Specificity of T cells in synovial fluid: high frequencies of CD8(+) T cells that are specific for certain viral epitopes

INTRODUCTION: Epstein-Barr virus (EBV) is transmitted orally, replicates in the oropharynx and establishes life-long latency in human B lymphocytes. T-cell responses to latent and lytic/replicative cycle proteins are readily detectable in peripheral blood from healthy EBV-seropositive individuals. EBV has also been detected within synovial tissue, and T-cell responses to EBV lytic proteins have been reported in synovial fluid from a patient with rheumatoid arthritis (RA). This raises the question regarding whether T cells specific for certain viruses might be present at high frequencies within synovial fluid and whether such T cells might be activated or able to secrete cytokines. If so, they might play a 'bystander' role in the pathogenesis of inflammatory joint disease. OBJECTIVES: To quantify and characterize T cells that are specific for epitopes from EBV, cytomegalovirus (CMV) and influenza in peripheral blood and synovial fluid from patients with arthritis. METHODS: Peripheral blood mononuclear cells (PBMCs) and synovial fluid mononuclear cells (SFMCs) were obtained from patients with inflammatory arthritis (including those with RA, osteoarthritis, psoriatic arthritis and reactive arthritis). Samples from human leucocyte antigen (HLA)-A2-positive donors were stained with fluorescent-labelled tetramers of HLA-A2 complexed with the GLCTLVAML peptide epitope from the EBV lytic cycle protein BMLF1, the GILGFVFTL peptide epitope from the influenza A matrix protein, or the NLVPMVATV epitope from the CMV pp65 protein. Samples from HLA-B8-positive donors were stained with fluorescent-labelled tetramers of HLA-B8 complexed with the RAKFKQLL peptide epitope from the EBV lytic protein BZLF1 or the FLRGRAYGL peptide epitope from the EBV latent protein EBNA3A. All samples were costained with an antibody specific for CD8. CD4(+) T cells were not analyzed. Selected samples were costained with antibodies specific for cell-surface glycoproteins, in order to determine the phenotype of the T cells within the joint and the periphery. Functional assays to detect release of IFN-γ or tumour necrosis factor (TNF)-α were also performed on some samples. RESULTS: The first group of 15 patients included 10 patients with RA, one patient with reactive arthritis, one patient with psoriatic arthritis and three patients with osteoarthritis. Of these, 11 were HLA-A2 positive and five were HLA-B8 positive. We used HLA-peptide tetrameric complexes to analyze the frequency of EBV-specific T cells in PBMCs and SFMCs (Figs 1 and 2). Clear enrichment of CD8(+) T cells specific for epitopes from the EBV lytic cycle proteins was seen within synovial fluid from almost all donors studied, including patients with psoriatic arthritis and osteoarthritis and those with RA. In donor RhA6, 9.5% of CD8(+ ) SFMCs were specific for the HLA-A2 restricted GLCTLVAML epitope, compared with 0.5% of CD8(+) PBMCs. Likewise in a donor with osteoarthritis (NR4), 15.5% of CD8(+) SFMCs were specific for the HLA-B8-restricted RAKFKQLL epitope, compared with 0.4% of CD8(+) PBMCs. In contrast, we did not find enrichment of T cells specific for the HLA-B8-restricted FLRGRAYGL epitope (from the latent protein EBNA3A) within SFMCs compared with PBMCs in any donors. In selected individuals we performed ELISpot assays to detect IFN-γ secreted by SFMCs and PBMCs after a short incubation in vitro with peptide epitopes from EBV lytic proteins. These assays confirmed enrichment of T cells specific for epitopes from EBV lytic proteins within synovial fluid and showed that subpopulations of these cells were able to secrete proinflammatory cytokines after short-term stimulation. We used a HLA-A2/GILGFVFTL tetramer to stain PBMCs and SFMCs from six HLA-A2-positive patients. The proportion of T cells specific for this influenza epitope was low (<0.2%) in all donors studied, and we did not find any enrichment within SFMCs. We had access to SFMCs only from a second group of four HLA-A2-positive patients with RA. A tetramer of HLA-A2 complexed to the NLVPMVATV epitope from the CMV pp65 protein reacted with subpopulations of CD8(+) SFMCs in all four donors, with frequencies of 0.2, 0.5, 2.3 and 13.9%. SFMCs from all four donors secreted TNF after short-term incubation with COS cells transfected with HLA-A2 and pp65 complementary DNA. We analyzed the phenotype of virus-specific cells within PBMCs and SFMCs in three donors. The SFMC virus-specific T cells were more highly activated than those in PBMCs, as evidenced by expression of high levels of CD69 and HLA-DR. A greater proportion of SFMCs were CD38(+), CD62L low, CD45RO bright, CD45RA dim, CD57(+) and CD28(-) when compared with PBMCs. DISCUSSION: This work shows that T cells specific for certain epitopes from viral proteins are present at very high frequencies (up to 15.5% of CD8(+) T cells) within SFMCs taken from patients with inflammatory joint disease. This enrichment does not reflect a generalized enrichment for the 'memory pool' of T cells; we did not find enrichment of T cells specific for the GILGFVFTL epitope from influenza A or for the FLRGRAYGL epitope from the EBV latent protein EBNA3A, whereas we found clear enrichment of T cells specific for the GLCTLVAML epitope from the EBV lytic protein BMLF1 and for the RAKFKQLL epitope from the EBV lytic protein BZLF1. The enrichment might reflect preferential recruitment of subpopulations of virus-specific T cells, perhaps based on expression of selectins, chemokine receptors or integrins. Alternatively, T cells specific for certain viral epitopes may be stimulated to proliferate within the joint, by viral antigens themselves or by cross-reactive self-antigens. Finally, it is theoretically possible that subpopulations of T cells within the joint are preferentially protected from apoptotic cell death. Whatever the explanation, the virus-specific T cells are present at high frequency, are activated and are able to secrete proinflammatory cytokines. They could potentially interact with synoviocytes and contribute to the maintenance of inflammation within joints in many different forms of inflammatory arthritis

