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Foster-Lemieur, K.

Publications and source records attributed to Foster-Lemieur, K..

2 recordsLinked to original sources

Modulation of gp130 Cytokine Receptor Family by Herpes Simplex Virus 1 as a Strategy for Immune Evasion?

HSV-1 is a neurotropic human pathogen that establishes lifelong latency in sensory neurons. Periodic reactivation causes mucocutaneous lesions and, in some cases, severe corneal and neurological disease. While HSV-1 utilizes numerous viral proteins to extensively reprogram host signaling pathways and evade antiviral responses, how it alters host cytokine receptor networks remains poorly understood. Here, we demonstrate that HSV-1 infection selectively downmodulates multiple members of the gp130 (glycoprotein 130) cytokine receptor family, including gp130, Oncostatin M receptor {beta} (OSMR-{beta}), and leukemia inhibitory factor receptor (LIFR), while sparing IL-6Ra and CNTFRa (Ciliary Neurotrophic Factor Receptor). Because gp130 is the central signaling component of the IL-6 cytokine family and mediates JAK/STAT3 activation, its elimination likely represents a viral strategy to suppress inflammatory and antiviral signaling. Consistent with this, HSV-1 does not induce IL-6 mRNA expression in productively infected cells, suggesting coordinated inhibition of both cytokine production and receptor availability. Mechanistically, we found that the viral RNase VHS is at least partially responsible for gp130 family receptor downmodulation, likely in combination with virus-induced endocytosis/degradation pathways. Functionally, activation of gp130 signaling significantly impairs HSV-1 infection, demonstrating that suppression of antiviral cytokine responses is critical for virus replication. Finally, we determined that CNTF causes reactivation of latent HSV-1 using the LUHMES in vitro latency model, illustrating CNTFRa signaling contribution to latency and reactivation. A similar effect has been reported for IL-6. Together, these findings reveal a previously unrecognized immune evasion mechanism by which HSV-1 remodels gp130 cytokine signaling to promote infection.

microbiology↗

Herpes simplex virus 1 subverts the mitochondrial network to support the infection: A lesson on mitochondrial versatility

Herpes simplex virus 1 (HSV-1) infects approximately 67% of the population worldwide. It establishes lifelong reservoirs in sensory neurons and has been linked to several diseases including neuronal dysfunction. Disruption of mitochondrial homeostasis is a hallmark of HSV-1 infection, however a molecular understanding of these changes and their significance is not yet well defined. HSV-1 infection causes a UL12.5-dependent inhibition of mitochondrial biogenesis through the loss of mitochondrial DNA and mitochondrial transcription factors, PGC-1 (peroxisome proliferator-activated receptor-gamma co-activator) and TFAM (mitochondrial transcription factor). Conversely, UL12.5-independent mechanisms inhibit mitochondrial fusion by activating the OMA1 metallopeptidase that cleaves the inner mitochondrial membrane fusion protein OPA1 (optic atrophy protein 1) and by down-modulating the outer mitochondrial membrane fusion protein MFN2 (mitofusin 2). This inhibition of fusion results in a smaller mitochondrial network that clusters to perinuclear regions, likely supplying energy for viral replication and envelopment. The inner mitochondrial membrane protein TIM23 is also down-modulated during infection in a UL12.5-independent mechanism. Failure of the virus to promote these changes negatively impacts the infection. Despite these changes, mitochondria are protected from mitophagy due to the viral-induced degradation of several mitophagy adaptor proteins, whereby damaged mitochondrial components, including mitochondrial DNA, are extruded via extracellular vesicles. These mitochondrial changes still support functions necessary for HSV-1 infection. Basal cell respiration is preserved, while spare respiratory capacity and extracellular acidification rates increase, indicating glycolytic activity. Mitochondrial membrane potential is also preserved. Overall, our studies provide mechanistic insight into how HSV-1 impacts mitochondria, which could contribute to viral pathogenesis.

microbiology↗