Early and Polyantigenic CD4 T Cell Responses Correlate with Mild Disease in Acute COVID-19 Donors.

We assessed SARS-CoV-2-specific CD4+ and CD8+ T cell responses in samples from 89 acute COVID-19 patients, utilizing blood samples collected during the first wave of COVID-19 in Italy. The goal of the study was to examine correlations between SARS-CoV-2-specific T cell responses in the early phase comparing mild, moderate, or severe COVID-19 disease outcomes. T cell responses to the spike (S) and non-S proteins were measured in a combined activation-induced marker (AIM) and intracellular cytokine staining (ICS) assay. Early CD4+ T cell responses to SARS-CoV-2 S correlated with milder disease by both AIM and IFNγ ICS readouts. The correlation of S-specific CD4+ T cell responses with milder disease severity was most striking within the first two weeks of symptom onset compared to later time points. Furthermore, donors with milder disease were associated with polyantigenic CD4+ T cell responses that recognized more prominently non-S proteins in addition to S, while severe acute COVID-19 was characterized by lower magnitudes of CD4+ T cell responses and a narrower repertoire. In conclusion, this study highlights that both the magnitude and breadth of early SARS-CoV-2-specific CD4+ T cell responses correlated with milder disease outcomes in acute COVID-19 patients.

Knowledge and Attitudes of Population Living in Rural and Semi-Rural Areas towards Covid-19 :Case of the Menoua Division, Cameroon.

BACKGROUND: The pandemic situation the world is facing caused by the new SARS-Cov-2 continues to evolve and still represent a real problem. With more than eight thousand reported cases infection, Cameroon stands as the seventh most affected country in Africa. Prevention remains the best way to fight against this zoonosis. However, the limited information available about this infection is a great barrier to stopping the propagation of the virus within the population, especially in rural and semi-rural areas, where the lack of financial and material resources is a reality. This study aimed to assessing Awareness and attitudes of the population of the Menoua Division on COVID-19 infection. METHODS: A cross-sectional study was conducted from March 9 to April 15 2020 amongst the populations of rural and semi-rural areas of the Menoua Division. Data were collected using a questionnaire administered face to face to each participant. The analysis was carried out using the Statistical Analysis System software (SAS version 9.4). The significance threshold was set at a P value of less than 0.05. RESULTS: A total of 434 participants of which male majority (sex ratio 1.07) were included in this study. The most represented age group was [21 - 40] years old representing 40.29% of the participants. Approximately all participants (98.57%) were aware of the world emergency state due to Coronavirus. 75.56%, 91% and 90.93% of the participants knew respectively that having close contacts, kissing and touching the face with the hands could favor the transmission of the virus. However, nearly 91.14% were not aware of the clinical symptoms of the disease. Moreover, 85.02% responded that they would not be able to comply with the confinement measures if they were applied at national level. The level of awareness varied significantly according to the occupation (p=0.038) and the educational level (p<0.001)of the participants. CONCLUSION: The average level of awareness of the population of the Menoua Division on COVID-19 infection was relatively low. Overcoming this pandemic disease means ensuring the flow of the correct information towards the population. Community outreach activities focus on clinical manifestations and what to do in case of COVID-19 infection as well as material and financial support should be help the population to protect themselves effectively against pandemic, particularly in rural areas and surrounding.

The Ebola virus disease outbreak in Tonkolili district, Sierra Leone: a retrospective analysis of the Viral Haemorrhagic Fever surveillance system, July 2014-June 2015.

