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1.
Viral Immunol ; 35(9): 579-585, 2022 Nov.
Article in English | MEDLINE | ID: covidwho-2107328

ABSTRACT

Tumor necrosis factor superfamily 14 (TNFSF14) (LIGHT) is an interesting costimulatory molecule associated with T lymphocyte activation, and it mainly exerts its biological effects by binding to its receptors herpesvirus invasion mediator (HVEM) and lymphotoxin-ß receptor. Research shows that TNFSF14 plays a critical regulatory role in immune responses to viral infection, but its role is different in different diseases. TNFSF14 can be a cytokine neutralization target during novel coronavirus infection, and anti-TNFSF14 monoclonal antibody treatment can reduce the risk of respiratory failure and mortality. When the host is infected with adenovirus, TNFSF14 can be used as an inflammatory biomarker to indicate whether there was an adenovirus infection in the host and the degree of disease caused by viral infection. When hosts suffer influenza virus infection, the TNFSF14-HVEM signaling pathway can stimulate the maturation and proliferation of memory CD8+ T cells, which helps the host immune system stimulate a second immune response against respiratory virus infection. TNFSF14 can act as an immune adjuvant and enhance the immunogenicity of the human papillomavirus (HPV) DNA vaccine when the host is infected with HPV. During hepatitis virus infection, TNFSF14 acts as a proinflammatory factor, participates in inflammation and causes tissue damage. In conclusion, TNFSF14 plays different and significant roles in diverse viral infections. This article reviews the current research on TNFSF14 in antiviral immunity.


Subject(s)
COVID-19 , Papillomavirus Infections , Humans , Tumor Necrosis Factor Ligand Superfamily Member 14/genetics , Tumor Necrosis Factor Ligand Superfamily Member 14/metabolism , CD8-Positive T-Lymphocytes/metabolism , Antiviral Agents , Signal Transduction , Tumor Necrosis Factor-alpha
2.
Open Access Macedonian Journal of Medical Sciences ; 10(C):246-251, 2022.
Article in English | EMBASE | ID: covidwho-2066676

ABSTRACT

BACKGROUND: Pregnancy state affects the immune regulation including physical barrier, innate, and adaptive immunity-related to susceptibility of infections and increasing risk for severe to critical case of COVID-19. Further, high risk of thrombosis becomes a challenge in the management of COVID19 in pregnancy due to the strong association with worse outcome. CASE REPORT: Here, we present three cases of pregnant women infected with COVID-19 pneumonia with different outcomes in maternal and fetal condition related to high-risk thrombosis. Serial inflammatory markers were needed to the early detect the disease progressivity in pregnant women with COVID-19. Further, complete assessment of fetus including reverse transcriptase-polymerase chain reaction and chest X-ray must be performed to the early diagnosis of COVID-19 in neonatal whose mother was infected by SARS-CoV-2. CONCLUSION: Pregnancy state affects the immune regulation including physical barrier, innate, and adaptive immunity-related to susceptibility of infections and increasing risk for severe to critical case of COVID-19. Further, high risk of thrombosis becomes a challenge in the management of COVID19 in pregnancy due to the strong association with worse outcome. Although fetal transmission of COVID-19 to fetus remains unclear, complete assessment of fetus including RT-PCR, and chest X-ray must be performed to the early diagnosis of COVID-19 in neonatal whose mother was infected by SARS-CoV-2.

3.
International Journal of Medical Dentistry ; 26(3):398-410, 2022.
Article in English | ProQuest Central | ID: covidwho-2057446

