Pre-existing polymerase-specific T cells expand in abortive seronegative SARS-CoV-2.

Individuals with potential exposure to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) do not necessarily develop PCR or antibody positivity, suggesting that some individuals may clear subclinical infection before seroconversion. T cells can contribute to the rapid clearance of SARS-CoV-2 and other coronavirus infections1-3. Here we hypothesize that pre-existing memory T cell responses, with cross-protective potential against SARS-CoV-2 (refs. 4-11), would expand in vivo to support rapid viral control, aborting infection. We measured SARS-CoV-2-reactive T cells, including those against the early transcribed replication-transcription complex (RTC)12,13, in intensively monitored healthcare workers (HCWs) who tested repeatedly negative according to PCR, antibody binding and neutralization assays (seronegative HCWs (SN-HCWs)). SN-HCWs had stronger, more multispecific memory T cells compared with a cohort of unexposed individuals from before the pandemic (prepandemic cohort), and these cells were more frequently directed against the RTC than the structural-protein-dominated responses observed after detectable infection (matched concurrent cohort). SN-HCWs with the strongest RTC-specific T cells had an increase in IFI27, a robust early innate signature of SARS-CoV-2 (ref. 14), suggesting abortive infection. RNA polymerase within RTC was the largest region of high sequence conservation across human seasonal coronaviruses (HCoV) and SARS-CoV-2 clades. RNA polymerase was preferentially targeted (among the regions tested) by T cells from prepandemic cohorts and SN-HCWs. RTC-epitope-specific T cells that cross-recognized HCoV variants were identified in SN-HCWs. Enriched pre-existing RNA-polymerase-specific T cells expanded in vivo to preferentially accumulate in the memory response after putative abortive compared to overt SARS-CoV-2 infection. Our data highlight RTC-specific T cells as targets for vaccines against endemic and emerging Coronaviridae.

Vaccine escape, increased breakthrough and reinfection in infliximab-treated patients with IBD during the Omicron wave of the SARS-CoV-2 pandemic.

OBJECTIVE: Antitumour necrosis factor (TNF) drugs impair serological responses following SARS-CoV-2 vaccination. We sought to assess if a third dose of a messenger RNA (mRNA)-based vaccine substantially boosted anti-SARS-CoV-2 antibody responses and protective immunity in infliximab-treated patients with IBD. DESIGN: Third dose vaccine induced anti-SARS-CoV-2 spike (anti-S) receptor-binding domain (RBD) antibody responses, breakthrough SARS-CoV-2 infection, reinfection and persistent oropharyngeal carriage in patients with IBD treated with infliximab were compared with a reference cohort treated with vedolizumab from the impaCt of bioLogic therApy on saRs-cov-2 Infection and immuniTY (CLARITY) IBD study. RESULTS: Geometric mean (SD) anti-S RBD antibody concentrations increased in both groups following a third dose of an mRNA-based vaccine. However, concentrations were lower in patients treated with infliximab than vedolizumab, irrespective of whether their first two primary vaccine doses were ChAdOx1 nCoV-19 (1856 U/mL (5.2) vs 10 728 U/mL (3.1), p<0.0001) or BNT162b2 vaccines (2164 U/mL (4.1) vs 15 116 U/mL (3.4), p<0.0001). However, no differences in anti-S RBD antibody concentrations were seen following third and fourth doses of an mRNA-based vaccine, irrespective of the combination of primary vaccinations received. Post-third dose, anti-S RBD antibody half-life estimates were shorter in infliximab-treated than vedolizumab-treated patients (37.0 days (95% CI 35.6 to 38.6) vs 52.0 days (95% CI 49.0 to 55.4), p<0.0001).Compared with vedolizumab-treated, infliximab-treated patients were more likely to experience SARS-CoV-2 breakthrough infection (HR 2.23 (95% CI 1.46 to 3.38), p=0.00018) and reinfection (HR 2.10 (95% CI 1.31 to 3.35), p=0.0019), but this effect was uncoupled from third vaccine dose anti-S RBD antibody concentrations. Reinfection occurred predominantly during the Omicron wave and was predicted by SARS-CoV-2 antinucleocapsid concentrations after the initial infection. We did not observe persistent oropharyngeal carriage of SARS-CoV-2. Hospitalisations and deaths were uncommon in both groups. CONCLUSIONS: Following a third dose of an mRNA-based vaccine, infliximab was associated with attenuated serological responses and more SARS-CoV-2 breakthrough infection and reinfection which were not predicted by the magnitude of anti-S RBD responses, indicative of vaccine escape by the Omicron variant. TRIAL REGISTRATION NUMBER: ISRCTN45176516.