In Sierra Leone, the Ebola virus disease (EVD) outbreak occurred with substantial differences between districts with someone even not affected. To monitor the epidemic, a community event-based surveillance system was set up, collecting data into the Viral Haemorrhagic Fever (VHF) database. We analysed the VHF database of Tonkolili district to describe the epidemiology of the EVD outbreak during July 2014-June 2015 (data availability). Multivariable analysis was used to identify risk factors for EVD, fatal EVD and barriers to healthcare access, by comparing EVD-positive vs. EVD-negative cases. Key-performance indicators for EVD response were also measured. Overall, 454 EVD-positive cases were reported. At multivariable analysis, the odds of EVD was higher among those reporting contacts with an EVD-positive/suspected case (odds ratio (OR) 2.47; 95% confidence interval (CI) 2.44-2.50; P < 0.01) and those attending funeral (OR 1.02; 95% CI 1.01-1.04; P < 0.01). EVD cases from Kunike chiefdom had a lower odds of death (OR 0.22; 95% CI 0.08-0.44; P < 0.01) and were also more likely to be hospitalised (OR 2.34; 95% CI 1.23-4.57; P < 0.05). Only 25.1% of alerts were generated within 1 day from symptom onset. EVD preparedness and response plans for Tonkolili should include social-mobilisation activities targeting Ebola/knowledge-attitudes-practice during funeral attendance, to avoid contact with suspected cases and to increase awareness on EVD symptoms, in order to reduce delays between symptom onset to alert generation and consequently improve the outbreak-response promptness.

Amino acid mutations in Ebola virus glycoprotein of the 2014 epidemic.

Zaire Ebola virus (EBOV) is an enveloped non-segmented negative strand RNA virus of 19 kb in length belonging to the family Filoviridae. The virus was isolated and identified in 1976 during the epidemic of hemorrhagic fever in Zaire. The most recent outbreak of EBOV among humans, was that occurred in the forested areas of south eastern Guinea, that began in February 2014 and is still ongoing. The recent Ebola outbreak, is affecting other countries in West Africa, in addiction to Guinea: Liberia, Nigeria, and Sierra Leone. In this article, a selective pressure analysis and homology modeling based on the G Glycoprotein (GP) sequences retrieved from public databases were used to investigate the genetic diversity and modification of antibody response in the recent outbreak of Ebola Virus. Structural and the evolutionary analysis underline the 2014 epidemic virus being under negative selective pressure does not change with respect to the old epidemic in terms of genome adaptation.

Role of individual's T-cell immunome in controlling HIV-1 progression.

Viral and host factors can influence HIV-1 progression, among them human leucocyte antigen (HLA) has shown the strongest effect. However, studies on the functional contribution of HLA in controlling HIV progression toward AIDS are limited by multiple issues, including the viral strain variability within the study subjects. In this study, in a cohort of children infected with a monophyletic strain (CRF02_AG) during an outbreak, we evaluated the HIV-1 Gag, Vif, Vpr, Tat and hepatitis C virus E1/E2 (as control) proteins circulating in a cohort for the capability to be presented by the HLA molecules in the same population. A total of 70 Non-progressors and 37 Progressors to AIDS were evaluated. In the presence of a constant capability of HIV-1 to mutate in the region containing epitopes of Gag protein, the number of epitopes recognized in silico by the combination of the HLA alleles along the Gag consensus sequence is significantly higher in the Non-progressors compared with Progressors (HLA-A: Non-progressors = 1.532 ± 1.211, Progressors = 0.7714 ± 1.031, P = 0.0016; HLA-B: Non-progressors = 1.556 ± 1.298, Progressors = 1.000 ± 0.817, P = 0.0319; HLA-DR: Non-progressors = 13.30 ± 9.488, Progressors = 7.294 ± 6.952, P = 0.0006). Similar results were obtained for the other HIV-1 proteins Vif and Vpr, whereas no differences were obtained in the number of epitopes for the hepatitis C virus E1/E2 protein sequence or for the scrambled HIV-1 sequence. Finally, the results were confirmed also in a subgroup of subjects where both HLA typing and Gag sequence were available. In conclusion, in the absence of bias due to viral strain diversity, it is the overall fitting of the HLA molecules that are capable of better binding HIV-1 proteins in determining the major role in the control of HIV-1 replication and progression to AIDS.

SARS-CoV-2 genomic surveillance and reliability of PCR single point mutation assay (SNPsig® SARS-CoV-2 EscapePLEX CE) for the rapid detection of variants of concern in Cameroon.

