Publications by authors named "Nandakumar Packiriswamy"

Serum titers of SARS-CoV-2-neutralizing antibodies (nAbs) correlate well with protection from symptomatic COVID-19 but decay rapidly in the months following vaccination or infection. In contrast, measles-protective nAb titers are lifelong after measles vaccination, possibly due to persistence of the live-attenuated virus in lymphoid tissues. We, therefore, sought to generate a live recombinant measles vaccine capable of driving high SARS-CoV-2 nAb responses.

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Introduction: Metastatic uveal melanoma (MUM) has a poor prognosis and treatment options are limited. These patients do not typically experience durable responses to immune checkpoint inhibitors (ICIs). Oncolytic viruses (OV) represent a novel approach to immunotherapy for patients with MUM.

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Oncolytic virotherapy aims to activate host antitumor immunity. In responsive tumors, intratumorally injected herpes simplex viruses (HSVs) have been shown to lyse tumor cells, resulting in local inflammation, enhanced tumor antigen presentation, and boosting of antitumor cytotoxic lymphocytes. In contrast to HSV, cytomegalovirus (CMV) is nonlytic and reprograms infected myeloid cells, limiting their antigen-presenting functions and protecting them from recognition by natural killer (NK) cells.

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Serum titers of SARS-CoV-2 neutralizing antibodies (nAb) correlate well with protection from symptomatic COVID-19, but decay rapidly in the months following vaccination or infection. In contrast, measles-protective nAb titers are life-long after measles vaccination, possibly due to persistence of the live-attenuated virus in lymphoid tissues. We therefore sought to generate a live recombinant measles vaccine capable of driving high SARS-CoV-2 nAb responses.

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An orally active vaccine capable of boosting SARS-CoV-2 immune responses in previously infected or vaccinated individuals would help efforts to achieve and sustain herd immunity. Unlike mRNA-loaded lipid nanoparticles and recombinant replication-defective adenoviruses, replicating vesicular stomatitis viruses with SARS-CoV-2 spike glycoproteins (VSV-SARS2) were poorly immunogenic after intramuscular administration in clinical trials. Here, by G protein trans-complementation, we generated VSV-SARS2(+G) virions with expanded target cell tropism.

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Clinical success with intravenous (IV) oncolytic virotherapy (OV) has to-date been anecdotal. We conducted a phase 1 clinical trial of systemic OV and investigated the mechanisms of action in responding patients. A single IV dose of vesicular stomatitis virus (VSV) interferon-β (IFN-β) with sodium iodide symporter (NIS) was administered to patients with relapsed/refractory hematologic malignancies to determine safety and efficacy across 4 dose levels (DLs).

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Oncolytic virus therapy leads to immunogenic death of virus-infected tumor cells and this has been shown in preclinical models to enhance the cytotoxic T-lymphocyte response against tumor-associated antigens (TAAs), leading to killing of uninfected tumor cells. To investigate whether oncolytic virotherapy can increase immune responses to tumor antigens in human subjects, we studied T-cell responses against a panel of known myeloma TAAs using PBMC samples obtained from ten myeloma patients before and after systemic administration of an oncolytic measles virus encoding sodium iodide symporter (MV-NIS). Despite their prior exposures to multiple immunosuppressive antimyeloma treatment regimens, T-cell responses to some of the TAAs were detectable even before measles virotherapy.

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Recent measles epidemics in US and European cities where vaccination coverage has declined are providing a harsh reminder for the need to maintain protective levels of immunity across the entire population. Vaccine uptake rates have been declining in large part because of public misinformation regarding a possible association between measles vaccination and autism for which there is no scientific basis. The purpose of this article is to address a new misinformed antivaccination argument-that measles immunity is undesirable because measles virus is protective against cancer.

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Urinary tract infection (UTI) is an extremely common infectious disease. Uropathogenic (UPEC) is the predominant etiological agent of UTI. Asymptomatic bacteriuric (ABEC) strains successfully colonize the urinary tract resulting in asymptomatic bacteriuria (ABU) and do not induce symptoms associated with UTI.

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Sepsis continues to be a major healthcare issue with one of the highest mortality rates in intensive care units. Toll-like receptors are pattern recognition receptors that are intricately involved in the pathogenesis of sepsis. TLR3 is a major receptor for double-stranded RNA and is largely associated with immunity to viral infection.

