Comparison of clinical characteristics and inflammatory cytokines between hypoxemic and non-hypoxemic human adenovirus 55 pneumonia

Indirubin-3'-monoxime exhibits potent antiviral and anti-inflammatory effects against human adenoviruses in vitro and in vivo

Human adenovirus (HAdV) infection is a major cause of respiratory disease, yet no antiviral drugs have been approved for its treatment. Herein, we evaluated the antiviral and anti-inflammatory effects of cyclin-dependent protein kinase (CDK) inhibitor indirubin-3'-monoxime (IM) against HAdV infection in cells and a transgenic mouse model. After evaluating its cytotoxicity, cytopathic effect reduction, antiviral replication kinetics, and viral yield reduction assays were performed to assess the anti-HAdV activity of IM. Quantitative real-time polymerase chain reaction (qPCR), quantitative reverse transcription PCR (qRT-PCR), and western blotting were used to assess the effects of IM on HAdV DNA replication, transcription, and protein expression, respectively. IM significantly inhibited HAdV DNA replication as well as E1A and Hexon transcription, in addition to significantly suppressing the phosphorylation of the RNA polymerase II C-terminal domain (CTD). IM mitigated body weight loss, reduced viral burden, and lung injury, decreasing cytokine and chemokine secretion to a greater extent than cidofovir. Altogether, IM inhibits HAdV replication by downregulating CTD phosphorylation to suppress viral infection and corresponding innate immune reactions as a promising therapeutic agent.

Comparisons of lymphocytes profiles and inflammatory cytokines levels in blood of patients with differed severity of infection by human adenovirus type 7

BACKGROUND

Human adenovirus (HAdV) infection outbreak causes community-acquired pneumonia. Cellular immune dysfunction and hypercytokinemia play important roles in the pathogenesis of adenovirus respiratory infection. Some soluble factors in peripheral blood can assist in judging the virus-induced disease severity. The expression levels of inflammatory cytokines differ among patients with different disease severity. However, whether and how HAdV-7 infection influences the composition of blood immune cells and serum cytokine levels in patients at different disease stages, as well as the diagnosis values of these parameters, have rarely been intensively studied. We aimed to investigate lymphocytes profiles and cytokines levels in blood of patients at different disease stages upon human adenovirus type 7 (HAdV-7) infections, and explored the diagnosis values of the investigated parameters.

METHODS

Patients from two outbreaks of HAdV-7 in military of China were categorized into upper respiratory infection (URI) group, common pneumonia (CP) group and severe pneumonia (SP) group according to disease severity. Peripheral blood samples were subjected to routine laboratory tests, while flow cytometry and ELISA were used to measure the lymphocyte subsets and cytokines in blood, respectively. The receiver operating characteristic (ROC) curves were performed to examine the diagnostic of these blood parameters.

RESULTS

Signs of imbalanced lymphocytes composition and hypercytokinemia were observed in HAdV-7-infected patients. The percentages of CD3⁺ T cells and NK cells were significantly decreased along with the aggravation of the disease, particularly for NK cells and CD4⁺ T cells. The neutrophil to lymphocyte ratio (NLR) increased significantly in patients with more severe disease. In addition, the levels of serum CXCL10, IL-2 and TNF-α were positively correlated with disease severity, while reduced levels of IFN-γ and IL-10 were found in SP patients. Furthermore, analysis of ROC showed that multiple parameters including the percentage of blood CD3⁺ cells and serum CXCL10 level could predict the progression of HAdV-7 infection.

CONCLUSION

Imbalance of immune state with hypercytokinemia occurred during HAdV-7 infection. The percentages of blood immune cells such as CD3⁺ T cells and the levels of serum cytokines such as CXCL10 showed potential diagnosis values in HAdV-7 infection.

Interleukin-6 serum levels are independently associated with severe adenovirus pneumonia in children: a cross-sectional study

BACKGROUND

This study aimed to explore the potential association between interleukin-6 (IL-6) serum levels and severe adenovirus pneumonia (SAP) in children.

METHODS

A retrospective hospital-based cross-sectional study was conducted on children with SAP who presented to the Tianjin Children's Hospital between January 2019 and December 2020. Serum IL-6 levels were categorized into quintiles (Q1-5). The primary outcome variable was the occurrence of SAP. The patients' clinical features, laboratory findings, and radiographic characteristics were also assessed, and a descriptive bivariate analysis was carried out. Multivariable logistic regression analysis was applied to evaluate the relationship of IL-6 with SAP after adjustment for confounders. The nonlinear relationship between IL-6 and SAP was also analyzed. P value <0.05 was considered statistically significant.

