Peptide microarray analysis of in-silico predicted B-cell epitopes in SARS-CoV-2 sero-positive healthcare workers in Bulawayo, Zimbabwe.

Immunogenic peptides that mimic linear B-cell epitopes coupled with immunoassay validation may improve serological tests for emerging diseases. This study reports a general approach for profiling linear B-cell epitopes derived from SARS-CoV-2 using an in-silico method and peptide microarray immunoassay, using healthcare workers' SARS-CoV-2 sero-positive sera. SARS-CoV-2 was tested using rapid chromatographic immunoassays and real-time reverse-transcriptase polymerase chain reaction. Immunogenic peptides mimicking linear B-cell epitopes were predicted in-silico using ABCpred. Peptides with the lowest sequence identity with human protein and proteins from other human pathogens were selected using the NCBI Protein BLAST. IgG and IgM antibodies against the SARS-CoV-2 spike protein, membrane glycoprotein and nucleocapsid derived peptides were measured in sera using peptide microarray immunoassay. Fifty-three healthcare workers included in the study were RT-PCR negative for SARS-CoV-2. Using rapid chromatographic immunoassays, 10 were SARS-CoV-2 IgM sero-positive and 7 were SARS-CoV-2 IgG sero-positive. From a total of 10 SARS-CoV-2 peptides contained on the microarray, 3 (QTH34388.1-1-14, QTN64908.1-135-148, and QLL35955.1-22-35) showed reactivity against IgG. Three peptides (QSM17284.1-76-89, QTN64908.1-135-148 and QPK73947.1-8-21) also showed reactivity against IgM. Based on the results we predicted one peptide (QSM17284.1-76-89) that had an acceptable diagnostic performance. Peptide QSM17284.1-76-89 was able to detect IgM antibodies against SARS-CoV-2 with area under the curve (AUC) 0.781 when compared to commercial antibody tests. In conclusion in silico peptide prediction and peptide microarray technology may provide a platform for the development of serological tests for emerging infectious diseases such as COVID-19. However, we recommend using at least three in-silico peptide prediction tools to improve the sensitivity and specificity of B-cell epitope prediction, to predict peptides with excellent diagnostic performances.

Unravelling the Mechanistic Role of ACE2 and TMPRSS2 in Hypertension: A Risk Factor for COVID-19.

BACKGROUND: This review explores the mechanistic action of angiotensin-converting enzyme- 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2) in the renin-angiotensinaldosterone system (RAAS) that predisposes hypertensive patients to the adverse outcome of severe COVID-19. METHODS AND RESULTS: Entry of SARS-CoV-2 into the host cell via ACE2 disrupts the RAAS system, creating an imbalance between ACE and ACE2, with an increased inflammatory response, leading to hypertension (HTN), pulmonary vasoconstriction and acute respiratory distress. SARSCoV- 2 may also predispose infected individuals with existing HTN to a greater risk of severe COVID-19 complications. In the duality of COVID-19 and HTN, the imbalance of ACE and ACE2 results in an elevation of AngII and a decrease in Ang (1-7), a hyperinflammatory response and endothelial dysfunction. Endothelial dysfunction is the main factor predisposing hypertensive patients to severe COVID-19 and vice-versa. CONCLUSION: Despite the increase in ACE2 expression in hypertensive SARS-CoV-2 infected patients, ARBs/ACE inhibitors do not influence their severity and clinical outcomes, implicating continued usage. Future large-scale clinical trials are warranted to further elucidate the association between HTN and SARS-CoV-2 infection and the use of ARBs/ACEIs in SARS-CoV-2 hypertensive patients.

The complement system in preeclampsia: a review of its activation and endothelial injury in the triad of COVID 19 infection and HIV-associated preeclampsia.

This review assessed the complement system and its activation with respect to the pathological features of severe acute respiratory syndrome (SARS-CoV-2), human immunodeficiency virus (HIV) infection, and preeclampsia (PE). The complement system is the first defensive response of the host innate immune system to viral pathogens, including SARS-Cov-2. SARS-CoV-2 entry results in the release of proinflammatory cytokines and chemical mediators to create a "cytokine storm". Endothelial cell (EC) dysfunction and cell-mediated injury are also observed. These factors exacerbate inflammation. During HIV infection and PE, various complement components are elevated, causing a hyperinflammatory state. Furthermore, EC dysfunction and cell-mediated injury are also observed. The similarities in the pathological aspects of these three disorders may emanate from excessive complement activation. This review serves as a platform for further research on the complement system, coronavirus disease-2019, HIV, and PE.

