Developmental plasticity allows outside-in immune responses by resident memory T cells.

Central memory T (TCM) cells patrol lymph nodes and perform conventional memory responses on restimulation: proliferation, migration and differentiation into diverse T cell subsets while also self-renewing. Resident memory T (TRM) cells are parked within single organs, share properties with terminal effectors and contribute to rapid host protection. We observed that reactivated TRM cells rejoined the circulating pool. Epigenetic analyses revealed that TRM cells align closely with conventional memory T cell populations, bearing little resemblance to recently activated effectors. Fully differentiated TRM cells isolated from small intestine epithelium exhibited the potential to differentiate into TCM cells, effector memory T cells and TRM cells on recall. Ex-TRM cells, former intestinal TRM cells that rejoined the circulating pool, heritably maintained a predilection for homing back to their tissue of origin on subsequent reactivation and a heightened capacity to redifferentiate into TRM cells. Thus, TRM cells can rejoin the circulation but are advantaged to re-form local TRM when called on.

Engagement of the costimulatory molecule ICOS in tissues promotes establishment of CD8+ tissue-resident memory T cells.

Elevated gene expression of the costimulatory receptor Icos is a hallmark of CD8+ tissue-resident memory (Trm) T cells. Here, we examined the contribution of ICOS in Trm cell differentiation. Upon transfer into WT mice, Icos-/- CD8+ T cells exhibited defective Trm generation but produced recirculating memory populations normally. ICOS deficiency or ICOS-L blockade compromised establishment of CD8+ Trm cells but not their maintenance. ICOS ligation during CD8+ T cell priming did not determine Trm induction; rather, effector CD8+ T cells showed reduced Trm differentiation after seeding into Icosl-/- mice. IcosYF/YF CD8+ T cells were compromised in Trm generation, indicating a critical role for PI3K signaling. Modest transcriptional changes in the few Icos-/- Trm cells suggest that ICOS-PI3K signaling primarily enhances the efficiency of CD8+ T cell tissue residency. Thus, local ICOS signaling promotes production of Trm cells, providing insight into the contribution of costimulatory signals in the generation of tissue-resident populations.

Sensing of ATP via the Purinergic Receptor P2RX7 Promotes CD8+ Trm Cell Generation by Enhancing Their Sensitivity to the Cytokine TGF-ß.

Tissue-resident memory (Trm) CD8+ T cells mediate protective immunity in barrier tissues, but the cues promoting Trm cell generation are poorly understood. Sensing of extracellular adenosine triphosphate (eATP) by the purinergic receptor P2RX7 is needed for recirculating CD8+ T cell memory, but its role for Trm cells is unclear. Here we showed that P2RX7 supported Trm cell generation by enhancing CD8+ T cell sensing of TGF-ß, which was necessary for tissue residency. P2RX7-deficient Trm cells progressively decayed in non-lymphoid tissues and expressed dysregulated Trm-specific markers. P2RX7 was required for efficient re-expression of the receptor TGF-ßRII through calcineurin signaling. Forced Tgfbr2 expression rescued P2RX7-deficient Trm cell generation, and TGF-ß sensitivity was dictated by P2RX7 agonists and antagonists. Forced Tgfbr2 also rescued P2RX7-deficient Trm cell mitochondrial function. Sustained P2RX7 signaling was required for long-term Trm cell maintenance, indicating that P2RX7 signaling drives induction and CD8+ T cell durability in barrier sites.

Responsiveness to interleukin-15 therapy is shared between tissue-resident and circulating memory CD8+ T cell subsets.

Interleukin-15 (IL-15) is often considered a central regulator of memory CD8+ T cells, based primarily on studies of recirculating subsets. However, recent work identified IL-15-independent CD8+ T cell memory populations, including tissue-resident memory CD8+ T cells (TRM) in some nonlymphoid tissues (NLTs). Whether this reflects the existence of IL-15-insensitive memory CD8+ T cells is unclear. We report that IL-15 complexes (IL-15c) stimulate rapid proliferation and expansion of both tissue-resident and circulating memory CD8+ T cell subsets across lymphoid and nonlymphoid tissues with varying magnitude by tissue and memory subset, in some sites correlating with differing levels of the IL-2Rß. This was conserved for memory CD8+ T cells recognizing distinct antigens and elicited by different pathogens. Following IL-15c-induced expansion, divided cells contracted to baseline numbers and only slowly returned to basal proliferation, suggesting a mechanism to transiently amplify memory populations. Through parabiosis, we showed that IL-15c drive local proliferation of TRM, with a degree of recruitment of circulating cells to some NLTs. Hence, irrespective of homeostatic IL-15 dependence, IL-15 sensitivity is a defining feature of memory CD8+ T cell populations, with therapeutic potential for expansion of TRM and other memory subsets in an antigen-agnostic and temporally controlled fashion.

