A library-based screening method identifies neoantigen-reactive T cells in peripheral blood prior to relapse of ovarian cancer.

Mutated cancer antigens, or neoantigens, represent compelling immunological targets and appear to underlie the success of several forms of immunotherapy. While there are anecdotal reports of neoantigen-specific T cells being present in the peripheral blood and/or tumors of cancer patients, effective adoptive cell therapy (ACT) against neoantigens will require reliable methods to isolate and expand rare, neoantigen-specific T cells from clinically available biospecimens, ideally prior to clinical relapse. Here, we addressed this need using "mini-lines", large libraries of parallel T cell cultures, each originating from only 2,000 T cells.

Mapping the human T cell repertoire to recurrent driver mutations in MYD88 and EZH2 in lymphoma.

Oncogenic "driver" mutations are theoretically attractive targets for the immunotherapy of lymphoid cancers, yet the proportion that can be recognized by T cells remains poorly defined. To address this issue without any confounding effects of the patient's immune system, we assessed T cells from 19 healthy donors for recognition of three common driver mutations in lymphoma: , and . Donors collectively expressed the 10 most prevalent HLA class I alleles, including HLA-A*02:01.

Low Mutation Burden in Ovarian Cancer May Limit the Utility of Neoantigen-Targeted Vaccines.

Due to advances in sequencing technology, somatically mutated cancer antigens, or neoantigens, are now readily identifiable and have become compelling targets for immunotherapy. In particular, neoantigen-targeted vaccines have shown promise in several pre-clinical and clinical studies. However, to date, neoantigen-targeted vaccine studies have involved tumors with exceptionally high mutation burdens.

Surveillance of the tumor mutanome by T cells during progression from primary to recurrent ovarian cancer.

Purpose: Cancers accumulate mutations over time, each of which brings the potential for recognition by the immune system. We evaluated T-cell recognition of the tumor mutanome in patients with ovarian cancer undergoing standard treatment.

Experimental Design: Tumor-associated T cells from 3 patients with ovarian cancer were assessed by ELISPOT for recognition of nonsynonymous mutations identified by whole exome sequencing of autologous tumor.

A novel, broad spectrum therapeutic HPV vaccine targeting the E7 proteins of HPV16, 18, 31, 45 and 52 that elicits potent E7-specific CD8T cell immunity and regression of large, established, E7-expressing TC-1 tumors.

Persistent infection by high risk genotypes of human papillomavirus (HPV) is the cause of cervical cancer, which remains one of the most common cancers among women worldwide. In addition, there is a growing appreciation that high risk HPVs are associated with a number of other cancers including anogenital cancers as well as a subset of head and neck cancers. Recently, prophylactic HPV vaccines targeting the two most prevalent high risk HPVs (HPV16 and HPV18) have been deployed in large-scale vaccination campaigns.

Polyfunctional T-cell responses are disrupted by the ovarian cancer ascites environment and only partially restored by clinically relevant cytokines.

Background: Host T-cell responses are associated with favorable outcomes in epithelial ovarian cancer (EOC), but it remains unclear how best to promote these responses in patients. Toward this goal, we evaluated a panel of clinically relevant cytokines for the ability to enhance multiple T-cell effector functions (polyfunctionality) in the native tumor environment.

Methodology/principal Findings: Experiments were performed with resident CD8+ and CD4+ T cells in bulk ascites cell preparations from high-grade serous EOC patients.

Profound CD8+ T cell immunity elicited by sequential daily immunization with exogenous antigen plus the TLR3 agonist poly(I:C).

The development of vaccines that elicit robust CD8(+) T cell immunity has long been a subject of intense investigation. Although whole exogenous protein has not historically been considered as useful for eliciting CD8(+) T cell immunity, we report herein that whole, protein antigen is capable of eliciting profound levels of CD8(+) T cell immunity if it is administered via repeated, daily subcutaneous immunization in combination with the TLR3 agonist poly(I:C). Mice immunized for four consecutive days with 100 μg of either whole exogenous OVA or whole HPV16 E7 protein combined with 10 μg of poly(I:C) mounted remarkable antigen-specific CD8(+) T cell responses as measured by tetramer staining and ELISPOT analysis of splenocytes and peripheral blood, with up to 30% of peripheral CD8(+) T cells being antigen specific within 7-8 days of vaccination.

An in vitro-transcribed-mRNA polyepitope construct encoding 32 distinct HLA class I-restricted epitopes from CMV, EBV, and Influenza for use as a functional control in human immune monitoring studies.

Interest and activity in the areas of clinical immunotherapy and therapeutic vaccines are growing dramatically, thus there is a pressing need to develop robust tools for assessment of vaccine-induced immunity. CD8+ T cell immunity against specific antigens is normally measured by either flow cytometry using MHC tetramer reagents or via biological assays such as intracellular cytokine staining or ELISPOT after stimulation with specific peptide epitopes. However, these methodologies depend on precise knowledge of HLA-restricted epitopes combined with HLA typing of subjects.

Profound elevation of CD8+ T cells expressing the intraepithelial lymphocyte marker CD103 (alphaE/beta7 Integrin) in high-grade serous ovarian cancer.

Introduction: Tumor-infiltrating CD8(+) T cells are strongly associated with survival in high-grade serous ovarian cancer, but their functional phenotype remains poorly defined. The mucosal integrin CD103 (alpha(E)/beta(7)) facilitates the infiltration of T cells into epithelial tissues, including gut and lung mucosa, solid organ allografts, and various epithelial cancers. We reasoned that CD103 might also be expressed by tumor-reactive T cells in ovarian cancer.

Tumor-infiltrating T cells correlate with NY-ESO-1-specific autoantibodies in ovarian cancer.

Background: Tumor-infiltrating CD8+ T cells are correlated with prolonged progression-free and overall survival in epithelial ovarian cancer (EOC). A significant fraction of EOC patients mount autoantibody responses to various tumor antigens, however the relationship between autoantibodies and tumor-infiltrating T cells has not been investigated in EOC or any other human cancer. We hypothesized that autoantibody and T cell responses may be correlated in EOC and directed toward the same antigens.

Conversion of tyrosine to the inflammation-associated analog 3'-nitrotyrosine at either TCR- or MHC-contact positions can profoundly affect recognition of the MHC class I-restricted epitope of lymphocytic choriomeningitis virus glycoprotein 33 by CD8 T cells.

Immunohistochemical detection of increased levels of protein-associated nitrotyrosine has become widely used as a surrogate marker of in situ inflammation. However, the potential consequences of protein-associated nitrotyrosine formation in terms of cellular immune recognition has received surprisingly little attention. Using a well-defined I-E(K)-restricted epitope of pigeon cytochrome c, we previously demonstrated that conversion of a single tyrosine residue to nitrotyrosine can have a profound effect on recognition by CD4 T cells.