ABSTRACT

Pathophysiologically, SARS-CoV-2 is similar to SARS-CoV-1, causing a strong characteristic inflammatory reaction that damages the airways [8]. [...]combined antiviral and host responses contribute to disease severity, as seen in cases of SARS-CoV-1 and MERS-CoV infections [9]. [...]a spurt of cytokines released in response to viral infection results in cytokine storm and sepsis, leading to a mortality rate of 28% in critical COVID-19 cases [10]. [...]SARS-CoV-2 decreases ACE2 receptor expression, which is associated with acute lung injury and disease pathology. Since ACE2 controls the renin-angiotensin system (RAS), its suppression can impair RAS homeostasis and influence blood pressure, electrolyte equilibrium, inflammation, and vascular permeability in the airways [14]. The enhanced requirement for antioxidants and consumption of vitamin C by leukocytes could explain the reduction in vitamin C levels observed during infections in general, during lung infections specifically [29], and in critically ill patients [30]. Besides the antioxidative effects of vitamin C, its beneficial functions during pneumonia act via signaling pathways associated with inflammation suppression and enhancement of immunoregulation [31].

4.
Alergia Astma Immunologia ; 27(2):68-74, 2022.
Article in Polish | EMBASE | ID: covidwho-2030741

ABSTRACT

The Coronaviridae family includes the seven known human coronavi-ruses (HCoV) that cause mild to moderate respiratory infections (HCo-V-229E, HCoV-NL63, HCoV-OC43, HCoV-HKU1) as well as severe illness and death (MERS-CoV, SARS-CoV, SARS-CoV-2). Severe infections in-duce inflammatory responses that are often intensified by host ada-ptive immune pathways. Proinflammatory responses are triggered by CoV entry mediated by host cell surface receptors. Interestingly, four of the seven strains use cell surface metallopeptidases as receptors. The entry receptors for specific coronaviruses are: aminopeptidase N (AP-N), dipeptidyl peptidase 4 (DPP4) and angiotensin-converting enzyme 2 (ACE2) for HCoV-229E, MERS-CoV, SARS-CoV and SARS-CoV2, respectively. In addition, these receptors perform many physiological functions, including the regulation of the circulatory and immune sys-tems. Coronavirus receptors are also highly expressed in human tissues and organs (intestines, kidneys, heart, lungs). Additionally, some cy-tokines, chemokines, and other proteins and immune cells influence the modulation of the expression of coronavirus receptors. This review presents the biological role of receptor proteins in the regulation of human physiological systems, the impact of the immune response on susceptibility to coronavirus infections, and the potential effects of glucocorticosteroids (GCS) and specific allergen immunotherapy (AIT) used in the treatment of asthma and allergy on the suscpetibility to coronaviral infections.

5.
J Med Food ; 2022 Sep 06.
Article in English | MEDLINE | ID: covidwho-2017653

ABSTRACT

The progression of SARS-CoV-2 (COVID-19) in humans heavily depends on the patient's overall health status, especially on its immunoregulatory capacity. Different plants and plant-derived preparations (infusions, encapsulated, etc.) have been used as immunoregulators, several of them with scientific support. Nevertheless, due to the composition complexity of such plant-derived preparations, the molecular and physiological mechanisms involved in their beneficial effects remain, in some cases, unclear. In this review article, the most reported plants used in traditional medicine to enhance immunoregulatory capacity are presented, and their effect on the innate immune response is discussed and correlated with their respective phytochemical profile. Understanding how the plant phytochemical profile relates to the observed impact on the innate and adaptative immune response is fundamental to designing plant-derived co-treatments to lessen the symptoms and favor the recovery of COVID-19 patients. In this regard, we propose a prospective guideline for using plants and plant-derived preparations as co-treatments for COVID-19 (and similar viral infections), which could be helpful in the context of the worldwide effort to end the current SARS-CoV-2 pandemic.

6.
Scandinavian Journal of Immunology ; 2022.
Article in English | EMBASE | ID: covidwho-1956794

ABSTRACT

There are two approaches to scientific investigation, the common approach (proving one’s theory) and Popper’s approach (falsification of one’s theories). Popper’s approach has advantages as well as dangers (being perceived as not sure of one’s theories, or even be hostile to them—an ‘auto-traitor’). Nevertheless, the Popper approach can bridge the gap between inhibition (directly observable) and inhibitory regulation (not directly observable). Suppression of immune responses by antigen-specific antibody has led to theories regarding immunoregulation by immune products. There are many immune products capable of regulating immune responses. The inhibitory outcomes of this regulation have been called coinhibition and immune checkpoint inhibition. Coinhibition should be used when regulation begins at the cell surface or in the cell cytoplasm, which opens up the possibility of antigen-specific regulation. Immune checkpoint inhibition should be used when the initiating inhibitory event occurs in the nucleus, such as by directly affecting the cell cycle, where the concept of antigen-specific regulation is more difficult to invoke. These forms of immunoregulation could be corrupted by viral infections, such as in COVID-19 infections.