Amphipathic Liponecrosis Impairs Bacterial Clearance and Causes Infection During Sterile Inflammation.

BACKGROUND & AIMS: Although transient bacteremia is common during dental and endoscopic procedures, infections developing during sterile diseases like acute pancreatitis (AP) can have grave consequences. We examined how impaired bacterial clearance may cause this transition. METHODS: Blood samples from patients with AP, normal controls, and rodents with pancreatitis or those administered different nonesterified fatty acids (NEFAs) were analyzed for albumin-unbound NEFAs, microbiome, and inflammatory cell injury. Macrophage uptake of unbound NEFAs using a novel coumarin tracer were done and the downstream effects-NEFA-membrane phospholipid (phosphatidylcholine) interactions-were studied on isothermal titration calorimetry. RESULTS: Patients with infected AP had higher circulating unsaturated NEFAs; unbound NEFAs, including linoleic acid (LA) and oleic acid (OA); higher bacterial 16S DNA; mitochondrial DNA; altered ß-diversity; enrichment in Pseudomonadales; and increased annexin V-positive myeloid (CD14) and CD3-positive T cells on admission. These, and increased circulating dead inflammatory cells, were also noted in rodents with unbound, unsaturated NEFAs. Isothermal titration calorimetry showed progressively stronger unbound LA interactions with aqueous media, phosphatidylcholine, cardiolipin, and albumin. Unbound NEFAs were taken into protein-free membranes, cells, and mitochondria, inducing voltage-dependent anion channel oligomerization, reducing ATP, and impairing phagocytosis. These were reversed by albumin. In vivo, unbound LA and OA increased bacterial loads and impaired phagocytosis, causing infection. LA and OA were more potent for these amphipathic interactions than the hydrophobic palmitic acid. CONCLUSIONS: Release of stored LA and OA can increase their circulating unbound levels and cause amphipathic liponecrosis of immune cells via uptake by membrane phospholipids. This impairs bacterial clearance and causes infection during sterile inflammation.

The Extracellular ATP Receptor P2RX7 Imprints a Promemory Transcriptional Signature in Effector CD8+ T Cells.

Development of CD8+ central memory T (Tcm) and resident memory T (Trm) cells, which promote immunity in the circulation and in barrier tissues, respectively, is not completely understood. Tcm and Trm cells may arise from common precursors; however, their fate-inducing signals are elusive. We found that virus-specific effector CD8+ T cells display heterogeneous expression of the extracellular ATP sensor P2RX7. P2RX7-high expression is confined, at peak effector phase, to CD62L+ memory precursors, which preferentially form Tcm cells. Among early effector CD8+ T cells, asymmetrical P2RX7 distribution correlated with distinct transcriptional signatures, with P2RX7-high cells enriched for memory and tissue residency sets. P2RX7-high early effectors preferentially form both Tcm and Trm cells. Defective Tcm and Trm cell formation in P2RX7 deficiency is significantly reverted when the transcriptional repressor Zeb2 is ablated. Mechanistically, P2RX7 negatively regulates Zeb2 expression, at least partially through TGF-ß sensing in early effector CD8+ T cells. Our study indicates that unequal P2RX7 upregulation in effector CD8+ T cells is a foundational element of the early Tcm/Trm fate.

The purinergic receptor P2RX7 directs metabolic fitness of long-lived memory CD8+ T cells.

