Coronavirus infection: An immunologists' perspective

Exploring the Contrasts and Similarities of Dengue and SARS-CoV-2 Infections During the COVID-19 Era

Extensive research has been conducted on the SARS-CoV-2 virus in association with various infectious diseases to understand the pathophysiology of the infection and potential co-infections. In tropical countries, exposure to local viruses may alter the course of SARS-CoV-2 infection and coinfection. Notably, only a portion of the antibodies produced against SARS-CoV-2 proteins demonstrate neutralizing properties, and the immune response following natural infection tends to be temporary. In contrast, long-lasting IgG antibodies are common after dengue virus infections. In cases where preexisting antibodies from an initial dengue virus infection bind to a different dengue serotype during a subsequent infection, there is a potential for antibody-dependent enhancement (ADE) and the formation of immune complexes associated with disease severity. Both SARS-CoV-2 and dengue infections can result in immunodeficiency. Viral proteins of both viruses interfere with the host's IFN-I signaling. Additionally, a cytokine storm can occur after viral infection, impairing a proper response, and autoantibodies against a wide array of proteins can appear during convalescence. Most of the reported autoantibodies are typically short-lived. Vaccines against both viruses alter the immune response, affecting the course of viral infection and enhancing clearance. A comprehensive analysis of both viral infections and pathogenicity is revisited to prevent infection, severity, and mortality.

Integrative analysis discovers Imidurea as dual multitargeted inhibitor of CD69, CD40, SHP2, lysozyme, GATA3, cCBL, and S-cysteinase from SARS-CoV-2 and M. tuberculosis

Two of the deadliest infectious diseases, COVID-19 and tuberculosis (TB), have combined to establish a worldwide pandemic, wreaking havoc on economies and claiming countless lives. The optimised, multitargeted medications may diminish resistance and counter them together. Based on computational expression studies, 183 genes were co-expressed in COVID-19 and TB blood samples. We used the multisampling screening algorithms on the top ten co-expressed genes (CD40, SHP2, Lysozyme, GATA3, cCBL, SIVmac239 Nef, CD69, S-adenosylhomocysteinase, Chemokine Receptor-7, and Membrane Protein). Imidurea is a multitargeted inhibitor for COVID-19 and TB, as confirmed by extensive screening and post-filtering utilising MM\GBSA algorithms. Imidurea has shown docking and MM\GBSA scores of -8.21 to -4.75 Kcal/mol and -64.16 to -29.38 Kcal/mol, respectively. The DFT, pharmacokinetics, and interaction patterns suggest that Imidurea may be a drug candidate, and all ten complexes were tested for stability and bond strength using 100 ns for all MD atoms. The modelling findings showed the complex's repurposing potential, with a cumulative deviation and fluctuation of <2 Å and significant intermolecular interaction, which validated the possibilities. Finally, an inhibition test was performed to confirm our in-silico findings on SARS-CoV-2 Delta variant infection, which was suppressed by adding imidurea to Vero E6 cells after infection.

Comparative Analysis of the Efficiency of Medicinal Plants for the Treatment and Prevention of COVID-19

The COVID-19 pandemic has once again prompted people to resort to the remedies of folk and alternative medicine. Medicinal plants, because of their chemical composition, pharmacological properties, and the action of biologically active substances, can stop and relieve the symptoms of the disease. The purpose of the work is a comparative flora analysis of medicinal plants to identify the most prospective plant and further production of a remedy for the avoidance, treatment, and rehabilitation of COVID-19. The search for prospective medicinal plants was performed by analyzing the literature in online databases: Web of Science, Scopus, Google Scholar, and PubMed, including official WHO media sites. According to recent studies related to COVID-19, a significant number of medicinal plants with anti-inflammatory, antiviral, and immunostimulatory effects have been identified. A comparative study of nine medicinal plants was conducted to determine the most suitable medicinal plant to treat coronavirus infection. According to the results of the comparative analysis, Chamaenerion angustifolium Seg. showed itself as the most prospective medicinal plant with the greatest pharmacological effect compared with other types of medicinal plants. Its therapeutic properties allow physiological relief of 18 symptoms of coronavirus infection. It is advisable to conduct further clinical trials for the treatment and rehabilitation of COVID-19 using preparations from this plant.

Overview of Memory NK Cells in Viral Infections: Possible Role in SARS-CoV-2 Infection

NK cells have usually been defined as cells of the innate immune system, although they are also involved in adaptative responses. These cells belong to the innate lymphocyte cells (ILC) family. They remove unwanted cells, tumoral cells and pathogens. NK cells are essential for viral infection clearance and are involved in tolerogenic responses depending on the dynamic balance of the repertoire of activating and inhibitory receptors. NK plasticity is crucial for tissue function and vigilant immune responses. They directly eliminate virus-infected cells by recognising viral protein antigens using a non-MHC dependent mechanism, recognising viral glycan structures and antigens by NCR family receptors, inducing apoptosis by Fas-Fas ligand interaction, and killing cells by antibody-dependent cell cytotoxicity via the FcγIII receptor. Activating receptors are responsible for the clearance of virally infected cells, while inhibitory KIR receptor activation impairs NK responses and facilitates virus escape. Effective NK memory cells have been described and characterised by a low NKG2A and high NKG2C or NKG2D expression. NK cells have also been used in cell therapy. In SARS-CoV-2 infection, several contradicting reports about the role of NK cells have been published. A careful analysis of the current data and possible implications will be discussed.

