Fernando Queiroz Cunha

Neutrophil extracellular traps (NETs) and inflammatory mediators have been implicated in head and neck squamous cell carcinoma, but their relationship with systemic inflammatory status during radiotherapy remains incompletely understood. This exploratory integrative study combined a literature‐guided network‐based bioinformatic prioritization strategy, public transcriptomic interrogation, and a small serum‐based clinical cohort evaluated during radiotherapy. Network and ontology analyses identified IL6 and CXCL8 as central inflammatory mediators within a NET‐associated condition‐specific interaction network. Public transcriptomic analyses showed altered expression patterns of selected NETosis‐related genes in tumor tissue. To provide complementary clinical context, circulating NET‐associated complexes, interleukin‐6 (IL‐6), and interleukin‐8 (IL‐8) were measured in patients with head and neck squamous cell carcinoma undergoing radiotherapy and in healthy controls. Patients showed higher serum levels of NET‐associated complexes, IL‐6, and IL‐8 than controls, whereas no significant differences were observed between the two intra‐treatment sampling time points. These findings support the relevance of NET‐associated inflammatory markers in HNSCC and indicate that systemic inflammatory alterations can be detected in patients sampled during radiotherapy. Given the exploratory design and limited sample size, these findings should be interpreted cautiously and require validation in larger longitudinal studies.

Psoriasis is a chronic and recurrent inflammatory skin disease characterized by abnormal proliferation and differentiation of keratinocytes and activation of immune cells. However, the molecular driver that triggers this immune response in psoriatic skin remains unclear. The inflammation-related gene absent in melanoma 2 (AIM2) was identified as a susceptibility gene/locus associated with psoriasis. In this study, we investigated the role of AIM2 in the pathophysiology of psoriasis. We found elevated levels of mitochondrial DNA in patients with psoriasis, along with high expression of AIM2 in both the human psoriatic epidermis and a mouse model of psoriasis induced by topical imiquimod (IMQ) application. Genetic ablation of AIM2 reduced the development of IMQ-induced psoriasis by decreasing the production of type 3 cytokines (such as IL-17A and IL-23) and infiltration of immune cells into the inflammatory site. Furthermore, we demonstrate that IL-17A induced AIM2 expression in keratinocytes. Finally, the genetic absence of inflammasome components downstream AIM2, ASC, and caspase-1 alleviated IMQ-induced skin inflammation. Collectively, our data show that AIM2 is involved in developing psoriasis through its canonical activation.

Neutrophil extracellular traps (NETs) play a dual role in SARS-CoV-2 infection, aiding early immune defense but also contributing to lung damage. While NET targeting may improve clinical outcomes in SARS-CoV-2 infection, its impact on adaptive immunity, crucial for fighting the virus, remains unclear. Our study demonstrates that both recombinant human DNase (rhDNase), degrading NET structure, and GSK484, inhibiting NET formation, reduce lung NET concentration and improve clinical outcomes in infected mice, yet they differ in their influence on T cell responses. We show that rhDNase does not impact T cell responses, whereas GSK484 diminishes virus-specific T cell responses. In vitro , GSK484 decreases dendritic cell antigen presentation by impairing antigen uptake and reduces IL-2 signaling by affecting its production by T cells. In a model of lung inflammation, GSK484 diminishes antigen-specific T cell activation and proliferation, while rhDNase shows a potential to boost T cell responses via the presence of NET fragments that reduce T cell activation threshold. Our findings suggest that NET targeting with rhDNase or GSK484 holds therapeutic potential for treating SARS-CoV-2 infection, while their distinct modes of action shape T cell responses during the infection.

