Natural killer (NK) cells are large granular lymphocytes of bone marrow origin that exhibit cytolytic activity against some tumor and virally infected cells in the absence of prior stimulation. We have previously identified murine 2B4 as an NK receptor expressed on a subset of T cells as well as on all murine NK cells. 2B4 is expressed early in NK cell development, before expression of other NK cell specific markers such NK 1.1 or Ly-49 family members. 2B4 is a member Df the CD2 subfamily of the immunoglobulin superfamily and is expressed as 2 alternative splice variants. Ligation of 2B4 with mAb modulates target cell lysis and IFN-y production. Recently, we have shown CD48 to be the high affinity counter-receptor for 2B4. CD48 is widely expressed on cells of hematopoietic origin, and is important in both T cell and B cell activation. The overall goal of this application is to investigate the role of 2B4 in the immune system, both as a NK cell receptor and as a counter-receptor for CD48. First, we will clone and characterize the human homologues of murine 2B4. To complement the murine 2B4 reagents we already have, we will generate monoclonal antibodies against human 2B4, and soluble fusion proteins of 2B4 and CD48. Using these reagents, we will study the expression pattern of 2B4 in detail. Next, the role of 2B4 in the cytolytic function and IFN-y production of human NK cells will be analyzed. Furthermore, these reagents will allow us to study the role of 2B4-CD48 interactions on the regulation of CD48+ lymphocytes by 2B4+ cells. The effect of 2B4-CD48 interactions on B cells will be studied by analyzing their ability to provide (or block) costimulatory signals. This effect will be measured by proliferation and immunoglobulin production. Finally, the role of 2B4 in NK cell development and function will be established by using a 2B4 gene knockout mouse model. The experiments proposed in this project should provide a clearer understanding of the role of 2B4 in modulating various functions of human NK cells and may reveal new insights and open new avenues for cancer immunotherapy.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
5R01CA085753-03
Application #
6626760
Study Section
Experimental Immunology Study Section (EI)
Program Officer
Howcroft, Thomas K
Project Start
2001-01-17
Project End
2004-12-31
Budget Start
2003-01-23
Budget End
2003-12-31
Support Year
3
Fiscal Year
2003
Total Cost
$141,492
Indirect Cost
Name
University of North Texas
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
110091808
City
Fort Worth
State
TX
Country
United States
Zip Code
76107
Mathew, Stephen O; Rao, Krithi K; Kim, Jong R et al. (2009) Functional role of human NK cell receptor 2B4 (CD244) isoforms. Eur J Immunol 39:1632-41
Mathew, Stephen O; Vaidya, Swapnil V; Kim, Jong R et al. (2007) Human natural killer cell receptor 2B4 (CD244) down-regulates its own expression by reduced promoter activity at an Ets element. Biochem Biophys Res Commun 355:483-7
Lee, Jae Kyung; Mathew, Stephen O; Vaidya, Swapnil V et al. (2007) CS1 (CRACC, CD319) induces proliferation and autocrine cytokine expression on human B lymphocytes. J Immunol 179:4672-8
Vaidya, Swapnil V; Stepp, Susan E; McNerney, Megan E et al. (2005) Targeted disruption of the 2B4 gene in mice reveals an in vivo role of 2B4 (CD244) in the rejection of B16 melanoma cells. J Immunol 174:800-7
Vaidya, Swapnil V; Mathew, Porunelloor A (2005) An Ets element regulates the transcription of the human 2B4 gene in natural killer cells. Biochim Biophys Acta 1728:181-5
Mathew, Stephen O; Kumaresan, Pappanaicken R; Lee, Jae Kyung et al. (2005) Mutational analysis of the human 2B4 (CD244)/CD48 interaction: Lys68 and Glu70 in the V domain of 2B4 are critical for CD48 binding and functional activation of NK cells. J Immunol 175:1005-13
Lee, Jae Kyung; Boles, Kent S; Mathew, Porunelloor A (2004) Molecular and functional characterization of a CS1 (CRACC) splice variant expressed in human NK cells that does not contain immunoreceptor tyrosine-based switch motifs. Eur J Immunol 34:2791-9
Mathew, Porunelloor A; Chuang, Samuel S; Vaidya, Swapnil V et al. (2004) The LLT1 receptor induces IFN-gamma production by human natural killer cells. Mol Immunol 40:1157-63
Chuang, Samuel S; Lee, Jae-Kyung; Mathew, Porunelloor A (2003) Protein kinase C is involved in 2B4 (CD244)-mediated cytotoxicity and AP-1 activation in natural killer cells. Immunology 109:432-9
Kumaresan, Pappanaicken R; Lai, Wayne C; Chuang, Samuel S et al. (2002) CS1, a novel member of the CD2 family, is homophilic and regulates NK cell function. Mol Immunol 39:1-8

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