Use of HLA-B27 tetramers to identify low-frequency antigen-specific T cells in Chlamydia-triggered reactive arthritis

Reports of the use of HLA-B27/peptide tetrameric complexes to study peptide-specific CD8(+ )T cells in HLA-B27(+)-related diseases are rare. To establish HLA-B27 tetramers we first compared the function of HLA-B27 tetramers with HLA-A2 tetramers by using viral epitopes. HLA-B27 and HLA-A2 tetramers loaded with immunodominant peptides from Epstein–Barr virus were generated with comparable yields and both molecules detected antigen-specific CD8(+ )T cells. The application of HLA-B27 tetramers in HLA-B27-related diseases was performed with nine recently described Chlamydia-derived peptides in synovial fluid and peripheral blood, to examine the CD8(+ )T cell response against Chlamydia trachomatis antigens in nine patients with Chlamydia-triggered reactive arthritis (Ct-ReA). Four of six HLA-B27(+ )Ct-ReA patients had specific synovial T cell binding to at least one HLA-B27/Chlamydia peptide tetramer. The HLA-B27/Chlamydia peptide 195 tetramer bound to synovial T cells from three of six patients and HLA-B27/Chlamydia peptide 133 tetramer to synovial T cells from two patients. However, the frequency of these cells was low (0.02–0.09%). Moreover, we demonstrate two methods to generate HLA-B27-restricted T cell lines. First, HLA-B27 tetramers and magnetic beads were used to sort antigen-specific CD8(+ )T cells. Second, Chlamydia-infected dendritic cells were used to stimulate CD8(+ )T cells ex vivo. Highly pure CD8 T cell lines could be generated ex vivo by magnetic sorting by using HLA-B27 tetramers loaded with an EBV peptide. The frequency of Chlamydia-specific, HLA-B27 tetramer-binding CD8(+ )T cells could be increased by stimulating CD8(+ )T cells ex vivo with Chlamydia-infected dendritic cells. We conclude that HLA-B27 tetramers are a useful tool for the detection and expansion of HLA-B27-restricted CD8(+ )T cells. T cells specific for one or more of three Chlamydia-derived peptides were found at low frequency in synovial fluid from HLA-B27(+ )patients with Ct-ReA. These cells can be expanded ex vivo, suggesting that they are immunologically functional

Levantamento de aspectos anatomoclínicos, biomecânicos e ergonomicos da posição sentada sobre a coluna vertebral - uma reflexão do trabalho home office durante a pandemia / Survey of anatomical, biomechanical and ergonomic aspects of the sitting position on the spine - a reflection of home office work during the pandemic

A pandemia causada pela COVID-19 levou a uma mudança rápida no estilo de vida e na jornada de trabalho da população mundial, despertando reflexões no que tange a rotina futura sobre o trabalho home office, a jornada prolongada na posição sentada, a importância de um ambiente adequado e ergonômico com caráter preventivo sobre distúrbios da coluna vertebral. Neste sentido, o objetivo foi desenvolver: uma análise biomecânica e fisiopatológica sobre os efeitos da posição sentada sobre a coluna vertebral, bem como agrupar orientações sobre posturas adequadas associadas à importância da ergonomia no trabalho remoto durante a pandemia. Para tanto, foi desenvolvido uma pesquisa por meio de uma revisão sistemática e integrativa da literatura. Foram utilizados livros técnicos de Anatomia Humana e Engenharia, bem como artigos científicos selecionados das principais bases de dados: LILACS; SciELO; PubMed; Periódicos CAPES e Elsevier dentro de um recorte temporal envolvendo os últimos vinte anos. Assim, constatou-se ser fundamental minimizar as consequências da postura sentada prolongada do trabalho home office durante e após a pandemia pelo COVID-19; constituir recomendações sobre posturas adequadas; além da análise do tempo de manutenção da postura sentada; a implantação e a manutenção da ergonomia no trabalho remoto, além da importância da prevenção de patologias degenerativas do sistema musculoesquelético

CERTIFICATION REPORT: The certification of Amyloid β1-42 in CSF in ERM®-DA480/IFCC, ERM®-DA481/IFCC and ERM®-DA482/IFCC

