Abstract 3707: Tumor-associated neutrophils with antigen-presenting features in early-stage human lung cancer

Abstract

Abstract To date there has been an increasing focus on the interactions between inflammatory myeloid cells and T cells in the tumor microenvironment because cytotoxic anti-tumoral T cells represent the chief effector mechanism of anti-tumoral immunity. Tumor-associated neutrophils (TANs) represent a significant portion of inflammatory cells in lung tumors; however, whether specialized neutrophil subpopulations capable of regulating T cell responses exist in human cancers is unknown. Our goal was to identify subsets of TANs and determine their specific roles in the regulation of T cell responses in patients with early stage lung cancer. An extensive phenotypic analysis of 55 early-stage human lung tumors revealed that TANs, defined as CD11b+Arg1+MPO+CD66b+CD15+ cells, contained two major sub-populations. One subset of “canonical” TANs expressed classic neutrophil markers. A second subset of TANs displayed a combination of neutrophil markers plus markers (CD14+HLA-DR+CCR7+CD86+) normally expressed on antigen-presenting cells (APC). We termed this unique neutrophil population “APC-like hybrid TANs”. The frequency of these hybrid TANs varied widely within lung cancers and ranged from 0.5-25% of all TANs. Interestingly, the frequency of this hybrid population declined as tumors enlarged, and they were almost completely absent in tumors greater than 5 cm in diameter. Mechanistically, we determined that low doses of IFN-γ and GM-CSF in the tumors were required for the development of APC-like hybrid neutrophils. The high proportion of hybrid TANs (>10% of all TANs) directly correlated with the presence of IFN-γ and GM-CSF in the autologous tumor tissue. Using bone marrow-derived immature granulocytes, which were found to have prolonged survival in vitro, we discovered that these APC-like hybrid neutrophils originate from CD11b+CD15+CD10-CD16-/low/int neutrophil progenitors in the presence of IFN-γ and GM-CSF or in tumor-conditioned media. Functionally, the APC-like hybrid neutrophils are superior to canonical neutrophils in their ability to: 1) stimulate antigen non-specific autologous T cell responses 2) directly stimulate antigen-specific autologous memory T cell responses, 4) augment NY-ESO-1 specific effector T cell responses by providing a co-stimulatory signals through the OX40L, 4-1BBL CD86, CD54 molecules, and 5) cross present tumor-associated antigen as IgG-immune complex. In summary, we provide the first evidence of two subsets of TANs in lung cancer. All TANs had an activated phenotype and could support (rather than inhibit) T cell functions to some degree. However, we identified a subset of TAN in early-stage lung tumors that can undergo a unique differentiation process resulting in formation of specialized subset of APC-like hybrid neutrophils. These hybrid neutrophils may provide new opportunities to boost the efficacy of vaccines based on cytotoxic T lymphocyte induction Citation Format: Jason Stadanlick, Abhishek Rao, Michael Annunziata, Edmund Moon, Shaun O'brien, Pratik Bhojnagarwala, Michael Feldman, Wayne Hancock, Jose Conejo-Garcia, Sunil Singhal, Stephen Albelda, Evgeniy Eruslanov. Tumor-associated neutrophils with antigen-presenting features in early-stage human lung cancer [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2017; 2017 Apr 1-5; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2017;77(13 Suppl):Abstract nr 3707. doi:10.1158/1538-7445.AM2017-3707