The ability of NLRs to mediate tumor surveillance has not been investigated to date

The ability of NLRs to mediate tumor surveillance has not been investigated to date. effect of granulocytic colony stimulating factor (G-CSF) expression. Our findings suggest that NLR pathways may be a novel modality to program TILs and influence tumor metastases. Introduction The context of the immune tumor microenvironment can be predictive of tumor stage, cancer-specific survival, TH5487 as well as response to chemotherapy [1]C[3]. In certain malignancies, the presence of infiltrating CD8+ T lymphocytes correlates with improved outcomes, whereas infiltrating B cells, TH5487 CD4+ T lymphocytes, and negative regulators including myeloid-derived suppression cells (MDSCs) and T regulatory cells (Tregs) negatively correlate with survival [4]. These observations underscore the importance Mouse monoclonal antibody to Placental alkaline phosphatase (PLAP). There are at least four distinct but related alkaline phosphatases: intestinal, placental, placentallike,and liver/bone/kidney (tissue non-specific). The first three are located together onchromosome 2 while the tissue non-specific form is located on chromosome 1. The product ofthis gene is a membrane bound glycosylated enzyme, also referred to as the heat stable form,that is expressed primarily in the placenta although it is closely related to the intestinal form ofthe enzyme as well as to the placental-like form. The coding sequence for this form of alkalinephosphatase is unique in that the 3 untranslated region contains multiple copies of an Alu familyrepeat. In addition, this gene is polymorphic and three common alleles (type 1, type 2 and type3) for this form of alkaline phosphatase have been well characterized in defining TH5487 pathways essential to programming the composition of tumor infiltrating lymphocytes (TILs), as selective modulation of the immune tumor microenvironment represents an emerging therapeutic modality. Pattern recognition receptors such as the prototypic Toll-like receptor (TLR) family and intracellular nucleotide-binding oligomerization domain (NOD)-like receptor (NLR) family recognize conserved motifs on pathogens as well as endogenous molecules released by damaged cells [5]. Activation of these signaling pathways initiates innate and adaptive immune responses, and may promote tissue repair and regeneration. We previously implicated TLR3 in a murine model of prostate cancer tumor surveillance critical in programming the infiltration of T lymphocytes and NK cells, while suppressing Treg expansion [6]. In bladder cancer, the efficacy of immune modulation is highlighted by the use of intravesical Bacillus Calmette Guerin, which promotes an influx of macrophages and neutrophils within the tumor microenvironment mediated in part by TLR2 and 4 [7], [8]. Receptor-interacting protein 2 (Rip2), a serine-threonine and tyrosine kinase downstream and common to Nod1 and Nod2, activates transcription factors such as NF-B and MAP kinases through its kinase activity as well as through recruitment of E3 ubiquitin ligase [9]C[14]. Rip2-dependent pathways have emerged as critical in sensing diverse pathogens ranging from to as well as in mediating inflammatory disorders such as autoimmune encephalomyelitis [15]C[17]. In addition, polymorphisms of Nod2 have been linked with susceptibility to Crohn’s disease, while polymorphisms of Rip2 have TH5487 been linked with systemic lupus erythematosus [18], [19]. The ability of NLRs to mediate tumor surveillance has not been investigated to date. Here, we postulate that Rip2 may mediate bladder cancer surveillance and explore its role using a murine orthotopic and subcutaneous bladder cancer model. We show that tumor bearing Rip2-deficient mice biases myeloid differentiation towards the MDSC lineage and plays an intrinsic role in the development of the CD11b+Ly6G+Ly6Clo granulocytic MDSC population. Our findings are the first to implicate Rip2 and NLRs in tumor surveillance and their importance in programming the immune tumor microenvironment. The NLR pathway may represent a therapeutic opportunity in modulating cancer immunity to prevent tumor invasion and metastasis. Materials and Methods Ethics Statement All animal work has been conducted in accordance with the Public Health Service Policy on Human Care and Use of Laboratory Animals and USDA Animal Welfare Act Regulations through an approved UCLA Institutional Animal Care and Use Committee protocol #2010-023-11C. Mice Rip2-deficient mice backcrossed to a C57Bl/6 background for 10 generations were genotyped as previously described [10]. Age-matched C57Bl/6 mice (Jackson Laboratories) were used as controls. Six- to 8-wk old female mice were used for the experiments. Mice were housed in pathogen-free conditions according to TH5487 UCLA Animal Research Committee protocols. Cell culture MB49 cell lines (gift from Tim Ratliff).