7.
Journal of Clinical Periodontology ; 49:84, 2022.
Article in English | EMBASE | ID: covidwho-1956753

ABSTRACT

The aim is to determine oral manifestations in patients with COVID-19 disease and in the postcovid period. Methods: A special survey (questionnaire) was made in 424 people who had COVID-19 confirmed by RT-PCR, ELISA for specific IgM and IgG antibodies and Chest CT scan (168 people). 123 people had complaints and clinical symptoms in the oral cavity 2-6 months after the illness and they came to the University dental clinic. Laboratory tests have been performed (clinical blood test, blood immunogram, virus and fungal identification). Results: Survey results showed that 16,0% participants had asymptomatic COVID-19, 23,6% - mild and 48,1% moderate disease. 12,3% with severe COVID-19 were treated in a hospital with oxygen support. In the first 2 weeks 44,3% indicated xerostomia, dysgeusia (21,7%), muscle pain during chewing (11,3%), pain during swallowing (30,2%), burning and painful tongue (1,9%), tongue swelling (30,2%), catharal stomatitis (16,0%), gingival bleeding (22,6%), painful ulcers (aphthae) (8,5%) and signs of candidiasis - white plaque in the tongue (12,3%). After illness (3-6 months), patients indicated dry mouth (12,3%), progressing of gingivitis (20,7%) and periodontitis (11,3%). In patients who applied to the clinic we identified such diagnoses: desquamative glossitis - 16 cases, glossodynia (11), herpes labialis and recurrent herpetic gingivostomatitis (27), hairy leukoplakia (1), recurrent aphthous stomatitis (22), aphthosis Sutton (4), necrotising ulcerative gingivitis (13), oral candidiasis (14), erythema multiforme (8), Stevens-Johnson syndrome (2), oral squamous cell papillomas on the gingiva (4) and the lower lip (1). According to laboratory studies, virus reactivation (HSV, VZV, EBV, CMV, Papilloma viruces) was noted in 52 patients (42,3%), immunodeficiency in 96 people (78,0%), immunoregulation disorders (allergic and autoimmune reactions) in 24 people (19,5%). Conclusions: Lack of oral hygiene, hyposalivation, vascular compromise, stress, immunodeficiency and reactivation of persistent viral and fungal infections in patients with COVID-19 disease are risk factors for progression of periodontal and oral mucosal diseases.

8.
Phytochem Rev ; 21(2): 537-563, 2022.
Article in English | MEDLINE | ID: covidwho-1864436

ABSTRACT

The immune system is one of the main defence mechanisms of the human body. Inadequacy of this system or immunodeficiency results in increased risk of infections and tumours, whereas over-activation of the immune system causes allergic or autoimmune disorders. A well-balanced immune system is important for protection and for alleviation of these diseases. There is a growing interest to maintain a well-balanced immune system, especially after the Covid-19 pandemic. Many biological extracts, as well as natural products, have become popular due to their wide array of immunomodulatory effects and influence on the immune system. Triterpenes, one of the secondary metabolite groups of medicinal plants, exhibit immunomodulatory properties by various mechanisms. Different triterpenes, including components of commonly consumed plants, can promote some protection and alleviation of disease symptoms linked with immune responses and thus enhance overall well-being. This review aims to highlight the efficacy of triterpenes in light of the available literature evidence regarding the immunomodulatory properties of triterpenes. We have reviewed widely investigated immunomodulatory triterpenes; oleanolic acid, glycyrrhizin, glycyrrhetinic acid, pristimerin, ursolic acid, boswellic acid, celastrol, lupeol, betulin, betulinic acid, ganoderic acid, cucumarioside, and astragalosides which have important immunoregulatory properties. In spite of many preclinical and clinical trials were conducted on triterpenes related to their immunoregulatory actions, current studies have several limitations. Therefore, especially more clinical studies with optimal design is essential.