Extracellular ATP (eATP) is an ancient 'danger signal' used by eukaryotes to detect cellular damage1. In mice and humans, the release of eATP during inflammation or injury stimulates both innate immune activation and chronic pain through the purinergic receptor P2RX72-4. It is unclear, however, whether this pathway influences the generation of immunological memory, a hallmark of the adaptive immune system that constitutes the basis of vaccines and protective immunity against re-infection5,6. Here we show that P2RX7 is required for the establishment, maintenance and functionality of long-lived central and tissue-resident memory CD8+ T cell populations in mice. By contrast, P2RX7 is not required for the generation of short-lived effector CD8+ T cells. Mechanistically, P2RX7 promotes mitochondrial homeostasis and metabolic function in differentiating memory CD8+ T cells, at least in part by inducing AMP-activated protein kinase. Pharmacological inhibitors of P2RX7 provoked dysregulated metabolism and differentiation of activated mouse and human CD8+ T cells in vitro, and transient P2RX7 blockade in vivo ameliorated neuropathic pain but also compromised production of CD8+ memory T cells. These findings show that activation of P2RX7 by eATP provides a common currency that both alerts the nervous and immune system to tissue damage, and promotes the metabolic fitness and survival of the most durable and functionally relevant memory CD8+ T cell populations.

An integrated view of cisplatin-induced nephrotoxicity, hepatotoxicity, and cardiotoxicity: characteristics, common molecular mechanisms, and current clinical management.

Cisplatin (CP) is a chemotherapy drug widely prescribed to treat various neoplasms. Although fundamental for the therapeutic action of the drug, its cytotoxic mechanisms trigger adverse effects in several tissues, such as the kidney, liver, and heart, which limit its clinical use. In this sense, studies point to an essential role of damage to nuclear and mitochondrial DNA associated with oxidative stress, inflammation, and apoptosis in the pathophysiology of tissue injuries. Due to the limitation of effective preventive and therapeutic measures against CP-induced toxicity, new strategies with potential cytoprotective effects have been studied. Therefore, this article is timely in reviewing the characteristics and main molecular mechanisms common to renal, hepatic, and cardiac toxicity previously described, in addition to addressing the main validated strategies for the current management of these adverse events in clinical practice. We also handle the main promising antioxidant substances recently presented in the literature to encourage the development of new research that consolidates their potential preventive and therapeutic effects against CP-induced cytotoxicity.

Challenges to the operation of Brazilian LTCIs and changes in oversight.

BACKGROUND: Despite 18 years since health surveillance regulations were promulgated in Brazil to govern Long-Term Care Institutions for Older Adults (LTCIs), many institutions fail to comply with the Differentiated Regime for Public Procurement (Resolution No. 502/2021) due to structural and operational conditions. This study aimed to investigate Brazilian LTCI managers' understanding of challenges that significantly impact institutional operation and gather suggestions for enhancing RDC No. 502/21. METHODS: A cross-sectional, exploratory, and qualitative study was conducted, involving 90 managers or technical supervisors from Brazilian LTCIs. Data were collected using a self-administered Google Forms instrument and analyzed through Thematic Analysis based on the Organizing for Quality (OQ) framework. RESULTS: The most impactful challenges for LTCIs were healthcare, financing, human resources, relationship with oversight bodies, and family members. DISCUSSION: Proposed improvements for RDC No. 502/21 included enhanced professional training, infrastructure revision, increased financial support from the state, realistic oversight/regulations, and tailored monitoring approaches. CONCLUSION: LTCIs in Brazil face numerous challenges, and the suggested improvements aim to adapt regulations to institutional realities. However, considering the regulations' variability and purposes, further investigation is warranted.

Imaging associations enhance the understanding of ECG abnormalities in male Brazilian football players: findings from the B-Pro Foot ECG study.