Background: Surveillance of SARS-CoV-2 variants of concern (VOCs) and lineages is crucial for decision-making. Our objective was to study the SARS-CoV-2 clade dynamics across epidemiological waves and evaluate the reliability of SNPsig® SARS-CoV-2 EscapePLEX CE in detecting VOCs in Cameroon. Material and methods: A laboratory-based study was conducted on SARS-CoV-2 positive nasopharyngeal specimens cycle threshold (Ct)≤30 at the Chantal BIYA International Reference Centre in Yaoundé-Cameroon, between April-2020 to August-2022. Samples were analyzed in parallel with Sanger sequencing and (SNPsig® SARS-CoV-2 EscapePLEX CE), and performance characteristics were evaluated by Cohen's coefficient and McNemar test. Results: Of the 130 sequences generated, SARS-CoV-2 clades during wave-1 (April-November 2020) showed 97 % (30/31) wild-type lineages and 3 % (1/31) Gamma-variant; wave-2 (December-2020 to May-2021), 25 % (4/16) Alpha-variant, 25 % (4/16) Beta-variant, 44 % (7/16) wild-type and 6 % (1/16) mu; wave-3 (June-October 2021), 94 % (27/29) Delta-variant, 3 % (1/29) Alpha-variant, 3 % (1/29) wild-type; wave-4 (November-2021 to August-2022), 98 % (53/54) Omicron-variant and 2 % (1/54) Delta-variant. Omicron sub-variants were BA.1 (47 %), BA.5 (34 %), BA.2 (13 %) and BA.4 (6 %). Globally, the two genotyping methods accurately identified the SARS-CoV-2 VOCs (P = 0.17, McNemar test; Ka = 0.67). Conclusion: Genomic surveillance reveals a rapid dynamic in SARS-CoV-2 strains between epidemiological waves in Cameroon. For wide-spread variant surveillance in resource-limited settings, SNPsig® SARS-CoV-2 EscapePLEX CEkit represents a suitable tool, pending upgrading for distinguishing Omicron sub-lineages.

An abnormal phenotype of lung Vγ9Vδ2 T cells impairs their responsiveness in tuberculosis patients.

Antigen-specific γδ T cells represent an early innate defense known to play an important role in anti-mycobacterial immunity. We have investigated the immune functions of Vγ9Vδ2 T cells from Broncho-Alveolar lavages (BAC) samples of active TB patients. We observed that BAC Vγ9Vδ2 T cells presented a strong down-modulation of CD3 expression compared with Vγ9Vδ2 T cells from peripheral blood. Furthermore, Vγ9Vδ2 T cells mainly showed a central memory phenotype, expressed high levels of NK inhibitory receptors and TEMRA cells showed low expression of CD16 compared to circulating Vγ9Vδ2 T cells. Interestingly, the ability of BAC Vγ9Vδ2 T cells to respond to antigen stimulation was dramatically reduced, differently from blood counterpart. These observations indicate that γδ T cell functions are specifically impaired in situ by active TB, suggesting that the alveolar ambient during tuberculosis may affect resident γδ T cells in comparison to circulating cells.

Identification of Laboratory Biomarkers for Early Detection and Clinical Management of Post-Acute Syndrome Among Survivors of the 2013-2016 West Africa Ebola Outbreak in Sierra Leone.

Background: The clinical management of persistent medical conditions affecting Ebola survivors, generally described as a post-Ebola syndrome, remains a public health concern. We aimed to analyze Ebola survivors' laboratory biomarkers as compared to their non-infected household relatives to identify biomarkers that could guide the identification of survivors at increased risk of developing severe at odds with the non-severe post-Ebola syndrome. Materials and Methods: Data were extracted from medical records of the Ebola survivors clinic, and we included only Ebola survivor's parameters recorded during the first baseline follow-up visit 2 weeks interval after their second negative PCR result. Moreover, household non-infected family contacts of survivors visiting the clinic during the same period were recruited as community control. Results: The mean age of survivors was 32.65 (IQR: 15.5, 38.25) years, and Ebola IgG immunoglobulin was detected in all, thus confirming their status. The statistical significance (all p < 0.05) observed in monocyte percentage (MONO%), cluster of differentiation 4 percentage (CD4%), alanine aminotransferase (ALT), creatinine (CREA), and creatinine kinase (C-kinase) proved to be clinically significant as compared to the household relatives' group. Interestingly, the linear regression analysis indicated that the duration at ETU was negatively associated with lymphocyte percentage with a 5% lymphocyte decrease per day spent at ETU. Finally, there was a significant (p < 0.05) association between hematological (Hb, PCV, MCV, MCH), biochemical (ALT, CREA, C-kinase, T-cholesterol, triglycerides) parameters and the risk of developing severe complications. Conclusion: We recommend clinicians closely monitor Hb, PCV, MCV, MCH, ALT, CREA, C-kinase, T-cholesterol, triglycerides and lymphocytes as clinically relevant laboratory biomarkers to identify survivors at higher risk of developing severe post-acute syndrome upon discharge from Ebola treatment unit including headache, abdominal pain, chest pain, ocular complication, arthralgia, hearing difficulty and erectile dysfunction which can impact health-related quality of life among Ebola survivors.

