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Introduction: Post-COVID syndrome (PCS) is characterized by a polymorphism of symptoms with hypothetical pathophysiological mechanisms. Here, we aimed to analyze the profile of inflammatory cytokines in patients with PCS and to study the relationship between this profile, the clinical symptoms as well as the endothelial function in PCS., Methods: Our analytical study involved all eligible patients (n = 66) with PCS included from April 2021 to December 2021. The serum concentration of cytokines IFN-γ, IL-1α, IL-1β, IL-6, IL-8, IL-10, IL-12p70, IL-27, IP-10, MCP-1 and TNF-α was quantified by flow cytometry. Endothelial function was explored by assessing microvascular flow and reactivity using thermal probes. A comparative study was carried out according to the presence of each PCS symptom., Results: The average age of our patients was 55.9 ± 16.2 years. The sex ratio was 0.69. Forty-one patients (62%) presented with a severe form of acute infection. The most frequently reported symptoms were dyspnea (67%), fatigue (50%), and memory problems (32%). Fifty-seven patients (86%) had endothelial dysfunction. The majority of patients had increased levels of IP-10 (100%), IL-8 (95%), IFN-γ (95%), MCP-1 (80%), and TNF-α (70%). The serum concentration of IL-10 was below the threshold of quantification in 89% of subjects. The severe form of acute infection was associated with elevated IL-10, MCP-1, and IL-27. Increased IL-6 and IL-27 levels were associated with fatigue while IL-8 concentrations were higher in patients who reported dyspnea. Elevation of IL-8 level was more common in patients with profound impairment of endothelial function., Conclusion: Our results further support the presence of endothelial dysfunction in PCS and show an elevation of pro-inflammatory cytokines with a downmodulation of the IL-10- anti-inflammatory response. In addition, immuno-clinical phenotypes emerge, such as an inflammatory profile mediated by IL-6 and IL-27 in fatigue and IL-8 in dyspnea. The identification of immuno-clinical phenotypes would allow a better understanding of the pathophysiology of PCS symptoms., Competing Interests: Declarations. Ethics approval and consent to participate: The study was approved by the ethics committee of Mongi Slim hospital (number 40/2023). All patients provided written informed consent for the collection of samples and subsequent analysis. All research was conducted according to the declaration of Helsinki principles. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2024. The Author(s).)

This study aimed to assess the kinetics of antibodies against the SARS-CoV-2, following natural infection in a cohort of employees of the Institut Pasteur de Tunis (IPT) and to assess the risk of reinfection over a 12-months follow-up period. A prospective study was conducted among an open cohort of IPT employees with confirmed SARS-CoV-2 infection that were recruited between September 2020 and March 2021. Sera samples were taken at 1, 3, 6, 9 and 12 months after confirmation of COVID-19 infection and tested for SARS-CoV-2-specific immunoglobulin G (IgG) antibodies to the spike (S-RBD) protein (IgG anti-S-RBD) and for neutralizing antibodies. Participants who had an initial decline of IgG anti-S-RBD and neutralizing antibodies followed by a subsequent rise in antibody titers as well as those who tested positive for SARS-CoV-2 by RT-PCR after at least 60 days of follow up were considered as reinfected. In total, 137 individuals were included with a mean age of 44.7 ± 12.3 years and a sex-ratio (Male/Female) of 0.33. Nearly all participants (92.7%) were symptomatic, and 2.2% required hospitalization. Among the 70 participants with three or more prospective blood samples, 32.8% were reinfected among whom 11 (47.8%) reported COVID-19 like symptoms. Up to 12 months of follow up, 100% and 42.9% of participants had detectable IgG anti-S-RBD and neutralizing antibodies, respectively. This study showed that humoral immune response following COVID-19 infection may persist up to 12 months after infection despite the potential risk for reinfection that is mainly explained by the emergence of new variants.

This study proposes to monitor the physical, immune and cognitive responses and adaptations of elite rugby players throughout the season based on the loads performed. Anthropometric measurements, physical fitness tests (e.g., muscle strength and power, linear and change-of-direction speed, cardiorespiratory fitness) and analyses of serum concentrations of markers of muscle damage (creatine kinase [CK] and lactate dehydrogenase [LDH]) and brain-derived neurotrophic factor (BDNF) were carried out over a sporting season (24 weeks) for 17 elite rugby players (10 forwards and 7 backs) aged 18.91 ± 0.76 years. The physical fitness test results show improvements in the performance of both forwards and backs over the season ( p < 0.05), with an advantage for backs compared with forwards in most tests ( p < 0.05). Muscle damage markers decreased at the end of the season compared with the baseline levels for forwards ( p < 0.05). CK levels were unchanged for the backs, but there were increased LDH concentrations at the end of the season compared with baseline ( p < 0.05). Serum BDNF levels decreased for the total group between the second and third sampling ( p < 0.05). The muscular and physical capacities of rugby players differ according to their playing position. Immune responses and adaptations, as well as BDNF levels, vary throughout the season and depend on the physical load performed.

