Autocrine vitamin D signaling switches off pro-inflammatory programs of TH1 cells.

The molecular mechanisms governing orderly shutdown and retraction of CD4+ type 1 helper T (TH1) cell responses remain poorly understood. Here we show that complement triggers contraction of TH1 responses by inducing intrinsic expression of the vitamin D (VitD) receptor and the VitD-activating enzyme CYP27B1, permitting T cells to both activate and respond to VitD. VitD then initiated the transition from pro-inflammatory interferon-γ+ TH1 cells to suppressive interleukin-10+ cells. This process was primed by dynamic changes in the epigenetic landscape of CD4+ T cells, generating super-enhancers and recruiting several transcription factors, notably c-JUN, STAT3 and BACH2, which together with VitD receptor shaped the transcriptional response to VitD. Accordingly, VitD did not induce interleukin-10 expression in cells with dysfunctional BACH2 or STAT3. Bronchoalveolar lavage fluid CD4+ T cells of patients with COVID-19 were TH1-skewed and showed de-repression of genes downregulated by VitD, from either lack of substrate (VitD deficiency) and/or abnormal regulation of this system.

The role of CD8+ T-cell clones in immune thrombocytopenia.

Immune thrombocytopenia (ITP) is traditionally considered an antibody-mediated disease. However, a number of features suggest alternative mechanisms of platelet destruction. In this study, we use a multidimensional approach to explore the role of cytotoxic CD8+ T cells in ITP. We characterized patients with ITP and compared them with age-matched controls using immunophenotyping, next-generation sequencing of T-cell receptor (TCR) genes, single-cell RNA sequencing, and functional T-cell and platelet assays. We found that adults with chronic ITP have increased polyfunctional, terminally differentiated effector memory CD8+ T cells (CD45RA+CD62L-) expressing intracellular interferon gamma, tumor necrosis factor α, and granzyme B, defining them as TEMRA cells. These TEMRA cells expand when the platelet count falls and show no evidence of physiological exhaustion. Deep sequencing of the TCR showed expanded T-cell clones in patients with ITP. T-cell clones persisted over many years, were more prominent in patients with refractory disease, and expanded when the platelet count was low. Combined single-cell RNA and TCR sequencing of CD8+ T cells confirmed that the expanded clones are TEMRA cells. Using in vitro model systems, we show that CD8+ T cells from patients with ITP form aggregates with autologous platelets, release interferon gamma, and trigger platelet activation and apoptosis via the TCR-mediated release of cytotoxic granules. These findings of clonally expanded CD8+ T cells causing platelet activation and apoptosis provide an antibody-independent mechanism of platelet destruction, indicating that targeting specific T-cell clones could be a novel therapeutic approach for patients with refractory ITP.

Magnitude and Kinetics of CD8+ T Cell Activation during Hyperacute HIV Infection Impact Viral Set Point.

CD8(+) T cells contribute to the control of HIV, but it is not clear whether initial immune responses modulate the viral set point. We screened high-risk uninfected women twice a week for plasma HIV RNA and identified 12 hyperacute infections. Onset of viremia elicited a massive HIV-specific CD8(+) T cell response, with limited bystander activation of non-HIV memory CD8(+) T cells. HIV-specific CD8(+) T cells secreted little interferon-γ, underwent rapid apoptosis, and failed to upregulate the interleukin-7 receptor, known to be important for T cell survival. The rapidity to peak CD8(+) T cell activation and the absolute magnitude of activation induced by the exponential rise in viremia were inversely correlated with set point viremia. These data indicate that rapid, high magnitude HIV-induced CD8(+) T cell responses are crucial for subsequent immune control of acute infection, which has important implications for HIV vaccine design.

Identification of occult cerebral microbleeds in adults with immune thrombocytopenia.

