scholarly journals Drawing Comparisons between SARS-CoV-2 and the Animal Coronaviruses

2020 ◽  
Vol 8 (11) ◽  
pp. 1840
Author(s):  
Souvik Ghosh ◽  
Yashpal S. Malik
Keyword(s):  
Immune Responses ◽  
Current Knowledge ◽  
Effective Control ◽  
Tissue Tropism ◽  
Prevention Strategies ◽  
Host Immune Responses ◽  
Clinical Presentations ◽  
Control And Prevention ◽  
Diversity Transmission ◽  
Complex Origin

The COVID-19 pandemic, caused by a novel zoonotic coronavirus (CoV), SARS-CoV-2, has infected 46,182 million people, resulting in 1,197,026 deaths (as of 1 November 2020), with devastating and far-reaching impacts on economies and societies worldwide. The complex origin, extended human-to-human transmission, pathogenesis, host immune responses, and various clinical presentations of SARS-CoV-2 have presented serious challenges in understanding and combating the pandemic situation. Human CoVs gained attention only after the SARS-CoV outbreak of 2002–2003. On the other hand, animal CoVs have been studied extensively for many decades, providing a plethora of important information on their genetic diversity, transmission, tissue tropism and pathology, host immunity, and therapeutic and prophylactic strategies, some of which have striking resemblance to those seen with SARS-CoV-2. Moreover, the evolution of human CoVs, including SARS-CoV-2, is intermingled with those of animal CoVs. In this comprehensive review, attempts have been made to compare the current knowledge on evolution, transmission, pathogenesis, immunopathology, therapeutics, and prophylaxis of SARS-CoV-2 with those of various animal CoVs. Information on animal CoVs might enhance our understanding of SARS-CoV-2, and accordingly, benefit the development of effective control and prevention strategies against COVID-19.

scholarly journals The Mycobacterium tuberculosis PE_PGRS Protein Family Acts as an Immunological Decoy to Subvert Host Immune Response

2022 ◽  
Vol 23 (1) ◽  
pp. 525
Author(s):  
Tarina Sharma ◽  
Anwar Alam ◽  
Aquib Ehtram ◽  
Anshu Rani ◽  
Sonam Grover ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Immune Responses ◽  
Current Knowledge ◽  
Immune Effector ◽  
Host Immune Responses ◽  
Intrinsically Disordered ◽  
Multiple Strategies ◽  
Latent Stage ◽  
Immune Mediated ◽  
Critical Edge

Mycobacterium tuberculosis (M.tb) is a successful pathogen that can reside within the alveolar macrophages of the host and can survive in a latent stage. The pathogen has evolved and developed multiple strategies to resist the host immune responses. M.tb escapes from host macrophage through evasion or subversion of immune effector functions. M.tb genome codes for PE/PPE/PE_PGRS proteins, which are intrinsically disordered, redundant and antigenic in nature. These proteins perform multiple functions that intensify the virulence competence of M.tb majorly by modulating immune responses, thereby affecting immune mediated clearance of the pathogen. The highly repetitive, redundant and antigenic nature of PE/PPE/PE_PGRS proteins provide a critical edge over other M.tb proteins in terms of imparting a higher level of virulence and also as a decoy molecule that masks the effect of effector molecules, thereby modulating immuno-surveillance. An understanding of how these proteins subvert the host immunological machinery may add to the current knowledge about M.tb virulence and pathogenesis. This can help in redirecting our strategies for tackling M.tb infections.

scholarly journals SeXX and COVID-19: Tussle between the Two

2020 ◽  
Author(s):  
Ashlesh Patil ◽  
Jaya Prasad Tripathy ◽  
Vishwajit Deshmukh ◽  
Bharat Sontakke ◽  
Satyendra C. Tripathi
Keyword(s):  
Immune Responses ◽  
Current Knowledge ◽  
Occupational Exposures ◽  
Point Of View ◽  
Host Immune Responses ◽  
Social Inequities ◽  
Biological Explanation ◽  
Novel Coronavirus ◽  
Biological Differences

