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Biology subjects

Ruan, D. F.

Publications and source records attributed to Ruan, D. F..

3 recordsLinked to original sources

HLA-E and NKG2A Mediate Resistance to M. bovis BCG Immunotherapy in Non-Muscle-Invasive Bladder Cancer

BackgroundBacillus Calmette-Guerin (BCG) is the standard of care treatment for high-risk non-muscle-invasive bladder cancer (NMIBC), yet many patients develop recurrent disease despite evidence of ongoing immune activation. We investigated mechanisms of immune escape in BCG-unresponsive tumors and evaluated the therapeutic potential of targeting the HLA-E/NKG2A axis. MethodsSingle-cell RNA sequencing, spatial immunophenotyping, proteomic profiling, and functional ex vivo assays were performed using tumors and urine samples from patients with BCG-naive and BCG-unresponsive NMIBC. ResultsBCG-unresponsive tumors were enriched for HLA-E-expressing malignant cells compared with BCG-naive tumors. Increased HLA-E expression was associated with enhanced IFN-{gamma} signaling and was induced by IFN-{gamma} stimulation in primary tumor cells and bladder cancer tumor lines. Spatial analyses demonstrated accumulation of NKG2A+ NK and CD8 T cells in proximity to HLA-Ehigh tumor cells, with increased NKG2A:HLA-E interactions in BCG-unresponsive tumors. Despite high expression of cytotoxic mediators, NKG2A+ effector cells displayed impaired degranulation. Blockade of NKG2A with monalizumab restored degranulation of and cytotoxicity by tumor-infiltrating lymphocytes in autologous tumor co-cultures. ConclusionsBCG-unresponsive NMIBC tumors are enriched for HLA-E-expressing tumor cells and NKG2A+ effector lymphocytes, with increased engagement of the HLA-E/NKG2A axis within the tumor microenvironment. These findings identify the HLA-E/NKG2A axis as a therapeutic vulnerability and provide a rationale for clinical evaluation of NKG2A blockade as a bladder-sparing strategy for patients with BCG-unresponsive disease.

cancer biology↗

Understanding the heterogeneity of alloreactive natural killer cell function inkidney transplantation

Human Natural Killer (NK) cells are heterogeneous lymphocytes regulated by variegated arrays of germline-encoded activating and inhibitory receptors. They acquire the ability to detect polymorphic self-antigen via NKG2A/HLA-E or KIR/HLA-I ligand interactions through an education process. Correlations among HLA/KIR genes, kidney transplantation pathology and outcomes suggest that NK cells participate in allograft injury, but mechanisms linking NK HLA/KIR education to antibody-independent pathological functions remain unclear. We used CyTOF to characterize pre- and post-transplant peripheral blood NK cell phenotypes/functions before and after stimulation with allogeneic donor cells. Unsupervised clustering identified unique NK cell subpopulations present in varying proportions across patients, each of which responded heterogeneously to donor cells based on donor ligand expression patterns. Analyses of pre-transplant blood showed that educated, NKG2A/KIR-expressing NK cells responded greater than non-educated subsets to donor stimulators, and this heightened alloreactivity persisted > 6 months post-transplant despite immunosuppression. In distinct test and validation sets of patients participating in two clinical trials, pre-transplant donor-induced release of NK cell Ksp37, a cytotoxicity mediator, correlated with 2-year and 5-year eGFR. The findings explain previously reported associations between NK cell genotypes and transplant outcomes and suggest that pre-transplant NK cell analysis could function as a risk-assessment biomarker for transplant outcomes.

immunology↗

MiDAS - Meaningful Immunogenetic Data at Scale

Human immunogenetic variation in the form of HLA and KIR types has been shown to be strongly associated with a multitude of immune-related phenotypes. We present MiDAS, an R package enabling statistical association analysis and using immunogenetic data transformation functions for HLA amino acid fine mapping, analysis of HLA evolutionary divergence as well as HLA-KIR interactions. MiDAS closes the gap between inference of immunogenetic variation and its efficient utilization to make meaningful discoveries.

bioinformatics↗