Established tumors create a condition of immunologic unresponsiveness (tolerance) toward their own antigens. This constitutes a barrier to the clinical immunotherapy of cancer, and represents a striking model of acquired peripheral tolerance. This project will address the hypothesis that murine plasmacytoid dendritic cells (pDCs) expressing the tolerogenic enzyme indoleamine 2,3-dioxygenase (IDO) are selectively recruited to tumor-draining lymph nodes, where they create tolerance to tumor antigens.
Aim 1 will test the hypothesis that IDO-expressing DCs from tumor-draining lymph nodes directly suppress T cell responses to tumor-derived antigens. This will first be done by adoptively transferring DCs isolated from murine tumor-draining lymph nodes, to test the hypothesis that these DCs render defined antigen-specific CD8+ T cells anergic in vivo, via IDO-induced tryptophan-withdrawal stress and cell-cycle arrest. Then a B16-OVA tumor model will be used with defined OVA-specific T cells to test the hypothesis that IDO expression in by pDCs in tumor-draining lymph nodes creates anergy to tumor-derived antigens in vivo.
Aim 2 will test the hypothesis that IDO-expressing DCs from tumor-draining LNs amplify and sustain their effect by creating tumor-specific regulatory T cells. First, an in vitro model will be used to test the hypothesis that pDCs from tumor-draining lymph nodes suppress normal cell-cycle progression and effector-cell differentiation of CD4+ T cells via expression of IDO, and that this drives the conversion of naive CD4+ T cells into antigen-specific Tregs. Then an in vivo tumor model and defined CD4+ T cells will be used to test the hypothesis that antigen-presentation by IDO+ cells in vivo creates new antigen-specific Tregs against a nominal tumor-derived antigen. Finally, genetically defined mice will be used to test the hypothesis that pDCs in tumor-draining lymph nodes constitutively express IDO because they receive CTLA4->B7 signals delivered by tumor-specific Tregs. Taken together, the proposed studies will provide mechanistic insight into the role of IDO in the pathologic state of tolerance displayed toward tumors. This is relevant to the basic biology of tumors and to acquired peripheral tolerance, and has direct implications for clinical immunotherapy of cancer. ? ?

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Research Project (R01)
Project #
1R01CA112431-01
Application #
6858906
Study Section
Cancer Immunopathology and Immunotherapy Study Section (CII)
Program Officer
Howcroft, Thomas K
Project Start
2005-01-14
Project End
2009-12-31
Budget Start
2005-01-14
Budget End
2005-12-31
Support Year
1
Fiscal Year
2005
Total Cost
$254,183
Indirect Cost
Name
Georgia Health Sciences University
Department
Pediatrics
Type
Schools of Medicine
DUNS #
966668691
City
Augusta
State
GA
Country
United States
Zip Code
30912
Sharma, Madhav D; Shinde, Rahul; McGaha, Tracy L et al. (2015) The PTEN pathway in Tregs is a critical driver of the suppressive tumor microenvironment. Sci Adv 1:e1500845
Hong, Yuan; Manoharan, Indumathi; Suryawanshi, Amol et al. (2015) ?-catenin promotes regulatory T-cell responses in tumors by inducing vitamin A metabolism in dendritic cells. Cancer Res 75:656-665
Ding, Zhi-Chun; Lu, Xiaoyun; Yu, Miao et al. (2014) Immunosuppressive myeloid cells induced by chemotherapy attenuate antitumor CD4+ T-cell responses through the PD-1-PD-L1 axis. Cancer Res 74:3441-53
Hong, Yuan; Peng, Yibing; Guo, Z Sheng et al. (2014) Epitope-optimized alpha-fetoprotein genetic vaccines prevent carcinogen-induced murine autochthonous hepatocellular carcinoma. Hepatology 59:1448-58
Li, Minghui; Bolduc, Aaron R; Hoda, Md Nasrul et al. (2014) The indoleamine 2,3-dioxygenase pathway controls complement-dependent enhancement of chemo-radiation therapy against murine glioblastoma. J Immunother Cancer 2:21
Sharma, Madhav D; Huang, Lei; Choi, Jeong-Hyeon et al. (2013) An inherently bifunctional subset of Foxp3+ T helper cells is controlled by the transcription factor eos. Immunity 38:998-1012
Ravishankar, Buvana; Liu, Haiyun; Shinde, Rahul et al. (2012) Tolerance to apoptotic cells is regulated by indoleamine 2,3-dioxygenase. Proc Natl Acad Sci U S A 109:3909-14
Divanovic, Senad; Sawtell, Nancy M; Trompette, Aurelien et al. (2012) Opposing biological functions of tryptophan catabolizing enzymes during intracellular infection. J Infect Dis 205:152-61
Zhou, Qing; Munger, Meghan E; Veenstra, Rachelle G et al. (2011) Coexpression of Tim-3 and PD-1 identifies a CD8+ T-cell exhaustion phenotype in mice with disseminated acute myelogenous leukemia. Blood 117:4501-10
Makala, Levi H C; Baban, Babak; Lemos, Henrique et al. (2011) Leishmania major attenuates host immunity by stimulating local indoleamine 2,3-dioxygenase expression. J Infect Dis 203:715-25

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