoid tissues. Proc Am Thorac Soc 4:439-42
Catron, Drew M; Rusch, Lori K; Hataye, Jason et al. (2006) CD4+ T cells that enter the draining lymph nodes after antigen injection participate in the primary response and become central-memory cells. J Exp Med 203:1045-54

Showing the most recent 10 out of 53 publications