Axonal response of mitochondria to demyelination and complex IV activity within demyelinated axons in experimental models of multiple sclerosis.

AIMS: Axonal injury in multiple sclerosis (MS) and experimental models is most frequently detected in acutely demyelinating lesions. We recently reported a compensatory neuronal response, where mitochondria move to the acutely demyelinated axon and increase the mitochondrial content following lysolecithin-induced demyelination. We termed this homeostatic phenomenon, which is also evident in MS, the axonal response of mitochondria to demyelination (ARMD). The aim of this study is to determine whether ARMD is consistently evident in experimental demyelination and how its perturbation relates to axonal injury. METHODS: In the present study, we assessed axonal mitochondrial content as well as axonal mitochondrial respiratory chain complex IV activity (cytochrome c oxidase or COX) of axons and related these to axonal injury in nine different experimental disease models. We used immunofluorescent histochemistry as well as sequential COX histochemistry followed by immunofluorescent labelling of mitochondria and axons. RESULTS: We found ARMD a consistent and robust phenomenon in all experimental disease models. The increase in mitochondrial content within demyelinated axons, however, was not always accompanied by a proportionate increase in complex IV activity, particularly in highly inflammatory models such as experimental autoimmune encephalomyelitis (EAE). Axonal complex IV activity inversely correlated with the extent of axonal injury in experimental disease models. CONCLUSIONS: Our findings indicate that ARMD is a consistent and prominent feature and emphasise the importance of complex IV activity in the context of ARMD, especially in autoimmune inflammatory demyelination, paving the way for the development of novel neuroprotective therapies.

Multimodal Analysis of the Visual Pathways in Friedreich's Ataxia Reveals Novel Biomarkers.

BACKGROUND: Optic neuropathy is a near ubiquitous feature of Friedreich's ataxia (FRDA). Previous studies have examined varying aspects of the anterior and posterior visual pathways but none so far have comprehensively evaluated the heterogeneity of degeneration across different areas of the retina, changes to the macula layers and combined these with volumetric MRI studies of the visual cortex and frataxin level. METHODS: We investigated 62 genetically confirmed FRDA patients using an integrated approach as part of an observational cohort study. We included measurement of frataxin protein levels, clinical evaluation of visual and neurological function, optical coherence tomography to determine retinal nerve fibre layer thickness and macular layer volume and volumetric brain MRI. RESULTS: We demonstrate that frataxin level correlates with peripapillary retinal nerve fibre layer thickness and that retinal sectors differ in their degree of degeneration. We also shown that retinal nerve fibre layer is thinner in FRDA patients than controls and that this thinning is influenced by the AAO and GAA1. Furthermore we show that the ganglion cell and inner plexiform layers are affected in FRDA. Our MRI data indicate that there are borderline correlations between retinal layers and areas of the cortex involved in visual processing. CONCLUSION: Our study demonstrates the uneven distribution of the axonopathy in the retinal nerve fibre layer and highlight the relative sparing of the papillomacular bundle and temporal sectors. We show that thinning of the retinal nerve fibre layer is associated with frataxin levels, supporting the use the two biomarkers in future clinical trials design. © 2022 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.

Multicenter study of the natural history and therapeutic responses of patients with chikungunya, focusing on acute and chronic musculoskeletal manifestations - a study protocol from the clinical and applied research in Chikungunya (REPLICK network).

