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Biology subjects

Orinska, Z.

Publications and source records attributed to Orinska, Z..

3 recordsLinked to original sources

SARS-CoV-2 (E)-protein induces rapid TLR2-mediated T cell activation in mouse lungs revealed by intravital lung microscopy

Mounting evidence indicates that T cells can operate in an innate-like mode challenging the classical description of T cells as strictly adaptive immune effectors. T cells can engage innate pattern recognition receptors to mount rapid but antigen-nonspecific responses to infection or cellular stress. This study observed that CD8+ T cells, and to a lesser extent also CD4+ T cells, responded to viral proteins in the mouse lung quickly in an innate-like fashion. We employed intravital lung microscopy to visualize infiltration of CD8+ T cells into the lung following intratracheal instillation of the SARS-CoV-2 envelope (E)-protein. Here, we demonstrate acute recruitment of CD8+ from the pulmonary microcirculation into the lung as early as 4 and 24 hours after (E)-protein instillation. The acute infiltration of CD8+ T cells was not observed in Tlr2-/- mice. Immunohistochemistry analysis of mouse lungs revealed T cell accumulation in nodular inflammatory foci (NIF) of the lung at perivascular regions and around large airways. Stimulating spleen-derived CD8+ T cells from wild-type mice with (E)-protein ex vivo in combination with cytokines or TCR agonists significantly upregulated CD69 and activated secretion of interferon (IFN){gamma} which was not observed with CD8+ T cells isolated from Tlr2-/- mice. These findings indicate rapid bystander activation of CD8+ T cells by the SARS-CoV-2 envelope (E)-protein that depends on (E)-protein sensing by TLR2. This innate-like CD8+ T cell response to SARS-CoV-2 (E)-protein may offer novel opportunities for diagnostic and therapeutic development, warranting further investigation.

immunology↗

Local IFNγ signaling contributes to the regenerative decline of aged alveolar progenitor cells

The lungs are highly susceptible to chronic disease in advanced age, likely due to the uniquely compromised repair function of alveolar type II (AT2) cells, facultative progenitor cells that maintain the gas exchange surface. Using aging mouse models, single-cell sequencing, and ex vivo organoid assays, we found that homeostatic aged AT2 cells exhibited an Interferon {gamma} (IFN{gamma}) response associated with IFN{gamma}+ CD8+ T cells in tertiary lymphoid structures (TLS). Aged AT2 cells exhibit impaired regeneration in organoid assays and lost markers of an IFN{gamma} response outside the lung microenvironment, demonstrating that elevated local IFN{gamma} influences the state of AT2 cells. Neutralization of IFN{gamma} signaling and immunoproteasome knockout mice with attenuated IFN{gamma} levels partially rescued aged AT2 cell regeneration. Our findings demonstrate that local IFN{gamma} signaling in aging lungs actively represses alveolar regeneration, establishing chronic inflammatory signaling as a cause of age-related decline in the lung. Halting chronic inflammatory processes restored alveolar regeneration and may provide a means to improve lung health in old age.

cell biology↗

Sex differences in vaccine induced immunity and protection against Mycobacterium tuberculosis

Tuberculosis (TB) is a disease that has evolved with humankind for millennia, causing approximately 1.3 million deaths worldwide per annum. Although increased male affliction for TB and other infections were long known from an epidemiological perspective, our mechanistic understanding of the underlying immunological divergences is relatively recent. As such, there is insufficient knowledge regarding the sexually dimorphic immune response to TB vaccines, where no accepted correlates of protection are yet available. In this context, our goal was to explore how individual sex influences the protective effects of TB vaccines. For this purpose, we vaccinated female and male C57BL/6 mice with Bacille Calmette-Guerin (BCG) and two recombinant derivatives, VPM1002 and BCG{Delta}BCG1419c, to analyse their protective efficacy against challenge with Mycobacterium tuberculosis HN878. We found poor efficacy of BCG in males and the ability of next generation vaccine candidates to improve protection specifically in males. To determine the underlying mechanisms for the differences in survival upon vaccination between females and males, as well as, among different vaccine candidates, we analysed the distribution and persistence of the vaccine strains, in addition to vaccine-induced immune responses at various time points in draining lymph nodes and spleen. We identified sex specific differences in CD8 T cell proliferation in response to mycobacterial antigens ex vivo, 90 days post-vaccination, that associates with vaccine mediated protection against HN878. By integrating our multi-parametric datasets into principal component analysis, followed by extraction of high-variance features, we have uncovered an additional significant association of early CD4 T cell responses with late CD8 T cell responses as well as with survival post HN878 infection. In addition, we have also identified specific clusters of responding CD8 T cells in spleen post-vaccination, that are globally deficient in males as compared to females, irrespective of the BCG strain administered.

immunology↗