Despite significant advancements in the field, the pathophysiology of multiple sclerosis (MS) remains partially understood, with limited therapeutic options available for this debilitating condition. The precise impact of Interleukin-22 (IL-22) in the context of MS is still incompletely elucidated with some evidence suggesting its protective role. To provide a more comprehensive understanding of the role of IL-22, we investigated its effect on remyelination in a mouse model of demyelination induced by Cuprizone. Mice underwent a 6 week regimen of Cuprizone or vehicle, followed or not by intraperitoneal administration of IL-22. Behavioral assessments including tail suspension and inverted screen tests were conducted, alongside histological, histochemical, and quantitative PCR analyses. In Cuprizone-treated mice, IL-22 significantly improved motor and behavioral performance and robustly promoted remyelination in the corpus callosum . Additionally, IL-22 administration led to a significant elevation in MBP transcription in brain biopsies of treated mice. These findings collectively suggest a crucial role for IL-22 in the pathophysiology of MS, particularly in supporting the process of remyelination. These results offer potential avenues for expanding therapeutic strategies for MS treatment. Ongoing experiments aim to further unravel the underlying mechanisms of IL-22 action., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Zamali, Elbini, Rekik, Neili, Ben Hamouda, Ben Hmid, Doghri and Ben Ahmed.)

Efficient precision vaccines against several highly pathogenic zoonotic viruses are currently lacking. Proteolytic activation is instrumental for a number of these viruses to gain host-cell entry and develop infectivity. For SARS-CoV-2, this process is enhanced by the insertion of a furin cleavage site at the junction of the spike protein S1/S2 subunits upstream of the metalloprotease TMPRSS2 common proteolytic site. Here, we describe a new approach based on specific epitopes selection from the region involved in proteolytic activation and infectivity for the engineering of precision candidate vaccinating antigens. This approach was developed through its application to the design of SARS-CoV-2 cross-variant candidates vaccinating antigens. It includes an in silico structural analysis of the viral region involved in infectivity, the identification of conserved immunogenic epitopes and the selection of those eliciting specific immune responses in infected people. The following step consists of engineering vaccinating antigens that carry the selected epitopes and mimic their 3D native structure. Using this approach, we demonstrated through a Covid-19 patient-centered study of a 500 patients' cohort, that the epitopes selected from SARS-CoV-2 protein S1/S2 junction elicited a neutralizing antibody response significantly associated with mild and asymptomatic COVID-19 (p<0.001), which strongly suggests protective immunity. Engineered antigens containing the SARS-CoV-2 selected epitopes and mimicking the native epitopes 3D structure generated neutralizing antibody response in mice. Our data show the potential of this combined computational and experimental approach for designing precision vaccines against viruses whose pathogenicity is contingent upon proteolytic activation., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Trabelsi, Ben Khalaf, Ramadan, Elsharkawy, Ashoor, Chlif, Boussoffara, Ben-Ahmed, Kumar and Fathallah.)

Background: Vaccination constitutes the best strategy against COVID-19. In Tunisia, seven vaccines standing for the three main platforms, namely RNA, viral vector, and inactivated vaccines, have been used to vaccinate the population at a large scale. This study aimed to assess, in our setting, the kinetics of vaccine-induced anti-RBD IgG and IgA antibody responses., Methods: Using in-house developed and validated ELISA assays, we measured anti-RBD IgG and IgA serum antibodies in 186 vaccinated workers at the Institut Pasteur de Tunis over 12 months., Results: We showed that RNA vaccines were the most immunogenic vaccines, as compared to alum-adjuvanted inactivated and viral-vector vaccines, either in SARS-CoV-2-naïve or in SARS-CoV-2-experienced individuals. In addition to the IgG antibodies, the vaccination elicited RBD-specific IgAs. Vaccinated individuals with prior SARS-CoV-2 infection exhibited more robust IgG and IgA antibody responses, as compared to SARS-CoV-2-naïve individuals., Conclusions: After following up for 12 months post-immunization, we concluded that the hierarchy between the platforms for anti-RBD antibody-titer dynamics was RNA vaccines, followed by viral-vector and alum-adjuvanted inactivated vaccines.

We investigated selected oxylipins and related synthesizing/signaling pathways in 28 patients with Crohn's disease (CD), 19 patients with ulcerative colitis (UC), and 39 controls. Plasma and mucosal PUFA/oxylipin profiles were analyzed by LC-MS/MS. mRNA expression of 5, 12 and 15-lipooxygenases, FPR2/ALXR, FFAR4/GPR120, annexin A1, and interleukin-10 were analyzed by qRT-PCR. Oxylipin profile and related metabolic pathways were altered in both CD and UC patients. The patterns were characterized by increased prostaglandins, leukotrienes, and lipoxins and overexpression of 5-lipoxygenase, FPR2/ALXR, annexin A1, and interleukin-10 genes, but decreased n-3 PUFAs and 18-hydroxyeisapentaenoic acid. The gene of 15-lipoxygenase was under-expressed mainly in UC patients. CD and UC are associated with unbalanced n-6 ​​and n-3 derivatives and pro-inflammatory and anti-inflammatory/pro-resolving mediators favoring the former compounds. The findings suggest that oxylipins engage in the pathophysiology of the diseases. Targeting oxylipin's metabolic pathways would be a promising therapy for inflammatory bowel diseases., Competing Interests: Declaration of competing interest The authors declare that they have no conflict of interest., (Copyright © 2024 Elsevier Ltd. All rights reserved.)