Inflammatory profile of vertically HIV-1 infected adolescents receiving ART in Cameroon: a contribution toward optimal pediatric HIV control strategies.

Antiretroviral therapy (ART) has improved the lifespan of people living with HIV. However, their immune system remains in a state of sustained activation/inflammation, which favors viral replication and depletion of helper T-cells with varying profiles according to ART-response. We herein sought to ascertain the inflammatory profile of adolescents living with perinatal HIV-1 infection (ALPHI) receiving ART in an African context. In this cross-sectional and comparative study among ART-experienced ALPHI in Yaoundé-Cameroon, HIV-1 RNA was measured by Abbott Real-time PCR; CD4 cells were enumerated using flow cytometry; serum cytokines were measured by ELISA; HIV-1 proviral DNA was genotyped by Sanger-sequencing; and archived drug resistance mutations (ADRMs) were interpreted using Stanford HIVdb.v9.0.1. Overall, 73 adolescents were enrolled (60 ALPHI and 13 HIV-1 negative peers) aged 15 (13-18) years; 60.00% were female. ART median duration was 92 (46-123) months; median viral load was 3.99 (3.17-4.66) RNA Log10 (copies)/mL and median CD4 count was 326 (201-654) cells/mm3. As compared to HIV-negative adolescents, TNFα was highly expressed among ALPHI (p<0.01). Following a virological response, inflammatory cytokines (IFNγ and IL-12), anti-inflammatory cytokines (IL-4 and IL-10) and inflammation-related cytokines (IL-6 and IL-1ß) were highly expressed with viral suppression (VS) vs. virological failure (VF), while the chemokine CCL3 was highly expressed with VF (p<0.01). Regarding the immune response, the inflammatory cytokine TNFα was highly expressed in those that are immunocompetent (CD4≥500 cell/mm3) vs. immunocompromised (CD4<500 cell/mm3), p ≤ 0.01; while chemokine CCL2 was highly expressed in the immunocompromised (p<0.05). In the presence of ADRMs, IL-4 and CCL3 were highly expressed (p=0.027 and p=0.043 respectively). Among ART-experienced ALPHI in Cameroon, the TNFα cytokine was found to be an inflammatory marker of HIV infection; IFNγ, IL-1ß, IL-6, and IL-12 are potential immunological markers of VS and targeting these cytokines in addition to antiretroviral drugs may improve management. Moreover, CCL3 and CCL2 are possible predictors of VF and/or being immunocompromised and could serve as surrogates of poor ART response.

Pre-existing immunity to SARS-CoV-2 before the COVID-19 pandemic era in Cameroon: A comparative analysis according to HIV-status.