This report describes the production of ERM®-DA480/IFCC, ERM®-DA481/IFCC and ERM®-DA482/IFCC, which are human cerebrospinal fluid (CSF) materials certified for the mass concentration of amyloid β1-42 peptide (Aβ1-42). These materials were produced by the European Commission, Joint Research Centre (EC-JRC) in collaboration with the International Federation for Clinical Chemistry and Laboratory Medicine (IFCC) following ISO Guide 34:2009 and are certified in accordance with ISO Guide 35:2006. The starting material used to prepare ERM-DA480/IFCC, ERM-DA481/IFCC and ERM-DA482/IFCC was human CSF collected from normal pressure hydrocephalus patients by continuous lumbar drainage. After collection, the CSF was aliquoted and frozen at -80 °C. For the preparation of each certified reference material (CRM) a selected number of CSF donations were thawed, pooled, mixed, filled in microvials and stored at (-70 ± 10) °C immediately thereafter. Between unit-homogeneity was quantified and stability during dispatch and storage were assessed in accordance with ISO Guide 35:2006 [ ]. The material was characterised by an interlaboratory comparison of laboratories of demonstrated competence and adhering to ISO/IEC 17025 [ ]. Technically invalid results were removed but no outlier was eliminated on statistical grounds only. Uncertainties of the certified values were calculated in accordance with the Guide to the Expression of Uncertainty in Measurement (GUM) [ ] and include uncertainties related to possible inhomogeneity, instability and characterisation. The materials are intended for the calibration of methods, quality control and/or the assessment of method performance. As with any reference material, they can be used for establishing control charts or validation studies. The CRMs are available in microvials containing at least 0.5 mL of frozen liquid. The minimum amount of sample to be used is 15 µL.JRC.F.6-Reference Material

Humanized Mouse Model Mimicking Pathology of Human Tuberculosis for in vivo Evaluation of Drug Regimens

Human immune system mice are highly valuable for in vivo dissection of human immune responses. Although they were employed for analyzing tuberculosis (TB) disease, there is little data on the spatial organization and cellular composition of human immune cells in TB granuloma pathology in this model. We demonstrate that human immune system mice, generated by transplanted human fetal liver derived hematopoietic stem cells develop a continuum of pulmonary lesions upon Mycobacterium tuberculosis aerosol infection. In particular, caseous necrotic granulomas, which contribute to prolonged TB treatment time, developed, and had cellular phenotypic spatial-organization similar to TB patients. By comparing two recommended drug regimens, we confirmed observations made in clinical settings: Adding Moxifloxacin to a classical chemotherapy regimen had no beneficial effects on bacterial eradication. We consider this model instrumental for deeper understanding of human specific features of TB pathogenesis and of particular value for the pre-clinical drug development pipeline

K(2P)18.1 translates T cell receptor signals into thymic regulatory T cell development

It remains largely unclear how thymocytes translate relative differences in T cell receptor (TCR) signal strength into distinct developmental programs that drive the cell fate decisions towards conventional (Tconv) or regulatory T cells (Treg). Following TCR activation, intracellular calcium (Ca2+) is the most important second messenger, for which the potassium channel K(2P)18.1 is a relevant regulator. Here, we identify K(2P)18.1 as a central translator of the TCR signal into the thymus-derived Treg (tTreg) selection process. TCR signal was coupled to NF-kappa B-mediated K(2P)18.1 upregulation in tTreg progenitors. K(2P)18.1 provided the driving force for sustained Ca2+ influx that facilitated NF-kappa B- and NFAT-dependent expression of FoxP3, the master transcription factor for Treg development and function. Loss of K(2P)18.1 ion-current function induced a mild lymphoproliferative phenotype in mice, with reduced Treg numbers that led to aggravated experimental autoimmune encephalomyelitis, while a gain-of-function mutation in K(2P)18.1 resulted in increased Treg numbers in mice. Our findings in human thymus, recent thymic emigrants and multiple sclerosis patients with a dominant-negative missense K(2P)18.1 variant that is associated with poor clinical outcomes indicate that K(2P)18.1 also plays a role in human Treg development. Pharmacological modulation of K(2P)18.1 specifically modulated Treg numbers in vitro and in vivo. Finally, we identified nitroxoline as a K(2P)18.1 activator that led to rapid and reversible Treg increase in patients with urinary tract infections. Conclusively, our findings reveal how K(2P)18.1 translates TCR signals into thymic T cell fate decisions and Treg development, and provide a basis for the therapeutic utilization of Treg in several human disorders.Peer reviewe

Secular improvements in cognitive aging: contribution of education, health, and routine activities

OBJECTIVES: Limited evidence exists regarding the reasons for secular changes in cognitive functioning over historical time. Thus, we examined potential explanatory factors for changes in cognitive speed, a central dimension of cognitive functioning. METHODS: Population-based data of middle-aged and older adults from Germany (N = 5443) was used with baseline participants from 2002 to 2014, comparing the time periods 2002–2014. RESULTS: Cognitive speed improved in middle-aged adults (40–65) and older adults (66+). In both age groups, increases were partly explained by education, employment status, volunteering status, routine activities, and physical functioning. Changes in education were more important in explaining increases in older than in middle-aged adults, whereas changes in health were more important for explaining increases in middle-aged adults. CONCLUSIONS: Cognitive speed increased in both age groups over historical time. Education, employment, volunteering, routine activities, and health were all important in explaining these changes, but their importance differed between age groups