scholarly journals Children and Adults in a Household Cohort Study Have Robust Longitudinal Immune Responses Following SARS-CoV-2 Infection or Exposure

2021 ◽  
Vol 12 ◽  
Author(s):  
Melanie R. Neeland ◽  
Samantha Bannister ◽  
Vanessa Clifford ◽  
Jill Nguyen ◽  
Kate Dohle ◽  
...  
Keyword(s):  
Immune Responses ◽  
Viral Infections ◽  
Immune Cell ◽  
Household Contacts ◽  
Age Related ◽  
Immunological Mechanisms ◽  
Changes Over Time ◽  
Asymptomatic Disease ◽  
Over Time ◽  
Close Contacts

Children have reduced severity of COVID-19 compared to adults and typically have mild or asymptomatic disease. The immunological mechanisms underlying these age-related differences in clinical outcomes remain unexplained. Here, we quantify 23 immune cell populations in 141 samples from children and adults with mild COVID-19 and their PCR-negative close household contacts at acute and convalescent time points. Children with COVID-19 displayed marked reductions in myeloid cells during infection, most prominent in children under the age of five. Recovery from infection in both children and adults was characterised by the generation of CD8 TCM and CD4 TCM up to 9 weeks post infection. SARS-CoV-2-exposed close contacts also had immunological changes over time despite no evidence of confirmed SARS-CoV-2 infection on PCR testing. This included an increase in low-density neutrophils during convalescence in both exposed children and adults, as well as increases in CD8 TCM and CD4 TCM in exposed adults. In comparison to children with other common respiratory viral infections, those with COVID-19 had a greater change in innate and T cell-mediated immune responses over time. These findings provide new mechanistic insights into the immune response during and after recovery from COVID-19 in both children and adults.

scholarly journals Towards Improved Use of Vaccination in the Control of Infectious Bronchitis and Newcastle Disease in Poultry: Understanding the Immunological Mechanisms

Vaccines ◽  
2021 ◽  
Vol 9 (1) ◽  
pp. 20
Author(s):  
Anthony C. Ike ◽  
Chukwuebuka M. Ononugbo ◽  
Okechukwu J. Obi ◽  
Chisom J. Onu ◽  
Chinasa V. Olovo ◽  
...  
Keyword(s):  
Immune Responses ◽  
Newcastle Disease ◽  
Viral Infections ◽  
Advanced Technology ◽  
Global Food Security ◽  
Infectious Bronchitis ◽  
Immunological Mechanisms ◽  
Inactivated Vaccines ◽  
Successful Control ◽  
Cellular Immune

Infectious bronchitis (IB) and Newcastle disease (ND) are two important diseases of poultry and have remained a threat to the development of the poultry industry in many parts of the world. The immunology of avian has been well studied and numerous vaccines have been developed against the two viruses. Most of these vaccines are either inactivated vaccines or live attenuated vaccines. Inactivated vaccines induce weak cellular immune responses and require priming with live or other types of vaccines. Advanced technology has been used to produce several types of vaccines that can initiate prime immune responses. However, as a result of rapid genetic variations, the control of these two viral infections through vaccination has remained a challenge. Using various strategies such as combination of live attenuated and inactivated vaccines, development of IB/ND vaccines, use of DNA vaccines and transgenic plant vaccines, the problem is being surmounted. It is hoped that with increasing understanding of the immunological mechanisms in birds that are used in fighting these viruses, a more successful control of the diseases will be achieved. This will go a long way in contributing to global food security and the economic development of many developing countries, given the role of poultry in the attainment of these goals.

scholarly journals Neutrophils in respiratory viral infections

2021 ◽  
Author(s):  
Cecilia Johansson ◽  
Freja C. M. Kirsebom
Keyword(s):  
Viral Infections ◽  
Immune Cell ◽  
Respiratory Infections ◽  
Fungal Infections ◽  
Severe Disease ◽  
The Elderly ◽  
Viral Control ◽  
Immunological Mechanisms ◽  
Respiratory Viral Infections ◽  
Viral Respiratory Infections