9.
Immunologiya ; 43(1):103-111, 2022.
Article in Russian | EMBASE | ID: covidwho-1863668

ABSTRACT

Nucleated erythroid cells (NEC) are the precursors of the most massive population of human cells – erythrocytes, for which functions of hemo- and immunoregulation have been shown at various stages of ontogenesis and in various organs and tissues of the human body. NEC perform this function by secreting cytokine proteins, growth factors, enzymes such as arginase-2, ROS, and by surface molecules PD-L1 and PD-L2. Their important regulatory role has been shown for the formation of fetoplacental immunosuppression, immunosuppression during pregnancy, suppression of the response against commensals in the gastrointestinal tract, in the pathogenesis of bacterial and viral infections in adults, in the pathogenesis of tumor growth and autoimmune diseases, as well as participation in the recognition of pathogen-associated molecular patterns using Toll-like receptors in fish and birds. Such qualities, together with their number and width of distribution, represent NEC as active participants in hemo- and immunoregulation, which makes it important to study their regulatory role in health and disease.

10.
Front Mol Biosci ; 9: 761173, 2022.
Article in English | MEDLINE | ID: covidwho-1847189

ABSTRACT

The seven pathogenic human coronaviruses (HCoVs) include HCoV-229E, HCoV-OC43, HCoV-NL63, and HCoV-HKU1, which usually cause mild upper respiratory tract diseases, and SARS-CoV, MERS-CoV, and SARS-CoV-2, which cause a severe acute respiratory syndrome. The nucleocapsid (N) protein, as the dominant structural protein from coronaviruses that bind to the genomic RNA, participates in various vital activities after virus invasion and will probably become a promising target of antiviral drug design. Therefore, a comprehensive literature review of human coronavirus' pathogenic mechanism and therapeutic strategies is necessary for the control of the pandemic. Here, we give a systematic summary of the structures, immunoregulation, and potential vaccines and targeted drugs of the HCoVs N protein. First, we provide a general introduction to the fundamental structures and molecular function of N protein. Next, we outline the N protein mediated immune regulation and pathogenesis mechanism. Finally, we comprehensively summarize the development of potential N protein-targeted drugs and candidate vaccines to treat coronavirus disease 2019 (COVID-19). We believe this review provides insight into the virulence and transmission of SARS-CoV-2 as well as support for further study on epidemic control of COVID-19.

11.
Cells ; 11(9):1490, 2022.
Article in English | ProQuest Central | ID: covidwho-1837098

ABSTRACT

γδ T cells, a small subset of T cells in blood, play a substantial role in influencing immunoregulatory and inflammatory processes. The functional impact of γδ T cells on angiogenesis in ischemic muscle tissue has never been reported and is the topic of the present work. Femoral artery ligation (FAL) was used to induce angiogenesis in the lower leg of γδ T cell depleted mice and wildtype and isotype antibody-treated control groups. Gastrocnemius muscle tissue was harvested 3 and 7 days after FAL and assessed using (immuno-)histological analyses. Hematoxylin and Eosin staining showed an increased area of tissue damage in γδ T cell depleted mice 7 days after FAL. Impaired angiogenesis was demonstrated by lower capillary to muscle fiber ratio and decreased number of proliferating endothelial cells (CD31+/BrdU+). γδ T cell depleted mice showed an increased number of total leukocytes (CD45+), neutrophils (MPO+) and neutrophil extracellular traps (NETs) (MPO+/CitH3+), without changes in the neutrophils to NETs ratio. Moreover, the depletion resulted in a higher macrophage count (DAPI/CD68+) caused by an increase in inflammatory M1-like macrophages (CD68+/MRC1−). Altogether, we show that depletion of γδ T cells leads to increased accumulation of leukocytes and M1-like macrophages, along with impaired angiogenesis.