Background: Allogeneic hematopoietic stem cell transplantation (ASCT) induces acquired immunodeficiency, potentially altering vaccine response. Herein, we aimed to explore the clinical tolerance and the humoral and cellular immune responses following anti-SARS-CoV-2 vaccination in ASCT recipients., Methods: A prospective, non-randomized, controlled study that involved 43 ASCT subjects and 31 healthy controls. Humoral response was investigated using the Elecsys ® test anti-SARS-CoV-2. Cellular response was assessed using the QFN ® SARS-CoV-2 test. The lymphocyte cytokine profile was tested using the LEGENDplex™ HU Th Cytokine Panel Kit (12-plex)., Results: Adverse effects (AE) were observed in 69% of patients, encompassing pain at the injection site, fever, asthenia, or headaches. Controls presented more side effects like pain in the injection site and asthenia with no difference in the overall AE frequency. Both groups exhibited robust humoral and cellular responses. Only the vaccine transplant delay impacted the humoral response alongside a previous SARS-CoV-2 infection. Noteworthily, controls displayed a Th1 cytokine profile, while patients showed a mixed Th1/Th2 profile., Conclusions: Pfizer-BioNTech ® anti-SARS-CoV-2 vaccination is well tolerated in ASCT patients, inducing robust humoral and cellular responses. Further exploration is warranted to understand the impact of a mixed cytokine profile in ASCT patients.

Introduction: Monogenic diabetes (MD) accounts for 3%-6% of all cases of diabetes. This prevalence is underestimated due to its overlapping clinical features with type 1 and type 2 diabetes. Hence, genetic testing is the most appropriate tool for obtaining an accurate diagnosis. In Tunisia, few cohorts of MD have been investigated until now. The aim of this study is to search for pathogenic variants among 11 patients suspected of having MD in Tunisia using whole-exome sequencing (WES). Materials and methods: WES was performed in 11 diabetic patients recruited from a collaborating medical center. The pathogenicity of genetic variation was assessed using combined filtering and bioinformatics prediction tools. The online ORVAL tool was used to predict the likelihood of combinations of pathogenic variations. Then, Sanger sequencing was carried out to confirm likely pathogenic predicted variants among patients and to check for familial segregation. Finally, for some variants, we performed structural modeling to study their impact on protein function. Results: We identified novel variants related to MD in Tunisia. Pathogenic variants are located in several MODY and non-MODY genes. We highlighted the presence of syndromic forms of diabetes, including the Bardet-Biedl syndrome, Alström syndrome, and severe insulin resistance, as well as the presence of isolated diabetes with significantly reduced penetrance for Wolfram syndrome-related features. Idiopathic type 1 diabetes was also identified in one patient. Conclusion: In this study, we emphasized the importance of genetic screening for MD in patients with a familial history of diabetes, mainly among admixed and under-represented populations living in low- and middle-income countries. An accurate diagnosis with molecular investigation of MD may improve the therapeutic choice for better management of patients and their families. Additional research and rigorous investigations are required to better understand the physiopathological mechanisms of MD and implement efficient therapies that take into account genomic context and other related factors., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2023 Kheriji, Dallali, Gouiza, Hechmi, Mahjoub, Mrad, Krir, Soltani, Trabelsi, Hamdi, Bahlous, Ben Ahmed, Jamoussi and Kefi.)

To map the spread of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) and evaluate immune response variations against this virus, it is essential to set up efficient serological tests locally. The SARS-CoV-2 immunogenic proteins were very expensive and not affordable for lower- middle-income countries (LMICs). For this purpose, the commonly used antigen, receptor-binding domain (RBD) of spike S1 protein (S1RBD), was produced using the baculovirus expression vector system (BEVS). In the current study, the expression of S1RBD was monitored using Western blot under different culture conditions. Different parameters were studied: the multiplicity of infection (MOI), cell density at infection, and harvest time. Hence, optimal conditions for efficient S1RBD production were identified: MOI 3; cell density at infection 2-3 × 10 6 cells/mL; and time post-infection (tPI or harvest time) of 72 h and 72-96 h, successively, for expression in shake flasks and a 7L bioreactor. A high production yield of S1RBD varying between 4 mg and 70 mg per liter of crude cell culture supernatant was achieved, respectively, in the shake flasks and 7L bioreactor. Moreover, the produced S1RBD showed an excellent antigenicity potential against COVID-19 (Wuhan strain) patient sera evaluated by Western blot. Thus, additional serological assays, such as in-house ELISA and seroprevalence studies based on the purified S1RDB, were developed.

(1) Background: Increased risk of myocardial infarction (MI) has been linked to several inflammatory conditions, including inflammatory bowel disease (IBD). However, the relationship between IBD and MI remains unclear. Here, we implemented an original mouse model combining IBD and MI to determine IBD's impact on MI severity and the link between the two diseases. (2) Methods: An IBD model was established by dextran sulfate sodium (DSS) administration in drinking water, alone or with oral C. albicans ( Ca ) gavage. IBD severity was assessed by clinical/histological scores and intestinal/systemic inflammatory biomarker measurement. Mice were subjected to myocardial ischemia-reperfusion (IR), and MI severity was assessed by quantifying infarct size (IS) and serum cardiac troponin I (cTnI) levels. (3) Results: IBD mice exhibited elevated fecal lipocalin 2 (Lcn2) and IL-6 levels. DSS mice exhibited almost two-fold increase in IS compared to controls, with serum cTnI levels strongly correlated with IS. Ca inoculation tended to worsen DSS-induced systemic inflammation and IR injury, an observation which is not statistically significant. (4) Conclusions: This is the first proof-of-concept study demonstrating the impact of IBD on MI severity and suggesting mechanistic aspects involved in the IBD-MI connection. Our findings could pave the way for MI therapeutic approaches based on identified IBD-induced inflammatory mediators.