AbstractViral respiratory infections are a common cause of severe disease, especially in infants, people who are immunocompromised, and in the elderly. Neutrophils, an important innate immune cell, infiltrate the lungs rapidly after an inflammatory insult. The most well-characterized effector mechanisms by which neutrophils contribute to host defense are largely extracellular and the involvement of neutrophils in protection from numerous bacterial and fungal infections is well established. However, the role of neutrophils in responses to viruses, which replicate intracellularly, has been less studied. It remains unclear whether and, by which underlying immunological mechanisms, neutrophils contribute to viral control or confer protection against an intracellular pathogen. Furthermore, neutrophils need to be tightly regulated to avoid bystander damage to host tissues. This is especially relevant in the lung where damage to delicate alveolar structures can compromise gas exchange with life-threatening consequences. It is inherently less clear how neutrophils can contribute to host immunity to viruses without causing immunopathology and/or exacerbating disease severity. In this review, we summarize and discuss the current understanding of how neutrophils in the lung direct immune responses to viruses, control viral replication and spread, and cause pathology during respiratory viral infections.

scholarly journals A functional spleen contributes to afucosylated IgG in humans

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Iwona Wojcik ◽  
David E. Schmidt ◽  
Lisa A. de Neef ◽  
Minke A. E. Rab ◽  
Bob Meek ◽  
...  
Keyword(s):  
Immune Responses ◽  
Viral Infections ◽  
Immune Cell ◽  
Lymphoid Organ ◽  
Immune Effector ◽  
Adaptive Immune ◽  
Wide Range ◽  
Humoral Responses ◽  
First Time

AbstractAs a lymphoid organ, the spleen hosts a wide range of immune cell populations, which not only remove blood-borne antigens, but also generate and regulate antigen-specific immune responses. In particular, the splenic microenvironment has been demonstrated to play a prominent role in adaptive immune responses to enveloped viral infections and alloantigens. During both types of immunizations, antigen-specific immunoglobulins G (IgGs) have been characterized by the reduced amount of fucose present on N-linked glycans of the fragment crystallizable (Fc) region. These glycans are essential for mediating the induction of immune effector functions. Therefore, we hypothesized that a spleen may modulate humoral responses and serve as a preferential site for afucosylated IgG responses, which potentially play a role in immune thrombocytopenia (ITP) pathogenesis. To determine the role of the spleen in IgG-Fc glycosylation, we performed IgG subclass-specific liquid chromatography–mass spectrometry (LC–MS) analysis of Fc glycosylation in a large cohort of individuals splenectomized due to trauma, due to ITP, or spherocytosis. IgG-Fc fucosylation was consistently increased after splenectomy, while no effects for IgG-Fc galactosylation and sialylation were observed. An increase in IgG1- and IgG2/3-Fc fucosylation level upon splenectomy has been reported here for the first time, suggesting that immune responses occurring in the spleen may be particularly prone to generate afucosylated IgG responses. Surprisingly, the level of total IgG-Fc fucosylation was decreased in ITP patients compared to healthy controls. Overall, our results suggest a yet unrecognized role of the spleen in either the induction or maintenance of afucosylated IgG responses by B cells.

scholarly journals Aging Dampens the Intestinal Innate Immune Response during Severe Clostridioides difficile Infection and Is Associated with Altered Cytokine Levels and Granulocyte Mobilization

2020 ◽  
Vol 88 (6) ◽  
Author(s):  
Lisa Abernathy-Close ◽  
Michael G. Dieterle ◽  
Kimberly C. Vendrov ◽  
Ingrid L. Bergin ◽  
Krishna Rao ◽  
...  
Keyword(s):  
Immune Responses ◽  
Disease Severity ◽  
Immune Cell ◽  
White Blood Cells ◽  
Host Susceptibility ◽  
Simultaneous Increase ◽  
Content Type ◽  
Aged Mice ◽  
Clostridioides Difficile ◽  
Age Related

ABSTRACT Clostridioides (formerly Clostridium) difficile is the most common cause of hospital-acquired infection, and advanced age is a risk factor for C. difficile infection. Disruption of the intestinal microbiota and immune responses contribute to host susceptibility and severity of C. difficile infection. However, the specific impact of aging on immune responses during C. difficile infection remains to be well described. This study explores the effect of age on cellular and cytokine immune responses during C. difficile infection. Young mice (2 to 3 months old) and aged mice (22 to 28 months old) were rendered susceptible to C. difficile infection with the antibiotic cefoperazone and then infected with C. difficile strains with varied disease-causing potentials. We observe that the host age and the infecting C. difficile strain influenced the severity of disease associated with infection. Tissue-specific CD45+ immune cell responses occurred at the time of peak disease severity in the ceca and colons of all mice infected with a high-virulence strain of C. difficile; however, significant deficits in intestinal neutrophils and eosinophils were detected in aged mice, with a corresponding decrease in circulating CXCL1, an important neutrophil recruiter and activator. Interestingly, this lack of intestinal granulocyte response in aged mice during severe C. difficile infection was accompanied by a simultaneous increase in circulating white blood cells, granulocytes, and interleukin 17A (IL-17A). These findings demonstrate that age-related alterations in neutrophils and eosinophils and systemic cytokine and chemokine responses are associated with severe C. difficile infection and support a key role for intestinal eosinophils in mitigating C. difficile-mediated disease severity.