BACKGROUND: Chikungunya is associated with high morbidity and the natural history of symptomatic infection has been divided into three phases (acute, post-acute, and chronic) according to the duration of musculoskeletal symptoms. Although this classification has been designed to help guide therapeutic decisions, it does not encompass the complexity of the clinical expression of the disease and does not assist in the evaluation of the prognosis of severity nor chronic disease. Thus, the current challenge is to identify and diagnose musculoskeletal disorders and to provide the optimal treatment in order to prevent perpetuation or progression to a potentially destructive disease course. METHODS: The study is the first product of the Clinical and Applied Research Network in Chikungunya (REPLICK). This is a prospective, outpatient department-based, multicenter cohort study in Brazil. Four work packages were defined: i. Clinical research; ii) Translational Science - comprising immunology and virology streams; iii) Epidemiology and Economics; iv) Therapeutic Response and clinical trials design. Scheduled appointments on days 21 (D21) ± 7 after enrollment, D90 ± 15, D120 ± 30, D180 ± 30; D360 ± 30; D720 ± 60, and D1080 ± 60 days. On these visits a panel of blood tests are collected in addition to the clinical report forms to obtain data on socio-demographic, medical history, physical examination and questionnaires devoted to the evaluation of musculoskeletal manifestations and overall health are performed. Participants are asked to consent for their specimens to be maintained in a biobank. Aliquots of blood, serum, saliva, PAXgene, and when clinically indicated to be examined, synovial fluid, are stored at -80° C. The study protocol was submitted and approved to the National IRB and local IRB at each study site. DISCUSSION: Standardized and harmonized patient cohorts are needed to provide better estimates of chronic arthralgia development, the clinical spectra of acute and chronic disease and investigation of associated risk factors. This study is the largest evaluation of the long-term sequelae of individuals infected with CHIKV in the Brazilian population focusing on musculoskeletal manifestations, mental health, quality of life, and chronic pain. This information will both define disease burden and costs associated with CHIKV infection, and better inform therapeutic guidelines.

HLA-DR polymorphism in SARS-CoV-2 infection and susceptibility to symptomatic COVID-19.

SARS-CoV-2 infection results in different outcomes ranging from asymptomatic infection to mild or severe disease and death. Reasons for this diversity of outcome include differences in challenge dose, age, gender, comorbidity and host genomic variation. Human leukocyte antigen (HLA) polymorphisms may influence immune response and disease outcome. We investigated the association of HLAII alleles with case definition symptomatic COVID-19, virus-specific antibody and T-cell immunity. A total of 1364 UK healthcare workers (HCWs) were recruited during the first UK SARS-CoV-2 wave and analysed longitudinally, encompassing regular PCR screening for infection, symptom reporting, imputation of HLAII genotype and analysis for antibody and T-cell responses to nucleoprotein (N) and spike (S). Of 272 (20%) HCW who seroconverted, the presence of HLA-DRB1*13:02 was associated with a 6·7-fold increased risk of case definition symptomatic COVID-19. In terms of immune responsiveness, HLA-DRB1*15:02 was associated with lower nucleocapsid T-cell responses. There was no association between DRB1 alleles and anti-spike antibody titres after two COVID vaccine doses. However, HLA DRB1*15:01 was associated with increased spike T-cell responses following both first and second dose vaccination. Trial registration: NCT04318314 and ISRCTN15677965.

Human NK cell receptor KIR2DS4 detects a conserved bacterial epitope presented by HLA-C.

Natural killer (NK) cells have an important role in immune defense against viruses and cancer. Activation of human NK cell cytotoxicity toward infected or tumor cells is regulated by killer cell immunoglobulin-like receptors (KIRs) that bind to human leukocyte antigen class I (HLA-I). Combinations of KIR with HLA-I are genetically associated with susceptibility to disease. KIR2DS4, an activating member of the KIR family with poorly defined ligands, is a receptor of unknown function. Here, we show that KIR2DS4 has a strong preference for rare peptides carrying a Trp at position 8 (p8) of 9-mer peptides bound to HLA-C*05:01. The complex of a peptide bound to HLA-C*05:01 with a Trp at p8 was sufficient for activation of primary KIR2DS4+ NK cells, independent of activation by other receptors and of prior NK cell licensing. HLA-C*05:01+ cells that expressed the peptide epitope triggered KIR2DS4+ NK cell degranulation. We show an inverse correlation of the worldwide allele frequency of functional KIR2DS4 with that of HLA-C*05:01, indicative of functional interaction and balancing selection. We found a highly conserved peptide sequence motif for HLA-C*05:01-restricted activation of human KIR2DS4+ NK cells in bacterial recombinase A (RecA). KIR2DS4+ NK cells were stimulated by RecA epitopes from multiple human pathogens, including Helicobacter, Chlamydia, Brucella, and Campylobacter. We predict that over 1,000 bacterial species could activate NK cells through KIR2DS4, and propose that human NK cells also contribute to immune defense against bacteria through recognition of a conserved RecA epitope presented by HLA-C*05:01.