Selected mucosal and plasma polyunsaturated fatty acids (PUFAs) and related oxylipins and endocannabinoids were determined in 28 Crohn's disease (CD) patients and 39 controls. Fasting blood and colonic biopsies were collected in all participants, during a disease flare for the patients. Thirty-two lipid mediators including PUFAs, oxylipins, and endocannabinoids were assessed by LC-MS/MS. The pattern of lipid mediators in CD patients is characterized by an increase in arachidonic acid-derived oxylipins and endocannabinoids and a decrease in n-3 PUFAs and related endocannabinoids. A model combining increased 6-epi-lipoxin A4 and 2-arachidonyl glycerol with decreased docoasapentaenoic acid in plasma fairly discriminates patients from controls and may represent a lipidomic signature for CD flare. The study findings suggest that lipid mediators are involved in CD pathophysiology and may serve as biomarkers for disease flare. Further research is required to confirm the role of these bioactive lipids and test their therapeutic potential in CD., Competing Interests: Conflicts of interests The authors declare that they have no conflict of interest., (Copyright © 2023 Elsevier Inc. All rights reserved.)

(1) Background: This study aimed to compare the immunogenicity of the mix-and-match CoronaVac/BNT162b2 vaccination to the homologous CoronaVac/CoronaVac regimen. (2) Methods: We conducted a simple-blinded randomized superiority trial to measure SARS-CoV-2 neutralization antibodies and anti-spike receptor binding domain (RBD) IgG concentrations in blood samples of participants who had received the first dose of CoronaVac vaccine followed by a dose of BNT162b2 or CoronaVac vaccine. The primary endpoint for immunogenicity was the serum-neutralizing antibody level with a percentage of inhibition at 90% at 21-35 days after the boost. A difference of 25% between groups was considered clinically relevant. (3) Results: Among the 240 eligible participants, the primary endpoint data were available for 100 participants randomly allocated to the mix-and-match group versus 99 participants randomly allocated to the homologous dose group. The mix-and-match regimen elicited significantly higher levels of neutralizing antibodies (median level of 96%, interquartile range (IQR) (95-97) versus median level of 94%, IQR (81-96) and anti-spike IgG antibodies (median level of 13,460, IQR (2557-29,930) versus median level of 1190, IQR (347-4964) compared to the homologous group. Accordingly, the percentage of subjects with a percentage of neutralizing antibodies > 90% was significantly higher in the mix-and-match group (90.0%) versus the homologous (60.6%). Interestingly, no severe events were reported within 30 days after the second dose of vaccination in both groups. (4) Conclusions: Our data showed the superiority of the mix-and-match CoronaVac/BNT162b2 vaccination compared to the CoronaVac/CoronaVac regimen in terms of immunogenicity, thus constituting a proof-of-concept study supporting the use of inactivated vaccines in a mix-and-match strategy while ensuring good immunogenicity and safety.

Snake natriuretic peptide (NP) Lebetin 2 (L2) has been shown to improve cardiac function and reduce fibrosis as well as inflammation by promoting M2-type macrophages in a reperfused myocardial infarction (MI) model. However, the inflammatory mechanism of L2 remains unclear. Therefore, we investigated the effect of L2 on macrophage polarization in lipopolysaccharide (LPS)-activated RAW264.7 cells in vitro and explored the associated underlying mechanisms. TNF-α, IL-6 and IL-10 levels were assessed using an ELISA assay, and M2 macrophage polarization was determined by flow cytometry. L2 was used at non-cytotoxic concentrations determined by a preliminary MTT cell viability assay, and compared to B-type natriuretic peptide (BNP). In LPS-activated cells, both peptides reduced TNF-α and IL-6 release compared to controls. However, only L2 increased IL-10 release in a sustained manner and promoted downstream M2 macrophage polarization. Pretreatment of LPS-activated RAW264.7 cells with the selective NP receptor (NPR) antagonist isatin abolished both IL-10 and M2-like macrophage potentiation provided by L2. In addition, cell pretreatment with the IL-10 inhibitor suppressed L2-induced M2 macrophage polarization. We conclude that L2 exerts an anti-inflammatory response to LPS by regulating the release of inflammatory cytokines via stimulating of NP receptors and promoting M2 macrophage polarization through activation of IL-10 signaling.

Immunotherapy by blocking immune checkpoint regulators has emerged as a new targeted therapy for some cancers. Among them V-domain Ig suppressor of Tcell activation (VISTA) which is identified as a novel checkpoint regulator in ovarian cancer. This study aimed to investigate the VISTA role in Epithelial ovarian cancer (EOC), and its relationship with tumor-infiltrating lymphocytes (TILs) markers and its prognostic value. The expression of VISTA, CD3, CD8, CD4, FOXP3, and CD56 was assessed in 168 EOC tissue microarrays (TMA) by immunohistochemistry (IHC). In addition, associations between VISTA, TILs, clinicopathological variables, and overall survival (OS) were analyzed. VISTA expression in IGRov1 cells, as well as in PBMC of EOC patient, was evaluated by western blot. VISTA expression was detected in 64,28% of tissues, among which 42.3% were positive for tumor cells (TCs), and 47,9% were positive for immune cells (ICs). In univariate analysis, VISTA expression was significantly associated with a high density of TILs:CD3+ (p = 0,001), CD4+ (p = 0,002) and CD8+ (p≤0,001), in ICs but not in TCs. In terms of OS, multivariate analysis showed a significant association between the high density of CD8+ TILs and VISTA positive staining in ICs (p = 0,044), but not in TCs (p = 0,108). Kaplan-Meier curves demonstrated no correlation between VISTA expression and prolonged OS in both ICs (p = 0,841) and TCs (p = 0,090). Classification of EOC tumor microenvironment based on VISTA and CD8+TILs expression, demonstrated four immune subtypes: VISTA+/CD8+, VISTA+/CD8-, VISTA-/CD8+ and VISTA-/CD8-. The dual positive VISTA+/CD8+ subtype was significantly associated with prolonged OS in both TCs and ICs (p = 0,012 and p≤0,01, respectively), whereas patients with VISTA+/CD8- had the worst OS. Our results showed that VISTA is highly expressed in the IGRov1 cell line and LT-CD8 from a patient with EOC. Our results highlighted the association of VISTA expression and CD8+ TILs in EOC, with prolonged OS in patients with VISTA+/CD8+ and proposed VISTA as a potential immunotherapeutic target in EOC., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Jlassi et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