scholarly journals Reliability of self-sampling for accurate assessment of respiratory virus viral and immunologic kinetics

2020 ◽  
Author(s):  
Alpana Waghmare ◽  
Elizabeth M. Krantz ◽  
Subhasish Baral ◽  
Emma Vasquez ◽  
Tillie Loeffelholz ◽  
...  
Keyword(s):  
Immune Responses ◽  
Respiratory Virus ◽  
Viral Infections ◽  
Immune Cell ◽  
Cell Of Origin ◽  
Virus Shedding ◽  
Viral Loads ◽  
Home Based ◽  
Cytokine Levels ◽  
Respiratory Viral Infections

AbstractThe SARS-CoV-2 pandemic demonstrates the need for accurate and convenient approaches to diagnose and therapeutically monitor respiratory viral infections. We demonstrated that self-sampling with foam swabs is well-tolerated and provides quantitative viral output concordant with flocked swabs. Using longitudinal home-based self-sampling, we demonstrate nasal cytokine levels correlate and cluster according to immune cell of origin. Periods of stable viral loads are followed by rapid elimination, which could be coupled with cytokine expansion and contraction using mathematical models. Nasal foam swab self-sampling at home provides a precise, mechanistic readout of respiratory virus shedding and local immune responses.

Memory Development or the Development of Memory?

2001 ◽  
Vol 10 (6) ◽  
pp. 202-205 ◽  
Author(s):  
Peter A. Ornstein ◽  
Catherine A. Haden
Keyword(s):  
Longitudinal Research ◽  
Developmental Change ◽  
Memory Performance ◽  
Memory Development ◽  
Research Paradigms ◽  
Age Related ◽  
Research Designs ◽  
Children's Memory ◽  
Changes Over Time ◽  
Over Time

For 30 years, the question “What is memory development the development of?” has guided research on children's memory. As theories and research paradigms have evolved over this period, so too has knowledge of the surprising mnemonic competence of young children and of age-related differences in memory performance. Never the less, there are serious limits to current understanding of the development of memory. Indeed, there have been few investigations of changes over time in the memory skills of individual children, and researchers have yet to shed much light on the more difficult question of “What are the forces that propel the development of skilled remembering?” From our perspective, the answer to this question will require movement toward longitudinal research designs that illuminate the mechanisms that bring about developmental change.

JP-8 jet fuel exposure suppresses the immune response to viral infections

2008 ◽  
Vol 24 (4) ◽  
pp. 209-216 ◽  
Author(s):  
DT Harris ◽  
D Sakiestewa ◽  
D Titone ◽  
X He ◽  
J Hyde ◽  
...  
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Viral Infection ◽  
Viral Infections ◽  
Immune Cell ◽  
Immunosuppressive Agents ◽  
Interleukin 10 ◽  
Jet Fuel ◽  
Us Air Force ◽  
Influenza Viral Infection

The US Air Force has implemented the widespread use of JP-8 jet fuel in its operations, although a thorough understanding of its potential effects upon exposed personnel is unclear. Previous work has reported that JP-8 exposure is immunosuppressive. Exposure of mice to JP-8 for 1 h/day resulted in immediate secretion of two immunosuppressive agents, namely, interleukin-10 and prostaglandin E2. Thus, it was of interest to determine if jet fuel exposure might alter the immune response to infectious agents. The Hong Kong influenza model was used for these studies. Mice were exposed to 1000 mg/m3 JP-8 (1 h/day) for 7 days before influenza viral infection. Animals were infected intra-nasally with virus and followed in terms of overall survival as well as immune responses. All surviving animals were killed 14 days after viral infection. In the present study, JP-8 exposure increased the severity of the viral infection by suppressing the anti-viral immune responses. That is, exposure of mice to JP-8 for 1 h/day for 7 days before infection resulted in decreased immune cell viability after exposure and infection, a greater than fourfold decrease in immune proliferative responses to mitogens, as well as an overall loss of CD3+, CD4+, and CD8+ T cells from the lymph nodes, but not the spleens, of infected animals. These changes resulted in decreased survival of the exposed and infected mice, with only 33% of animals surviving as compared with 50% of mice infected but not jet fuel–exposed (and 100% of mice exposed only to JP-8). Thus, short-term, low-concentration JP-8 jet fuel exposures have significant suppressive effects on the immune system which can result in increased severity of viral infections.