Synaptic Loss in Multiple Sclerosis Spinal Cord.

Disability in multiple sclerosis (MS) is considered primarily a result of axonal loss. However, correlation with spinal cord cross-sectional area-a predictor of disability-is poor, questioning the unique role of axonal loss. We investigated the degree of synaptic loss in postmortem spinal cords (18 chronic MS, 8 healthy controls) using immunohistochemistry for synaptophysin and synapsin. Substantial (58-96%) loss of synapses throughout the spinal cord was detected, along with moderate (47%) loss of anterior horn neurons, notably in demyelinating MS lesions. We conclude that synaptic loss is significant in chronic MS, likely contributing to disability accrual. ANN NEUROL 2020;88:619-625.

A 30-Year Clinical and Magnetic Resonance Imaging Observational Study of Multiple Sclerosis and Clinically Isolated Syndromes.

OBJECTIVE: Clinical outcomes in multiple sclerosis (MS) are highly variable. We aim to determine the long-term clinical outcomes in MS, and to identify early prognostic features of these outcomes. METHODS: One hundred thirty-two people presenting with a clinically isolated syndrome were prospectively recruited between 1984 and 1987, and followed up clinically and radiologically 1, 5, 10, 14, 20, and now 30 years later. All available notes and magnetic resonance imaging scans were reviewed, and MS was defined according to the 2010 McDonald criteria. RESULTS: Clinical outcome data were obtained in 120 participants at 30 years. Eighty were known to have developed MS by 30 years. Expanded Disability Status Scale (EDSS) scores were available in 107 participants, of whom 77 had MS; 32 (42%) remained fully ambulatory (EDSS scores ≤3.5), all of whom had relapsing-remitting MS (RRMS), 3 (4%) had RRMS and EDSS scores >3.5, 26 (34%) had secondary progressive MS (all had EDSS scores >3.5), and MS contributed to death in 16 (20%). Of those with MS, 11 received disease-modifying therapy. The strongest early predictors (within 5 years of presentation) of secondary progressive MS at 30 years were presence of baseline infratentorial lesions and deep white matter lesions at 1 year. INTERPRETATION: Thirty years after onset, in a largely untreated cohort, there was a divergence of MS outcomes; some people accrued substantial disability early on, whereas others ran a more favorable long-term course. These outcomes could, in part, be predicted by radiological findings from within 1 year of first presentation. ANN NEUROL 2020;87:63-74.

Phenotypical characterization of regulatory T cells in acute Zika infection.

Zika virus (ZIKV), alongside Dengue virus (DENV), Chikungunya virus (CHIKV), and Yellow Fever Virus (YFV) are prevalent arboviruses in the Americas. Each of these infections is associated with the development of associated disease immunopathology. Immunopathological processes are an outcome of counter-balancing impacts between effector and regulatory immune mechanisms. In this context, regulatory T cells (Tregs) are key in modulating the immune response and, therefore, in tissue damage control. However, to date, Treg phenotypes and mechanisms during acute infection of the ZIKV in humans have not been fully investigated. The main aim of this work was to characterize Tregs and their immunological profile related to cytokine production and molecules that are capable of controlling the exacerbated inflammatory profile in acute Zika infected patients. Using whole blood analyses of infected patients, an ex vivo phenotypical characterization of Tregs, circulating during acute Zika virus infection, was conducted by flow cytometry. We found that though there are no differences in absolute Treg frequency between infected and healthy control groups. However, pro-inflammatory cytokine up-regulation such as IFN-γ and LAP was observed in the acute disease. Furthermore, acute ZIKV patients expressed increased levels of CD39/CD73, perforin/granzyme B, PD-1, and CTLA-4, all markers involved in mechanisms used by Tregs to attempt to control strong inflammatory responses. Thus, the data indicates a potential contribution of Tregs during the inflammatory ZIKV infection response.

Bioluminescent Reporting of In Vivo IFN-γ Immune Responses during Infection and Autoimmunity.

