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Biology subjects

Kelly, K. A.

Publications and source records attributed to Kelly, K. A..

3 recordsLinked to original sources

Plectin promotes an aggressive phenotype and represses cytotoxic T cell activity in pancreatic cancer

BackgroundPancreatic adenocarcinoma (PDAC) is an abysmal disease, with a poor clinical outcome, largely due to limited life-extending treatments for patients. Notoriously, PDAC displays a T cell-suppressive tumor microenvironment where underlying molecular mechanisms that lead to this phenotype remain poorly understood. To unravel specific mechanisms, we utilized bioinformatic analyses with functional studies and revealed the cytolinker protein plectin (PLEC) as a novel player in regulating the T cell-suppressive tumor microenvironment of PDAC. MethodsUtilizing the TCGA-PAAD dataset, tumor samples were separated by PLEC expression to evaluate patient survival, and pathway analyses associated with increased tumorigenesis. Evaluation of immune infiltration and subsequent immune deconvolution was performed using tidyestimate and CIBERSORTx R packages. Single-cell RNA-seq (scRNA-seq) analysis from 229 PDAC patients was analyzed to investigate signaling dynamics and immune cell infiltration in PLECHigh patients. Functional validation was provided using a monoclonal antibody (mAb) against cell surface plectin (CSP) in two murine PDAC models to examine changes in tumor growth and immune cell subset abundance. ResultsOur studies revealed that high plectin expression results in an overall worse survival associated with activation of pro-tumorigenic pathways and decreased anti-tumor immune signature in PDAC patients. Analysis via GSEA indicates PLECHigh patients display an aggressive phenotype and suppressed pro-inflammatory signaling pathways. Immune ESTIMATE scores were significantly decreased in PLECHigh patients, and scRNA-seq analysis revealed that PLECHigh tumors display a decrease in anti-tumor CD8+ T cells. In vivo analyses using an anti-CSP mAb revealed a reduction in tumor growth kinetics compared to IgG control corresponding with a significant increase in proliferating and activated cytotoxic CD8+ T cells. Anti-CSP-mediated tumor suppression was inhibited when CD8+ T cells were depleted, indicating that anti-CSP treatment is contingent on cytotoxic T cell functionality. ConclusionOur findings identify plectin as a biomarker of aggressive disease in PDAC, with high plectin expression associated with decreased T cell infiltration, and that treatment with anti-CSP mAb reinstates anti-tumor immunity and decreases tumor volume in vivo. These findings position plectin as a high-priority therapeutic target, with the potential to fundamentally reshape immune responses in PDAC and improve outcomes for patients with few remaining options.

cancer biology↗

Computational modeling-directed combination treatment with etanercept and mifepristone mitigates neuroinflammation in a mouse model of Gulf War Illness.

Gulf War Illness is a chronic multi-symptom disorder experienced by over 30% of veterans from the 1990-1991 Gulf War and is increasingly recognized to be driven by underlying persistent neuroinflammation resulting from chemical and physiological exposures experienced during deployment. Despite significant advances in identifying Gulf War-relevant exposures and underlying pathobiology, effective treatment strategies for Gulf War Illness are still largely lacking. Many studies that have evaluated potential therapies for Gulf War Illness have primarily focused on a single treatment. However, through a mechanistically informed computational evaluation of blood biomarkers and gene expression in veterans with Gulf War Illness, we identified that a combination of anti-inflammatory and anti-glucocorticoid treatment may prove effective in treating Gulf War Illness. Here, we have evaluated combined treatment with the anti-TNF drug, etanercept, and anti-glucocorticoid, mifepristone, in an established long-term mouse model of Gulf War Illness of combined physiological stress and nerve agent exposure. Supporting results from the computational modeling of this treatment, we found that this drug combination significantly alleviates the underlying neuroinflammation associated with Gulf War Illness. The fusion of computational and in vivo preclinical treatment evaluation may provide a highly useful and translationally relevant means by which to identify successful treatment paradigms for Gulf War Illness.

neuroscience↗

CD4 Effectors Need to Recognize Antigen Locally to Become Cytotoxic CD4 and Follicular Helper T Cells

Cytotoxic CD4 T cells (ThCTL) are tissue-resident effectors that enhance viral clearance by MHC-II-restricted cytotoxicity of infected cells. Using a model of influenza A virus (IAV) infection, we identify key factors that drive CD4 effectors to differentiate into lung-resident ThCTL. We find that, to become ThCTL, CD4 effectors must again recognize cognate antigen on antigen presenting cells (APC) within the lung. Different APC subsets can drive this transition, including dendritic cells, B cells, and to a lesser extent non-hematopoietic MHC-II+ APC. CD28 co-stimulation is not required and can reduce ThCTL development. In contrast, T follicular helper cells (TFH) that are another specialized CD4 effector subset, require CD28 during this time. Optimal ThCTL generation also requires ongoing infection in the effector phase, that acts independently of antigen presentation. The mechanism involves production of Type I IFN, that induces IL-15 which acts to support further differentiation of CD4 effectors to ThCTL. The multiple spatial, temporal and cellular requirements for ThCTL generation from CD4 effectors described here would be expected to prevent cytotoxic CD4 responses in the lung after pathogen has already been cleared, while ensuring the development of potent lung-restricted ThCTL effectors when pathogen persists.

immunology↗