The aim of this study was to measure the extent of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection among workers at the Institut Pasteur de Tunis (IPT), a public health laboratory involved in the management of the COVID-19 pandemic in Tunisia, and to identify risk factors for infection in this occupational setting. A cross-sectional survey was conducted on IPT workers not vaccinated against coronavirus disease 2019 (COVID-19). Participants completed a questionnaire that included a history of reverse transcription-polymerase chain reaction (RT-PCR)-confirmed SARS-CoV-2 infection. Immunoglobulin G antibodies against the receptor-binding domain of the spike antigen (anti-S-RBD IgG) and the nucleocapsid protein (anti-N IgG) of the SARS-CoV-2 virus were detected by enzyme-linked immunoassay (ELISA). A multivariate analysis was used to identify factors significantly associated with SARS-CoV-2 infection. A total of 428 workers were enrolled in the study. The prevalence of anti-S-RBD and/or anti-N IgG antibodies was 32.9% [28.7-37.4]. The cumulative incidence of SARS-CoV-2 infection (positive serology and/or previous positive RT-PCR test) was 40.0% [35.5-44.9], while the proportion with asymptomatic infection was 32.9%. One-third of the participants with RT-PCR-confirmed infection tested seronegative more than 90 days postinfection. Participants aged over 40 and laborers were more susceptible to infection (adjusted OR [AOR] = 1.65 [1.08-2.51] and AOR = 2.67 [1.45-4.89], respectively), while tobacco smokers had a lower risk of infection (AOR = 0.54 [0.29-0.97]). The SARS-CoV-2 infection rate among IPT workers was not significantly different from that detected concurrently in the general population. Hence, the professional activities conducted in this public health laboratory did not generate additional risk to that incurred outside the institute in day-to-day activities., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.)

Background: The saliva of sand flies, vectors of Leishmania parasites, contains several components that exert pharmacological activity facilitating the acquisition of blood by the insect and contributing to the establishment of infection. Previously, we demonstrated that PpSP32 is the immunodominant salivary antigen in humans exposed to Phlebotomus papatasi bites and validated its usefulness as a predictive biomarker of disease. PpSP32, whose functions are little known to date, is an intriguing protein due to its involvement in the etiopathogenesis of pemphigus, an auto-immune disease. Herein, we aimed to better decipher its role through the screening of several immunomodulatory activity either on lymphocytes or on monocytes/macrophages., Methods: Peripheral mononuclear cells from healthy volunteers were stimulated with anti-CD3/anti-CD28 antibodies, phytohemagglutinin, phorbol 12-myristate 13-acetate/ionomycin, or lipopolysaccharide in the presence of increasing doses of PpSP32. Cell proliferation was measured after the addition of tritiated thymidine. Monocyte activation was tested by analyzing the expression of CD86 and HLA-DR molecules by flow cytometry. Cytokine production was analyzed in culture supernatants by ELISA. THP-1-derived macrophages were stimulated with LPS in the presence of increasing doses of PpSP32, and cytokine production was analyzed in culture supernatants by ELISA and multiplex technique. The effect of PpSP32 on NF-kB signaling was tested by Western blot. The anti-inflammatory activity of PpSP32 was assessed in vivo in an experimental inflammatory model of carrageenan-induced paw edema in rats., Results: Our data showed that PpSP32 down-modulated the expression of activation markers in LPS-stimulated monocytes and THP1-derived macrophages. This protein negatively modulated the secretion of Th1 and Th2 cytokines by human lymphocytes as well as pro-inflammatory cytokines by monocytes, and THP1-derived macrophages. PpSP32 treatment led to a dose-dependent reduction of IκB phosphorylation. When PpSP32 was injected into the paw of carrageenan-injected rats, edema was significantly reduced., Conclusions: Our data indicates that PpSP32 induces a potent immunomodulatory effect on monocytes and THP-1-derived macrophages. This inhibition could be mediated, among others, by the modulation of the NF-kB signaling pathway. The anti-inflammatory activity of PpSP32 was confirmed in vivo in the carrageenan-induced paw edema model in rats., (© 2023. The Author(s).)