Potential COVID-19 therapeutic approaches targeting angiotensin-converting enzyme 2; An updated review

COVID-19 has spread swiftly throughout the world posing a global health emergency. The significant numbers of deaths attributed to this pandemic have researchers battling to understand this new, dangerous virus. Researchers are looking to find possible treatment regimens and develop effective therapies. This study aims to provide an overview of published scientific information on potential treatments, emphasizing angiotensin-converting enzyme II (ACE2) inhibitors as one of the most important drug targets. SARS-CoV-2 receptor-binding domain (RBD); as a viral attachment or entry inhibitor against SARS-CoV-2, human recombinant soluble ACE2; as a genetically modified soluble form of ACE2 to compete with membrane-bound ACE2, and microRNAs (miRNAs); as a negative regulator of the expression of ACE2/TMPRSS2 to inhibit SARS-CoV2 entry into cells, are the potential therapeutic approaches discussed thoroughly in this article. This review provides the groundwork for the ongoing development of therapeutic agents and effective treatments against SARS-COV-2.

Antibodies specific to SARS-CoV-2 proteins N, S and E in COVID-19 patients in the normal population and in historical samples

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread globally; recognition of immune responses to this virus will be crucial for coronavirus disease 2019 (COVID-19) control, prevention and treatment. We comprehensively analysed IgG and IgA antibody responses to the SARS-CoV-2 nucleocapsid protein (N), spike protein domain 1 (S1) and envelope protein (E) in: SARS-CoV-2-infected patient, healthy, historical and pre-epidemic samples, including patients' medical, epidemiological and diagnostic data, virus-neutralizing capability and kinetics. N-specific IgG and IgA are the most reliable diagnostic targets for infection. Serum IgG levels correlate to IgA levels. Half a year after infection, anti-N and anti-S1 IgG decreased, but sera preserved virus-inhibitory potency; thus, testing for IgG may underestimate the protective potential of antibodies. Historical and pre-epidemic sera did not inhibit SARS-CoV-2, thus its circulation before the pandemic and a protective role from antibodies pre-induced by other coronaviruses cannot be confirmed by this study.

Secondary immunodeficiencies: An overview

OBJECTIVE

To review the different causes of secondary immunodeficiencies and provide clinicians with an updated overview of potential factors that contribute to immunodeficiency.

DATA SOURCES

Recent published literature obtained through PubMed database searches, including research articles, review articles, and case reports.

STUDY SELECTIONS

PubMed database searches were conducted using the following keywords: immunodeficiency, antibody deficiency, immunosuppressive drugs, genetic syndrome, malignancy, HIV infection, viral infection, secondary immunodeficiency, nutrition, prematurity, aging, protein-losing enteropathy, nephropathy, trauma, space travel, high altitude, and ultraviolet light. Studies published in the last decade and relevant to the pathogenesis, epidemiology, and clinical characteristics of secondary immunodeficiencies were selected and reviewed.

RESULTS

Researchers continue to investigate and report abnormal immune parameters in the different entities collectively known as secondary immunodeficiencies. Immunodeficiency might occur as a consequence of malnutrition, metabolic disorders, use of immunosuppressive medications, chronic infections, malignancies, severe injuries, and exposure to adverse environmental conditions. The neonate and the elderly may have decreased immune responses relative to healthy adults. Each of these conditions may present with different immune defects of variable severity. The acquired immunodeficiency syndrome results from infections by the human immunodeficiency virus, which targets CD4 T cells leading to defective immune responses. Rituximab is a monoclonal antibody that targets CD20 B cells, and its use might result in persistent hypogammaglobulinemia.

CONCLUSION

Clinicians should consider secondary immunodeficiencies in the differential diagnosis of a patient with recurrent infections and abnormal immunologic evaluation. The use of biological agents for the treatment of inflammatory conditions and malignancies is an increasingly important cause of secondary immunodeficiency.

Coronavirus infection: An immunologists' perspective

Coronavirus infections are frequent viral infections in several species. As soon as the severe acute respiratory syndrome (SARS) appeared in the early 2000s, most of the research focused on pulmonary disease. However, disorders in immune response and organ dysfunctions have been documented. Elderly individuals with comorbidities exhibit worse outcomes in all the coronavirus that cause SARS. Disease severity in SARS-CoV-2 infection is related to severe inflammation and tissue injury, and effective immune response against the virus is still under analysis. ACE2 receptor expression and polymorphism, age, gender and immune genetics are factors that also play an essential role in patients' clinical features and immune responses and have been partially discussed. The present report aims to review the physiopathology of SARS-CoV-2 infection and propose new research topics to understand the complex mechanisms of viral infection and viral clearance.

COVID-19 infection presented as Guillain-Barre Syndrome: Report of two new cases and review of 116 reported cases and case series

BACKGROUND

/Aims: Corona virus disease 2019 (COVID 19) is a pandemic infectious disease of 2020, which often presents with respiratory and gastrointestinal symptoms. The behavior of the virus and its full clinical picture has not been fully studied yet. Many case reports and case series have been running in order to elaborate different presentations and associations. Pulmonary and gastrointestinal features of COVID-19 infection are well outlined; however, neurological manifestations are less defined.

CASE PRESENTATION

We report two adult cases of COVID-19 infection presented with acute Guillain-Barre Syndrome (GBS), and a literature review on the causal association between COVID-19 and GBS.

CONCLUSION

Our two case reports in addition to literature review of 116 published cases may help offer insight into the clinical course of COVID-19 infection. Our two COVID-19 patients presented with neurological manifestations of GBS which were not preceded with any respiratory, gastrointestinal or other systemic infection. This leads us to raise the possibility of establish direct causal association between COVID-19 infection and GBS. Physicians should have high clinical suspicions when encounter GBS patient during the current COVID-19 pandemic and consider co-existence of COVID-19 infection that may warrant SARS-CoV-2 testing, isolation precautions, and specific treatment for Covid-19 infection.