T cell-specific P2RX7 favors lung parenchymal CD4+ T cell accumulation in response to severe lung infections

Finding and filling the knowledge gaps in mechanisms of T cell-mediated TB immunity to inform vaccine design

Mycobacterium tuberculosis, the bacterium that causes tuberculosis (TB), results in more human mortality than any other single pathogen, in part because of the lack of an effective vaccine. Although T cells are essential for immunity to TB, the mechanisms that provide protective immunity are poorly understood. In this Review, we describe current gaps in our knowledge about T cell-mediated immune responses to M. tuberculosis and discuss how recent technologies, including multiphoton intravital microscopy, spatial multiomics and high-resolution in vivo analyses of cell-cell interactions, may be used to gain insights that can inform the design of T cell-targeted TB vaccines.

Aromatic Molecular Compatibility Attenuates Influenza Virus-Induced Acute Lung Injury via the Lung-Gut Axis and Lipid Droplet Modulation

Background: Acute lung injury (ALI) is a major cause of death in patients with various viral pneumonias. Our team previously identified four volatile compounds from aromatic Chinese medicines. Based on molecular compatibility theory, we defined their combination as aromatic molecular compatibility (AC), though its therapeutic effects and underlying mechanisms remain unclear. Methods: This study used influenza A virus (IAV) A/PR/8/34 to construct cell and mouse models of ALI to explore AC's protective effects against viral infection. The therapeutic effect of AC was verified by evaluating the antiviral efficacy in the mouse models, including improvements in their lung and colon inflammation, oxidative stress, and the suppression of the NLRP3 inflammasome. In addition, 16S rDNA and lipid metabolomics were used to analyze the potential therapeutic mechanisms of AC. Results: Our in vitro and in vivo studies demonstrated that AC increased the survival of the IAV-infected cells and mice, inhibited influenza virus replication and the expression of proinflammatory factors in the lung tissues, and ameliorated barrier damage in the colonic tissues. In addition, AC inhibited the expression of ROS and the NLRP3 inflammasome and improved the inflammatory cell infiltration into the lung tissues. Finally, AC effectively regulated intestinal flora disorders and lipid metabolism in the model mice, significantly reduced cholesterol and triglyceride expression, and thus reduced the abnormal accumulation of lipid droplets (LDs) after IAV infection. Conclusions: In this study, we demonstrated that AC could treat IAV-induced ALIs through multiple pathways, including antiviral and anti-inflammatory pathways and modulation of the intestinal flora and the accumulation of LDs.

Risk factors for pneumonia among children with coinfection of influenza A virus and Mycoplasma pneumoniae

OBJECTIVE

To investigate the clinical characteristics and risk factors for pneumonia in children co-infected with influenza A virus (IAV) and Mycoplasma pneumoniae (MP).

METHODS

Children who were diagnosed with IAV and MP infection between January and December, 2023 were enrolled and divided into a non-pneumonia group and a pneumonia group. Univariate analysis and logistic regression analysis were used to evaluate each index, and the risk factors for pneumonia caused by coinfection in the two groups were explored.

RESULTS

A total of 209 patients were enrolled, of which 107 and 102 patients were in the pneumonia and non-pneumonia groups, respectively. The patients in the pneumonia group were older and had a longer duration of fever (P < 0.05). Univariate analysis revealed that the median age, duration of fever, and CD3+, CD4+, CD8+ and IL-10 levels were significantly correlated with pneumonia (P < 0.05). Multivariate logistic regression analysis revealed that the median age, duration of fever, and CD4+, CD8+ and IL-10 levels were independent risk factors for pneumonia. Area under the curve of the five combined indicators in the ROC (receiver operator characteristic) analysis was 0.883, was higher than single factor.

CONCLUSION

Children with IAV and MP infection whose age older than 6.08 years, had a fever longer than 4 days, had a CD4+ count < 22.12%, had a CD8+ count < 35.21%, had an IL-10 concentration > 22.08 ng/ml were more likely to develop pneumonia.

Location versus ID: what matters to lung-resident memory T cells?

Tissue-resident memory T cells (TRM cells) are vital for the promotion of barrier immunity. The lung, a tissue constantly exposed to foreign pathogenic or non-pathogenic antigens, is not devoid of these cells. Lung TRM cells have been considered major players in either the protection against respiratory viral infections or the pathogenesis of lung allergies. Establishment of lung TRM cells rely on intrinsic and extrinsic factors. Among the extrinsic regulators of lung TRM cells, the magnitude of the impact of factors such as the route of antigen entry or the antigen natural tropism for the lung is not entirely clear. In this perspective, we provide a summary of the literature covering this subject and present some preliminary results on this potential dichotomy between antigen location versus antigen type. Finally, we propose a hypothesis to synthesize the potential contributions of these two variables for lung TRM cell development.