Management of symptoms and prevention of life-threatening hemorrhage in immune thrombocytopenia (ITP) must be balanced against adverse effects of therapies. Because current treatment guidelines based on platelet count are confounded by variable bleeding phenotypes, there is a need to identify new objective markers of disease severity for treatment stratification. In this cross-sectional prospective study of 49 patients with ITP and nadir platelet counts <30 × 109/L and 18 aged-matched healthy controls, we used susceptibility-weighted magnetic resonance imaging to detect cerebral microbleeds (CMBs) as a marker of occult hemorrhage. CMBs were detected using a semiautomated method and correlated with clinical metadata using multivariate regression analysis. No CMBs were detected in health controls. In contrast, lobar CMBs were identified in 43% (21 of 49) of patients with ITP; prevalence increased with decreasing nadir platelet count (0/4, ≥15 × 109/L; 2/9, 10-14 × 109/L; 4/11, 5-9 × 109/L; 15/25 <5 × 109/L) and was associated with longer disease duration (P = 7 × 10-6), lower nadir platelet count (P = .005), lower platelet count at time of neuroimaging (P = .029), and higher organ bleeding scores (P = .028). Mucosal and skin bleeding scores, number of previous treatments, age, and sex were not associated with CMBs. Occult cerebral microhemorrhage is common in patients with moderate to severe ITP. Strong associations with ITP duration may reflect CMB accrual over time or more refractory disease. Further longitudinal studies in children and adults will allow greater understanding of the natural history and clinical and prognostic significance of CMBs.

HLA-A is a Predictor of Hepatitis B e Antigen Status in HIV-Positive African Adults.

Outcomes of chronic infection with hepatitis B virus (HBV) are varied, with increased morbidity reported in the context of human immunodeficiency virus (HIV) coinfection. The factors driving different outcomes are not well understood, but there is increasing interest in an HLA class I effect. We therefore studied the influence of HLA class I on HBV in an African HIV-positive cohort. We demonstrated that virologic markers of HBV disease activity (hepatitis B e antigen status or HBV DNA level) are associated with HLA-A genotype. This finding supports the role of the CD8(+) T-cell response in HBV control, and potentially informs future therapeutic T-cell vaccine strategies.

The value of angiogenetic biomarkers in the detection of early onset fetal growth restriction.

OBJECTIVE: The identification of fetal growth restriction (FGR) due to uteroplacental insufficiency is important to improve perinatal outcomes. To distinguish FGR from small for gestational age (SGA), FGR consensus definition is currently based on biometry and/or additional biophysical parameters. This study aims to verify if this definition might be modified by including circulating angiogenic factors. STUDY DESIGN: This historical cohort study included singleton pregnancies with SGA fetuses after 20 weeks. All patients underwent detailed ultrasound and measurements of soluble fms-like tyrosine kinase 1 (sFlt-1) and placental growth factor (PlGF) at first assessment. ISUOG criteria for FGR were applied. Total PlGF was calculated using free PlGF, sFlt-1 and a receptor pharmacology model, and multiple of the median (MoM) values for sFlt-1, free PlGF, total PlGF and sFlt-1/PlGF ratio were calculated to adjust for gestational age. RESULTS: 72 pregnancies with SGA were first evaluated at median (IQR) of 28+5 (26+2 -31+3) weeks' gestation, and 51 fetuses (70.8 %) satisfied the FGR consensus definition. Pregnancies with FGR showed significantly lower levels of free and total PlGF MoM (0.12, 95 % IQR: 0.07-0.36 vs 0.32, 95 % IQR: 0.20-0.53, p = 0.008) and 0.26, 95 % CI: 0.16-0.55 vs 0.43, 95 % IQR: 0.23-0.53, p = 0.028) respectively; and higher sFlt-1 MoM (4.62, 95 % IQR: 1.80-7.30 vs 1.74, 95 % IQR:1.11-3.61, p = 0.014) than pregnancies not classified as FGR. Free and total PlGF MoM correlated significantly with gestational age at delivery (r = 0.776, p < 0.001 and r = 0.707, p < 0.001, respectively). sFlt-1 MoM and sFlt-1/PlGF ratio MoM also correlated with gestational age at delivery (r = -0.681, p < 0.001 and r = -0.823, p < 0.001). Six cases identified as FGR at first ultrasound were not confirmed at birth showing significantly higher levels of free PlGF MoM (0.77, 95 % IQR: 0.27-3.07 vs 0.17, 95 % IQR: 0.08-0.43, p = 0.022). CONCLUSION: These findings show that total as well as free PlGF levels are lower in pregnancies affected with placental growth restriction. Angiogenic biomarkers might improve the differentiation between placental growth restriction and constitutional smallness. Further studies are needed to determine how to integrate them into the current definitions of FGR.