Background: The lower burden of COVID-19 in tropical settings may be due to preexisting cross-immunity, which might vary according to geographical locations and potential exposure to other pathogens. We sought to assess the overall prevalence of SARS-CoV-2 antibodies and determine SARS-CoV-2 seropositivity according to HIV-status before the COVID-19 pandemic era. Methods: A cross-sectional and comparative study was conducted at the Chantal BIYA International Reference Centre (CIRCB) on 288 stored plasma samples (163 HIV-positive versus 125 HIV-negative); all collected in 2017-2018, before the COVID-19 pandemic era. Abbott Panbio™ COVID-19 IgG/IgM assay was used for detecting SARS-CoV-2 immunoglobulin G (IgG) and M (IgM). Among people living with HIV (PLHIV), HIV-1 viral load and TCD4 cell count (LTCD4) were measured using Abbott Real Time PCR and BD FACSCalibur respectively. Statistical analyses were performed, with p<0.05 considered statistically significant. Results: The median [IQR] age was 25 [15-38] years. Overall seropositivity to SARS-CoV-2 antibodies was 13.5% (39/288) of which 7.3% (21) was IgG, 7.3% (21) IgM and 1.0% (3) IgG/IgM. According to HIV-status in the study population, SARS-CoV-2 seropositivity was 11.0% (18/163) among HIV-positive versus 16.8% (21/125) among HIV-negative respectively, p=0.21. Specifically, IgG was 6.1% (10/163) versus 8.8% (11/125), p=0.26; IgM was 5.5% (9/163) versus 9.6%, (12/125), p=0.13 and IgG/IgM was 0.6% (1/163) versus 1.6% (2/125) respectively. Among PLHIV, SARS-CoV-2 seropositivity according to CD4 count was 9.2% (≥500 cells/µL) versus 1.8% (200-499 cells/µL), (OR=3.5; p=0.04) and 0.6% (<200 cells/µL), (OR=17.7; p<0.01). According to viral load, SARS-CoV-2 seropositivity was 6.7% (≥40 copies/mL) versus 4.9% (<40 copies/mL), (OR= 3.8; p<0.01). Conclusion: Before COVID-19 in Cameroon, cross-reactive antibodies to SARS-CoV-2 were in circulation, indicating COVID-19 preexisting immunity. This preexisting immunity may contribute in attenuating disease severity in tropical settings like Cameroon. Of relevance, COVID-19 preexisting immunity is lower with HIV-infection, specifically with viral replication and poor CD4-cell count. As poor CD4-count leads to lower cross-reactive antibodies (regardless of viral load), people living with HIV appear more vulnerable to COVID-19 and should be prioritized for vaccination.

Exogenous miRNAs from Moringa oleifera Lam. recover a dysregulated lipid metabolism.

A balanced diet is critical for human health, and edible plants play an important role in providing essential micronutrients as well as specific microRNAs (miRNAs) that can regulate human gene expression. Here we present the effects of Moringa oleifera (MO) miRNAs (mol-miRs) on lipid metabolism. Through in silico studies we identified the potential genes involved in lipid metabolism targeted by mol-miRs. To this end, we tested the efficacy of an aqueous extract of MO seeds (MOES), as suggested in traditional African ethnomedicine, or its purified miRNAs. The biological properties of MO preparations were investigated using a human derived hepatoma cell line (HepG2) as a model. MOES treatment decreased intracellular lipid accumulation and induced apoptosis in HepG2. In the same cell line, transfection with mol-miRs showed similar effects to MOES. Moreover, the effect of the mol-miR pool was investigated in a pre-obese mouse model, in which treatment with mol-miRs was able to prevent dysregulation of lipid metabolism.

Performance of the SD Bioline rapid diagnostic test as a good alternative to the detection of human African trypanosomiasis in Cameroon.

Background: Case detection is essential for the management of human African trypanosomiasis (HAT), which is caused by Trypanosoma brucei gambiense. Prior to parasitological confirmation, routine screening using the card agglutination test for trypanosomiasis (CATT) is essential. Recently, individual rapid diagnostic tests (RDTs) for the serodiagnosis of HAT have been developed. Objective: The purpose of this study was to evaluate the contribution of SD Bioline HAT to the serological screening of human African trypanosomiasis in Cameroonian foci.Methods. Between June 2014 and January 2015, blood samples were collected during surveys in the foci of Campo, Yokadouma, and Fontem. The sensitivity (Se) and specificity (Sp) of SD Bioline HAT were determined using the CATT as the gold standard for the detection of specific antibodies against Trypanosoma brucei gambiense. Results: A total of 88 samples were tested: 59.1% (n=52) in Campo, 31.8% (n=28) in Yokadouma, and 9.1% (n=8) in Fontem. There were 61.4% (n=54) males and 38.4% (n=34) females, and the average age was 35.4 19.0 years. In probed foci, the overall seroprevalence was 11.4% (95% confidence interval: 6.3-19.7) with the CATT method and 18.2% (95% confidence interval: 11.5-27.2%) with the SD Bioline HAT RDT method. The SD Bioline HAT's Se and Sp were 80.0% and 89.7%, respectively. Conclusions: This study demonstrated that the overall performance of the SD Bioline HAT was comparable to that of the CATT, with high specificity in the serological detection of HAT.