IFN-γ is a key cytokine of innate and adaptive immunity. It is important to understand temporal changes in IFN-γ production and how these changes relate to the role of IFN-γ in diverse models of infectious and autoimmune disease, making the ability to monitor and track IFN-γ production in vivo of a substantial benefit. IFN-γ ELISPOTs have been a central methodology to measure T cell immunity for many years. In this study, we add the capacity to analyze IFN-γ responses with high sensitivity and specificity, longitudinally, in vitro and in vivo. This allows the refinement of experimental protocols because immunity can be tracked in real-time through a longitudinal approach. We have generated a novel murine IFN-γ reporter transgenic model that allows IFN-γ production to be visualized and quantified in vitro and in vivo as bioluminescence using an imaging system. At baseline, in the absence of an inflammatory stimulus, IFN-γ signal from lymphoid tissue is detectable in vivo. Reporter transgenics are used in this study to track the IFN-γ response to Pseudomonas aeruginosa infection in the lung over time in vivo. The longitudinal development of the adaptive T cell immunity following immunization with Ag is identified from day 7 in vivo. Finally, we show that we are able to use this reporter transgenic to follow the onset of autoimmune T cell activation after regulatory T cell depletion in an established model of systemic autoimmunity. This IFN-γ reporter transgenic, termed "Gammaglow," offers a valuable new modality for tracking IFN-γ immunity, noninvasively and longitudinally over time.

Third generation autologous chondrocyte implantation is a good treatment option for athletic persons.

PURPOSE: Autologous chondrocyte implantation is an established method for the treatment of joint cartilage damage. However, to date it has not been established that autologous chondrocyte implantation is an appropriate procedure for cartilage defects therapy in athletic persons. The aim of this study is to analyze if third-generation autologous chondrocyte implantation is an appropriate treatment for athletic persons with full cartilage defect of the knee joints. METHODS: A total of 84 patients were treated with third-generation autologous chondrocyte implantation (NOVOCART® 3D). The mean follow-up time was 8 years (5-14). Sports activity was measured via UCLA Activity Score and Tegner Activity Scale before the onset of knee pain and postoperatively in an annual clinical evaluation. 41 athletic persons and 43 non-athletic persons (UCLA-Cut-off: 7; Tegner Activity Scale-Cut-off: 4) were analyzed. Patient reported outcomes were captured using IKDC subjective, KOOS, Lysholm score and VAS score on movement. RESULTS: Patient reported outcomes (IKDC, VAS at rest, VAS on movement) showed significant improvement (p < 0.001) postoperatively. Athletic persons demonstrated significantly better results than non-athletic persons in the analyzed outcome scores (IKDC: p < 0.01, KOOS: p < 0.01, Lysholm score: p < 0.01). 96.4% of the patients were able to return to sport and over 50% returned or surpassed their preinjury sports level. The remaining patients were downgraded by a median of two points on the UCLA- and 2.5 on the Tegner Activity Scale. A shift from high-impact sports to active events and moderate or mild activities was found. Furthermore, it was shown that preoperative UCLA score and Tegner Activity Scale correlated significantly with the patient reported outcome postoperatively. CONCLUSION: Autologous chondrocyte implantation is a suitable treatment option for athletic persons with full-thickness cartilage defects in the knee. The return to sports activity is possible, but includes a shift from high-impact sports to less strenuous activities.

Enhanced axonal response of mitochondria to demyelination offers neuroprotection: implications for multiple sclerosis.

Axonal loss is the key pathological substrate of neurological disability in demyelinating disorders, including multiple sclerosis (MS). However, the consequences of demyelination on neuronal and axonal biology are poorly understood. The abundance of mitochondria in demyelinated axons in MS raises the possibility that increased mitochondrial content serves as a compensatory response to demyelination. Here, we show that upon demyelination mitochondria move from the neuronal cell body to the demyelinated axon, increasing axonal mitochondrial content, which we term the axonal response of mitochondria to demyelination (ARMD). However, following demyelination axons degenerate before the homeostatic ARMD reaches its peak. Enhancement of ARMD, by targeting mitochondrial biogenesis and mitochondrial transport from the cell body to axon, protects acutely demyelinated axons from degeneration. To determine the relevance of ARMD to disease state, we examined MS autopsy tissue and found a positive correlation between mitochondrial content in demyelinated dorsal column axons and cytochrome c oxidase (complex IV) deficiency in dorsal root ganglia (DRG) neuronal cell bodies. We experimentally demyelinated DRG neuron-specific complex IV deficient mice, as established disease models do not recapitulate complex IV deficiency in neurons, and found that these mice are able to demonstrate ARMD, despite the mitochondrial perturbation. Enhancement of mitochondrial dynamics in complex IV deficient neurons protects the axon upon demyelination. Consequently, increased mobilisation of mitochondria from the neuronal cell body to the axon is a novel neuroprotective strategy for the vulnerable, acutely demyelinated axon. We propose that promoting ARMD is likely to be a crucial preceding step for implementing potential regenerative strategies for demyelinating disorders.