Retrocecal Ascending Appendix Attached to the Hepatic Flexure and Right Intra-abdominal Testis Identified During Open Appendicectomy: A Case Report.

Appendicectomy, or the removal of the appendix, is an emergency procedure following symptomatic acute appendicitis. Diagnosis is made on clinical examination but can be confirmed on imaging if other abnormalities are suspected. A few variants of appendix anatomical position exist that can be difficult to manage. In addition, secondary findings during surgery can come unexpectedly. We report a case of a 14-year-old male, who presented to the emergency department at our government institution with abdominal pain and vomiting. Examination revealed an empty right scrotum, which was unnoticed by the patient and never examined previously due to residence in an area of limited healthcare access. Ultrasound done elsewhere was inconclusive. The surgical intervention showed a retrocecal appendix attached to an ascending colon terminating at hepatic flexure. The procedure was further complicated by the presence of the right intra-abdominal testis located below the cecum. Excised samples were sent for histopathology, and the patient was followed with biopsy reports. This case highlights the challenges encountered during routine appendicectomy with unusual findings.

Smartphone use and its association with body image distortion and weight loss behaviours among adolescents in Saudi Arabia.

BACKGROUND: Concerns about the harmful effects of smartphone use on teenage development have been raised as the use of cell phones among adolescents has risen. OBJECTIVE: This study aimed to examine the associations of smartphone usage patterns with Body Image Distortion (BID) and weight loss behaviors among adolescent smartphone users in Saudi Arabia. METHODS: This population-based, cross-sectional study was conducted from July to October 2022. We assessed the mean daily length of smartphone use and classified it into quartiles using data from a self-reported survey and data on weekday and weekend use. Self-reported body weight and height were collected via an online survey. Out of the 11384 adolescents, the majority was females (65.7%) and was secondary school students (68.9%). RESULTS: The prolonged smartphone use (301 min/d) was found in 36.4% of adolescents, 181-300 min/d in 27.6% of respondents, 121-180 min/d in 22.4% of respondents, while the modest smartphone use (1-120 min/d) was found only in 13.6% of participants. The duration of smartphone use was significantly associated with BID (P= 0.000); students with middle perceived stress levels (51.4%) and no depressive symptoms (68.9%) used smartphones 121-180 min/d sparingly. However, prolonged smartphone use was significantly associated with the presence of depressive symptoms (42.6%) and high perceived stress levels (21.5%). Weight loss behaviors were significantly associated with smartphone use duration. Modest smartphone use was significantly found in students with normal weight (P= 0.00, 71.9%); however, aerobic physical activity weight loss strategy (P= 0.00, 30.9%) was correlated with prolonged smartphone use. CONCLUSION: Adequate parental advice is required to assist teenagers in developing healthy smartphone usage practices. Digital platform companies may increase their social responsibility for the information generated and delivered on their networks, boosting its beneficial effect.

Unmet expectations about material properties delay perceptual decisions.

Based on our expectations about material properties, we can implicitly predict an object's future states, e.g., a wine glass falling down will break when it hits the ground. How these expectations affect relatively low-level perceptual decisions, however, has not been systematically studied previously. To seek an answer to this question, we conducted a behavioral experiment using animations of various familiar objects (e.g., key, wine glass, etc.) freely falling and hitting the ground. During a training session, participants first built expectations about the dynamic properties of those objects. Half of the participants (N = 28) built expectations consistent with their daily lives (e.g., a key bounces rigidly), whereas the other half learned an atypical behavior (e.g., a key wobbles). This was followed by experimental sessions, in which expectations were unmet in 20% of the trials. In both training and experimental sessions, the participant's task was to report whether the objects broke or not upon hitting the ground. Critically, a specific object always remained intact or broke - only the manner in which it did so differed. For example, a key could wobble or remain rigid but never break. We found that participants' reaction times were longer when expectations were unmet, not only for typical material behavior but also when those expectations were atypical and learned during the training session. Furthermore, we found an interplay between long-term and newly learned expectations. Overall, our results show that expectations about material properties can impact relatively low-level perceptual decision-making processes.