The 2018-2020 Ebola Outbreak in the Democratic Republic of Congo: A Better Response Had Been Achieved Through Inter-State Coordination in Africa.

The Ebola virus disease, formerly known as Ebola hemorrhagic fever, is a severe and often fatal zoonosis in humans. The 2013-2016 West African Ebola outbreak had distinctive characteristics, and it was the largest and most complex epidemic since the virus discovery in 1976. Although the 2018-2020 Ebola outbreak in the Democratic Republic of the Congo had many similarities, there were additional challenges due to the presence of armed rebel groups at the epicenters of the epidemic. Despite these challenges, the extraordinary commitment of the World Health Organization (WHO) regional office for Africa, in collaboration with Africa Union (AU) member states through the Africa Centres for Disease Control and Prevention (Africa CDC), and WHO's prompt declaration of a Public Health Emergency of International Concern (PHEIC) shepherded an effective coordinated response to contain the epidemic. Learning from previous Ebola virus epidemics and the current Coronavirus disease 2019 (COVID-19) pandemic, the AU member states should strengthen inter-state coordination towards the development and implementation of a preparedness and readiness plan which will enable the continent to build and sustain resilient capacities to prevent, detect, and respond to future outbreaks following the International Health Regulations (IHR).

Micro-Vesicles of Moringa oleifera Seeds in Heterozygous Rats for DAT Gene: Effects of Oral Intake on Behavioral Profile and Hematological Parameters.

Previous studies have shown multiple biological properties of Moringa oleifera, a plant native to Africa and Asia. In the present study, potential physiological properties of microvesicles extracted from Moringa oleifera seeds were assessed. For this purpose, we investigated behavioral profile and hematological parameters in a recent rat model characterized by dysregulation in dopamine transporter, a key regulator of dopaminergic system. Experimental design consisted of male Wistar-DAT rats aged between two and four months: wild-type (WT) (n = 5) and heterozygous (DATHET) (n = 4) control groups, which drank tap water; WT (n = 5) and DATHET (n = 6) groups which drank a solution of Moringa microvesicles and water (2: 68 mL per day), which was orally administered for two months. Rats were monitored for spontaneous locomotor activity on a 24/7 basis. In the early lit hours, treated DATHET subjects showed higher locomotor activity, proposing a sleep-delay effect of Moringa. In forced swimming test, WT subjects who took Moringa exhibited more depressive behavior. In DATHET rats, Moringa seemed to potentiate the struggle to find a way out, counteracting an initial panic. Hemoglobin and hematocrit underwent opposite changes in either genotype, supporting the opposite effects on behavioral phenotype observed. Future work is clearly needed to further explore these preliminary profiles.

NH-sulfoximine: A novel pharmacological inhibitor of the mitochondrial F1 Fo -ATPase, which suppresses viability of cancerous cells.