Novel coronavirus disease (COVID-19) has affected nearly 7 million individuals and claimed more than 0.4 million lives to date. There are several reports of gender differences related to infection and death due to COVID-19. This raises important questions such as “Whether there are differences based on gender in risk and severity of infection or mortality rate?” and “What are the biological explanation and mechanisms underlying these differences?” Emerging evidence has proposed sex-based immunological, genetic, and hormonal differences to explain this ambiguity. Besides biological differences, women have also faced social inequities and economic hardships due to this pandemic. Several recent studies have shown that independent of age males are at higher risk for severity and mortality in COVID-19 patients. Although susceptibility to SARS-CoV-2 was found to be similar across both genders in several disease cohorts, a disproportionate death ratio in men can be partly explained by the higher burden of pre-existing diseases and occupational exposures among men. From an immunological point of view, females can engage a more active immune response, which may protect them and counter infectious diseases as compared to men. This attribute of better immune responses towards pathogens is thought to be due to high estrogen levels in females. Here we review the current knowledge about sex differences in susceptibility, the severity of infection and mortality, host immune responses, and the role of sex hormones in COVID-19 disease.

scholarly journals Immunological Responses and Survival Outcome in HIV and SARS-CoV-2 Coinfected Patients

2021 ◽  
Vol SP (2) ◽  
Author(s):  
Uzma A. Jilani ◽  
Zulhabri Othman ◽  
Syed A. Jilani
Keyword(s):  
Immune Responses ◽  
Current Knowledge ◽  
People Living With Hiv ◽  
Immunological Responses ◽  
Host Immune Responses ◽  
Acute Infections ◽  
Living With Hiv ◽  
The Impact ◽  
Special Subgroup ◽  
Hiv Aids

The coronavirus disease 2019 (COVID‐19) has created a worldwide crisis, raising fears and concerns regarding clinical outcomes in patients with comorbidities. Some of the highly prevalent communicable and non-communicable diseases worldwide are cardiovascular diseases, diabetes, HIV/AIDS, and hepatitis B and C, which reduce the host immune responses to concurrent acute infections. Despite over 170 million confirmed cases of COVID‐19 worldwide as of 24 June 2021, insufficient data is reporting the prognosis of HIV and SARS-CoV-2 co‐infection. This narrative review aims to present current knowledge on the impact of SARS-CoV-2 on people living with HIV/AIDS, in terms of immunological responses and clinical outcome. Although some studies have been performed and are in progress to determine the impact of SARS-CoV-2 infection on patients living with HIV/AIDS, controversies still exist whether COVID-19 severity and mortality are higher among this special subgroup or similar to the general population.

scholarly journals A model symbiosis reveals a role for sheathed-flagellum rotation in the release of immunogenic lipopolysaccharide

eLife ◽  
2014 ◽  
Vol 3 ◽  
Author(s):  
Caitlin A Brennan ◽  
Jason R Hunt ◽  
Natacha Kremer ◽  
Benjamin C Krasity ◽  
Michael A Apicella ◽  
...  
Keyword(s):  
Immune Responses ◽  
Unknown Function ◽  
Vibrio Fischeri ◽  
Host Responses ◽  
Tissue Tropism ◽  
Human Pathogens ◽  
Bacterial Flagella ◽  
Host Immune Responses ◽  
Microbe Interactions ◽  
Host Microbe Interactions

Bacterial flagella mediate host–microbe interactions through tissue tropism during colonization, as well as by activating immune responses. The flagellar shaft of some bacteria, including several human pathogens, is encased in a membranous sheath of unknown function. While it has been hypothesized that the sheath may allow these bacteria to evade host responses to the immunogenic flagellin subunit, this unusual structural feature has remained an enigma. Here we demonstrate that the rotation of the sheathed flagellum in both the mutualist Vibrio fischeri and the pathogen Vibrio cholerae promotes release of a potent bacteria-derived immunogen, lipopolysaccharide, found in the flagellar sheath. We further present a new role for the flagellar sheath in triggering, rather than circumventing, host immune responses in the model squid-vibrio symbiosis. Such an observation not only has implications for the study of bacterial pathogens with sheathed flagella, but also raises important biophysical questions of sheathed-flagellum function.

scholarly journals Battle Royale: Innate Recognition of Poxviruses and Viral Immune Evasion

Biomedicines ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 765
Author(s):  
Huibin Yu ◽  
Ryan C. Bruneau ◽  
Greg Brennan ◽  
Stefan Rothenburg
Keyword(s):  
Immune Responses ◽  
Current Knowledge ◽  
Immune Defense ◽  
Innate Immune ◽  
Host Immune Responses ◽  
Antiviral Responses ◽  
Activation Of Transcription ◽  
Immune Sensing ◽  
Molecular Patterns ◽  
Innate Immune Sensing