OBJECTIVES: To evaluate the prevalence of abnormal ECG findings and their association with imaging results in male Brazilian football players. METHODS: The 'B-Pro Foot ECG' is a multicentre observational study conducted in 82 Brazilian professional clubs. It analysed 6125 players aged 15-35 years (2496 white, 2004 mixed-race and 1625 black individuals) who underwent cardiovascular screening from 2002 to 2023. All ECGs were reviewed by two experienced cardiologists in the athlete's care. Those with abnormal findings underwent further investigations, including a transthoracic echocardiogram (TTE). Cardiac magnetic resonance (CMR) was subsequently performed based on TTE findings or clinical suspicion. RESULTS: In total, 180 (3%) players had abnormal ECGs and 176 (98%) showed normal TTE results. Athletes aged 26-35 years had a higher prevalence of abnormal ECGs than younger athletes (15-25 years). Black players had a higher prevalence of T-wave inversion (TWI) in the inferior leads than white players (2.6% vs 1.4%; p=0.005), as well as in V5 (2.9%) and V6 (2.1%) compared with white (1.2% and 1.0%; p<0.001) and mixed-race (1.5% and 1.2%; p<0.05) players, respectively. TTE parameters were similar across ethnicities. However, four out of 75 players with inferolateral TWI showed abnormal TTEs and CMR findings consistent with cardiomyopathies. CMR also showed cardiomyopathies or myocarditis in four players with inferolateral TWI and normal TTEs. In total, nine (0.1%) athletes were diagnosed with cardiac diseases and were followed for 40±30 months, with no cardiac events documented. CONCLUSION: This study found a 3% prevalence of abnormal ECGs in male Brazilian football players. Inferolateral TWI was associated with cardiac pathologies confirmed by CMR, even in athletes with a normal TTE.

3-min All-out Test to Evaluate Aerobic and Anaerobic Indexes in Court Team Sports.

This study aimed to test the reproducibility of the 3-min all-out effort applied using shuttle running and compare its values to aerobic parameters. On the first day, 14 futsal players underwent an exhaustive test to determine the maximal incremental speed (MIS) and anaerobic threshold (AnT). On the second day, the participants performed the 3-min all-out effort (n=14), which was repeated after 48 h (third day) to test its reproducibility (n=11). Peak oxygen consumption (V̇ O2PEAK) and peak blood lactate concentrations ([La-]) were determined from 3-min all-out efforts performed through a 20-m shuttle run on the official court. The distance covered, mean speed, and critical speed (CS) during the 3-min all-out presented direct relationships with aerobic parameters determined through the incremental test (r>0.62). The distance covered above CS (D') presented a direct relationship with peak lactate concentrations induced by a 3-min all-out effort (r=0.81). Despite the acceptable levels of reproducibility observed for most of the 3-min all-out variables, the minimal detectable change for D' was high (72%). Our results demonstrated the potential use of mean speed to evaluate aerobic fitness. However, the applicability of the 3-min all-out shuttle run test to monitor training adaptations should be avoided, at least in nonexperienced athletes.

A simplified BRADEN scale for the risk of developing pressure injuries.

BACKGROUND: Pressure injuries (PIs) are a major problem for healthcare providers, impacting both care costs and patients' quality of life, although they are predominately preventable. These injuries are especially present in Intensive Care Units (ICUs) as a result of the severity of the clinical conditions of patients in this unit. AIM: To develop a simplified version of the Braden scale by removing two of the most subjective subscores-Nutrition and Sensory Perception-in an attempt to reduce the chance of errors by the nursing team during the application of the scale. STUDY DESIGN: A cross-sectional study was conducted on data collected from patients admitted to the ICU of a private Brazilian tertiary hospital. The resulting data consisted of 5194 patients, 6353 hospital admissions, and 6974 ICU stays. The overall prevalence of PI was 1.09%. RESULTS: The T-test showed that both the Braden and the simplified Braden scores were significantly different between patients with and without PI (p < .001). Patients who developed PIs scored lower than those who did not. The area under the Receiver Operating Characteristic curve of the Braden Scale was 74.21% (95% CI: 68.61%-79.8%) and of the simplified scale was 72.54% (95% CI: 66.87%-78.22%). The Positive Predictive Value of the Braden Scale was 3.17% when interpolated at the same sensitivity as the simplified scale (47.37%), which achieved 3.26%. CONCLUSIONS: By removing two of the six subscores of the Braden scale we propose a new tool for identifying patients at risk of developing PI in a more objective and fast way. Our results show that classification performance had little negative impact. RELEVANCE TO CLINICAL PRACTICE: A simplified, less subjective scale allows for more precise and less time-consuming risk classification.

A new protein requirement system for dairy cows.

