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Relying on this study, holding compulsory ergonomic lifting training courses could be proposed for workers and regulations adjusting an upper limit for maximum baggage weight must be also enacted in order to improve occupational health and prevent the prevalence of increasing MSDs.

Toll-like receptors (TLRs) play a central role in both the innate and adaptive immune systems by recognizing pathogen-associated molecular patterns and inducing the release of the effector molecules of the immune system. The dysregulation of the TLR system may cause various autoimmune diseases and septic shock. A series of molecular dynamics simulations and free energy calculations were performed to investigate the ligand-free, lipopolysaccharide (LPS)-bound, and neoseptin3-bound (TLR4-MD2)2 tetramers. Compared to earlier simulations done by others, our simulations showed that TLR4 structure was well maintained with stable interfaces. Free energy decomposition by molecular mechanics Poisson-Boltzmann surface area (MM-PBSA) method suggests critical roles that two hydrophobic clusters I85-L87-P88 and I124-L125-P127 of MD2, together with LPS and neoseptin3, may play in TLR4 activation. We propose that 1) direct contacts between TLR4 convex surface and LPS and neoseptin3 at the region around L442 significantly increase the binding and 2) binding of LPS and neoseptin3 in the central hydrophobic cavity of MD2 triggers burial of F126 and exposure of I85-L87-P88 that facilitate formation of (TLR4-MD2)2 tetramer and activation of TLR4 system.

BackgroundA growing body of evidence suggests that T-cell responses against neoantigens are critical regulators of response to immune checkpoint blockade. We previously showed that circulating neoantigen-specific CD8 T cells in patients with lung cancer responding to anti-Programmed death-ligand 1 (PD-L1) (atezolizumab) exhibit a unique phenotype with high expression of CD57, CD244, and KLRG1. Here, we extended our analysis on neoantigen-specific CD8 T cells to patients with metastatic urothelial cancer (mUC) and further profiled total CD8 T cells to identify blood-based predictive biomarkers of response to atezolizumab.MethodsWe identified tumor neoantigens from 20 patients with mUC and profiled their peripheral CD8 T cells using highly multiplexed combinatorial tetramer staining. Another set of patients with mUC treated with atezolizumab (n=30) or chemotherapy (n=40) were selected to profile peripheral CD8 T cells by mass cytometry. Using single-cell transcriptional analysis (single-cell RNA sequencing (scRNA-seq)), together with CITE-seq (cellular indexing of transcriptomes and epitopes by sequencing) and paired T-cell receptor (TCR) sequencing, we further characterized peripheral CD8 T cells in a subset of patients (n=16).ResultsHigh frequency of CD57 was observed in neoantigen-specific CD8 T cells in patients with mUC responding to atezolizumab. Extending these findings to bulk CD8 T cells, we found higher frequency of CD57 expressing CD8 T cells before treatment in patients responding to atezolizumab (n=20, p<0.01) but not to chemotherapy. These findings were corroborated in a validation cohort (n=30, p<0.01) and notably were independent of known biomarkers of response. scRNA-seq analysis identified a clonally expanded cluster enriched within CD57+ CD8 T cells in responding patients characterized by higher expression of genes associated with activation, cytotoxicity, and tissue-resident memory markers. Furthermore, compared with CD57− CD8 T cells, TCRs of CD57+ CD8 T cells showed increased overlap with the TCR repertoire of tumor-infiltrating T cells.ConclusionsCollectively, we show high frequencies of CD57 among neoantigen-specific and bulk CD8 T cells in patients responding to atezolizumab. The TCR repertoire overlap between peripheral CD57+ CD8 T cells and tumor-infiltrating lymphocytes suggest that accumulation of peripheral CD57+ CD8 T cells is reflective of an ongoing antitumor T-cell response. Our findings provide evidence and rationale for using circulating CD8 T cells expressing CD57 as a readily accessible blood-based biomarker for selecting patients with mUC for atezolizumab therapy.

The recent success of immune checkpoint blockade has revolutionized cancer treatment for many cancers, however, only a fraction of patients with advanced stages of cancers experience clinical benefit. Many studies have suggested that T cells against tumor neoantigens are critical mediators of response to checkpoint blockade. We showed previously that neoantigen-specific CD8 T cells in cancer patients responding to anti-PD-L1 (atezolizumab) therapy express high levels of CD57 and KLRG1. Here, we extended the study to bladder cancer patients treated with atezolizumab to identify predictive biomarkers of response. We immune profiled circulating CD8 T cells using multidimensional mass cytometry and single cell sequencing, and compared patients with objective response and progressive disease. We found a higher frequency of CD57-expressing CD8 T cells at baseline in responding patients compared to patients who progressed during therapy (n=20, p&lt;0.01). High expression of CD57 was also observed in neoantigen-specific CD8 T cells in responding patients. These findings were corroborated in a validation cohort (n=30, p&lt;0.01) and notably, higher frequency of CD57+ T cells was only observed in patients responding to atezolizumab and not in patients responding to chemotherapy treatment (n=40). We further used single-cell transcriptomics, together with CITE-seq and paired TCR sequencing, to characterize CD57+ CD8 T cells in a subset of patients (n=16) and identified a cluster within CD57+ CD8 T cells, which was characterized by enrichment of genes associated with activation, cytotoxicity and tissue resident memory markers in responding patients. Compared to patients with progressive disease, there was an increased clonal expansion among CD57+ CD8 T cells at baseline in responders, which was driven specifically by the activated cluster. Furthermore, we found increased overlap between TCR repertoires of tumor-infiltrating T cells and CD57+CD8 T cells, compared to CD57- CD8 T cells in the periphery, suggesting that levels of CD57+ CD8 T cells in the periphery could be indicative of quality of anti-tumor T cell response.This study identified and confirmed that elevated levels of circulating CD8 T cells expressing CD57 are associated with response to atezolizumab in bladder cancer patients. These data provide evidence and rationale for an easily accessible blood-based biomarker for selecting patients for atezolizumab therapy. Citation Format: Mahesh Yadav, Michael Fehlings, Leesun Kim, Xiangnan Guan, Kobe C. Yuen, Alireza Tafazzol, Deepali Rishipathak, Shomyesh Sanjabi, Andrew Wallace, Alessandra Nardin, Siming Ma, Ana Milojkovic, Evan Newell, Sanjeev Mariathasan. Single-cell analysis reveals clonally expanded CD57+ CD8 T cells in periphery are associated with response to PD-L1 blockade in bladder cancer patients [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6226.