Coxsackie-adenovirus receptor expression is enhanced in pancreas from patients with type 1 diabetes

Objectives: One of the theories connecting enterovirus (EV) infection of human islets with type 1 diabetes (T1D) is the development of a fertile field in the islets. This implies induction of appropriate proteins for the viral replication such as the coxsackie–adenovirus receptor (CAR). The aim of this study was to investigate to what extent CAR is expressed in human islets of Langerhans, and what conditions that would change the expression. Design: Immunohistochemistry for CAR was performed on paraffin-embedded pancreatic tissue from patients with T1D (n=9 recent onset T1D, n=4 long-standing T1D), islet autoantibody-positive individuals (n=14) and non-diabetic controls (n=24) individuals. The expression of CAR was also examined by reverse transcription PCR on microdissected islets (n=5), exocrine tissue (n=5) and on explanted islets infected with EV or exposed to chemokines produced by EV-infected islet cells. Results: An increased frequency of patients with T1D and autoantibody-positive individuals expressed CAR in the pancreas (p<0.039). CAR staining was detected more frequently in pancreatic islets from patients with T1D and autoantibody-positive subjects (15/27) compared with (6/24) non-diabetic controls (p<0.033). Also in explanted islets cultured in UV-treated culture medium from coxsackievirus B (CBV)-1-infected islets, the expression of the CAR gene was increased compared with controls. Laser microdissection of pancreatic tissue revealed that CAR expression was 10-fold higher in endocrine compared with exocrine cells of the pancreas. CAR was also expressed in explanted islets and the expression level decreased with time in culture. CBV-1 infection of explanted islets clearly decreased the expression of CAR (p<0.05). In contrast, infection with echovirus 6 did not affect the expression of CAR. Conclusions: CAR is expressed in pancreatic islets of patients with T1D and the expression level of CAR is increased in explanted islets exposed to proinflammatory cytokines/chemokines produced by infected islets. T1D is associated with increased levels of certain chemokines/cytokines in the islets and this might be the mechanism behind the increased expression of CAR in TID islets

Molecular dynamics simulation of the early stages of the synthesis of periodic mesoporous silica

We present results of detailed atomistic modeling of the early stages of the synthesis of periodic mesoporous silica using molecular dynamics. Our simulations lead to the proposal of a mechanism that validates several previous experimental and modeling studies and answers many controversial issues regarding the synthesis of mesoporous silicas. In particular, we show that anionic silicates interact very strongly with cationic surfactants and, significantly adsorb on the surface of micelles, displacing a fraction of previously bound bromide counterions. This induces an increase in micelle size and also enhances silica condensation at the micelle surface. The presence of larger silica aggregates in solution further promotes the growth of micelles and, by binding to surfactant molecules in different micelles, their aggregation. This work demonstrates the crucial role played by silica in influencing, by way of a cooperative templating mechanism, the structure of the eventual liquid-crystal phase, which in turn determines the structure of the porous material

Robust T cell immunity in convalescent individuals with asymptomatic or mild COVID-19

SARS-CoV-2-specific memory T cells will likely prove critical for long-term immune protection against COVID-19. Here, we systematically mapped the functional and phenotypic landscape of SARS-CoV-2-specific T cell responses in unexposed individuals, exposed family members, and individuals with acute or convalescent COVID-19. Acute-phase SARS-CoV-2-specific T cells displayed a highly activated cytotoxic phenotype that correlated with various clinical markers of disease severity, whereas convalescent-phase SARS-CoV-2-specific T cells were polyfunctional and displayed a stem-like memory phenotype. Importantly, SARS-CoV-2-specific T cells were detectable in antibody-seronegative exposed family members and convalescent individuals with a history of asymptomatic and mild COVID-19. Our collective dataset shows that SARS-CoV-2 elicits broadly directed and functionally replete memory T cell responses, suggesting that natural exposure or infection may prevent recurrent episodes of severe COVID-19