12.
Clin Transl Immunology ; 11(4): e1387, 2022.
Article in English | MEDLINE | ID: covidwho-1820890

ABSTRACT

Background and objectives: Because of its beneficial off-target effects against non-mycobacterial infectious diseases, bacillus Calmette-Guérin (BCG) vaccination might be an accessible early intervention to boost protection against novel pathogens. Multiple epidemiological studies and randomised controlled trials (RCTs) are investigating the protective effect of BCG against coronavirus disease 2019 (COVID-19). Using samples from participants in a placebo-controlled RCT aiming to determine whether BCG vaccination reduces the incidence and severity of COVID-19, we investigated the immunomodulatory effects of BCG on in vitro immune responses to SARS-CoV-2. Methods: This study used peripheral blood taken from participants in the multicentre RCT and BCG vaccination to reduce the impact of COVID-19 on healthcare workers (BRACE trial). The whole blood taken from BRACE trial participants was stimulated with γ-irradiated SARS-CoV-2-infected or mock-infected Vero cell supernatant. Cytokine responses were measured by multiplex cytokine analysis, and single-cell immunophenotyping was made by flow cytometry. Results: BCG vaccination, but not placebo vaccination, reduced SARS-CoV-2-induced secretion of cytokines known to be associated with severe COVID-19, including IL-6, TNF-α and IL-10. In addition, BCG vaccination promoted an effector memory phenotype in both CD4+ and CD8+ T cells, and an activation of eosinophils in response to SARS-CoV-2. Conclusions: The immunomodulatory signature of BCG's off-target effects on SARS-CoV-2 is consistent with a protective immune response against severe COVID-19.

13.
Trials ; 23(1): 255, 2022 Apr 04.
Article in English | MEDLINE | ID: covidwho-1775328

ABSTRACT

BACKGROUND: The 2019 coronavirus disease (COVID-19) pandemic continues to spread and affects large numbers of people with unprecedented impacts. Experimental evidence has already been obtained for use of the standardized extract of Brazilian green propolis (EPP-AF) against viral targets, and clinical rationality has been demonstrated for testing this extract as an adjunct to treatment in patients affected by COVID-19. The BeeCovid2 study aims to assess whether EPP-AF has an impact on the improvement of patients hospitalized with COVID-19 by reducing the length of hospital stay. METHODS: BeeCovid2 is a randomized, double-blinded, placebo-controlled clinical study being conducted in Brazil to provide further evidence on the effectiveness of standardized green propolis extract as an adjunctive treatment for adults hospitalized with COVID-19. Hospitalized patients over 18 years of age with a confirmed diagnosis of COVID-19 and up to 14 days of symptoms were included. Patients under mechanical ventilation at randomization, pregnant women, cancer patients, transplanted or using immunosuppression, HIV patients, patients who used propolis in the last 30 days, bacterial or fungal infection at randomization, impossibility of using medication orally or enterally, and advanced chronic diseases (e.g., advanced heart failure, severe liver disease, and end-stage chronic kidney disease). Enrolled patients are randomized at a 1:1 ratio to receive placebo or standardized propolis extract (900 mg/day) for 10 days. The study treatments are administered in a double-blinded manner, and patients are followed for 28 days. The primary outcome is the difference in length of hospital stay in days between groups. Secondary outcomes include the need for mechanical ventilation, the rate of secondary infection, rate of acute kidney injury, the need for renal replacement therapy, the requirement for vasoactive drugs, the use of an intra-aortic balloon pump (IABP), and the use of extracorporeal membrane oxygenation (ECMO). DISCUSSION: This trial is very useful and will provide more data on the effectiveness of using the standardized Brazilian green propolis extract as an adjunctive treatment in association with standard care in adults hospitalized with moderate to severe acute COVID-19. TRIAL REGISTRATION: ClinicalTrials.gov NCT04800224 . Registered on March 16, 2021.