Accurate prediction of protein requirements for maintenance and lactation is needed to develop more profitable diets and reduce N loss and its environmental impact. A new factorial approach for accounting for net protein requirement for maintenance (NPM) and metabolizable protein (MP) efficiency for lactation (EMPL) was developed from a meta-analysis of 223 N balance trials. We defined NPM as the sum of the endogenous protein fecal and urinary excretion and estimated it from the intercept of a nonlinear equation between N intake and combined total N fecal and urinary excretion. Our model had a strong goodness-of-fit to estimate NPM (6.32 ± 0.15 g protein/kg metabolic body weight; n = 807 treatment means; r = 0.91). We calculated the EMPL as a proportion of the N intake, minus N excreted in feces and urine, that was secreted in milk. A fixed-EMPL value of 0.705 ± 0.020 was proposed. In a second independent data set, nonammonia-nonmicrobial-N and microbial-N ruminal outflows were measured, and the adequacy of the MP prediction (51 studies; n = 192 means treatments) was assessed. Our system based on the fixed-EMPL model predicted the MP requirement for lactation and maintenance with higher accuracy than several North American and European dairy cattle nutrition models, including the INRA (2018) and NASEM (2021). Only the NRC (2001), CNCPS 6.5, and Feed into Milk (2004) models had similar accuracy to predict MP requirement. Our system may contribute to improve the prediction for MP requirements of maintenance and lactation. However, most refined predictive models of intestinal digestibility for rumen undegradable protein and microbial protein are still needed to reduce the evaluation biases in our model and external models for predicting the MP requirements of dairy cows.

Acute ecotoxicological effects of Hg(CN)2 in Danio rerio (zebrafish).

Artisanal and small-scale gold mining (ASGM) is the largest source of anthropogenic Hg emissions on the planet. In addition, Hg-contaminated tailings are often reprocessed with sodium cyanide (NaCN) to extract the residual gold remaining in the material. This leads to the formation of mercury cyanide (Hg(CN)2) complexes, which are often discharged in untreated form into local drainages, leading to large amounts of free cyanide being released. However, data on mercury-cyanide interactions are scarce. In this study, we investigated the impact of cyanide and Hg bioavailability in zebrafish when added as Hg(CN)2. Different concentrations of Hg(CN)2 and NaCN were used, leading to an LC50 of 0.53 mg.L-1 for NaCN and 0.16 mg.L-1 for Hg(CN)2. Analyzing free cyanide concentrations in aquarium water, >40% dissociation was observed for NaCN and about 5% for Hg(CN)2. The accumulation of total Hg (THg) in the brain, gills, muscle and kidney was quantified. All fish exposed to Hg(CN)2 had higher THg levels than their controls and kidney was the tissue with higher Hg(CN)2 accumulation. Histological effects on the kidney and gills of both cyanides in D. rerio tissues were investigated, suggesting renal alterations in fish exposed to Hg(CN)2 and showing hyperplasia in the gills of animals exposed to NaCN and Hg(CN)2. The results alert to the risks of the presence of these complexes in aquatic environments.

Downregulation of Sirtuin 1 Does Not Account for the Impaired Long-Term Potentiation in the Prefrontal Cortex of Female APPswe/PS1dE9 Mice Modelling Alzheimer's Disease.

Alzheimer's disease (AD), which predominantly affects women, involves at its onset a metabolic deregulation associated with a synaptic failure. Here, we performed a behavioral, neurophysiological and neurochemical characterization of 9-month-old female APPswe/PS1dE9 (APP/PS1) mice as a model of early AD. These animals showed learning and memory deficits in the Morris water maze, increased thigmotaxis and anxiety-like behavior and showed signs of fear generalization. Long-term potentiation (LTP) was decreased in the prefrontal cortex (PFC), but not in the CA1 hippocampus or amygdala. This was associated with a decreased density of sirtuin-1 in cerebrocortical synaptosomes and a decreased density of sirtuin-1 and sestrin-2 in total cerebrocortical extracts, without alterations of sirtuin-3 levels or of synaptic markers (syntaxin, synaptophysin, SNAP25, PSD95). However, activation of sirtuin-1 did not affect or recover PFC-LTP deficit in APP/PS1 female mice; instead, inhibition of sirtuin-1 increased PFC-LTP magnitude. It is concluded that mood and memory dysfunction in 9-month-old female APP/PS1 mice is associated with a parallel decrease in synaptic plasticity and in synaptic sirtuin-1 levels in the prefrontal cortex, although sirtiun1 activation failed to restore abnormal cortical plasticity.

