scholarly journals Arboviruses: How Saliva Impacts the Journey from Vector to Host

2021 ◽  
Vol 22 (17) ◽  
pp. 9173
Author(s):  
Christine A. Schneider ◽  
Eric Calvo ◽  
Karin E. Peterson
Keyword(s):  
Immune Response ◽  
Viral Encephalitis ◽  
Severe Disease ◽  
Blood Feeding ◽  
Viral Pathogenesis ◽  
Salivary Proteins ◽  
Life Threatening ◽  
Animal Hosts ◽  
Arbovirus Infection ◽  
Cellular Immune

Arthropod-borne viruses, referred to collectively as arboviruses, infect millions of people worldwide each year and have the potential to cause severe disease. They are predominately transmitted to humans through blood-feeding behavior of three main groups of biting arthropods: ticks, mosquitoes, and sandflies. The pathogens harbored by these blood-feeding arthropods (BFA) are transferred to animal hosts through deposition of virus-rich saliva into the skin. Sometimes these infections become systemic and can lead to neuro-invasion and life-threatening viral encephalitis. Factors intrinsic to the arboviral vectors can greatly influence the pathogenicity and virulence of infections, with mounting evidence that BFA saliva and salivary proteins can shift the trajectory of viral infection in the host. This review provides an overview of arbovirus infection and ways in which vectors influence viral pathogenesis. In particular, we focus on how saliva and salivary gland extracts from the three dominant arbovirus vectors impact the trajectory of the cellular immune response to arbovirus infection in the skin.

scholarly journals Neutralization of Delta variant with sera of Covishield vaccinees and COVID-19 recovered vaccinated individuals

2021 ◽  
Author(s):  
Gajanan Sapkal ◽  
Pragya D Yadav ◽  
Rima R Sahay ◽  
Gururaj Deshpande ◽  
Nivedita Gupta ◽  
...  
Keyword(s):  
Immune Response ◽  
Severe Disease ◽  
Public Health Problem ◽  
World Health ◽  
Limited Information ◽  
Recent Emergence ◽  
Health Organization ◽  
Cellular Immune ◽  
Second Wave ◽  
Response Post

The recent emergence of B.1.617 lineage has created grave public health problem in India. The lineage further mutated to generate sub-lineages B.1.617.1 (Kappa), B.1.617.2 (Delta), B.1.617.3. Apparently, the Delta variant has slowly dominated the other variants including B.1.617.1 (Kappa), B.1.617.2 (Delta), B.1.617.3. With this, World Health Organization has described this sub-lineage as variant of concern. The high transmissibility associated with Delta variant has led to second wave of pandemic in India which affected millions of people. Besides this, variant of concerns has been reported to show lower neutralization to several approved vaccines. This has led to breakthrough infections after completion of vaccination regimen. There is limited information available on the duration of protective immune response post-infection, vaccination or breakthrough infection with SARS-CoV-2. In this study, we have evaluated immune response in sera of the Covishield vaccinated individuals belonging to category: I. one dose vaccinated, II. two doses vaccinated, III. COVID-19 recovered plus one dose vaccinated, IV. COVID-19 recovered plus two doses vaccinated and V. breakthrough COVID-19 cases. The findings of the study demonstrated that the breakthrough cases and the COVID-19 recovered individuals with one or two dose of vaccine had relatively higher protection against Delta variant in comparison to the participants who were administered either one or two doses of Covishield. Prior vaccination results in less severe disease against subsequent infection provide evidence that both humoral and cellular immune response play an important role in protection.

scholarly journals Possible harm from glucocorticoid drugs misuse in the early phase of SARS-CoV-2 infection: a narrative review of the evidence

2021 ◽  
Author(s):  
Riccardo Sarzani ◽  
Francesco Spannella ◽  
Federico Giulietti ◽  
Chiara Di Pentima ◽  
Piero Giordano ◽  
...  
Keyword(s):  
Immune Response ◽  
Viral Infections ◽  
Severe Disease ◽  
Positive Outcome ◽  
Supplemental Oxygen ◽  
Time Interval ◽  
Type I ◽  
Life Threatening ◽  
The Right ◽  
Supplemental Oxygen Therapy