Subject(s)
COVID-19 , HIV Infections , Propolis , Adolescent , Adult , Brazil , COVID-19/drug therapy , Female , HIV Infections/drug therapy , Humans , Plant Extracts , Pregnancy , Propolis/adverse effects , Randomized Controlled Trials as Topic
14.
Current Topics in Peptide & Protein Research ; 22:67, 2021.
Article in English | ProQuest Central | ID: covidwho-1762621

ABSTRACT

The human cathelicidin LL-37 plays a major role in the innate immune system for protection against bacterial infections. LL-37 can interact with molecules of the cell wall, perforate cell membranes, and finally lead to bacterial cell death. Moreover, LL-37 participates in immune regulation, chemotaxis of immune cells, and tissue repair. This peptide is produced by white blood cells (mainly neutrophils) and different epithelial cells (in the testicles, epidermis, intestinal system, respiratory system), and may be detected all over the body. LL-37 peptide has dual effects: a) it can increase inflammation and immunological responses and possess anti-infective and anti-cancer properties;b) it can suppress inflammation and enhance carcinogenesis. LL-37 is related to the risk of autoimmune diseases including systemic lupus erythematosus, rheumatoid arthritis atherosclerosis, and psoriasis. This peptide binds to self-DNA, and acts as an autoantigen. On the other hand, targeting the antiviral and immunomodulatory activities of LL37 peptide can reduce virus transmission and pathogenicity such as human immunodeficiency virus (HIV-1) and the severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2). This peptide and its variants can directly attach to HIV-1 reverse transcriptase and inhibit its function in a dose-dependent approach. Moreover, in silico studies showed the potency of LL-37 as a therapeutic agent against SARS-CoV-2 infection. It is interesting that vitamin D, a candidate preventive molecule against coronavirus disease 2019 (COVID-19), can upregulate the expression of LL-37. The LL-37 cationic peptide can also penetrate the membrane of eukaryotic cells likely through lipid rafts. Indeed, it can transport the nucleic acid to endosomes, and facilitate oligonucleotide delivery to the cells. Regarding major functions of LL-37 peptide in body, this review will concentrate on its structure and functions as the only cathelicidin-derived defensive peptide identified in human.

15.
Viruses ; 14(3)2022 02 25.
Article in English | MEDLINE | ID: covidwho-1737037

ABSTRACT

Coronavirus disease 2019, or COVID-19, is a major challenge facing scientists worldwide. Alongside the lungs, the system of organs comprising the GI tract is commonly targeted by COVID-19. The dysbiotic modulations in the intestine influence the disease severity, potentially due to the ability of the intestinal microbiota to modulate T lymphocyte functions, i.e., to suppress or activate T cell subpopulations. The interplay between the lungs and intestinal microbiota is named the gut-lung axis. One of the most usual comorbidities in COVID-19 patients is type 2 diabetes, which induces changes in intestinal microbiota, resulting in a pro-inflammatory immune response, and consequently, a more severe course of COVID-19. However, changes in the microbiota in this comorbid pathology remain unclear. Metformin is used as a medication to treat type 2 diabetes. The use of the type 2 diabetes drug metformin is a promising treatment for this comorbidity because, in addition to its hypoglycemic action, it can increase amount of intestinal bacteria that induce regulatory T cell response. This dual activity of metformin can reduce lung damage and improve the course of the COVID-19 disease.