Limited risks of major congenital anomalies in children of mothers with IBD and effects of medications

Background & aims: Concerns persist about the risk of major congenital anomalies in children of women with inflammatory bowel disease (IBD), and whether medication use affects risk. We assessed these risks, and variations in use of medications by women with IBD before, during, and after pregnancy. Methods: We accessed data on children born to women 15-45 y old from 1990 through 2010, using a mother-child linked dataset from an electronic database of primary care records containing medical diagnoses, events, and drug prescriptions from across the United Kingdom. We identified pregnant women with IBD, and all prescriptions for 5-aminosalicylates azathioprine/6-mercaptopurine, and corticosteroids were extracted from their primary care records. We calculated risks of major congenital anomaly in children of mothers with and without IBD, and in children exposed or not exposed to 5-aminosalicylates, azathioprine/6-mercaptopurine, or corticosteroids during their first trimester of fetal development. Logistic regression with a generalized estimating equation was used to provide risk estimates adjusted for confounders. We calculated proportions of women taking medications before, during, and after pregnancy and assessed whether cessation was associated with subsequent disease flares. Results: Risks of a major congenital anomaly in 1703 children of mothers with IBD and 384,811 children of mothers without IBD were 2.7% and 2.8%, respectively. This corresponded to an adjusted odds ratio of 0.98 (95% confidence interval [CI], 0.73-1.31). In children of women with IBD, the adjusted odds ratios of a major congenital anomaly associated with drug use were 0.82 (95% CI, 0.42-1.61) for 5-aminosalicylates 0.48 (95% CI, 0.15-1.50) for corticosteroids, and 1.27 (95% CI, 0.48-3.39) for azathioprine/6-mercaptopurine. No increases in heart, limb, or genital anomalies were found in children of women with IBD; 31.2% of women discontinued 5-aminosalicylates and 24.6% discontinued azathioprine/6-mercaptopurine in early pregnancy. The risk of flares later in pregnancy was not related to cessation of medication. Conclusions: We found no evidence that IBD during pregnancy or medical therapy for IBD during pregnancy increases the risk of a major congenital anomaly in children. Patients should receive appropriate guidance on use of medication before and during pregnancy