AbstractSince the publication of the RECOVERY trial, the use of glucocorticoid drugs (GC) has spread for the treatment of severe COVID-19 worldwide. However, the benefit of dexamethasone was largest in patients who received mechanical ventilation or supplemental oxygen therapy, while no benefit was found among patients without hypoxemia. In addition, a positive outcome was found in patients who received dexamethasone after several days of symptoms, while possible harm could exist if administered early. The right time interval for GC administration is still a matter of debate. Previous studies showed that an early GC use during the first phase of the disease, when viral replication peaks, may negatively affect the innate immune response through several mechanisms, such as the inhibition of pro-inflammatory and antiviral cytokine production and signaling pathway, including type I interferon, that is fundamental to counteract the virus and that was found to be impaired in several patients with life-threatening COVID-19. The GC misuse can lead to a more severe disease even in patients who do not have the established risk factors, such as obesity and cardiovascular diseases. In our focused review, we describe the role of immune response in viral infections, especially SARS-CoV-2, and discuss the potential harms of GC misuse in COVID-19.

scholarly journals Harnessing Cellular Immunity for Vaccination against Respiratory Viruses

Vaccines ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 783
Author(s):  
Nicholas W. Lukacs ◽  
Carrie-Anne Malinczak
Keyword(s):  
Immune Response ◽  
Viral Infection ◽  
Cellular Immune Response ◽  
Severe Disease ◽  
Clinical Signs ◽  
Neutralizing Antibody ◽  
Respiratory Illness ◽  
Vaccine Candidates ◽  
Cell Responses ◽  
Cellular Immune

Severe respiratory viral infections, such as influenza, metapneumovirus (HMPV), respiratory syncytial virus (RSV), rhinovirus (RV), and coronaviruses, including severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), cause significant mortality and morbidity worldwide. These viruses have been identified as important causative agents of acute respiratory disease in infants, the elderly, and immunocompromised individuals. Clinical signs of infection range from mild upper respiratory illness to more serious lower respiratory illness, including bronchiolitis and pneumonia. Additionally, these illnesses can have long-lasting impact on patient health well beyond resolution of the viral infection. Aside from influenza, there are currently no licensed vaccines against these viruses. However, several research groups have tested various vaccine candidates, including those that utilize attenuated virus, virus-like particles (VLPs), protein subunits, and nanoparticles, as well as recent RNA vaccines, with several of these approaches showing promise. Historically, vaccine candidates have advanced, dependent upon the ability to activate the humoral immune response, specifically leading to strong B cell responses and neutralizing antibody production. More recently, it has been recognized that the cellular immune response is also critical in proper resolution of viral infection and protection against detrimental immunopathology associated with severe disease and therefore, must also be considered when analyzing the efficacy and safety of vaccine candidates. These candidates would ideally result in robust CD4+ and CD8+ T cell responses as well as high-affinity neutralizing antibody. This review will aim to summarize established and new approaches that are being examined to harness the cellular immune response during respiratory viral vaccination.

scholarly journals The Immune Response to SARS-CoV-2 and Variants of Concern

Viruses ◽  
2021 ◽  
Vol 13 (10) ◽  
pp. 1911
Author(s):  
Elham Torbati ◽  
Kurt L. Krause ◽  
James E. Ussher
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Severe Disease ◽  
Severe Pneumonia ◽  
Functional Changes ◽  
Cell Responses ◽  
Cellular Immune Responses ◽  
Number Of Patients ◽  
Cellular Immune ◽  
Prior Infection

At the end of 2019 a newly emerged betacoronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), was identified as the cause of an outbreak of severe pneumonia, subsequently termed COVID-19, in a number of patients in Wuhan, China. Subsequently, SARS-CoV-2 rapidly spread globally, resulting in a pandemic that has to date infected over 200 million individuals and resulted in more than 4.3 million deaths. While SARS-CoV-2 results in severe disease in 13.8%, with increasing frequency of severe disease with age, over 80% of infections are asymptomatic or mild. The immune response is an important determinant of outcome following SARS-CoV-2 infection. While B cell and T cell responses are associated with control of infection and protection against subsequent challenge with SARS-CoV-2, failure to control viral replication and the resulting hyperinflammation are associated with severe COVID-19. Towards the end of 2020, several variants of concern emerged that demonstrate increased transmissibility and/or evasion of immune responses from prior SARS-CoV-2 infection. This article reviews what is known about the humoral and cellular immune responses to SARS-CoV-2 and how mutation and structural/functional changes in the emerging variants of concern impact upon the immune protection from prior infection or vaccination.

scholarly journals Characterisation of the blood RNA host response underpinning severity in COVID-19 patients