Background: Auto-antibodies (auto-Abs) neutralizing type I interferons (IFN) have been found in about 15% of critical cases COVID-19 pneumonia and less than 1% of mild or asymptomatic cases. Determining whether auto-Abs influence presentation and outcome of critically ill COVID-19 patients could lead to specific therapeutic interventions. Our objectives were to compare the severity at admission and the mortality of patients hospitalized for critical COVID-19 in ICU with versus without auto-Abs., Results: We conducted a prospective multicentre cohort study including patients admitted in 11 intensive care units (ICUs) from Great Paris area hospitals with proven SARS-CoV-2 infection and acute respiratory failure. 925 critically ill COVID-19 patients were included. Auto-Abs neutralizing type I IFN-α2, β and/or ω were found in 96 patients (10.3%). Demographics and comorbidities did not differ between patients with versus without auto-Abs. At ICU admission, Auto-Abs positive patients required a higher FiO 2 (100% (70-100) vs. 90% (60-100), p = 0.01), but were not different in other characteristics. Mortality at day 28 was not different between patients with and without auto-Abs (18.7 vs. 23.7%, p = 0.279). In multivariable analysis, 28-day mortality was associated with age (adjusted odds ratio (aOR) = 1.06 [1.04-1.08], p < 0.001), SOFA score (aOR = 1.18 [1.12-1.23], p < 0.001) and immunosuppression (aOR = 1.82 [1.1-3.0], p = 0.02), but not with the presence of auto-Abs (aOR = 0.69 [0.38-1.26], p = 0.23)., Conclusions: In ICU patients, auto-Abs against type I IFNs were found in at least 10% of patients with critical COVID-19 pneumonia. They were not associated with day 28 mortality., (© 2022. The Author(s).)

Double-negative T (DNT) cells are a T-cell subset with a CD4-CD8- phenotype. They represent 1% to 5% of circulating lymphocytes, but an increase in this proportion can be found during lymphoproliferative and autoimmune diseases. This increase has also been reported in persons with HIV (PWH). The aim of this work was to better describe the proportion of DNT cell subset in PWH. We retrospectively collected 984 samples from PWH referred for lymphocyte immunophenotyping over a 7.5-year period. Quantification of DNT cells was performed by flow cytometry. DNT cell proportion was calculated by subtracting the CD4+ and CD8+ subsets proportions from the total of T cells. A total of 984 blood samples from PWH were collected. Mean CD4 T-cell count was decreased in such patients while DNT cell frequency was increased with a mean of 6.7%. More than half of the patients had a DNT cell proportion >5%. Patients with DNT cell proportion over 5% exhibited significantly reduced CD3+ and CD4+ T-cell counts, while CD8+ T-cell count was unchanged compared to patients with normal DNT cell rates. Interestingly, DNT cell percentage was negatively correlated with CD4 and CD3 T-cell counts in all included patients. Moreover, the DNT cell proportion was significantly increased in subjects with CD4+ T cells <200/mm3 compared to those with CD4+ T cells >200/mm3. Interestingly, DNT cell proportions were significantly higher in patients with high viral load compared with those presenting undetectable viral load. HIV infection is associated with an increase in DNT cell proportion. This increase is more frequent as the CD4 count is decreased and the viral load is increased. DNT cell subset should not be omitted when interpreting immunophenotyping in PWH as it appears to be associated with disease progression in patients under antiretroviral therapy., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2022 the Author(s). Published by Wolters Kluwer Health, Inc.)

Xeroderma pigmentosum (XP) is a DNA repair disease that predisposes to early skin cancers as cutaneous melanoma. Melanoma microenvironment contains inflammatory mediators, which would be interesting biomarkers for the prognosis or for the identification of novel therapeutic targets. We used a PCR array to evaluate the transcriptional pattern of 84 inflammatory genes in melanoma tumors obtained from XP patients (XP-Mel) and in sporadic melanoma (SP-Mel) compared to healthy skin. Commonly expressed inflammatory genes were further explored via GTEx and GEPIA databases. The differentially expressed inflammatory genes in XP were compared to their expression in skin exposed to UVs, and evaluated on the basis of the overall survival outcomes of patients with melanoma. Monocyte subsets of patients with SP-Mel, XP and healthy donors were also assessed. PCR array data revealed that 34 inflammatory genes were under-expressed in XP-Mel compared to SP-Mel. Differentially expressed genes that were common in XP-Mel and SP-Mel were correlated with the transcriptomic datasets from GEPIA and GTEx and highlighted the implication of KLK1 and IL8 in the tumorigenesis. We showed also that in XP-Mel tumors, there was an overexpression of KLK6 and KLK10 genes, which seems to be associated with a bad survival rate. As for the innate immunity, we observed a decrease of intermediate monocytes in patients with SP-Mel and in XP. We highlight an alteration in the immune response in XP patients. We identified candidate biomarkers involved in the tumorigenesis, and in the survival of patients with melanoma. Intermediate monocyte's in patients at risk could be a prognostic biomarker for melanoma outcome., (© 2022. The Author(s).)