Single-subject structural cortical networks in clinically isolated syndrome.

BACKGROUND: Structural cortical networks (SCNs) represent patterns of coordinated morphological modifications in cortical areas, and they present the advantage of being extracted from previously acquired clinical magnetic resonance imaging (MRI) scans. SCNs have shown pathophysiological changes in many brain disorders, including multiple sclerosis. OBJECTIVE: To investigate alterations of SCNs at the individual level in patients with clinically isolated syndrome (CIS), thereby assessing their clinical relevance. METHODS: We analyzed baseline data collected in a prospective multicenter (MAGNIMS) study. CIS patients (n = 60) and healthy controls (n = 38) underwent high-resolution 3T MRI. Measures of disability and cognitive processing were obtained for patients. Single-subject SCNs were extracted from brain 3D-T1 weighted sequences; global and local network parameters were computed. RESULTS: Compared to healthy controls, CIS patients showed altered small-world topology, an efficient network organization combining dense local clustering with relatively few long-distance connections. These disruptions were worse for patients with higher lesion load and worse cognitive processing speed. Alterations of centrality measures and clustering of connections were observed in specific cortical areas in CIS patients when compared with healthy controls. CONCLUSION: Our study indicates that SCNs can be used to demonstrate clinically relevant alterations of connectivity in CIS.

A multi-shell multi-tissue diffusion study of brain connectivity in early multiple sclerosis.

BACKGROUND: The potential of multi-shell diffusion imaging to produce accurate brain connectivity metrics able to unravel key pathophysiological processes in multiple sclerosis (MS) has scarcely been investigated. OBJECTIVE: To test, in patients with a clinically isolated syndrome (CIS), whether multi-shell imaging-derived connectivity metrics can differentiate patients from controls, correlate with clinical measures, and perform better than metrics obtained with conventional single-shell protocols. METHODS: Nineteen patients within 3 months from the CIS and 12 healthy controls underwent anatomical and 53-direction multi-shell diffusion-weighted 3T images. Patients were cognitively assessed. Voxel-wise fibre orientation distribution functions were estimated and used to obtain network metrics. These were also calculated using a conventional single-shell diffusion protocol. Through linear regression, we obtained effect sizes and standardised regression coefficients. RESULTS: Patients had lower mean nodal strength (p = 0.003) and greater network modularity than controls (p = 0.045). Greater modularity was associated with worse cognitive performance in patients, even after accounting for lesion load (p = 0.002). Multi-shell-derived metrics outperformed single-shell-derived ones. CONCLUSION: Connectivity-based nodal strength and network modularity are abnormal in the CIS. Furthermore, the increased network modularity observed in patients, indicating microstructural damage, is clinically relevant. Connectivity analyses based on multi-shell imaging can detect potentially relevant network changes in early MS.

Patient-Reported and Magnetic Resonance Imaging Outcomes of Third-Generation Autologous Chondrocyte Implantation After 10 Years.