BACKGROUND AND PURPOSE: The mitochondrial F1 Fo -ATPsynthase is pivotal for cellular homeostasis. When respiration is perturbed, its mode of action everts becoming an F1 Fo -ATPase and therefore consuming rather producing ATP. Such a reversion is an obvious target for pharmacological intervention to counteract pathologies. Despite this, tools to selectively inhibit the phases of ATP hydrolysis without affecting the production of ATP remain scarce. Here, we report on a newly synthesised chemical, the NH-sulfoximine (NHS), which achieves such a selectivity. EXPERIMENTAL APPROACH: The chemical structure of the F1 Fo -ATPase inhibitor BTB-06584 was used as a template to synthesise NHS. We assessed its pharmacology in human neuroblastoma SH-SY5Y cells in which we profiled ATP levels, redox signalling, autophagy pathways and cellular viability. NHS was given alone or in combination with either the glucose analogue 2-deoxyglucose (2-DG) or the chemotherapeutic agent etoposide. KEY RESULTS: NHS selectively blocks the consumption of ATP by mitochondria leading a subtle cytotoxicity associated via the concomitant engagement of autophagy which impairs cell viability. NHS achieves such a function independently of the F1 Fo -ATPase inhibitory factor 1 (IF1). CONCLUSION AND IMPLICATIONS: The novel sulfoximine analogue of BTB-06584, NHS, acts as a selective pharmacological inhibitor of the mitochondrial F1 Fo -ATPase. NHS, by blocking the hydrolysis of ATP perturbs the bioenergetic homoeostasis of cancer cells, leading to a non-apoptotic type of cell death.

HIV replication leads to skewed maturation of CD8-positive T-cell responses in infected children.

HIV-1 infection causes a severe T-cell impairment with alteration of immune response. However, in children the natural decline of lymphocytes and CD4 cells in early life makes it more difficult to monitor immunocompetence and progression of HIV-infection. Aim of this study was to characterize the CD8 response in non-vertically HIV-infected children exposed persistently to viremia and in HIV-infected children controlling efficiently viremia by ART, by analysing the effect of persistent viremia on CD4 and CD8 T-cells count, HIV-specific immune-response and naive/memory pattern of CD8 T-cell. Whereas, no differences of CD4 count between viremic patients and viral controllers were observed (1046.9 +/- 472.1 cells/microl vs 1101.3 +/- 415.4 cells/microl; p > 0.05), CD8 count was higher in the viremic patients (1080.6 +/- 652.1 cells/microl vs 747.5 +/- 389.9 cells/microl, p < 0.05). In viremic patients, HIV-specific CD8 T-cells correlated with viral load. However, in this group a loss of HIV-specific CD8 response was associated with a 7 fold decrease of naïve and increase of pre-effector CD8 T-cells (62.8% +/- 10.21% vs 10.37% +/- 7.91%, p < 0.03). Persistent exposure to viremia alters HIV-specific CD8 response possibly through a persistent immune activation process leading to exhaustion of naive CD8 T-cells and skewed maturation of memory subset. Therefore, memory CD8 T-cells might lose the ability to respond correctly and efficiently to HIV-antigen exposure.

Effect of microvesicles from Moringa oleifera containing miRNA on proliferation and apoptosis in tumor cell lines.

Human microvesicles are key mediators of cell-cell communication. Exosomes function as microRNA transporters, playing a crucial role in physiological and pathological processes. Plant microvesicles (MVs) display similar features to mammalian exosomes, and these MVs might enhance plant microRNA delivery in mammals. Considering that plant microRNAs have been newly identified as bioactive constituents in medicinal plants, and that their potential role as regulators in mammals has been underlined, in this study, we characterized MVs purified from Moringa oleifera seeds aqueous extract (MOES MVs) and used flow cytometry methods to quantify the ability to deliver their content to host cells. The microRNAs present in MOES MVs were characterized, and through a bioinformatic analysis, specific human apoptosis-related target genes of plant miRNAs were identified. In tumor cell lines, MOES MVs treatment reduced viability, increased apoptosis levels associated with a decrease in B-cell lymphoma 2 protein expression and reduced mitochondrial membrane potential. Interestingly, the effects observed with MOES MVs treatment were comparable to those observed with MOES treatment and transfection with the pool of small RNAs isolated from MOES, used as a control. These results highlight the role of microRNAs transported by MOES MVs as natural bioactive plant compounds that counteract tumorigenesis.

Plant microRNAs from Moringa oleifera Regulate Immune Response and HIV Infection.