Background: The mass vaccination campaign against SARS-CoV-2 was started in Tunisia on 13 March 2021 by using progressively seven different vaccines approved for emergency use. Herein, we aimed to evaluate the humoral and cellular immunity in subjects aged 40 years and over who received one of the following two-dose regimen vaccines against SARS-CoV-2, namely mRNA-1273 or Spikevax (Moderna), BNT162B2 or Comirnaty (Pfizer-BioNTech), Gam-COVID-Vac or Sputnik V (Gamaleya Research Institute), ChAdOx1-S or Vaxzevria (AstraZeneca), BIBP (Sinopharm), and Coronavac (Sinovac)., Material and Methods: For each type of vaccine, a sample of subjects aged 40 and over was randomly selected from the national platform for monitoring COVID-19 vaccination and contacted to participate to this study. All consenting participants were sampled for peripheral blood at 3-7 weeks after the second vaccine dose to perform anti-S and anti-N serology by the Elecsys ® (Lenexa, KS, USA) anti-SARS-CoV-2 assays (Roche ® Basel, Switzerland). The CD4 and CD8 T cell responses were evaluated by the QuantiFERON ® SARS-CoV-2 (Qiagen ® Basel, Switzerland) for a randomly selected sub-group., Results: A total of 501 people consented to the study and, of them, 133 were included for the cellular response investigations. Both humoral and cellular immune responses against SARS-CoV-2 antigens differed significantly between all tested groups. RNA vaccines induced the highest levels of humoral and cellular anti-S responses followed by adenovirus vaccines and then by inactivated vaccines. Vaccines from the same platform induced similar levels of specific anti-S immune responses except in the case of the Sputnik V and the AstraZeneca vaccine, which exhibited contrasting effects on humoral and cellular responses. When analyses were performed in subjects with negative anti-N antibodies, results were similar to those obtained within the total cohort, except for the Moderna vaccine, which gave a better cellular immune response than the Pfizer vaccine and RNA vaccines, which induced similar cellular immune responses to those of adenovirus vaccines., Conclusion: Collectively, our data confirmed the superiority of the RNA-based COVID-19 vaccines, in particular that of Moderna, for both humoral and cellular immunogenicity. Our results comparing between different vaccine platforms in a similar population are of great importance since they may help decision makers to adopt the best strategy for further national vaccination programs.

COVID-19 pandemic underscored the need for a rapid tool supporting decision-makers in prioritizing patients in the immediate and overwhelming context of pandemics, where shortages in different healthcare resources are faced. We have proposed Multi-Criteria Decision Analysis (MCDA) to create a system of criteria and weights to prioritize uses of COVID-19 vaccines in groups of people at significantly higher risk of severe COVID-19 disease or death, when vaccines are in short supply, for use in Tunisia. The prioritization criteria and the levels within each criterion were identified based on available COVID-19 evidence with a focus on the criteria selected by Tunisian scientific committees. To determine the weights for the criteria and levels, reflecting their relative importance, a panel of frontline physicians treating COVID-19 were invited to participate in an online survey using 1,000 minds MCDA software (www.1000minds.com) which implements the PAPRIKA (Potentially All Pairwise RanKings of all possible Alternatives) method. Ten criteria and twenty-three levels have been selected for prioritizing the uses of COVID-19 vaccines in groups of people at significantly higher risk of severe disease or death. Among the invited physicians, sixty have completed the survey. The obtained scores were, in decreasing order of importance (mean weights in parentheses, summing to 100%). Obesity (16.2%), Age (12.7%), Chronic pulmonary diseases (10.8%), Chronic cardiovascular conditions (10.3%), Bone marrow or organ transplantation (10.1%), Immunodeficiency or Immunosuppression (9.6%), Diabetes (9%), Renal failure (8.4%), evolutive cancer (6.9%), and high blood pressure (6%). MCDA-based prioritization scoring system comprising explicit criteria and weights provides an adaptable and multicriteria approach that can assist policy-makers to prioritize uses of COVID-19 vaccines., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Chaker Masmoudi, Rhili, Zamali, Ben Hmid, Ben Ahmed and Khrouf.)

Seroprevalence studies are essential to get an accurate estimate of the actual SARS-CoV-2 diffusion within populations. We report on the findings of the first serosurvey conducted in Tunis prior to the implementation of mass vaccination and analyzed factors associated with seropositivity. A household cross sectional survey was conducted (March-April 2021) in Tunis, spanning the end of the second wave and the beginning of the third wave of COVID-19. SARS-CoV-2 specific immunoglobulin G (IgG) antibodies to the spike (S-RBD) or the nucleocapsid (N) proteins were detected by in-house ELISA tests. The survey included 1676 individuals from 431 households. The mean age and sex ratio were 43.3 ± 20.9 years and 0.6, respectively. The weighted seroprevalence of anti-N and/or anti-S-RBD IgG antibodies was equal to 38.0% (34.6-41.5). In multivariate analysis, age under 10, no tobacco use, previous diagnosis of COVID-19, a history of COVID-19 related symptoms and contact with a COVID-19 case within the household, were independently associated with higher SARS-CoV-2 seroprevalence. More than one third of people living in Tunis obtained antibodies to SARS-CoV-2. Further studies are needed to monitor changes in these figures as Tunisian population is confronted to the subsequent epidemic waves and to guide the vaccine strategy.

Background and Study Aims: Antiphospholipid antibodies (aPL) have been reported not only in various autoimmune conditions but also in other infections, such as chronic hepatitis C (CHC) infection. The aim of this study is to evaluate the frequency of aPL in patients with CHC., Patients and Methods: Ninety-six CHC patients and 90 healthy blood donors (HBD) were studied. Fifty-three of the patients were under treatment, and 43 had not yet received any treatment. IgG, IgA, and IgM antibodies against cardiolipin (aCL) and beta-2 glycoprotein I (aβ2GPI) were detected by ELISA., Results: We found that the frequency of aPL (aCL and/or aβ2GPI) was significantly higher in CHC patients than in controls (51% vs 11.1%, p <10 -6 ). The frequencies of aCL and aβ2GPI were significantly higher in patients than in HBD (27.1% vs 5.5%, p < 10 -3 , and 44.8% vs 11.1%, p < 10 -6 , respectively). The isotype distribution of aCL and aβ2GPI demonstrated that aCL-IgG and aβ2GPI-IgA were more frequent in patients than in healthy subjects (21.9% vs 2.2%, p < 10 -3 , and 38.5% vs 7.8%, p < 10 -6 , respectively). In CHC patients, the frequency of aβ2GPI was significantly higher than that of aCL (44.8% vs 27.1%, p = 0.01). aβ2GPI-IgA was significantly more frequent than aβ2GPI-IgG (38.5% vs 7.3%, p <10 -6 ), aβ2GPI-IgM (38.5% vs 9.4%, p <10 -3 ), and aCL-IgG (38.5% vs 21.9%, p = 0.01). No difference in aPL frequency was observed between the treated and untreated patients., Conclusion: On the basis of the findings of this study, aPL, particularly aβ2GPI-IgA and aCL-IgG, are frequent in CHC patients., Competing Interests: Declaration of competing interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Pan-Arab Association of Gastroenterology. Published by Elsevier B.V. All rights reserved.)