Subject(s)
COVID-19 , Diabetes Mellitus, Type 2 , Gastrointestinal Microbiome , Diabetes Mellitus, Type 2/complications , Diabetes Mellitus, Type 2/drug therapy , Dysbiosis , Humans , Immunity
16.
Nat Prod Bioprospect ; 12(1): 4, 2022 Feb 14.
Article in English | MEDLINE | ID: covidwho-1682152

ABSTRACT

The most recent outbreak of 2019 novel coronavirus, named as COVID-19, caused pneumonia epidemic in Wuhan with 2121 deaths cases as of February 20th 2020. Identification of effective antiviral agents to combat the novel coronavirus is urgently needed. Citrus fruit peel or wild citrus are rich in flavonoids, and clinically documented for roles in relief of cough and promotion of digestive health. Therefore, citrus fruits are assumed to possess antivirus activities or enhance the host immunity. A previous study found that hesperetin could act as a high potent inhibitor of SARS-CoV 3CLpro. We determined six flavonoid compounds' content in three citrus species by using LC-MS technique. The content of naringin and naringenin was at higher levels in pummelo. Hesperetin and hesperidin were highly accumulated in mandarin and sweet orange. The subsequent in vitro and in vivo experiments indicated that naringin could inhibit the expression of the proinflammatory cytokines (COX-2, iNOS, IL-1ß and IL-6) induced by LPS in Raw macrophage cell line, and may restrain cytokine through inhibiting HMGB1 expression in a mouse model. The results revealed that naringin may have a potential application for preventing cytokine storm. We simulated molecular docking to predict the binding affinity of those flavonoids to bind Angiotensin-converting enzyme 2 (ACE 2), which is a receptor of the coronavirus. Consideration of the potential anti-coronavirus and anti-inflammatory activity of flavonoids, the citrus fruit or its derived phytochemicals are promising in the use of prevention and treatment of SARS-CoV-2 infection.

17.
Journal of Biosciences ; 46(4), 2021.
Article in English | EMBASE | ID: covidwho-1664506

ABSTRACT

Lectins are widely distributed proteins having ability of binding selectively and reversibly with carbohydrates moieties and glycoconjugates. Although lectins have been reported from different biological sources, the legume lectins are the best-characterized family of plant lectins. Legume lectins are a large family of homologous proteins with considerable similarity in amino acid sequence and their tertiary structures. Despite having strong sequence conservation, these lectins show remarkable variability in carbohydrate specificity and quaternary structures. The ability of legume lectins in recognizing glycans and glycoconjugates on cells and other intracellular structures make them a valuable research tool in glycomic research. Due to variability in binding with glycans, glycoconjugates and multiple biological functions, legume lectins are the subject of intense research for their diverse application in different fields such as glycobiology, biomedical research and crop improvement. The present review specially focuses on structural and functional characteristics of legume lectins along with their potential areas of application.

18.
Elife ; 102021 07 22.
Article in English | MEDLINE | ID: covidwho-1513065

ABSTRACT

Immature neutrophils and HLA-DRneg/low monocytes expand in cancer, autoimmune diseases and viral infections, but their appearance and immunoregulatory effects on T-cells after acute myocardial infarction (AMI) remain underexplored. We found an expansion of circulating immature CD16+CD66b+CD10neg neutrophils and CD14+HLA-DRneg/low monocytes in AMI patients, correlating with cardiac damage, function and levels of immune-inflammation markers. Immature CD10neg neutrophils expressed high amounts of MMP-9 and S100A9, and displayed resistance to apoptosis. Moreover, we found that increased frequency of CD10neg neutrophils and elevated circulating IFN-γ levels were linked, mainly in patients with expanded CD4+CD28null T-cells. Notably, the expansion of circulating CD4+CD28null T-cells was associated with cytomegalovirus (CMV) seropositivity. Using bioinformatic tools, we identified a tight relationship among the peripheral expansion of immature CD10neg neutrophils, CMV IgG titers, and circulating levels of IFN-γ and IL-12 in patients with AMI. At a mechanistic level, CD10neg neutrophils enhanced IFN-γ production by CD4+ T-cells through a contact-independent mechanism involving IL-12. In vitro experiments also highlighted that HLA-DRneg/low monocytes do not suppress T-cell proliferation but secrete high levels of pro-inflammatory cytokines after differentiation to macrophages and IFN-γ stimulation. Lastly, using a mouse model of AMI, we showed that immature neutrophils (CD11bposLy6GposCD101neg cells) are recruited to the injured myocardium and migrate to mediastinal lymph nodes shortly after reperfusion. In conclusion, immunoregulatory functions of CD10neg neutrophils play a dynamic role in mechanisms linking myeloid cell compartment dysregulation, Th1-type immune responses and inflammation after AMI.


