bioRxiv Science⌕ Search

Biology subjects

Deniger, D. C.

Publications and source records attributed to Deniger, D. C..

3 recordsLinked to original sources

HER2 mutation-derived neoantigens in NSCLC as actionable targets for TCR therapy

HER2 mutations are oncogenic drivers in 1-6% of non-small cell lung cancers (NSCLC), but therapeutic resistance limits the durability of current HER2-targeted treatments. Here, we identify T-cell receptors (TCRs) targeting recurrent HER2 hotspot mutations as a potential immunotherapeutic strategy for HER2-mutant NSCLC. Using neoepitope prediction and antigen-specific T-cell enrichment, we isolated HLA-A*02:01restricted TCRs recognizing HER2 A775insYVMA, S310F, and G776delinsVC mutations, collectively covering approximately 60% of HER2-mutant NSCLC. These TCRs selectively recognized mutant HER2 epitopes without detectable wild-type reactivity and some displayed cross-recognition of related hotspot variants, expanding the spectrum of targetable tumors. The G776delinsVC-specific TCR also exhibited co-receptorindependent activity showcased by its ability to activate CD4+ T cells. Importantly, timelapse single-cell flow cytometry analyses demonstrated that TCR-engineered T cells repeatedly reacquired activated polyfunctional states following serial antigen stimulation, while serial tumor rechallenge assays confirmed sustained cytotoxic activity across multiple rounds of tumor killing. These findings identify recurrent HER2 mutations as shared immunotherapeutic targets and provide a foundation for the development of TCR-based therapies for HER2-mutant NSCLC.

immunology↗

Internal checkpoint regulates T cell neoantigen reactivity and susceptibility to PD1 blockade

While neoantigen-specific tumor infiltrating lymphocytes (TIL) can be derived from in antigen-expressing tumors, their adoptive transfer fails to consistently elicit durable tumor regression. There has been much focus on the role of activation/exhaustion markers such as PD1, CD39 and TOX in TIL senescence. We found these markers were inversely expressed to Cytokine-Induced SH2 protein (CISH), a negative regulator of TCR signaling and tumor immunity in mice. To evaluate the physiological role of CISH in human TIL we developed a high-efficiency CRIPSR-based method to knock out CISH in fully mature TIL. CISH KO resulted in increased T cell receptor (TCR) avidity, tumor cytolysis and neoantigen recognition. CISH expression in the tumor resections correlated with TIL inactivity against p53 hotspot mutations and CISH KO in TIL unmasked reactivity against these universal neoantigens. While CISH KO resulted in T cell hyperactivation and expansion it did not alter maturation, perhaps by preferential PLC{gamma}-1 and not AKT inhibition. Lastly, CISH KO in T cells increased PD1 expression and the adoptive transfer of Cish KO T cells synergistically combines with PD1 antibody blockade resulting in durable tumor regression and survival in a preclinical animal model. These data offer new insights into the regulation of neoantigen recognition, expression of activation/exhaustion markers, and functional/maturation signals in tumor-specific T cells.

immunology↗

Genome-wide profiling of druggable active tumor defense mechanisms to enhance cancer immunotherapy

All current highly effective anti-tumor immunotherapeutics depend on the activity of T cells, but tumor cells can escape immune recognition by several mechanisms including loss of function in antigen presentation and inflammatory response genes, expression of immunomodulatory proteins and an immunosuppressive tumor microenvironment. In contrast, the comprehensive identification of strategies that sensitize tumor cells to immunotherapy in vivo has remained challenging. Here, we combine a two-cell type (2CT) whole-genome CRISPR-Cas9 screen with dynamic transcriptional analysis (DTA) of tumor upon T cell encounter to identify a set of genes that tumor cells express as an active defense against T cell-mediated killing. We then employed small molecule and biologic screens designed to antagonize gene products employed by tumor cells to actively defend against T cell-mediated tumor destruction and found that the inhibition of BIRC2, ITGAV or DNPEP enhanced tumor cell destruction by T cells. Mechanistically, we found that BIRC2 promoted immunotherapy resistance through inhibiting non-canonical NF-{kappa}B signaling and limiting inflammatory chemokine production. These findings show the path forward to improving T cell-mediated tumor destruction in the clinic.

immunology↗