Vascular Endothelial Growth Factor Receptor 2: Molecular Mechanism and Therapeutic Potential in Preeclampsia Comorbidity with Human Immunodeficiency Virus and Severe Acute Respiratory Syndrome Coronavirus 2 Infections.

This review explored the role of vascular endothelial growth factor receptor-2 (VEGFR-2) in the synergy of preeclampsia (PE), human immunodeficiency virus (HIV), and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Downregulation of VEGFR-2 in PE promotes endothelial dysfunction and prevents endothelial cell (EC) migration, proliferation, and differentiation. The HIV-1 accessory protein, tat (trans-activator of transcription), prevents VEGFR-2 signaling via the vascular endothelial growth factor A (VEGF-A) ligand. Combined antiretroviral therapy (cART) may cause immune reconstitution, impaired decidualization, and endothelial injury, thus may be a risk factor for PE development. The VEGF/VEGFR-2 interaction may be associated with SARS-CoV-2-related pulmonary oedema. Endothelial dysfunction and heightened inflammation are both associated with PE, HIV, and SARS-CoV-2 infection; therefore, it is plausible that both characteristics may be exacerbated in the synergy of these events. In addition, this review explored microRNAs (miR) regulating VEGFR-2. An overexpression of miR-126 is evident in PE, HIV, and SARS-CoV-2 infection; thus, modulating the expression of miR-126 may be a therapeutic strategy. However, the involvement of microRNAs in PE, HIV, and SARS-CoV-2 infection needs further investigating. Since these conditions have been evaluated independently, this review attempts to predict their clinical manifestations in their synergy, as well as independently; thereby providing a platform for early diagnosis and therapeutic potential in PE, HIV, and SARS-CoV-2 infection.

Neuropilin-1 in the pathogenesis of preeclampsia, HIV-1, and SARS-CoV-2 infection: A review.

This review explores the role of transmembrane neuropilin-1 (NRP-1) in pregnancy, preeclampsia (PE), human immunodeficiency virus type 1 (HIV-1) and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections. Since these conditions are assessed independently, this review attempts to predict their comorbid clinical manifestations. Dysregulation of NRP-1 contributes to the pathogenesis of PE by (a) impairing vascular endothelial growth factor (VEGF) signaling for adequate spiral artery remodeling and placentation, (b) inducing syncytiotrophoblast (ST) cell apoptosis and increasing ST-derived microparticle circulation and (c) by decreasing regulatory T cell activity predisposing maternal immune intolerance. Although NRP-1 is upregulated in SARS-CoV-2 placentae, its exploitation for SARS-CoV-2 internalization and increased infectivity may alter angiogenesis through the competitive inhibition of VEGF. The anti-inflammatory nature of NRP-1 may aid its upregulation in HIV-1 infection; however, the HIV-accessory protein, tat, reduces NRP-1 expression. Upregulated NRP-1 in macrophages and dendritic cells also demonstrated HIV-1 resistance/reduced infectivity. Notably, HIV-1-infected pregnant women receiving antiretroviral therapy (ART) to prevent vertical transmission may experience immune reconstitution, impaired decidualization, and elevated markers of endothelial injury. Since endothelial dysfunction and altered immune responses are central to PE, HIV-1 infection, ART usage and SARS-CoV-2 infection, it is plausible that an exacerbation of both features may prevail in the synergy of these events. Additionally, this review identifies microRNAs (miRNAs) mediating NRP-1 expression. MiR-320 and miR-141 are overexpressed in PE, while miR-206 and miR-124-3p showed increased expression in PE and HIV-1 infection. Additionally, miR-214 is overexpressed in PE, HIV-1 and SARS-CoV-2 infection, implicating treatment strategies to reduce these miRNAs to upregulate and normalize NRP-1 expression. However, inconsistencies in the data of the role and regulation of miRNAs in PE, HIV-1 and SARS-CoV-2 infections require clarification. This review provides a platform for early diagnosis and potential therapeutic intervention of PE, HIV-1, and SARS-CoV-2 infections independently and as comorbidities.

The Contribution of Complement Protein C1q in COVID-19 and HIV Infection Comorbid with Preeclampsia: A Review.

