Microbiology and Cell Science Department, IFAS, University of Florida, Gainesville, FL 32611, USA.
Viruses. 2022 Jul 22;14(8):1596. doi: 10.3390/v14081596.
Norovirus is the leading cause of acute viral gastroenteritis. Both human and murine noroviruses attach to commensal bacteria belonging to the mammalian gut flora, and binding levels are influenced by nutrients present in bacterial media. However, it is not known which nutrients are responsible for altering viral binding or why binding is altered. Gene expression of commensal bacteria can be changed by the external environment as well as by interaction with pathogens. For example, growth phase and incubation conditions impact expression levels of specific bacterial genes in . We have previously shown that binding by both human and murine noroviruses to the commensal bacterium induces genome-wide changes in gene expression with a large number of differentially expressed genes associated with the surface structure of the bacterial cell. The current study evaluated norovirus binding under nutrient-limited conditions and assessed the expression of a select panel of these genes that are significantly altered by norovirus binding under these conditions. The goal of this work was to determine how norovirus attachment to affected the expression of these genes under varying nutrient and growth phase conditions. We found that the presence of glucose in minimal media reduced murine norovirus binding to and viral binding in the presence of glucose reduced gene expression for surface structures previously associated with norovirus attachment. Changes in viral binding and gene expression occurred in a growth phase-dependent manner. Collectively, these data demonstrate that both the growth phase and nutrient availability alter viral interactions with commensal bacteria and the subsequent changes in gene expression. Ultimately, this work advances our understanding of norovirus-bacterium interactions and provides a foundation for elucidating the conditions and surface structures that regulate norovirus attachment to bacteria.
诺如病毒是急性病毒性肠胃炎的主要病因。人类和鼠类诺如病毒均附着在哺乳动物肠道菌群中的共生细菌上，而结合水平受细菌培养基中存在的营养物质的影响。然而，目前尚不清楚是哪些营养物质导致了病毒结合的改变，也不知道为什么结合会发生改变。共生细菌的基因表达可以被外部环境以及与病原体的相互作用所改变。例如，生长阶段和孵育条件会影响特定细菌基因的表达水平在. 我们之前已经表明，人类和鼠类诺如病毒与共生菌 的结合会诱导全基因组基因表达的变化，大量与细菌细胞表面结构相关的差异表达基因与结合有关。本研究在营养受限的条件下评估了诺如病毒的结合，并评估了这些基因中一组选择基因的表达，这些基因在这些条件下由于诺如病毒的结合而发生了显著改变。这项工作的目的是确定诺如病毒与 的结合如何在不同的营养和生长阶段条件下影响这些基因的表达。我们发现，最小培养基中葡萄糖的存在会降低鼠类诺如病毒与 的结合，而葡萄糖存在时病毒的结合会降低先前与诺如病毒附着相关的表面结构的基因表达。病毒结合和基因表达的变化以生长阶段依赖的方式发生。总的来说，这些数据表明，生长阶段和营养供应都会改变病毒与共生细菌的相互作用以及随后的基因表达变化。最终，这项工作增进了我们对诺如病毒-细菌相互作用的理解，并为阐明调节诺如病毒附着到细菌的条件和表面结构提供了基础。