Subject(s)
CD4-Positive T-Lymphocytes/immunology , HLA-DR Antigens/immunology , Monocytes/immunology , Myocardial Infarction/immunology , Neprilysin/immunology , Neutrophils/immunology , Aged , Animals , Biomarkers , Cell Differentiation , Cell Proliferation , Cytokines , Female , Humans , Inflammation , Lymphocyte Activation , Male , Mice , Middle Aged , Myocardial Infarction/pathology , T-Lymphocytes/immunology
19.
Front Biosci (Landmark Ed) ; 26(10): 948-961, 2021 10 30.
Article in English | MEDLINE | ID: covidwho-1498509

ABSTRACT

Background: Corona Virus Disease 2019 (COVID-19) is an acute respiratory infectious disease caused by severe respiratory syndrome coronavirus 2 (SARS-CoV-2). The primary pathogenesis is over-activation of the immune system. SARS-CoV-2 continues to mutate and spread rapidly and no effective treatment options are yet available. Mesenchymal stem cells (MSCs) are known to induce anti-inflammatory macrophages, regulatory T cells and dendritic cells. There are a rapidly increasing number of clinical investigations of cell-based therapy approaches for COVID-19. Objective: To summarize the pathogenic mechanism of SARS-CoV-2, and systematically formulated the immunomodulation of COVID-19 by MSCs and their exosomes, as well as research progress. Method: Searching PubMed, clinicaltrials.gov and Chictr.cn for eligible studies to be published or registered by May 2021. Main keywords and search strategies were as follows: ((Mesenchymal stem cells) OR (MSCs)) AND (COVID-19). Results: MSCs regulate the immune system to prevent cytokine release syndrome (CRS) and to promote endogenous repair by releasing various paracrine factors and exosomes. Conclusions: MSC therapy is thus a promising candidate for COVID-19.


Subject(s)
COVID-19/therapy , Exosomes/transplantation , Immunomodulation/immunology , Lung Injury/therapy , Mesenchymal Stem Cell Transplantation/methods , Mesenchymal Stem Cells/metabolism , COVID-19/epidemiology , COVID-19/virology , Clinical Trials as Topic , Exosomes/immunology , Exosomes/metabolism , Humans , Lung Injury/physiopathology , Lung Injury/virology , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/immunology , Outcome Assessment, Health Care/methods , Outcome Assessment, Health Care/statistics & numerical data , Pandemics , Regeneration/immunology , Regeneration/physiology , SARS-CoV-2/immunology , SARS-CoV-2/physiology
20.
Int J Environ Health Res ; : 1-19, 2021 Oct 24.
Article in English | MEDLINE | ID: covidwho-1479873

ABSTRACT

COVID-19 is a worldwide health emergency, therapy for this disease is based on antiviral drugs and immunomodulators, however, there is no treatment to effectively reduce the COVID-19 mortality rate. Fucoidan is a polysaccharide obtained from marine brown algae, with anti-inflammatory, antiviral, and immune-enhancing properties, thus, fucoidan may be used as an alternative treatment (complementary to prescribed medical therapy) for the recovery of COVID-19.  This work aimed to determine the effects of ex-vivo treatment with fucoidan on cytotoxicity, apoptosis, necrosis, and senescence, besides functional parameters of calcium flux and mitochondrial membrane potential (ΔΨm) on human peripheral blood mononuclear cells isolated from SARS-CoV-2 infected, recovered and healthy subjects. Data suggest that fucoidan does not exert cytotoxicity or senescence, however, it induces the increment of intracellular calcium flux. Additionally, fucoidan promotes recovery of ΔΨm in PBMCs from COVID-19 recovered females. Data suggest that fucoidan could ameliorate the immune response in COVID-19 patients.

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