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Biology subjects

Zyulina, V.

Publications and source records attributed to Zyulina, V..

4 recordsLinked to original sources

Contemporary Victoria and Yamagata Influenza B Viruses Elicit Lineage-Specific Differences in Innate Immunity

The two influenza B virus (FLUBV) lineages, Victoria and Yamagata, have continued to diverge since their separation in the 1970s, resulting in distinct antigenic characteristics and differences in immunity and cross-protection. Human epidemiological observations and experimental studies have identified lineage-specific differences in adaptive immune responses elicited by contemporary viruses, suggesting that innate immune signaling may contribute to these divergent outcomes. To understand in-depth immunity to contemporary influenza B viruses, we compared viral replication, cytokine production, gene expression, and cellular tropism following infection with representative Victoria- and Yamagata-lineage viruses. We found that, despite broadly similar cytokine profiles in the ferret upper respiratory tract, the two lineages exhibited distinct innate immune kinetics. Yamagata viruses induced rapid early expression of antiviral and inflammatory genes, including SOCS1 and multiple interferon-stimulated genes, whereas Victoria viruses displayed delayed innate immune activation accompanied by greater viral replication. Consistent with the ferret data, Yamagata viruses also induced elevated SOCS1 expression in human PBMCs early after infection. In addition, Yamagata viruses exhibited broader cellular tropism, infecting a wider range of immune cell populations than Victoria viruses. Together, these findings demonstrate that contemporary influenza B virus lineages distinctly engage the host immune system and provide new insight into how lineage-specific innate immune responses may contribute to differences in immunity, cross-protection, and the divergent evolutionary trajectories of Victoria and Yamagata viruses

microbiology↗

Dengue viruses serotypes 2 and 4 exhibit distinct infection kinetics and modulation of anti-viral immune responses in human tonsil histocultures

Dengue virus (DENV) is the most prevalent mosquito-borne viral disease with over ten million cases worldwide. There are four antigenically distinct, co-circulating DENV serotypes (DENV 1-4) capable of infecting humans. Given the lack of immunocompetent animal models and the limitations of known cell culture models, more physiologically relevant experimental models are needed to recapitulate DENV infection and host immune responses. Building on previous observations that DENV-2 and DENV-4 serotypes elicit distinct innate immune responses in monocyte-derived dendritic cells (moDC) in vitro, we utilized a human tonsil histoculture (HC) model to further investigate serotype-specific differences within the physiologically relevant human lymphoid environment. We show that human tonsil HCs preserved their tissue cytoarchitecture for up to 6 days in culture, including maintaining functional germinal centers and diverse immune populations within T and B cell compartments. Exposure of tonsil HCs to DENV-2 and DENV-4 showed that DENV-4 replication peaked earlier and induced enhanced innate immune activation compared to DENV-2, consistent with previous observations in human DCs. Moreover, by leveraging the structural and cellular complexity of the HC system, we further identified that DENV E protein co-localized with HLA-DR+ antigen-presenting cells, confirming that DENV-infected cells within tonsil HCs predominantly express antigen-presenting cell markers. Altogether, these findings demonstrate that different DENV serotypes can exhibit different viral replication dynamics and induce distinct immune responses within human lymphoid tissue. This establishes human tonsil HCs as human model system with intact cytoarchitecture that closely mirrors lymph node structure and function, providing a powerful platform to study antigen-driven and virus-specific human immune responses and ultimately to evaluate vaccine candidates and antiviral therapeutics.

microbiology↗

GM-CSF and M-CSF Driven Differentiation Differentially Regulates Chikungunya Virus Infection and Antiviral Responses in Human Monocyte-Derived Macrophages

Chikungunya virus is an arthritogenic alphavirus causing debilitating joint pain in infected individuals. The mechanisms driving CHIKV-associated arthralgia is poorly understood, however, macrophages have been implicated as potential reservoirs of persistent viral material and mediators of immunopathology. Granulocyte Macrophage-Colony Stimulating Factor (GM-CSF) and Macrophage-Colony Stimulating Factor (M-CSF) are cytokines that serve as myeloid growth factors that bias macrophages toward pro-inflammatory and anti-inflammatory phenotypes, respectively. In this study, we examined how cytokine-driven macrophage differentiation via GM-CSF and M-CSF influences susceptibility to and responses against CHIKV infection in vitro. Using parallel donor-matched cultures of primary macrophages, we show that GM-CSF-differentiated macrophages are highly permissive to CHIKV and Mayaro virus (MAYV) infection and support robust viral replication, whereas M-CSF-differentiated macrophages are resistant to CHIKV replication and lack detectable levels of viral protein expression. Despite these differences, we observed pro-inflammatory, M1-skewing of CHIKV-infected macrophages, regardless of differentiation state. Interestingly, we observe higher production of IFN and IP10/CXCL10 in M-CSF differentiated macrophages, suggesting that M-CSF promotes an antiviral state that restricts CHIKV infection. Stimulation of macrophages with double-stranded RNA (polyinosinic:polycytidylic acid; poly(I:C)), but not with single-stranded RNA (resiquimod, R848), recapitulated the antiviral cytokine and chemokine response induced by CHIKV infection. These findings suggest that dsRNA sensing plays a more prominent role than ssRNA sensing in driving the macrophage antiviral response to CHIKV. Together, these findings highlight macrophage differentiation as a critical determinant of CHIKV susceptibility and antiviral immunity in humans, with implications for understanding inflammatory pathogenesis during infection.

microbiology↗

miR-424(322) is a molecular switch controlling pro-inflammatory vs anti-inflammatory skin DC subset differentiation by modulating TGF-β signaling

TGF-{beta} family ligands are key regulators of dendritic cell (DC) differentiation and activation. Epidermal Langerhans cells (LCs) require TGF- {beta} family signaling for their differentiation and canonical TGF-{beta}1 signaling secures a non-activated LC state. LCs reportedly control skin inflammation and are replenished from peripheral blood monocytes, which also give rise to pro-inflammatory monocyte-derived DCs (moDCs). Among all the miRNAs differentially expressed in LC vs moDCs, we observed miR-424 to be strongly induced during moDC differentiation from monocytes. We discovered that miR-424 is required for moDC differentiation from human and murine precursor cells in vitro and for inflammation-associated moDC in vivo. Mechanistically we found that low levels of miR-424 facilitate TGF-{beta}1-dependent LC differentiation at the expense of moDC differentiation. Loss of miR-424 in monocyte/DC precursors resulted in the induction of TGF-{beta} pathway. Therefore, miR-424 plays a decisive role in anti-inflammatory LC vs pro-inflammatory moDC differentiation from monocytes, and its repression allows TGF-{beta} ligands to promote LC differentiation. Short summaryMonocytes give rise to two distinct DC subsets in skin inflammation, exhibiting opposite roles in inflammation. This study identified miR-424(322) as a molecular switch controlling pro-inflammatory (moDC) vs anti-inflammatory LC subset differentiation by modulating TGF-{beta} signaling.

immunology↗