Umbilical Pilonidal Sinus.

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Frequency of Urinary Tract Infection Among Patients Undergoing Implant Fixation for Acute Trauma.

OBJECTIVE: This study aims to determine the frequency of urinary tract infection (UTI), identify the isolated bacteria, and assess antibiotic sensitivity in patients undergoing orthopedic implant fixation for hip fractures. METHODOLOGY: After ethical approval from the institutional review board, this retrospective cross-sectional study was conducted at the Orthopedic Surgery Department of Dow University Hospital Karachi from June 2022 to June 2023. Through non-probability consecutive sampling, 186 patients above 16 years of age, of either gender, presenting with hip fractures such as intracapsular or extracapsular fractures, who underwent surgical fixation, were included in the study. A urine sample for urinalysis of these patients was sent on admission. Patients who presented with open fractures or those treated with conservative management were excluded from the study. The fracture diagnosis was confirmed on radiographs. All other relevant baseline investigations were also performed before surgery, per protocol, and urine-detailed and cultured reports were followed. In addition, each patient was asked about common symptoms of UTI before surgery and then diagnosed with UTI on positive urine culture and sensitivity (CS). RESULTS: Out of 186 hip fracture patients, 98 (52.7%) were males and 88 (47.3%) were females, with a mean age of 61.03 ± 16.43 (16-96) years. Pre-operative UTI symptoms were reported by 79 patients, including dysuria (16; 20.3%), polyuria (19; 24.0%), and burning (44; 55.7%). UTI was diagnosed on culture and sensitivity report in 65 (34.9%) patients with Escherichia coli as commonly diagnosed bacteria 35 (53.8%), followed by Enterococcus 8 (12.4%), Klebsiella 7 (10.9%), Pseudomonas aeruginosa 3 (4.7%), and Acinetobacter 2 (3.1%) patients. E. coli was sensitive to amikacin, amoxicillin/clavulanic acid, ampicillin, cefixime, ceftriaxone, cefuroxime, ciprofloxacin, colistin, cotrimoxazole, fosfomycin, gentamycin, levofloxacin, meropenem, nitrofurantoin, polymyxin B, and piperacillin-tazobactam. CONCLUSION: Urinary tract infection is common in patients undergoing orthopedic implant fixation for hip fractures, which can lead to potentially serious outcomes. Overall, hygiene, prompt treatment, and standard protocol should be utilized to treat those infected and minimize the spread.

Exploring the Indications, Levels, and Outcomes of Lower Extremity Amputation at a Tertiary Care Hospital in Pakistan.

BACKGROUND: Lower extremity amputation (LEA) is a surgical procedure performed to remove either a part or the entire lower limb due to medical conditions such as trauma, infection, peripheral vascular disease, or malignancy. The procedure is becoming increasingly common in Pakistan, with a bulk of patients presenting from rural areas in tertiary care centers. Understanding the indications, levels, and outcomes of LEA is essential for improving patient care and adopting preventive strategies, especially in developing countries. METHODOLOGY: This study was conducted at Dow University Hospital in Karachi, Pakistan. Retrospective data of 384 patients who underwent non-traumatic lower extremity amputations between January 2016 and December 2020 was collected to include relevant history and characteristics, amputation indication and level, type of anesthesia used, and outcome within hospital stay. The data was analyzed using descriptive statistics. RESULTS: The data is composed of a wide age range (18 to 91 years) of patients, including a male majority (76.3%, n = 293). The employment status of the patients was taken into consideration, with a reported high number of unemployed individuals (60.4%, n = 232). Diabetes mellitus (84.4%, n = 324) was a commonly reported past medical condition, followed by hypertension (4.4%, n = 17). Indications for amputation exceedingly recorded were diabetic foot ulcers (84.4%, n = 324), followed by infections (9.4%, n = 36) and peripheral arterial disease (3.6%, n = 14). The anesthetic approach that was observed most in these patients was regional anesthesia (74.7%, n = 287). Right-sided amputations (52.9%, n = 203) were dominant, with below-knee amputations leading by the level of amputation performed (42.5%, n = 163). Many patients delayed seeking treatment (71.6%, n = 275) and indicated denial of severity (18%, n = 69) as a reason for the delay. Regarding outcome, many patients were successfully discharged following treatment (85.9%, n = 330). CONCLUSION: Overall, LEAs are being frequently performed in developing countries, such as Pakistan, especially with a large population living with diabetes mellitus. The implications of this disease are reflected in this study population, with the majority of patients reporting delays in treatment due to reasons such as the unknown severity of the disease or financial burdens. The challenges faced by these individuals, especially in this country, can be tackled with widespread affordability and availability of care and education on early management.