Circulating microparticles from subjects with active pulmonary tuberculosis infection modulate immune response.

Microparticles (MPs) which circulate within the plasma are elevated in patients with active pulmonary tuberculosis infection. Circulating MPs isolated from the plasma of patients with active pulmonary tuberculosis infection modulate the cytokine production of immune cells in vitro.

Distinct impact of DMARD combination and monotherapy in immunogenicity of an inactivated SARS-CoV-2 vaccine in rheumatoid arthritis.

OBJECTIVES: To evaluate the distinct impact of disease modifying antirheumatic drugs (DMARD) combination and monotherapy in immune response to an inactivated SARS-CoV-2 vaccine in patients with rheumatoid arthritis (RA). METHODS: This phase 4 prospective study analysed seroconversion (SC) of anti-SARS-CoV-2 immunoglobulin G (IgG) and neutralising antibodies (NAb) induced by the inactivated vaccine (CoronaVac) in patients with RA in comparison to controls (CG). Disease activity and treatment were also assessed. Only participants with baseline negative IgG/NAb were included. RESULTS: Patients with RA (N=260) and CG (N=104) had comparable median ages (59 years (50-65 years) vs 58 years (49.8-64 years), p=0.483). Patients with RA had moderate but lower SC (61.8% vs 94.2%, p<0.001) and NAb positivity (45% vs 78.6%, p<0.001) in comparison to CG after full vaccination. Baseline disease activity did not influence immunogenicity (p>0.05). After multivariate analyses, factors independently related to reduced SC were: older age (OR=0.79 (0.70-0.89) for each 5-year interval, p<0.001), methotrexate (OR=0.54 (0.29-0.98), p=0.044), abatacept (OR=0.37 (0.19-0.73), p=0.004) and number of DMARD (OR=0.55 (0.33-0.90), p=0.018). Regarding NAb, age (OR=0.87 (0.78-0.96) for each 5-year interval, p=0.007) and prednisone >7.5 mg/day (OR=0.38 (0.19-0.74), p=0.004) were negatively related to the presence of NAb. Further comparison of SC/NAb positivity among RA treatment subgroups and CG revealed that methotrexate/tofacitinib/abatacept/tocilizumab use, in monotherapy or in combination, resulted in lower responses (p<0.05), while tumour necrosis factor inhibitor and other conventional synthetic DMARD interfered solely when combined with other therapies. CONCLUSIONS: Patients with RA under DMARD have a moderate immunogenicity to CoronaVac. We identified that nearly all DMARD combinations have a deleterious effect in immunogenicity, whereas a more restricted number of drugs (methotrexate/tofacitinib/abatacept/tocilizumab) also hampered this response as monotherapy. These findings reinforce the need of a broader approach, not limited to specific drugs, to improve vaccine response for this population. TRIAL REGISTRATION DETAILS: NCT04754698.

Predictors of progression to systemic sclerosis: analysis of very early diagnosis of systemic sclerosis in a large single-centre cohort.

OBJECTIVE: This study analysed the very early disease of SSc (VEDOSS) characteristics in a group of 217 patients with RP and at least one manifestation of SSc in search of predictors for the progression to SSc. METHODS: This was a cross-sectional single-centre analysis of patients presenting with RP with a specific SSc clinical manifestation or SSc autoantibody or SD pattern at nailfold capillaroscopy (SD-NFC), without skin involvement, who attended a scleroderma outpatient clinic between 2010 and 2019. The performance of VEDOSS and the importance of the combination of VEDOSS characteristics to predict the progression to SSc were evaluated. RESULTS: Among 217 patients, 153 (70.5%) were classified as SSc, including 65 (30%) in the first investigation; 69.3% of the SSc patients met VEDOSS criteria compared with 6.3% of patients who did not progress to SSc. The combinations most associated with progression to SSc were RP + puffy fingers (PF) + positive ANA + SD-NFC and/or SSc-specific antibody (VEDOSS level 2), with an odds ratio (OR) of 19.52 (95% CI 4.48, 85.06; P < 0.001) and RP + PF + positive ANA (VEDOSS level 1; 'red flags') (OR 15.45; P < 0.001), while combinations without non-RP clinical symptoms, as RP + SD-NFC (OR 0.03; P < 0.001) and RP + anticentromere + SD-NFC (OR 0.06; P = 0.006) were associated with non-progression to SSc. CONCLUSION: Among patients with RP with at least one manifestation of SSc, without skin involvement, combinations of VEDOSS characteristics were the strongest predictors of progression to SSc at a median follow-up of 4 years.

