Presenter of 2 Presentations
IMMUNOTHERAPIES, DNA VACCINES, EGFR INHIBITORS AND CHECK-POINT INHIBITORS: STATE-OF-THE-ART TREATMENTS OF HPV-ASSOCIATED RRP IN ADULTS
SINGLE-CELL TRANSCRIPTIONAL PROFILING REVEALS A DIVERSE IMMUNE LANDSCAPE IN HUMAN PAPILLOMAVIRUS 6 OR 11-DRIVEN RECURRENT RESPIRATORY PAPILLOMAS
Abstract
Introduction
Immune constituency within HPV 6 or 11-related recurrent respiratory papillomas (RRP) is incompletely understood.
Methods
We performed single-cell transcriptomics and single-cell T cell receptor (TCR) sequencing on 13 papilloma specimens obtained from adult patients with RRP.
Results
Bioinformatic study of the myeloid cell compartment revealed multiple distinct clusters of neutrophilic and monocytic cells, including several that express high levels of immunosuppression-associated transcripts TREM2 and ARG1. Small populations of FOXP3, IL2RA and CTLA4 positive CD4 regulatory T cells were identified. Other CD4 T cell populations harbored expression profiles indicative of skewing away from anti-tumor Th1 helper function and toward production of Th2-related cytokines. Study of CD8 T cells revealed a broad diversity of transcriptional phenotypes, with some populations expressing high levels of exhaustion markers TOX, PDCD1, and LAG3 and the tissue retention marker CD103, all previously associated with tumor-antigen specificity in studies of malignancy. Overall, expression of activation markers IFNG, PRF and GZMs was low in most CD8 and CD4 clusters, indicating a lack of strong active HPV-specific T cell immunity and possibly local immunosuppression. TCRs from clonotypes within two distinct exhausted, CD103+ CD8 clusters were reconstructed and cloned into expression vectors to allow determination of antigen-specificity. Using a panel of in silico predicted HLA class I binding HPV6 and 11 epitopes and autologous antigen presenting cells, co-culture experiments are underway to identify and validate a library of HPV6 and 11-specific TCRs.
Conclusions
Our single cell analysis of RRP reveals immune-related cellular diversity and transcriptional phenotypes implying the presence of immunosuppressive myeloid cells and regulatory CD4 T cells. Experimental validation of the antigen-specificity of TCRs from papilloma infiltrating CD8 T cells is underway to determine if the inability of CD8 TIL to detect and eliminate HPV infected epithelial cells is due to lack of HPV antigen-specificity or local immunosuppression.