2021 ◽  
Author(s):  
Heather Jackson ◽  
Irene Rivero Calle ◽  
Claire Broderick ◽  
Dominic Habgood-Coote ◽  
Giselle D'Souza ◽  
...  
Keyword(s):  
Immune Response ◽  
Whole Blood ◽  
Severe Disease ◽  
Differential Expression Analysis ◽  
Clinical Manifestations ◽  
Enrichment Analysis ◽  
Asymptomatic Infection ◽  
Pathway Enrichment Analysis ◽  
Life Threatening ◽  
Inflammatory Immune Response

Infection with SARS-CoV-2 has highly variable clinical manifestations, ranging from asymptomatic infection through to life-threatening disease. Host whole blood transcriptomics can offer unique insights into the biological processes underpinning infection and disease, as well as severity. We performed whole blood RNA Sequencing of individuals with varying degrees of COVID-19 severity. We used differential expression analysis and pathway enrichment analysis to explore how the blood transcriptome differs between individuals with mild, moderate, and severe COVID-19, performing pairwise comparisons between groups. Increasing COVID-19 severity was characterised by an abundance of inflammatory immune response genes and pathways, including many related to neutrophils and macrophages, in addition to an upregulation of immunoglobulin genes. Our insights into COVID-19 severity reveal the role of immune dysregulation in the progression to severe disease and highlight the need for further research exploring the interplay between SARS-CoV-2 and the inflammatory immune response.

Humoral and cellular immune response to a crude exo-antigen and purified keratinase of Microsporum canis in experimentally infected guinea pigs

1999 ◽  
Vol 37 (2) ◽  
pp. 123-129 ◽  
Author(s):  
B. R. Mignon ◽  
T. Leclipteux ◽  
CH. Focant ◽  
A. J. Nikkels ◽  
G. E. PIErard ◽  
...  
Keyword(s):  
Immune Response ◽  
Cellular Immune Response ◽  
Guinea Pigs ◽  
Microsporum Canis ◽  
Cellular Immune

The humoral and cellular immune response of sheep against Borna disease virus in endemic and non-endemic areas

2004 ◽  
Vol 146 (4) ◽  
pp. 159-172 ◽  
Author(s):  
D. Müller-Doblies ◽  
S. Baumann ◽  
P. Grob ◽  
A. Hülsmeier ◽  
U. Müller-Doblies ◽  
...  
Keyword(s):  
Immune Response ◽  
Disease Virus ◽  
Cellular Immune Response ◽  
Borna Disease Virus ◽  
Endemic Areas ◽  
Cellular Immune ◽  
Borna Disease

Does gamma knife surgery stimulate cellular immune response to metastatic brain tumors? A histopathological and immunohistochemical study

2005 ◽  
Vol 102 (Special_Supplement) ◽  
pp. 180-184 ◽  
Author(s):  
György T. Szeifert ◽  
Isabelle Salmon ◽  
Sandrine Rorive ◽  
Nicolas Massager ◽  
Daniel Devriendt ◽  
...  
Keyword(s):  
Immune Response ◽  
Brain Tumors ◽  
Gamma Knife ◽  
Cellular Immune Response ◽  
Lymphocytic Infiltration ◽  
Gamma Knife Surgery ◽  
Metastatic Brain Tumors ◽  
Content Type ◽  
Cellular Immune ◽  
Fine Print

Object. The aim of this study was to analyze the cellular immune response and histopathological changes in secondary brain tumors after gamma knife surgery (GKS). Methods. Two hundred ten patients with cerebral metastases underwent GKS. Seven patients underwent subsequent craniotomy for tumor removal between 1 and 33 months after GKS. Four of these patients had one tumor, two patients had two tumors, and one patient had three. Histological and immunohistochemical investigations were performed. In addition to routine H & E and Mallory trichrome staining, immunohistochemical reactions were conducted to characterize the phenotypic nature of the cell population contributing to the tissue immune response to neoplastic deposits after radiosurgery. Light microscopy revealed an intensive lymphocytic infiltration in the parenchyma and stroma of tumor samples obtained in patients in whom surgery was performed over 6 months after GKS. Contrary to this, extensive areas of tissue necrosis with either an absent or scanty lymphoid population were observed in the poorly controlled neoplastic specimens obtained in cases in which surgery was undertaken in patients less than 6 months after GKS. Immunohistochemical characterization demonstrated the predominance of CD3-positive T cells in the lymphoid infiltration. Conclusions. Histopathological findings of the present study are consistent with a cellular immune response of natural killer cells against metastatic brain tumors, presumably stimulated by the ionizing energy of focused radiation.

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