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G protein-coupled receptor kinase-6 (GRK6) is a serine/threonine kinase that is important in inflammatory processes. In this study, we examined the role of GRK6 in -induced lung infection and inflammation using GRK6 knockout (KO) and wild-type (WT) mice. Intratracheal instillation of significantly enhanced bacterial load in the bronchoalveolar lavage (BAL) of KO compared with WT mice.

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Aim: To determine how a normal human colon cell line reacts to microbial challenge as a way to study oxidative stress-induced responses associated with inflammatory bowel disease.

Methods: Normal human colon epithelial cells (ATCC CRL.1790™) were stimulated with either heat killed or heat killed murine cecal contents (HKC) and examined for several relevant biomarkers associated with inflammation and oxidative stress including cytokine production, mitochondrial autophagy and oxidant status.

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Inflammation is an essential host response during bacterial infections such as bovine mastitis. Endothelial cells are critical for an appropriate inflammatory response and loss of vascular barrier integrity is implicated in the pathogenesis of -induced mastitis. Previous studies suggested that accumulation of linoleic acid (LA) oxygenation products derived from 15-lipoxygenase-1 (15-LOX-1) metabolism could regulate vascular functions.

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G protein-coupled receptor kinase 5 (GRK5) is a serine/threonine kinase previously shown to mediate polymicrobial sepsis-induced inflammation. The goal of the present study was to examine the role of GRK5 in monomicrobial pulmonary infection by using an intratracheal Escherichia coli infection model of pneumonia. We used sublethal and lethal doses of E.

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The bovine mammary gland is a dynamic and complex organ composed of various cell types that work together for the purpose of milk synthesis and secretion. A layer of endothelial cells establishes the blood-milk barrier, which exists to facilitate the exchange of solutes and macromolecules necessary for optimal milk production. During bacterial challenge, however, endothelial cells divert some of their lactation function to protect the underlying tissue from damage by initiating inflammation.

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β-Arrestin-1 (βArr1), a scaffolding protein critical in G-protein coupled receptor desensitization has more recently been found to be important in the pathogenesis of various inflammatory diseases. We sought to understand the role of βArr1 in sepsis pathogenesis using a mouse model of polymicrobial sepsis. Although in previous studies we established that βArr1 deficiency protects mice from endotoxemia, here we demonstrate that the absence of βArr1 remarkably renders mice more susceptible to mortality in polymicrobial sepsis.

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NFκB-dependent signaling is an important modulator of inflammation in several diseases including sepsis. G-protein-coupled receptor kinase-5 (GRK5) is an evolutionarily conserved regulator of the NFκB pathway. We hypothesized that GRK5 via NFκB regulation plays an important role in the pathogenesis of sepsis.

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Previous studies have implicated a critical role for G-protein coupled receptor kinase-2 (GRK2) in sepsis owing to its ability to regulate inflammatory response and chemotaxis of immune cells. We therefore, hypothesized that deletion of GRK2 in myeloid cells would significantly modulate the pathogenesis of polymicrobial sepsis. To test this hypothesis, we induced cecal ligation and puncture (CLP), in mice with myeloid-specific deletion of GRK2 and the corresponding GRK2 wild type littermates and determined the inflammatory response (IL-6 and IL-10), immune cell infiltration, bacterial load and survival.

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G-protein coupled receptor kinase-5 (GRK5) is a recently described NFκB regulator in TLR4 signaling pathway. To determine whether the role of GRK5 is MyD88- or TRIF-dependent, we injected wild type and GRK5 knockout mice with Pam3CSK4 (MyD88-dependent TLR1/2 ligand) and Poly(I:C) (TRIF-dependent TLR3 ligand) and examined the in vivo systemic inflammatory response. Our results demonstrate that GRK5 regulates IL-12p40 and G-CSF via a mechanism that is common to both MyD88 and TRIF.

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G-protein coupled receptor kinase-5 (GRK5) is a serine/threonine kinase discovered for its role in the regulation of G-protein coupled receptor signaling. Recent studies have shown that GRK5 is also an important regulator of signaling pathways stimulated by non-GPCRs. This study was undertaken to determine the physiological role of GRK5 in Toll-like receptor-4-induced inflammatory signaling pathways in vivo and in vitro.

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