Dysregulation in component 1q (C1q) levels is associated with weak placental development in preeclampsia (PE). Human immunodeficiency virus infection (HIV-1) triggers the C1q complex, resulting in opsonization of healthy host cells, contributing to their removal, and augmented progression of HIV disease. In coronavirus disease 2019 (COVID-19)-infected patients, the deposition of C1q activates the complement. Considering the paucity of data, this review highlights a significant gap in the potential of C1q in the immunocompromised state of preeclamptic HIV-infected women and COVID-19 infection. In PE, C1q is downregulated; while in antiretroviral treatment-treated HIV/COVID-19 infected patients, C1q is upregulated. It is plausible that C1q is augmented in the triad and may exacerbate severity of disease. This thereby provides a foundation for future intended research which involves the investigation of single nucleotide polymorphism expression of the C1q gene, specifically in these diseases.

A systematic and meta-analysis review on the diagnostic accuracy of antibodies in the serological diagnosis of COVID-19.

BACKGROUND: Serological testing based on different antibody types are an alternative method being used to diagnose SARS-CoV-2 and has the potential of having higher diagnostic accuracy compared to the current gold standard rRT-PCR. Therefore, the objective of this review was to evaluate the diagnostic accuracy of IgG and IgM based point-of-care (POC) lateral flow immunoassay (LFIA), chemiluminescence enzyme immunoassay (CLIA), fluorescence enzyme-linked immunoassay (FIA) and ELISA systems that detect SARS-CoV-2 antigens. METHOD: A systematic literature search was carried out in PubMed, Medline complete and MedRxiv. Studies evaluating the diagnostic accuracy of serological assays for SARS-CoV-2 were eligible. Study selection and data-extraction were performed by two authors independently. QUADAS-2 checklist tool was used to assess the quality of the studies. The bivariate model and the hierarchical summary receiver operating characteristic curve model were performed to evaluate the diagnostic accuracy of the serological tests. Subgroup meta-analysis was performed to explore the heterogeneity. RESULTS: The pooled sensitivity for IgG (n = 17), IgM (n = 16) and IgG-IgM (n = 24) based LFIA tests were 0.5856, 0.4637 and 0.6886, respectively compared to rRT-PCR method. The pooled sensitivity for IgG (n = 9) and IgM (n = 10) based CLIA tests were 0.9311 and 0.8516, respectively compared to rRT-PCR. The pooled sensitivity the IgG (n = 10), IgM (n = 11) and IgG-IgM (n = 5) based ELISA tests were 0.8292, 0.8388 and 0.8531 respectively compared to rRT-PCR. All tests displayed high specificities ranging from 0.9693 to 0.9991. Amongst the evaluated tests, IgG based CLIA expressed the highest sensitivity signifying its accurate detection of the largest proportion of infections identified by rRT-PCR. ELISA and CLIA tests performed better in terms of sensitivity compared to LFIA. IgG based tests performed better compared to IgM except for the ELISA. CONCLUSIONS: We report that IgG-IgM based ELISA tests have the best overall diagnostic test accuracy. Moreover, irrespective of the method, a combined IgG/IgM test seems to be a better choice in terms of sensitivity than measuring either antibody type independently. Given the poor performances of the current LFIA devices, there is a need for more research on the development of highly sensitivity and specific POC LFIA that are adequate for most individual patient applications and attractive for large sero-prevalence studies. SYSTEMATIC REVIEW REGISTRATION: PROSPERO CRD42020179112.

The Involvement of MicroRNAs in SARS-CoV-2 Infection Comorbid with HIV-Associated Preeclampsia.

PURPOSE OF REVIEW: This review investigated the potential role of microRNAs (miRNAs) in the synergy of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection, preeclampsia (PE), and human immunodeficiency virus (HIV) infection. Maternal health is a great concern when treating pregnant women fighting this triad of diseases, which is highly prevalent in South Africa. MicroRNAs are involved in fine-tuning of physiological processes. Disruptions to the balance of this minute protein can lead to various physiological changes that are sometimes pathological. RECENT FINDINGS: MicroRNAs have recently been implicated in PE and have been linked to the anti-angiogenic imbalance evident in PE. Recent in silico studies have identified potential host miRNAs with anti-viral properties against SARS-CoV-2 infection. Studies have demonstrated dysregulated expression of several miRNAs in HIV-1 infection along with the ability of HIV-1 to downregulate anti-viral host microRNAs. This review has highlighted the significant gap in literature on the potential of miRNAs in women with HIV-associated PE in synergy with the novel SARS-CoV-2 infection. In addition, this review has provided evidence of the critical role that the epigenetic regulatory mechanism of miRNA plays in viral infections and PE, thereby providing a foundation for further research investigating the potential of therapeutic miRNA development with fewer side-effects for pregnant women.