Traditional medicine is often chosen due to its affordability, its familiarity with patient's cultural practices, and its wider access to the local community. Plants play an important role in providing indispensable nutrients, while specific small RNAs can regulate human gene expression in a cross-kingdom manner. The aim of the study was to evaluate the effects of plant-enriched purified extract microRNAs from Moringa oleifera seeds (MO) on the immune response and on HIV infection. Bioinformatic analysis shows that plant microRNAs (p-miRs) from MO belonging to 18 conserved families, including p-miR160h, p-miR166, p-miR482b, p-miR159c, p-miR395d, p-miR2118a, p-miR393a, p-miR167f-3p, and p-miR858b are predicted to target with high affinity BCL2, IL2RA, TNF, and VAV1, all these being involved in the cell cycle, apoptosis, immune response and also in the regulation of HIV pathogenesis. The effects of MO p-miRs transfected into HIV+ PBMCs were analyzed and revealed a decrease in viability associated with an increase of apoptosis; an increase of T helper cells expressing Fas and a decrease of intracellular Bcl2 protein expression. Meanwhile no effects were detected in PBMCs from healthy donors. In CD4+ T cells, transfection significantly reduced cell activation and modified the T cell differentiation, thereby decreasing both central and effector memory cells while increasing terminal effector memory cells. Interestingly, the p-miRs transfection induces a reduction of intracellular HIV p24 protein and a reduction of viral DNA integration. Finally, we evaluated the effect of synthetic (mimic) p-miR858b whose sequence is present in the MO p-miR pool and predicted to target VAV1, a protein involved in HIV-Nef binding. This protein plays a pivotal role in T cell antigen receptor (TCR) signaling, so triggering the activation of various pathways. The transfection of HIV+ PBMCs with the synthetic p-miR858b showed a reduced expression of VAV1 and HIV p24 proteins. Overall, our evidence defines putative mechanisms underlying a supplementary benefit of traditional medicine, alongside current antiretroviral therapy, in managing HIV infection in resource-limited settings where MO remains widely available.

Adoptive Cell Therapy-Harnessing Antigen-Specific T Cells to Target Solid Tumours.

In recent years, much research has been focused on the field of adoptive cell therapies (ACT) that use native or genetically modified T cells as therapeutic tools. Immunotherapy with T cells expressing chimeric antigen receptors (CARs) demonstrated great success in the treatment of haematologic malignancies, whereas adoptive transfer of autologous tumour infiltrating lymphocytes (TILs) proved to be highly effective in metastatic melanoma. These encouraging results initiated many studies where ACT was tested as a treatment for various solid tumours. In this review, we provide an overview of the challenges of T cell-based immunotherapies of solid tumours. We describe alternative approaches for choosing the most efficient T cells for cancer treatment in terms of their tumour-specificity and phenotype. Finally, we present strategies for improvement of anti-tumour potential of T cells, including combination therapies.

Cytotoxic and apoptotic effects of different extracts of Moringa oleifera Lam on lymphoid and monocytoid cells.

Moringa oleifera Lam. (MO) is one of the most well-known and widely distributed species of the Moringaceae family in African communities, and various preparations of M. oleifera are used for the treatment of several diseases. Due to the extensive worldwide use of MO products, and the use of MO aqueous extract in traditional African medicine, the aim of the present study was to investigate the anti-proliferative, cytotoxic and pro-apoptotic activities of different aqueous extracts from leaves and seeds of M. oleifera (MOE), which have been prepared using different protocols, in lymphoid and monocytoid cells. The results of the present study demonstrated the anti-proliferative and pro-apoptotic effects of the aqueous extracts obtained from M. oleifera leaves and seeds on tumour cells; however, not on peripheral blood mononuclear cells (PBMCs) from healthy donors. The pro-apoptotic effect of MO seed aqueous extract (MOE-S) was correlated with decreased B-cell lymphoma 2 (BCL2) and sirtuin-1 (SIRT1) protein expression, which are involved in apoptosis. Considering the effects of plant secondary metabolites on human cells and the role of plant microRNA in cross-kingdom interactions, the presence of secondary metabolites and microRNA in MOE was characterised. In conclusion, M. oleifera aqueous extracts appeared to be able to differentially regulate proliferation and apoptosis in healthy cells and cancer cells, and this ability could be associated with the microRNA present in the extracts. These results highlighted the possible use of MOE as an adjuvant in traditional cancer therapy.