Th17-to-Tfh plasticity during periodontitis limits disease pathology.

Th17 cell plasticity is crucial for development of autoinflammatory disease pathology. Periodontitis is a prevalent inflammatory disease where Th17 cells mediate key pathological roles, yet whether they exhibit any functional plasticity remains unexplored. We found that during periodontitis, gingival IL-17 fate-mapped T cells still predominantly produce IL-17A, with little diversification of cytokine production.

Kidney resident macrophages have distinct subsets and multifunctional roles.

Background: The kidney contains distinct glomerular and tubulointerstitial compartments with diverse cell types and extracellular matrix components. The role of immune cells in glomerular environment is crucial for dampening inflammation and maintaining homeostasis. Macrophages are innate immune cells that are influenced by their tissue microenvironment.

Monocyte migration profiles define disease severity in acute COVID-19 and unique features of long COVID.

Background: COVID-19 is associated with a dysregulated immune response but it is unclear how immune dysfunction contributes to the chronic morbidity persisting in many COVID-19 patients during convalescence (long COVID).

Methods: We assessed phenotypical and functional changes of monocytes in COVID-19 patients during hospitalisation and up to 9 months of convalescence following COVID-19, respiratory syncytial virus or influenza A. Patients with progressive fibrosing interstitial lung disease were included as a positive control for severe, ongoing lung injury.

Alterations in T and B cell function persist in convalescent COVID-19 patients.

Background: Emerging studies indicate that some coronavirus disease 2019 (COVID-19) patients suffer from persistent symptoms, including breathlessness and chronic fatigue; however, the long-term immune response in these patients presently remains ill-defined.

Methods: Here, we describe the phenotypic and functional characteristics of B and T cells in hospitalized COVID-19 patients during acute disease and at 3-6 months of convalescence.

Findings: We report that the alterations in B cell subsets observed in acute COVID-19 patients were largely recovered in convalescent patients.

A Potent and Selective Kallikrein-5 Inhibitor Delivers High Pharmacological Activity in Skin from Patients with Netherton Syndrome.

Regulation of proteolytic activity in the skin plays a pivotal role in epidermal homeostasis. This is best exemplified in Netherton syndrome, a severe genetic skin condition caused by loss-of-function mutations in the gene serine protease inhibitor Kazal-type 5 encoding lympho-epithelial Kazal-type-related inhibitor, a serine protease inhibitor that regulates kallikrein (KLK)-related peptidase 5, 7, and 14 activities. KLK5 plays a central role in stratum corneum shedding and inflammatory cell signaling, activates KLK7 and KLK14, and is therefore an optimal therapeutic target.