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Biology subjects

Sides, M.

Publications and source records attributed to Sides, M..

3 recordsLinked to original sources

Epstein-Barr Virus in HIV-Associated Conjunctival Squamous Cell Carcinoma and Transcriptional Reprogramming of Conjunctival Epithelial Cells

The involvement of Epstein-Barr virus (EBV) in conjunctival squamous cell carcinoma (cSCC) remains incompletely defined. This study integrated analyses of primary tumors with an experimental model of the conjunctival epithelium. Five Nigerian tumors from patients with HIV and three Japanese tumors from patients without HIV were examined by EBV-encoded RNA in situ hybridization (EBER-ISH), EBV DNA PCR, and virome analysis of RNA sequencing data. EBER localized to epithelial tumor cells in four Nigerian specimens and none of the Japanese specimens. EBV DNA and RNA were each detected in three Nigerian tumors, with every EBER-positive tumor supported by at least one additional assay. Human telomerase reverse transcriptase-immortalized conjunctival epithelial cells infected with Akata-GFP-EBV expressed latency-associated and lytic viral genes. Comparison of three infected and three control cultures identified 96 differentially expressed host genes and 23 enriched Hallmark gene sets at a false discovery rate below 0.05. RT-qPCR confirmed increased HES1, CXCL8, CXCL2, and LOX and decreased FGFBP1, CSTA, SAPCD2, and TMEM40 expression. Prominent responses involved inflammatory signaling, epithelial remodeling, metabolism, and cell-cycle regulation. These findings identify tumor-cell-associated EBV in a subset of HIV-associated cSCC and establish an epithelial model for investigating infection-associated host responses.

microbiology↗

Interleukin-17 directly triggers Epstein-Barr virus lytic reactivation in latently infected human B cells

Epstein-Barr virus (EBV) is a ubiquitous human gammaherpesvirus implicated in a wide spectrum of inflammatory and malignant diseases. Although EBV toggles between latent and lytic states, the host cues that control this switch remain incompletely defined. Interleukin-17A (IL-17A; hereafter IL-17), a signature Th17 cytokine, is abundant in EBV-associated tissues, and EBV products can augment IL-17 responses. Whether IL-17 directly modulates the EBV life cycle has remained unknown. Here we show that IL-17 alone is sufficient to induce EBV lytic reactivation in latently infected human B cells. Across RT-qPCR, immunoblotting, and RNA-seq, IL-17 increased the immediate-early regulator BZLF1 (Zta) and upregulated downstream early and late viral genes, consistent with activation of a transcriptome-wide lytic program. Culture supernatants from IL-17-treated cells contained elevated DNase-resistant extracellular EBV DNA, indicating productive replication with encapsidated genomes. Transcriptomic pathway analyses confirmed engagement of IL-17-linked signaling and highlighted inflammatory modules, including NF-{kappa}B and JAK-STAT. Gene Ontology analysis further enriched for regulation of B-cell receptor signaling and B-cell activation, situating IL-17 within B-cell inflammatory circuitry. Together, these findings identify IL-17 as a cytokine cue for EBV lytic entry and provide a mechanistic link between Th17-skewed inflammation and episodic EBV reactivation. This cytokine-driven pathway complements existing models centered on B-cell receptor signaling, hypoxia/HIF-1, COX-2/PGE2, and TGF-{beta} and motivates testing whether modulation of the IL-17/IL-17R axis can alter EBV reactivation in IL-17-rich settings. To our knowledge, this is the first demonstration that IL-17 alone directly triggers EBV lytic reactivation in human cells. IMPORTANCEEpstein-Barr virus (EBV) persists for life by maintaining latency with intermittent lytic reactivation, yet the physiological cues that initiate the latency-lytic switch remain poorly defined. Here we identify the Th17 cytokine interleukin-17A (IL-17) as a direct host trigger of EBV lytic reactivation in latently infected human B cells. IL-17 alone induced the immediate-early transactivator Zta, activated a transcriptome-wide lytic program, and promoted release of DNase-resistant extracellular EBV DNA consistent with encapsidated virions. Transcriptomic analyses confirmed engagement of IL-17-linked inflammatory modules and implicated convergence on signaling nodes shared with canonical B-cell receptor pathways. These findings establish a mechanistic link between Th17-skewed inflammation and EBV reactivation burden, providing a framework to interrogate how IL-17-rich microenvironments influence EBV dissemination and immunopathology and to evaluate whether targeting the IL-17/IL-17R axis can modulate EBV reactivation in disease settings.

microbiology↗

Characterization of Three Variants of SARS-CoV-2 in vivo Shows Host-Dependent Pathogenicity in Hamsters

Animal models are used in preclinical trials to test vaccines, antivirals, monoclonal antibodies, and immunomodulatory drug therapies against SARS-CoV-2. However, these drugs often do not produce equivalent results in human clinical trials. Here, we show how different animal models infected with some of the most clinically relevant SARS-CoV-2 variants, WA1/2020, B.1.617.2/Delta, B.1.1.529/Omicron and BA5.2/Omicron, have independent outcomes. We show that in mice, B.1.617.2 is more pathogenic, followed by WA1, while B.1.1.529 showed an absence of clinical signs. Only B.1.1.529 was able to infect C57BL/6J mice, which lack the human ACE2 receptor. B.1.1.529-infected ACE2 mice had different T cell profiles compared to infected K18-hACE2 mice, while viral shedding profiles and viral titers in lungs were similar between the ACE2 and the C57BL/6J mice. These data suggest B.1.1.529 virus adaptation to a new host and shows that asymptomatic carriers can accumulate and shed virus. Next, we show how B.1.617.2, WA1 and BA5.2/Omicron have similar viral replication kinetics, pathogenicity, and viral shedding profiles in hamsters, demonstrating that the increased pathogenicity of B.1.617.2 observed in mice is host-dependent. Overall, these findings suggest that small animal models are useful to parallel human clinical data, but the experimental design places an important role in interpreting the data. IMPORTANCEThere is a need to investigate SARS-CoV-2 variants phenotypes in different animal models due to the lack of reproducible outcomes when translating experiments to the human population. Our findings highlight the correlation of clinically relevant SARS-CoV-2 variants in animal models with human infections. Experimental design and understanding of correct animal models are essential to interpreting data to develop antivirals, vaccines, and other therapeutic compounds against COVID-19.

microbiology↗