PURPOSE: To evaluate the long-term clinical and radiologic outcomes of third-generation autologous chondrocyte implantation (ACI) for the treatment of focal cartilage defects of the knee. METHODS: Data capture was carried out between 2004 and 2018. Included were patients with cartilage defects of the knee joint with an International Cartilage Repair Society grade of III or higher treated with third-generation ACI who had a minimum follow-up period of 10 years. International Knee Documentation Committee scores and assessment of pain at rest and on movement using visual analog scale scores were captured preoperatively and at 6 months postoperatively, as well as annually thereafter. In addition, we performed magnetic resonance imaging examinations in 13 cases after 10 years. The MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) score was used to evaluate the ACI cartilage. RESULTS: A total of 54 patients met the inclusion criteria. Of these, 30 reached the 10-year follow-up point and were included in this assessment. At 10 years postoperatively, all clinical outcome parameters showed a statistically significant improvement compared with the preoperative situation, with a responder rate of 70%. The average MOCART (Magnetic Resonance Observation of Cartilage Repair Tissue) score after 10 years was 59.2 points (range, 20-100 points), and over 60% of the evaluated patients showed good integration of the implant at 10 years postoperatively. CONCLUSIONS: The clinical and radiologic findings of this study show that third-generation ACI is a suitable and effective option in the treatment of full-thickness cartilage defects of the knee. At 10 years after surgery, third-generation ACI shows stable results and leads to significant improvement in all clinical outcome parameters. Despite these results, revision surgery after third-generation ACI is common and was needed in 23% of patients in this study. LEVEL OF EVIDENCE: Level IV, therapeutic case series.

Dietary supplementation with inulin-propionate ester or inulin improves insulin sensitivity in adults with overweight and obesity with distinct effects on the gut microbiota, plasma metabolome and systemic inflammatory responses: a randomised cross-over trial.

OBJECTIVE: To investigate the underlying mechanisms behind changes in glucose homeostasis with delivery of propionate to the human colon by comprehensive and coordinated analysis of gut bacterial composition, plasma metabolome and immune responses. DESIGN: Twelve non-diabetic adults with overweight and obesity received 20 g/day of inulin-propionate ester (IPE), designed to selectively deliver propionate to the colon, a high-fermentable fibre control (inulin) and a low-fermentable fibre control (cellulose) in a randomised, double-blind, placebo-controlled, cross-over design. Outcome measurements of metabolic responses, inflammatory markers and gut bacterial composition were analysed at the end of each 42-day supplementation period. RESULTS: Both IPE and inulin supplementation improved insulin resistance compared with cellulose supplementation, measured by homeostatic model assessment 2 (mean±SEM 1.23±0.17 IPE vs 1.59±0.17 cellulose, p=0.001; 1.17±0.15 inulin vs 1.59±0.17 cellulose, p=0.009), with no differences between IPE and inulin (p=0.272). Fasting insulin was only associated positively with plasma tyrosine and negatively with plasma glycine following inulin supplementation. IPE supplementation decreased proinflammatory interleukin-8 levels compared with cellulose, while inulin had no impact on the systemic inflammatory markers studied. Inulin promoted changes in gut bacterial populations at the class level (increased Actinobacteria and decreased Clostridia) and order level (decreased Clostridiales) compared with cellulose, with small differences at the species level observed between IPE and cellulose. CONCLUSION: These data demonstrate a distinctive physiological impact of raising colonic propionate delivery in humans, as improvements in insulin sensitivity promoted by IPE and inulin were accompanied with different effects on the plasma metabolome, gut bacterial populations and markers of systemic inflammation.

'Just 17 if you know what I mean' but what do we really mean to say about Th17 immunity?

Th17-derived IL-17 might be considered the archetypal pro-inflammatory cytokine of adaptive immunity, to be targeted by new therapeutics for alleviation of autoimmune and inflammatory disease. However, the IL-17 family of cytokines is produced by diverse innate and adaptive cells, including Th17, Tc17, ILC3, NK cells and γδ T-cells. These responses are appreciated to underpin diverse aspects of protective, physiological immunity, from dialogue with the gut microbiota to bacterial and fungal immunity in the lung.

Knowns and unknowns of tissue-resident memory T cells.

Advances in transcriptomics and other approaches are shedding considerable light on tissue-resident immune cells as distinct from recirculating cells. The advances encompass antigen-presenting cell subsets, Tregs and importantly, tissue-resident memory cells (TRM). What are the transcriptional programmes and functional properties that distinguish the requirements for an effective tissue resident cell in brain relative to lung, skin, adipose tissue or the genital tract? Another important conundrum has been the extent to which TRM cells are specialized either as a 'sense and alarm' population or as a local, primed, effector cell population in themselves. These are questions that challenge immunologists to stop thinking in terms of a generic, model, immune response and focus instead on events in the tissue in question.