scholarly journals Regulation of Antiviral Immune Response by N6-Methyladenosine of mRNA

2021 ◽  
Vol 12 ◽  
Author(s):  
Baoxin Zhao ◽  
Weijie Wang ◽  
Yan Zhao ◽  
Hongxiu Qiao ◽  
Zhiyun Gao ◽  
...  
Keyword(s):  
Immune Responses ◽  
Viral Infection ◽  
Viral Infections ◽  
Immune Cell ◽  
Vital Role ◽  
Immune Defense ◽  
Interferon Response ◽  
Adaptive Immune Responses ◽  
Antiviral Immune Response ◽  
Adaptive Immune

Host innate and adaptive immune responses play a vital role in clearing infected viruses. Meanwhile, viruses also evolve a series of mechanisms to weaken the host immune responses and evade immune defense. Recently, N6-methyladenosine (m6A), the most prevalent mRNA modification, has been revealed to regulate multiple steps of RNA metabolism, such as mRNA splicing, localization, stabilization, and translation, thus participating in many biological phenomena, including viral infection. In the process of virus–host interaction, the m6A modification that presents on the virus RNA impedes capture by the pattern recognition receptors, and the m6A modification appearing on the host immune-related molecules regulate interferon response, immune cell differentiation, inflammatory cytokine production, and other immune responses induced by viral infection. This review summarizes the research advances about the regulatory role of m6A modification in the innate and adaptive immune responses during viral infections.

scholarly journals Social effects on age-related and sex-specific immune cell profiles in a wild mammal

2019 ◽  
Author(s):  
Sil H. J. van Lieshout ◽  
Elisa Perez Badas ◽  
Michael W.T. Mason ◽  
Chris Newman ◽  
Christina D. Buesching ◽  
...  
Keyword(s):  
Immune Responses ◽  
Social Environment ◽  
Immune Cell ◽  
Meles Meles ◽  
Wild Mammal ◽  
Age Related ◽  
In The Wild ◽  
The Individual ◽  
The Impact ◽  
Age Related Changes

Evidence for age-related changes in innate and adaptive immune responses is increasing in wild populations. Such changes have been linked to fitness, and understanding the factors driving variation in immune responses is important for the evolution of immunity and senescence. Age-related changes in immune profiles may be due to sex-specific behaviour, physiology and responses to environmental conditions. Social conditions may also contribute to variation in immunological responses, for example, through transmission of pathogens and stress from resource and mate competition. Yet, the impact of the social environment on age-related changes in immune cell profile requires further investigation in the wild. Here, we tested the relationship between leukocyte cell composition (agranulocyte proportion, i.e. adaptive and innate immunity) and age, sex, and group size in a wild population of European badgers (Meles meles). We found that the proportion of agranulocytes decreased with age only in males living in small groups. In contrast, females in larger groups exhibited a greater age-related decline in the proportion of agranulocytes compared to females in smaller groups. Our results provide evidence for age-related changes in immune cell profiles in a wild mammal, which are influenced by both the sex of the individual and their social environment.

scholarly journals SLAM Family Receptor Signaling in Viral Infections: HIV and Beyond

Vaccines ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 184
Author(s):  
O’Connell ◽  
Amalfitano ◽  
Aldhamen
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Viral Infections ◽  
Immune Cell ◽  
Adaptor Protein ◽  
Adaptor Proteins ◽  
Cell Types ◽  
Receptor Signaling ◽  
Slam Family ◽  
Signaling Lymphocytic Activation Molecule

The signaling lymphocytic activation molecule (SLAM) family of receptors are expressed on the majority of immune cells. These receptors often serve as self-ligands, and play important roles in cellular communication and adhesion, thus modulating immune responses. SLAM family receptor signaling is differentially regulated in various immune cell types, with responses generally being determined by the presence or absence of two SLAM family adaptor proteins—Ewing’s sarcoma-associated transcript 2 (EAT-2) and SLAM-associated adaptor protein (SAP). In addition to serving as direct regulators of the immune system, certain SLAM family members have also been identified as direct targets for specific microbes and viruses. Here, we will discuss the known roles for these receptors in the setting of viral infection, with special emphasis placed on HIV infection. Because HIV causes such complex dysregulation of the immune system, studies of the roles for SLAM family receptors in this context are particularly exciting.

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