Host pattern recognition receptors (PRRs) sense pathogen-associated molecular patterns (PAMPs), which are molecular signatures shared by different pathogens. Recognition of PAMPs by PRRs initiate innate immune responses via diverse signaling pathways. Over recent decades, advances in our knowledge of innate immune sensing have enhanced our understanding of the host immune response to poxviruses. Multiple PRR families have been implicated in poxvirus detection, mediating the initiation of signaling cascades, activation of transcription factors, and, ultimately, the expression of antiviral effectors. To counteract the host immune defense, poxviruses have evolved a variety of immunomodulators that have diverse strategies to disrupt or circumvent host antiviral responses triggered by PRRs. These interactions influence the outcomes of poxvirus infections. This review focuses on our current knowledge of the roles of PRRs in the recognition of poxviruses, their elicited antiviral effector functions, and how poxviral immunomodulators antagonize PRR-mediated host immune responses.

scholarly journals Venom-Induced Immunosuppression: An Overview of Hemocyte-Mediated Responses

2011 ◽  
Vol 2011 ◽  
pp. 1-14 ◽  
Author(s):  
Aylin Er ◽  
Olga Sak ◽  
Ekrem Ergin ◽  
Fevzi Uçkan ◽  
David B. Rivers
Keyword(s):  
Immune Responses ◽  
Natural Enemies ◽  
Insect Pests ◽  
Current Knowledge ◽  
Host Immunity ◽  
Insect Host ◽  
Parasitic Wasps ◽  
Parasitoid Species ◽  
Female Wasp ◽  
Host Immune Responses

Parasitic wasps are important natural enemies of several insect pests. They use a variety of methods to modulate their insect host for their progeny to develop. For example, the female wasp needs to avoid or suppress the host immune responses by introducing venom with or without virus like particles and/or polydnaviruses. The aim of this paper is to provide a synthesis of current knowledge regarding the immunosuppression of host immunity with venom in parasitoids that are devoid of symbiotic viruses. Special emphasis is given through disabling host hemocytes by venom of the endoparasitoidPimpla turionellae(Hymenoptera: Ichneumonidae) with comparisons of venoms from other parasitoid species.

scholarly journals Innate Immune Activation and Subversion of Mammalian Functions byLeishmaniaLipophosphoglycan

2012 ◽  
Vol 2012 ◽  
pp. 1-11 ◽  
Author(s):  
Luis H. Franco ◽  
Stephen M. Beverley ◽  
Dario S. Zamboni
Keyword(s):  
Immune Responses ◽  
Current Knowledge ◽  
Innate Immune ◽  
Sand Fly ◽  
Mammalian Host ◽  
Innate Immune Cells ◽  
Host Immune Responses ◽  
Parasite Survival ◽  
Mammalian Infection

Leishmaniapromastigotes express several prominent glycoconjugates, either secreted or anchored to the parasite surface. Of these lipophosphoglycan (LPG) is the most abundant, and along with other phosphoglycan-bearing molecules, plays important roles in parasite infectivity and pathogenesis in both the sand fly and the mammalian host. Besides its contribution for parasite survival in the sand fly vector, LPG is important for modulation the host immune responses to favor the establishment of mammalian infection. This review will summarize the current knowledge regarding the role of LPG inLeishmaniainfectivity, focusing on the interaction of LPG and innate immune cells and in the subversion of mammalian functions by this molecule.

scholarly journals SeXX and COVID-19: tussle between the two

2020 ◽  
Vol 90 (4) ◽  
Author(s):  
Ashlesh Patil ◽  
Jaya Prasad Tripathy ◽  
Vishwajit Deshmukh ◽  
Bharat Sontakke ◽  
Satyendra C. Tripathi
Keyword(s):  
Immune Responses ◽  
Current Knowledge ◽  
Occupational Exposures ◽  
Point Of View ◽  
Host Immune Responses ◽  
Social Inequities ◽  
Biological Explanation ◽  
Novel Coronavirus ◽  
Biological Differences