SARS-CoV-2 vaccine in patients with systemic sclerosis: impact of disease subtype and therapy.

OBJECTIVE: To analyse the safety, immunogenicity and factors affecting antibody response to Severe Acute Respiratory Syndrome-Coronavirus-2 (SARS-CoV-2) vaccination in patients with SSc. METHODS: This is a phase 4 prospective study within a larger trial of two doses of inactivated SARS-CoV-2 vaccine (CoronaVac) in 51 SSc patients compared with 153 controls. Anti-SARS-CoV-2-IgG and neutralizing antibodies (NAb) were assessed at each vaccine shot (D0/D28) and 6 weeks after the second dose(D69), only in individuals with negative baseline IgG/NAb and those who did not have coronavirus-19(COVID19) during follow-up. Vaccine safety was also assessed in all participants. RESULTS: Patients and controls had comparable median ages [48(38.5-57) vs 48(38-57) years, P =0.945]. Patients had mostly diffuse SSc (68.6%) and the majority (74.5%) had interstitial lung disease. Most patients were under immunosuppressive therapy (72.5%), mainly MMF (52.9%). After full vaccination (D69), anti-SARS-CoV-2-IgG frequency (64.1% vs 94.2%, P < 0.001) and NAb positivity (53.8% vs 76.9%; P =0.006) were moderate, although lower than controls. The first dose response (D28) was low and comparable for both seroconvertion rates (SC) (P =0.958) and NAb positivity (P =0.537). SSc patients under MMF monotherapy vs other (no therapy/other DMARDs) had lower immunogenicity (SC: 31.3% vs 90%, P < 0.001) and NAb(18.8% vs 85%, P < 0.001). Multiple regression analysis confirmed that MMF use, but not disease subtype, is associated with insufficient seroconversion [odds ratio (OR)=0.056(95% CI: 0.009, 0.034), P =0.002] and NAb positivity [OR = 0.047(95% CI: 0.007, 0.036), P =0.002]. No moderate/severe side-effects were observed. CONCLUSION: CoronaVac has an excellent safety profile and moderate response to anti-SARS-CoV-2 vaccine in SSc. Vaccine antibody response is not influenced by disease subtype and is greatly affected by MMF, reinforcing the need for additional strategies to up-modulate vaccine response in this subgroup of patients. TRIAL REGISTRATION: ClinicalTrials.gov, https://clinicaltrials.gov, NCT04754698.

KLRG1+ Memory CD8 T Cells Combine Properties of Short-Lived Effectors and Long-Lived Memory.

CD8 effector T cells with a CD127hi KLRG1- phenotype are considered precursors to the long-lived memory pool, whereas KLRG1+CD127low cells are viewed as short-lived effectors. Nevertheless, we and others have shown that a KLRG1+CD127low population persists into the memory phase and that these T cells (termed long-lived effector cells [LLEC]) display robust protective function during acute rechallenge with bacteria or viruses. Whether these T cells represent a true memory population or are instead a remnant effector cell population that failed to undergo initial contraction has remained unclear. In this study, we show that LLEC from mice express a distinct phenotypic and transcriptional signature that shares characteristics of both early effectors and long-lived memory cells. We also find that in contrast to KLRG1+ effector cells, LLEC undergo homeostatic proliferation and are not critically dependent on IL-15 for their maintenance. Furthermore, we find that LLEC are predominantly derived from KLRG1+ effector cells when isolated at day 12 of the response. Our work challenges the concept that the KLRG1+CD127low population is dominated by short-lived cells and shows that KLRG1 downregulation is not a prerequisite to become a long-lived protective memory T cell.