Background and PurposeSepsis-surviving adult individuals commonly develop immunosuppression and increased susceptibility to secondary infections, an outcome mediated by the axis IL-33/ILC2s/M2 macrophages/Tregs. Nonetheless, the long-term immune consequences of paediatric sepsis are indeterminate. We sought to investigate the role of age in the genesis of immunosuppression following sepsis.Experimental ApproachHere, we compared the frequency of Tregs, the activation of the IL-33/ILC2s axis in M2 macrophages and the DNA methylation of epithelial lung cells from post-septic infant and adult mice. Likewise, sepsis-surviving mice were inoculated intranasally with Pseudomonas aeruginosa or by subcutaneous inoculation of the B16 melanoma cell line. Finally, blood samples from sepsis-surviving patients were collected and the concentration of IL-33 and Tregs frequency were assessed.Key ResultsIn contrast to 6-week-old mice, 2-week-old mice were resistant to secondary infection and did not show impairment in tumour controls upon melanoma challenge. Mechanistically, increased IL-33 levels, Tregs expansion, and activation of ILC2s and M2-macrophages were observed in 6-week-old but not 2-week-old post-septic mice. Moreover, impaired IL-33 production in 2-week-old post-septic mice was associated with increased DNA methylation in lung epithelial cells. Notably, IL-33 treatment boosted the expansion of Tregs and induced immunosuppression in 2-week-old mice. Clinically, adults but not paediatric post-septic patients exhibited higher counts of Tregs and seral IL-33 levels.Conclusion and ImplicationsThese findings demonstrate a crucial and age-dependent role for IL-33 in post-sepsis immunosuppression. Thus, a better understanding of this process may lead to differential treatments for adult and paediatric sepsis. image

This study evaluated the changes in the composition of oral–gut microbiota in patients with rheumatoid arthritis (RA) caused by methotrexate (MTX) and non-surgical periodontal treatment (NSPT). Assessments were performed at baseline (T0), 6 months after MTX treatment (T1), and 45 days after NSPT (T2). The composition of the oral and gut microbiota was assessed by amplifying the V4 region of the 16S gene from subgingival plaques and stools. The results of the analysis of continuous variables were presented descriptively and non-parametric tests and Spearman’s correlation were adopted. A total of 37 patients (27 with periodontitis) were evaluated at T0; 32 patients (24 with periodontitis) at T1; and 28 patients (17 with periodontitis) at T2. MTX tended to reduce the alpha diversity of the oral–gut microbiota, while NSPT appeared to increase the number of different species of oral microbiota. MTX and NSPT influenced beta diversity in the oral microbiota. The relative abundance of oral microbiota was directly influenced by periodontal status. MTX did not affect the periodontal condition but modified the correlations that varied from weak to moderate (p < 0.05) between clinical parameters and the microbiota. MTX and NSPT directly affected the composition and richness of the oral–gut microbiota. However, MTX did not influence periodontal parameters.

Aim: We sought to investigate the release of neutrophil extracellular traps (NETs) in neutrophils from individuals with rheumatoid arthritis (RA) and controls and compare the presence of NETs in gingival tissues according to periodontal status. Also, the association between single nucleotide polymorphisms (SNPs) of the peptidyl arginine deaminase type 4 (PADI4) gene and the GTG haplotype with RA, periodontitis and NETs was evaluated in vitro.Materials and Methods: Peripheral neutrophils were isolated by density gradient, and NET concentration was determined by the PicoGreen method. Immunofluorescence was studied to identify NETs by co‐localization of myeloperoxidase (MPO)‐citrullinated histone H3 (H3Cit). Genotyping for SNPs (PADI4_89; PADI4_90; PADI4_92; and PADI4_104) was performed in 87 individuals with RA and 111 controls.Results: The release of NETs in vitro was significantly higher in individuals with RA and periodontitis and when stimulated with Porphyromonas gingivalis. Gingival tissues from subjects with RA and periodontitis revealed increased numbers of MPO‐H3Cit‐positive cells. Individuals with the GTG haplotype showed a higher release of NETs in vitro and worse periodontal parameters.Conclusions: The release of NETs by circulating neutrophils is associated with RA and periodontitis and is influenced by the presence of the GTG haplotype.