Novel coronavirus disease (COVID-19) has affected nearly 7 million individuals and claimed more than 0.4 million lives to date. There are several reports of gender differences related to infection and death due to COVID-19. This raises important questions such as “Whether there are differences based on gender in risk and severity of infection or mortality rate?” and “What are the biological explanation and mechanisms underlying these differences?” Emerging evidences have proposed sex-based immunological, genetic, and hormonal differences to explain this ambiguity. Besides biological differences, women have also faced social inequities and economic hardships due to this pandemic. Several recent studies have shown that independent of age males are at higher risk for severity and mortality in COVID-19 patients. Although susceptibility to SARS-CoV-2 was found to be similar across both genders in several disease cohorts, a disproportionate death ratio in men can be partly explained by the higher burden of pre-existing diseases and occupational exposures among men. At immunological point of view, females can engage a more active immune response, which may protect them and counter infectious diseases as compared to men. This attribute of better immune responses towards pathogens is thought to be due to high estrogen levels in females. Here we review the current knowledge about sex differences in susceptibility, the severity of infection and mortality, host immune responses, and the role of sex hormones in COVID-19 disease.

scholarly journals Host Immunity and Francisella tularensis: A Review of Tularemia in Immunocompromised Patients

2021 ◽  
Vol 9 (12) ◽  
pp. 2539
Author(s):  
Olivier Bahuaud ◽  
Cécile Le Brun ◽  
Adrien Lemaignen
Keyword(s):  
Immune Responses ◽  
Francisella Tularensis ◽  
Delayed Diagnosis ◽  
Molecular Techniques ◽  
Diagnostic Strategy ◽  
Immunocompromised Patients ◽  
Zoonotic Infection ◽  
Host Immune Responses ◽  
Clinical Presentations ◽  
Unexplained Fever

Tularemia, caused by the bacterium Francisella tularensis, is an infrequent zoonotic infection, well known in immunocompetent (but poorly described in immunocompromised) patients. Although there is no clear literature data about the specific characteristics of this disease in immunocompromised patients, clinical reports seem to describe a different presentation of tularemia in these patients. Moreover, atypical clinical presentations added to the fastidiousness of pathogen identification seem to be responsible for a delayed diagnosis, leading to a” loss of chance” for immunocompromised patients. In this article, we first provide an overview of the host immune responses to Francisella infections and discuss how immunosuppressive therapies or diseases can lead to a higher susceptibility to tularemia. Then, we describe the particular clinical patterns of tularemia in immunocompromised patients from the literature. We also provide hints of an alternative diagnostic strategy regarding these patients. In conclusion, tularemia should be considered in immunocompromised patients presenting pulmonary symptoms or unexplained fever. Molecular techniques on pathological tissues might improve diagnosis with faster results.

scholarly journals Host Immune Responses to Clostridioides difficile: Toxins and Beyond

2021 ◽  
Vol 12 ◽  
Author(s):  
Britt Nibbering ◽  
Dale N. Gerding ◽  
Ed J. Kuijper ◽  
Romy D. Zwittink ◽  
Wiep Klaas Smits
Keyword(s):  
Immune Responses ◽  
Bacterial Infections ◽  
Plasma Cells ◽  
Current Knowledge ◽  
Treatment Options ◽  
T Cell Response ◽  
Medical Community ◽  
Future Research ◽  
Host Immune Responses ◽  
Clostridioides Difficile

Clostridioides difficile is often resistant to the actions of antibiotics to treat other bacterial infections and the resulting C. difficile infection (CDI) is among the leading causes of nosocomial infectious diarrhea worldwide. The primary virulence mechanism contributing to CDI is the production of toxins. Treatment failures and recurrence of CDI have urged the medical community to search for novel treatment options. Strains that do not produce toxins, so called non-toxigenic C. difficile, have been known to colonize the colon and protect the host against CDI. In this review, a comprehensive description and comparison of the immune responses to toxigenic C. difficile and non-toxigenic adherence, and colonization factors, here called non-toxin proteins, is provided. This revealed a number of similarities between the host immune responses to toxigenic C. difficile and non-toxin proteins, such as the influx of granulocytes and the type of T-cell response. Differences may reflect genuine variation between the responses to toxigenic or non-toxigenic C. difficile or gaps in the current knowledge with respect to the immune response toward non-toxigenic C. difficile. Toxin-based and non-toxin-based immunization studies have been evaluated to further explore the role of B cells and reveal that plasma cells are important in protection against CDI. Since the success of toxin-based interventions in humans to date is limited, it is vital that future research will focus on the immune responses to non-toxin proteins and in particular non-toxigenic strains.

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