Endothelial cell (EC) injury has been widely documented in certain infections, autoimmunity, allograft rejection, graft versus host disease and following immunotherapy with cytokines or immunotoxins. It is becoming increasingly clear that ECs are primary targets of immunologic attack, although the precise mechanism remains unclear. We have used interleukin-2 (IL-2)-induced vascular leak syndrome (VLS) as a model to study EC injury. IL-2 is the only FDA approved systemic therapy for treating metastatic renal cell carcinoma. It is also being used to treat metastatic melanomas, immunodeficiencies and viral infections including AIDS. Despite much success, the efficacy is limited by severe, life-threatening toxicity resulting from EC injury leading to VLS. Using CD44 knockout (KO), perforin KO and FasL mutant mice, we have demonstrated that IL-2 activates cytotoxic lymphocytes and such cells use CD44 to kill EC by triggering perforin and FasL. More recently, we have demonstrated that CD44v7 exon KO mice also exhibit decreased VLS and EC killing. Based on these studies, we will test the hypothesis that IL-2 treatment up regulates CD44 variant isoforms on cytolytic lymphocytes of which v7 isoform plays a key role in EC injury and induction of VLS.
The specific aims are 1) To test the susceptibility of EC isolated from various organs to cytotoxicity mediated by IL-2 activated T/NK/NKT cells from WT, pefforin KO, Fas and FasL mutant mice. Using NK cell-deficient (NKCD-Tg) mice, the role of NK cells in IL-2 induced VLS will also be investigated. 2) To examine whether down regulation of killer cell inhibitory receptor (KIR)-like molecules and/or up regulation of stimulatory receptors on NK cells is responsible for CD44-mediated EC injury. Specifically, the expression of KiR-like molecules, including Ly49 and CD94/NKG2 present on NK cells, and the classical and non-classical MHC ligands on Ecs, will be studied. 3) Identification of the CD44 isoforms involved in EC injury caused by cytotoxic lymphocytes. 4) To address the mechanism by which CD44v7KO mice exhibit increased resistance to VLS. 5) Use of mimetics of CD44 or its ligand including mAbs against CD44s and CD44v isoforms, Pep-l(an inhibitor of HA), CD44Rg and CD44MutRg fusion proteins to prevent EC injury and vascular leak. Together, the current study should provide novel insights into the mechanism of immune cell-mediated EC injury and development of strategies to prevent vascular leak.

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Research Project (R01)
Project #
5R01HL058641-06
Application #
6734681
Study Section
Pathology A Study Section (PTHA)
Program Officer
Ershow, Abby
Project Start
1998-04-01
Project End
2007-04-30
Budget Start
2004-05-01
Budget End
2005-04-30
Support Year
6
Fiscal Year
2004
Total Cost
$254,180
Indirect Cost
Name
Virginia Commonwealth University
Department
Microbiology/Immun/Virology
Type
Schools of Medicine
DUNS #
105300446
City
Richmond
State
VA
Country
United States
Zip Code
23298
Nagarkatti, Mitzi; Rieder, Sadiye Amcaoglu; Nagarkatti, Prakash S (2018) Evaluation of Cell Proliferation and Apoptosis in Immunotoxicity Testing. Methods Mol Biol 1803:209-230
Hassuneh, Mona R; Nagarkatti, Mitzi; Nagarkatti, Prakash S (2013) Role of interleukin-10 in the regulation of tumorigenicity of a T cell lymphoma. Leuk Lymphoma 54:827-34
Guan, Hongbing; Singh, Narendra P; Singh, Udai P et al. (2012) Resveratrol prevents endothelial cells injury in high-dose interleukin-2 therapy against melanoma. PLoS One 7:e35650
Zhou, Juhua; Nagarkatti, Prakash S; Zhong, Yin et al. (2011) Implications of single nucleotide polymorphisms in CD44 exon 2 for risk of breast cancer. Eur J Cancer Prev 20:396-402
Guan, Hongbing; Nagarkatti, Prakash S; Nagarkatti, Mitzi (2011) CD44 Reciprocally regulates the differentiation of encephalitogenic Th1/Th17 and Th2/regulatory T cells through epigenetic modulation involving DNA methylation of cytokine gene promoters, thereby controlling the development of experimental autoimmune ence J Immunol 186:6955-64
Nagarkatti, Mitzi; Rieder, Sadiye Amcaoglu; Vakharia, Dilip et al. (2010) Evaluation of apoptosis in immunotoxicity testing. Methods Mol Biol 598:241-57
Zhou, Juhua; Nagarkatti, Prakash; Zhong, Yin et al. (2010) Immune modulation by chondroitin sulfate and its degraded disaccharide product in the development of an experimental model of multiple sclerosis. J Neuroimmunol 223:55-64
Singh, Udai P; Singh, Narendra P; Singh, Balwan et al. (2010) Resveratrol (trans-3,5,4'-trihydroxystilbene) induces silent mating type information regulation-1 and down-regulates nuclear transcription factor-kappaB activation to abrogate dextran sulfate sodium-induced colitis. J Pharmacol Exp Ther 332:829-39
Zhou, Juhua; Nagarkatti, Prakash S; Zhong, Yin et al. (2010) Unique SNP in CD44 intron 1 and its role in breast cancer development. Anticancer Res 30:1263-72
Hegde, Venkatesh L; Nagarkatti, Mitzi; Nagarkatti, Prakash S (2010) Cannabinoid receptor activation leads to massive mobilization of myeloid-derived suppressor cells with potent immunosuppressive properties. Eur J Immunol 40:3358-71

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