Jha, H. C. | Search bioRxiv

bioRxiv2025

Epstein-Barr virus and Helicobacter pylori Coinfection Drives Gut and Brain Barrier Dysfunction

Biological barriers, including blood-brain barrier (BBB) and gut epithelial barrier, are essential to maintain homeostasis and provide protection against pathogenic stress. Here, we investigated the impact of Helicobacter pylori-Epstein Barr Virus coinfection on gut-brain axis integrity. Our results demonstrate that coinfection induces significant disruptions in tight and adherens junction (TJ and AJ respectively) proteins in gastric epithelial cells, including downregulation of ZO-1 and E-cadherin. The secretome from these coinfected cells significantly compromises the integrity of BBB-derived endothelial cells, including cleavage of VE-cadherin, loss of TJ proteins such as Claudin-5, and enhanced permeability. Furthermore, the sole exposure of mice to coinfected secretome lead to the loss of cerebral VE-cadherin and ZO-1 and the induction of neuroinflammation, characterized by elevated pro-inflammatory cytokines, TNF-, amyloidogenic accumulation, and neurocognitive deficits. The secretome driving such forces potentially carries pathogenic metabolites, host inflammatory cytokines and metabolites that might contribute to disease pathogenesis as observed in this study. Together, our current study provides novel insights into how coinfections contribute to gut-brain axis dysregulation and neurological pathogenesis. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=174 SRC="FIGDIR/small/655045v1_ufig1.gif" ALT="Figure 1"> View larger version (51K): org.highwire.dtl.DTLVardef@138ca23org.highwire.dtl.DTLVardef@15eccc4org.highwire.dtl.DTLVardef@d588c6org.highwire.dtl.DTLVardef@106a485_HPS_FORMAT_FIGEXP M_FIG Graphical Abstract C_FIG

microbiology↗

bioRxiv2020

Helicobacter pylori and Epstein-Barr virus coinfection stimulates the aggressiveness in gastric cancer through the regulation of gankyrin

Persistent coinfection of Helicobacter pylori (H. pylori) and Epstein-Barr virus (EBV) promotes aggressive gastric carcinoma. The molecular mechanisms underlying the aggressiveness in H. pylori and EBV coinfected gastric cancer is not well characterized. In the current study, we investigated the molecular mechanism involved in the cooperation of H. pylori and EBV-driven proliferation of gastric epithelial cells. Results showed that the coinfections are significantly more advantageous to the pathogens to create a microenvironment that favors the higher pathogen-associated gene expression. The EBV latent genes EBNA1 and EBNA3C are highly overexpressed in the coinfections compared to individual EBV infection at different time points (12 and 24 hrs). The H. pylori-associated genes 16s rRNA, CagA, and BabA has also been highly overexpressed in coinfections compared to H. pylori alone. Gankyrin is a small protein of 25 KDa involved in multiple biological and physiological processes. The upregulation of gankyrin modulates the various cell signaling pathways, leading to oncogenesis. The gankyrin shows a similar expression pattern as EBNA3C at both transcript and protein levels, suggesting a possible correlation. Further EBV and H. pylori create microenvironments that induce cell transformation and oncogenesis by dysregulation of the cell-cycle regulator, GC marker, cell migration, DNA response, and antiapoptotic genes in infected gastric epithelial cells by enhancing the expression of gankyrin. Our study provides new insights into the molecular mechanism where the interplay between two oncogenic agents (H. pylori and EBV) leads to the enhanced carcinogenic activity of gastric epithelial cells through overexpression of oncoprotein gankyrin. ImportanceIn the present study, we have evaluated the synergistic effect of EBV and H. pylori infection on gastric epithelial cells in various coinfection models. These coinfection models depict the first exposures of gastric epithelial cells with EBV and then the H. pylori. While other coinfection models narrated the first exposures of H. pylori followed by the infection of EBV. This led to an enhanced oncogenic phenotype in gastric epithelial cells. We determined the coinfection of EBV and H. pylori enhanced the expression of oncogenic protein gankyrin. The interplay between EBV and H. pylori promotes the oncogenic properties of AGS cells through the newly discovered oncoprotein gankyrin. EBV and H. pylori mediated upregulation of gankyrin further dysregulates various cancer-associated hallmarks of genes such as cell-migratory, gastric cancer marker, tumor suppressor, DNA damage response, and proapoptotic genes.

microbiology↗