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Biology subjects

Bochkov, Y. A.

Publications and source records attributed to Bochkov, Y. A..

3 recordsLinked to original sources

Rhinovirus Infection of Human Airway Epithelial Cells Stimulates Neutrophil Superoxide

Background: Neutrophils migrate to the respiratory epithelium during rhinovirus (RV) infection, but whether RV directly activates neutrophils or whether activation arises from epithelial responses remains unclear. Objective: To determine whether RV directly activates human neutrophils or indirectly activates them through RV infected airway epithelial cells. Methods: Human neutrophils were exposed to purified RV, and activation was assessed by myeloperoxidase activity, CD11b/CD66b expression, and reactive oxygen species (ROS) production. Neutrophils were co-cultured with RV-infected air liquid interface (ALI) bronchial epithelium evaluated for effects on epithelial integrity. At 48 to 72 hours post-infection, we used live-cell imaging to measure ROS responses and neutrophil-tracking assays to measure migration velocity and ROS responses to basolateral supernatants, clarified apical washes, and apical debris from RV-infected epithelial cells. Plaque assays were used to assess for RV infectivity after incubation with apical neutrophils. Results: RV did not directly activate neutrophils. Adding neutrophils to the apical surface of airway epithelial cells increased neutrophil ROS production at 48 to 72 hrs post-infection but did not alter epithelial cytotoxicity. Conversely, basolateral supernatants from infected cells enhanced neutrophil migration but not ROS, consistent with cytokine-mediated priming. Clarified apical washes had no effect on migration or ROS. By contrast, apical debris from infected cultures triggered a robust ROS response. Basolateral fractions from medium control or RV infected cultures did not induce ROS. Infectivity is not impacted by apical neutrophil presence. Conclusion: RV does not directly activate neutrophils. Instead, RV infected epithelial cells release basolateral factors that enhance neutrophil migration, while apical debris from infected cells drives ROS activation. These findings indicate that epithelial injury, not RV itself, is the dominant trigger of neutrophil activation during infection.

immunology↗

Assessing Immune Factors in Maternal Milk and Paired Infant Plasma Antibody Binding to Human Rhinoviruses

Before they can produce their own antibodies, newborns are protected from infections by transplacental transfer of maternal IgG antibodies and after birth through breast milk IgA antibodies. Rhinovirus (RV) infections are extremely common in early childhood, and while RV infections often result in only mild upper respiratory illnesses, they can also cause severe lower respiratory illnesses such as bronchiolitis and pneumonia. We used high-density peptide arrays to profile infant and maternal antibody reactivity to capsid and full proteome sequences of three human RVs - A16, B52, and C11. Numerous plasma IgG and breast milk IgA RV epitopes were identified that localized to regions of the RV capsid surface and interior, and also to several non-structural proteins. While most epitopes were bound by both IgG and IgA, there were several instances where isotype-specific and RV-specific binding were observed. We also profiled 62 unique RV-C dominant protein loop sequences characteristic of this species capsid VP1 protein. Many of these RV-C sites were highly bound by IgG from one-year-old infants, indicating recent or ongoing active infections, or alternatively, a level of cross-reactivity among homologous RV-C sites.

immunology↗

Dynamics of the upper airway microbiome in the pathogenesis of asthma-associated persistent wheeze in preschool children

Repeated cycles of infection-associated lower airway inflammation drives the pathogenesis of persistent wheezing disease in children. Tracking these events across a birth cohort during their first five years, we demonstrate that >80% of infectious events indeed involve viral pathogens, but are accompanied by a shift in the nasopharyngeal microbiome (NPM) towards dominance by a small range of pathogenic bacterial genera. Unexpectedly, this change in NPM frequently precedes the appearance of viral pathogens and acute symptoms. In non-sensitized children these events are associated only with \"transient wheeze\" that resolves after age three. In contrast, in children developing early allergic sensitization, they are associated with ensuing development of persistent wheeze, which is the hallmark of the asthma phenotype. This suggests underlying pathogenic interactions between allergic sensitization and antibacterial mechanisms.

genetics↗