RESULTS

In total, 542 patients met our inclusion criteria (223 males and 319 females). The mean IL-6 serum level was 38.51 pg/mL (range, 1.50-659.2 pg/mL). After adjustment for confounders, the odds ratio (OR) per SD (standard deviation) increase in IL-6 was 1.66 [95% confidence interval (CI): 1.14, 2.41]. The multivariable-adjusted OR (95% CI) of SAP across the Q1-Q5 categories of IL-6 were as follows: 1.00 (reference), 1.17 (0.59, 2.35), 1.79 (0.88, 3.63), 2.31 (1.12, 4.76), and 2.85 (1.32, 6.14) (P for trend =0.002). The risk of SAP increased with the IL-6 serum level up to 40.78 pg/mL (adjusted OR 1.029, 95% CI: 1.008-1.051; P=0.007); however, when the IL-6 level exceeded 40.78 pg/mL, it had no association with the risk of SAP (OR 1.003, 95% CI: 0.996-1.010; P=0.384).

CONCLUSIONS

Our findings suggest that the serum level of IL-6 is associated with the risk of SAP in children. The levels of IL-6 in children should therefore be of concern to clinicians.

Roles of Interleukin-6-mediated immunometabolic reprogramming in COVID-19 and other viral infection-associated diseases

Interleukin-6 (IL-6) is a highly pleiotropic glycoprotein factor that can modulate innate and adaptive immunity as well as various aspects of metabolism, including glycolysis, fatty acid oxidation and oxidative phosphorylation. Recently, the expression and release of IL-6 is shown to be significantly increased in numerous diseases related to virus infection, and this increase is positively correlated with the disease severity. Immunity and metabolism are two highly integrated and interdependent systems, the balance between them plays a pivotal role in maintaining body homeostasis. IL-6-elicited inflammatory response is found to be closely associated with metabolic disorder in patients with viral infection. This brief review summarizes the regulatory role of IL-6 in immunometabolic reprogramming among seven viral infection-associated diseases.

Potential Diagnostic and Prognostic Biomarkers for Adenovirus Respiratory Infection in Children and Young Adults

Human Adenoviruses (HAdV) are known to be potentially associated with strong inflammatory responses and morbidity in pediatric patients. Although most of the primary infections are self-limiting, the severity of clinical presentation, the elevation of the white blood cell count and inflammatory markers often mimic a bacterial infection and lead to an inappropriate use of antibiotics. In infections caused by HAdV, rapid antigen detection kits are advisable but not employed routinely; costs and feasibility of rapid syndromic molecular diagnosis may limit its use in the in-hospital setting; lymphocyte cultures and two-sampled serology are time consuming and impractical when considering the use of antibiotics. In this review, we aim to describe the principal diagnostic tools and the immune response in HAdV infections and evaluate whether markers based on the response of the host may help early recognition of HAdV and avoid inappropriate antimicrobial prescriptions in acute airway infections.

Chinese tree shrew: a permissive model for in vitro and in vivo replication of human adenovirus species B

Human adenovirus (HAdV) species B can cause severe acute respiratory diseases. However, the researches to combat this infection have been hampered by the lack of an animal model permissive to the virus. Here, we report in vitro and in vivo HAdV species B infections of tree shrews, the closest relative of primates. HAdV-3, -7, -14, and -55 efficiently replicated in primary cell cultures. After intranasal inoculation of tree shrews with HAdV-55, the viral replication in the oropharyngeal region remained high until day 5 post-infection and was still detected until day 12. HAdV-55 in the lung or turbinate bone tissues reached the highest levels between days 3 and 5 post-infection, which indicated viral replication in the upper and lower respiratory tracts. HAdV-55 infection caused severe interstitial pneumonia in the animal. IL-8, IL-10, IL-17A, and IFN-γ expression in the peripheral blood mononuclear cells from infected animals was up-regulated. The pre-vaccination with HAdV-55 cleared the virus faster in the respiratory tract, mitigated lung pathological changes. Finally, HAdV-55 infection was propagated among tree shrews. Our study demonstrated that the tree shrew is a permissive animal model for HAdV species B infection and may serve as a valuable platform for testing multiple anti-viral treatments.