Insulin resistance in COVID-19 and diabetes.

BACKGROUND: The epidemiology of COVID-19 and its association with cardiometabolic disorders is poorly understood. This is a narrative review that investigates the effects of COVID-19 infection on insulin resistance in patients with diabetes. METHODS: An online search of all published literature was done via PubMed and Google Scholar using the MeSH terms "COVID-19," "SARS-CoV-2," "coronavirus," "insulin resistance," and "diabetes." Only articles that were directly applicable to insulin resistance in COVID-19 and diabetes was reviewed. RESULTS: Current data shows an increased risk of mortality in patients with diabetes and COVID-19 compared to those without diabetes. COVID-19 triggers insulin resistance in patients, causing chronic metabolic disorders that were non-existent prior to infection. CONCLUSION: Patients with diabetes are more susceptible to COVID-19 infection than those without diabetes. ACE2 expression decreases with infection, exaggerating Ang II activity with subsequent insulin resistance development, an exaggerated immune response and severe SARS-COV-2 infection.

The COVID-19 Pandemic: an Appraisal of its Impact on Human Immunodeficiency Virus Infection and Pre-Eclampsia.

PURPOSE OF REVIEW: The impact of the coronavirus disease 2019 (COVID-19) pandemic is profound, with distressing consequences on many individuals, especially those with co-morbidities. Pregnant women are one such group of individuals who are at in increased risk of contracting COVID-19, due to their immunocompromised state. In South Africa, HIV infection and pre-eclampsia are the leading causes of maternal morbidity and mortality, with South Africa being the HIV epicentre of the world. The relationship between COVID-19 superimposed on HIV infection and preeclampsia is complex and uncertain due to their different immune responses, and therefore requires further research. RECENT FINDINGS: Notably evidence suggests that pregnant women with chronic comorbidities (HIV and pre-eclampsia) may be at a greater risk of contracting or encountering complications from COVID-19. Maternal stress, during a pandemic, as well as home delivery have become potential options for pregnant woman. Nonetheless there is currently a paucity of information on the combined effect of COVID-19 in HIV-associated preeclampsia. Understanding the pathogenesis of COVID-19 could potentially aid in developing effective treatment strategies for COVID-19 in HIV associated preeclampsia. This review article presents a comprehensive analysis of the current data in relation to COVID-19 and its effect on pregnant women, including symptoms, pathogenesis and the possible risk of vertical transmission. This paper also reviews its' interactions and effects on preeclamptic and HIV positive pregnant women with suspected or confirmed COVID-19.

Maternal endothelial dysfunction in HIV-associated preeclampsia comorbid with COVID-19: a review.

This review assesses markers of endothelial dysfunction (ED) associated with the maternal syndrome of preeclampsia (PE). We evaluate the role of antiretroviral therapy (ART) in human immunodeficiency virus (HIV)-infected preeclamptic women. Furthermore, we briefly discuss the potential of lopinavir/ritonavir (LPV/r), dolutegravir (DTG) and remdesivir (RDV) in drug repurposing and their safety in pregnancy complicated by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. In HIV infection, the trans-activator of transcription protein, which has homology with vascular endothelial growth factor, impairs angiogenesis, leading to endothelial injury and possible PE development despite neutralization of their opposing immune states. Markers of ED show strong evidence supporting the adverse role of ART in PE development and mortality compared to treatment-naïve pregnancies. Coronavirus disease 2019 (COVID-19), caused by SARS-CoV-2 infection, exploits angiotensin-converting enzyme 2 (ACE 2) to induce ED and hypertension, thereby mimicking angiotensin II-mediated PE in severe cases of infection. Upregulated ACE 2 in pregnancy is a possible risk factor for SARS-CoV-2 infection and subsequent PE development. The potential effectiveness of LPV/r against COVID-19 is inconclusive; however, defective decidualization, along with elevated markers of ED, was observed. Therefore, the safety of these drugs in HIV-positive pregnancies complicated by COVID-19 requires attention. Despite the observed endothelial protective properties of DTG, there is a lack of evidence of its effects on pregnancy and COVID-19 therapeutics. Understanding RDV-ART interactions and the inclusion of pregnant women in antiviral drug repurposing trials is essential. This review provides a platform for further research on PE in the HIV-COVID-19 syndemic.