School Playground Surfacing and Arm Fractures in Children: A Cluster Randomized Trial Comparing Sand to Wood Chip Surfaces

In a randomized trial of elementary schools in Toronto, Andrew Howard and colleagues show that granitic sand playground surfaces reduce the risk of arm fractures from playground falls when compared with wood fiber surfaces

AI is a viable alternative to high throughput screening: a 318-target study

: High throughput screening (HTS) is routinely used to identify bioactive small molecules. This requires physical compounds, which limits coverage of accessible chemical space. Computational approaches combined with vast on-demand chemical libraries can access far greater chemical space, provided that the predictive accuracy is sufficient to identify useful molecules. Through the largest and most diverse virtual HTS campaign reported to date, comprising 318 individual projects, we demonstrate that our AtomNet® convolutional neural network successfully finds novel hits across every major therapeutic area and protein class. We address historical limitations of computational screening by demonstrating success for target proteins without known binders, high-quality X-ray crystal structures, or manual cherry-picking of compounds. We show that the molecules selected by the AtomNet® model are novel drug-like scaffolds rather than minor modifications to known bioactive compounds. Our empirical results suggest that computational methods can substantially replace HTS as the first step of small-molecule drug discovery

A História da Alimentação: balizas historiográficas

Os M. pretenderam traçar um quadro da História da Alimentação, não como um novo ramo epistemológico da disciplina, mas como um campo em desenvolvimento de práticas e atividades especializadas, incluindo pesquisa, formação, publicações, associações, encontros acadêmicos, etc. Um breve relato das condições em que tal campo se assentou faz-se preceder de um panorama dos estudos de alimentação e temas correia tos, em geral, segundo cinco abardagens Ia biológica, a econômica, a social, a cultural e a filosófica!, assim como da identificação das contribuições mais relevantes da Antropologia, Arqueologia, Sociologia e Geografia. A fim de comentar a multiforme e volumosa bibliografia histórica, foi ela organizada segundo critérios morfológicos. A seguir, alguns tópicos importantes mereceram tratamento à parte: a fome, o alimento e o domínio religioso, as descobertas européias e a difusão mundial de alimentos, gosto e gastronomia. O artigo se encerra com um rápido balanço crítico da historiografia brasileira sobre o tema

Listening as health care.

What we know alreadyListening is an essential part of caring practice. Being listened to and telling our story is in itself therapeutic and life affirming. Listening is time consuming and whilst acknowledged as central to care in practice is hard to accomplish given the pressures on health and social care staff in terms of targets, paperwork and protocols.What this paper addsThe sociological background to listening and its practice in contemporary health services.Why this is importantCommunity Chaplaincy listening is based on the assumption of careful, agenda free listening.How this impacts on ChaplaincyChaplains are primarily the bearers and witnesses of stories of suffering and triumph. Understanding the link between wellbeing and the act of listening gives theoretical substance to the core work of chaplaincy

Listening as health care.

What we know alreadyListening is an essential part of caring practice. Being listened to and telling our story is in itself therapeutic and life affirming. Listening is time consuming and whilst acknowledged as central to care in practice is hard to accomplish given the pressures on health and social care staff in terms of targets, paperwork and protocols.What this paper addsThe sociological background to listening and its practice in contemporary health services.Why this is importantCommunity Chaplaincy listening is based on the assumption of careful, agenda free listening.How this impacts on ChaplaincyChaplains are primarily the bearers and witnesses of stories of suffering and triumph. Understanding the link between wellbeing and the act of listening gives theoretical substance to the core work of chaplaincy