Distorted TCR repertoires define multisystem inflammatory syndrome in children.

While the majority of children infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) display mild or no symptoms, rare individuals develop severe disease presenting with multisystem inflammatory syndrome (MIS-C). The reason for variable clinical manifestations is not understood. Here, we carried out TCR sequencing and conducted comparative analyses of TCR repertoires between children with MIS-C (n = 12) and mild (n = 8) COVID-19. We compared these repertoires with unexposed individuals (samples collected pre-COVID-19 pandemic: n = 8) and with the Adaptive Biotechnologies MIRA dataset, which includes over 135,000 high-confidence SARS-CoV-2-specific TCRs. We show that the repertoires of children with MIS-C are characterised by the expansion of TRBV11-2 chains with high junctional and CDR3 diversity. Moreover, the CDR3 sequences of TRBV11-2 clones shift away from SARS-CoV-2 specific T cell clones, resulting in distorted TCR repertoires. In conclusion, our study reports that CDR3-independent expansion of TRBV11-2+ cells, lacking SARS-CoV-2 specificity, defines MIS-C in children.

Lead tolerant endophyte Trametes hirsuta improved the growth and lead accumulation in the vegetative parts of Triticum aestivum L.

Rapid industrialization and increasing population are continuously adding contaminants to our environment. Among those, heavy metals are considered to be one of the serious threats to the ecosystem due to their persistent nature. Microbe assisted phytoremediation is an effective tool for metal remediation as microbes enhance the metal availability and uptake to the host plants or reduce it by binding them intracellularly or extracellularly. An endophytic fungus, Trametes hirsuta, was isolated from Chenopodium album L. plant growing in the lead (Pb) contaminated soil of an industrial area. This is the first study citing Trametes hirsuta, as a root endophyte of Chenopodium album L. This endophytic fungus was found to be tolerant to high concentration of Pb i.e., 1500 mg L-1, when tested in-vitro. Wheat (Triticum aestivum L.) seedlings were infected by Trametes hirsuta and Pb tolerance was observed. With the fungal inoculation plants cumulative growth and total chlorophyll content increased by 24% and 18%, respectively as compared to their respective non-inoculated controls at 1000 mg kg-1 Pb. Similary, 50% more Pb accumulation was measured in the shoots of fungal inoculated plants at 1500 mg kg-1 Pb as compared to control. Thus, the results of the present study suggest that mutualism with endophytic fungi can improve the survival of host plants in metal contaminated soils, additionally it can also assist the phytoextraction of heavy metals from polluted sites by increasing their uptake by the host plants.

Corrigendum: Cytomegalovirus-Mediated T Cell Receptor Repertoire Perturbation Is Present in Early Life.

[This corrects the article DOI: 10.3389/fimmu.2020.01587.].

Cytomegalovirus-Mediated T Cell Receptor Repertoire Perturbation Is Present in Early Life.