Background and Study Aims: To determine the sensitivity and specificity of anti-gp210 and anti-Sp100 autoantibodies in primary biliary cholangitis (PBC) PATIENTS AND METHODS: Sera of 106 PBC patients with positive anti-mitochondrial antibodies and 58 healthy blood donors were analyzed. A line immunoassay was used to evaluate the reactivity of anti-gp210 and anti-Sp100 antibodies., Results: The frequency of anti-gp210 and anti-Sp100 autoantibodies was 29.2% and 28.3%, respectively. Eight patients had both anti-gp210 and anti-Sp100 antibodies. Of 106 patients, 23 (21.7%) had anti-gp210 antibody, although not anti-Sp100 antibody, and 22 (20.7%) had anti-Sp100, although not anti-gp210 antibodies. Their combination increased the frequency of anti-gp210 and anti-Sp100 antibodies from 29.2% to 50% (P = 0.002) and 28.3% to 50% (P = 0.0012), respectively. In the control group, two subjects had anti-gp210 antibody and none had anti-Sp100 antibody. Thus, the specificity of anti-gp210 and anti-Sp100 antibodies was 96.5% and 100%, respectively. The positive predictive value (PPV) of anti-gp210 antibody was 94%; its negative predictive value (NPV) was 42.7%. The PPV and NPV of anti-Sp100 antibody were 100% and 43.3%, respectively., Conclusion: It is important to combine anti-gp210 and anti-Sp100 antibodies in the immunological exploration of PBC., Competing Interests: Declaration of competing interests The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021 Pan-Arab Association of Gastroenterology. Published by Elsevier B.V. All rights reserved.)

Background: Autoimmune encephalitis (AE) is a rapidly progressive encephalopathy caused by antibodies targeting neurons in the central nervous system generating specific immune responses. It is increasingly recognized in children., Objective: To describe clinical, neuroimaging, and laboratory features, treatment, and outcome in a cohort of Tunisian children with AE., Methods: We conducted a retrospective review of the medical records of all children attending the Department of Child and Adolescent Neurology (Tunis) with autoimmune encephalitis between 2004 and 2020. Clinical, neuroimaging, laboratory features, therapeutic data, and outcome were analyzed., Results: Nineteen children were included in the study (12 girls and 7 boys). The median age at diagnosis was 7.68 years (range: 10 months-13 years). The most frequent manifestations were seizures and behavioral disorders. Eleven cases were diagnosed with anti-NMDA receptor encephalitis, 4 cases with anti-Ma2 encephalitis, 3 cases with anti-GAD encephalitis, and 1 case with anti-SOX1 encephalitis. Brain MRI showed increased T2 and fluid-attenuated inversion recovery (FLAIR) signal of the temporal lobe in 5 patients. Eighteen patients showed improvement following first-line immunotherapy (high-dose corticosteroids, intravenous immunoglobulin). One patient with anti-GAD encephalitis died despite escalating immunotherapy., Conclusion: Diagnosis of autoimmune encephalitis is challenging in children, because of misleading presentations. An early and accurate diagnosis is important to enable proper therapeutic interventions., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2021 Bissene Douma et al.)

A possible etiological link between the onset of endemic pemphigus in Tunisia and bites of Phlebotomus papatasi, the vector of zoonotic cutaneous leishmaniasis, has been previously suggested. We hypothesized that the immunodominant P. papatasi salivary protein PpSP32 binds to desmogleins 1 and 3 (Dsg1 and Dsg3), triggering loss of tolerance to these pemphigus target autoantigens. Here, we show using far-Western blot that the recombinant PpSP32 protein (rPpSP32) binds to epidermal proteins with a MW of approximately 170 kDa. Coimmunoprecipitation revealed the interaction of rPpSP32 with either Dsg1 or Dsg3. A specific interaction between PpSP32 and Dsg1 and Dsg3 was further demonstrated by ELISA assays. Finally, mice immunized with rPpSP32 twice per week exhibited significantly increased levels of anti-Dsg1 and -Dsg3 antibodies from day 75 to 120. Such antibodies were specific for Dsg1 and Dsg3 and were not the result of cross-reactivity to PpSP32. In this study, we demonstrated for the first time to our knowledge a specific binding between PpSP32 and Dsg1 and Dsg3, which might underlie the triggering of anti-Dsg antibodies in patients exposed to sand fly bites. We also confirmed the development of specific anti-Dsg1 and -Dsg3 antibodies in vivo after PpSP32 immunization in mice. Collectively, our results provide evidence that environmental factors, such as the exposure to P. papatasi bites, can trigger the development of autoimmune antibodies.