Human cytomegalovirus (CMV) is a highly prevalent herpesvirus, particularly in sub-Saharan Africa, where it is endemic from infancy. The T cell response against CMV is important in keeping the virus in check, with CD8 T cells playing a major role in the control of CMV viraemia. Human leukocyte antigen (HLA) B*44:03-positive individuals raise a robust response against the NEGVKAAW (NW8) epitope, derived from the immediate-early-2 (IE-2) protein. We previously showed that the T cell receptor (TCR) repertoire raised against the NW8-HLA-B*44:03 complex was oligoclonal and characterised by superdominant clones, which were shared amongst unrelated individuals (i.e., "public"). Here, we address the question of how stable the CMV-specific TCR repertoire is over the course of infection, and whether substantial differences are evident in TCR repertoires in children, compared with adults. We present a longitudinal study of four HIV/CMV co-infected mother-child pairs, who in each case express HLA-B*44:03 and make responses to the NW8 epitope, and analyse their TCR repertoire over a period spanning more than 10 years. Using high-throughput sequencing, the paediatric CMV-specific repertoire was found to be highly diverse. In addition, paediatric repertoires were remarkably similar to adults, with public TCR responses being shared amongst children and adults alike. The CMV-specific repertoire in both adults and children displayed strong fluctuations in TCR clonality and repertoire architecture over time. Previously characterised superdominant clonotypes were readily identifiable in the children at high frequency, suggesting that the distortion of the CMV-specific repertoire is incurred as a direct result of CMV infection rather than a product of age-related "memory inflation." Early distortion of the TCR repertoire was particularly apparent in the case of the TCR-ß chain, where oligoclonality was low in children and positively correlated with age, a feature we did not observe for TCR-α. This discrepancy between TCR-α and -ß chain repertoire may reflect differential contribution to NW8 recognition. Altogether, the results of the present study provide insight into the formation of the TCR repertoire in early life and pave the way to better understanding of CD8 T cell responses to CMV at the molecular level.

An autocrine Vitamin D-driven Th1 shutdown program can be exploited for COVID-19.

Pro-inflammatory immune responses are necessary for effective pathogen clearance, but cause severe tissue damage if not shut down in a timely manner 1,2 . Excessive complement and IFN-γ-associated responses are known drivers of immunopathogenesis 3 and are among the most highly induced immune programs in hyper-inflammatory SARS-CoV2 lung infection 4 . The molecular mechanisms that govern orderly shutdown and retraction of these responses remain poorly understood. Here, we show that complement triggers contraction of IFN-γ producing CD4 + T helper (Th) 1 cell responses by inducing expression of the vitamin D (VitD) receptor (VDR) and CYP27B1, the enzyme that activates VitD, permitting T cells to both activate and respond to VitD. VitD then initiates the transition from pro-inflammatory IFN-γ + Th1 cells to suppressive IL-10 + Th1 cells. This process is primed by dynamic changes in the epigenetic landscape of CD4 + T cells, generating superenhancers and recruiting c-JUN and BACH2, a key immunoregulatory transcription factor 5-7 . Accordingly, cells in psoriatic skin treated with VitD increased BACH2 expression, and BACH2 haplo-insufficient CD4 + T cells were defective in IL-10 production. As proof-of-concept, we show that CD4 + T cells in the bronchoalveolar lavage fluid (BALF) of patients with COVID-19 are Th1-skewed and that VDR is among the top regulators of genes induced by SARS-CoV2. Importantly, genes normally down-regulated by VitD were de-repressed in CD4 + BALF T cells of COVID-19, indicating that the VitD-driven shutdown program is impaired in this setting. The active metabolite of VitD, alfacalcidol, and cortico-steroids were among the top predicted pharmaceuticals that could normalize SARS-CoV2 induced genes. These data indicate that adjunct therapy with VitD in the context of other immunomodulatory drugs may be a beneficial strategy to dampen hyperinflammation in severe COVID-19.

Hospital preparedness and management of pediatric population during COVID-19 outbreak.

With the recent pandemic of Coronavirus disease-2019 (COVID-19), there has been a higher number of reported cases in children more than to the prior Corona Virus-related diseases, namely, severe acute respiratory syndrome and the Middle East respiratory syndrome. The rate of COVID-19 in children is lower than adults; however, due to high transmission rate, the number of reported cases in children has been increasing. With the rising numbers among children, it is imperative to develop preparedness plans for the pediatric population at the hospital level, departmental level, and patient care areas. This paper summarizes important considerations for pediatric hospital preparedness at the hospital level that includes workforce, equipment, supply; capacity planning, and infection prevention strategies, it also span over the management of COVID-19 pediatric patients in high-risk areas such as critical care areas, Emergency Department and operative rooms.