scholarly journals Temperature Variation and Host Immunity Regulate Viral Persistence in a Salmonid Host

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 855
Author(s):  
David J. Páez ◽  
Rachel L. Powers ◽  
Peng Jia ◽  
Natalia Ballesteros ◽  
Gael Kurath ◽  
...  
Keyword(s):  
Immune Responses ◽  
Water Temperature ◽  
Host Immunity ◽  
Effect Of Temperature ◽  
Virus Persistence ◽  
Host Immune Responses ◽  
In Vivo Experiments ◽  
Host Pathogen

Environmental variation has important effects on host–pathogen interactions, affecting large-scale ecological processes such as the severity and frequency of epidemics. However, less is known about how the environment interacts with host immunity to modulate virus fitness within hosts. Here, we studied the interaction between host immune responses and water temperature on the long-term persistence of a model vertebrate virus, infectious hematopoietic necrosis virus (IHNV) in steelhead trout (Oncorhynchus mykiss). We first used cell culture methods to factor out strong host immune responses, allowing us to test the effect of temperature on viral replication. We found that 15 ∘C water temperature accelerated IHNV replication compared to the colder 10 and 8 ∘C temperatures. We then conducted in vivo experiments to quantify the effect of 6, 10, and 15 ∘C water temperatures on IHNV persistence over 8 months. Fish held at 15 and 10 ∘C were found to have higher prevalence of neutralizing antibodies compared to fish held at 6 ∘C. We found that IHNV persisted for a shorter time at warmer temperatures and resulted in an overall lower fish mortality compared to colder temperatures. These results support the hypothesis that temperature and host immune responses interact to modulate virus persistence within hosts. When immune responses were minimized (i.e., in vitro) virus replication was higher at warmer temperatures. However, with a full potential for host immune responses (i.e., in vivo experiments) longer virus persistence and higher long-term virulence was favored in colder temperatures. We also found that the viral RNA that persisted at later time points (179 and 270 days post-exposure) was mostly localized in the kidney and spleen tissues. These tissues are composed of hematopoietic cells that are favored targets of the virus. By partitioning the effect of temperature on host and pathogen responses, our results help to better understand environmental drivers of host–pathogen interactions within hosts, providing insights into potential host–pathogen responses to climate change.

scholarly journals Adeno-Associated Viruses (AAV) and Host Immunity – A Race Between the Hare and the Hedgehog

2021 ◽  
Vol 12 ◽  
Author(s):  
Kleopatra Rapti ◽  
Dirk Grimm
Keyword(s):  
Immune Responses ◽  
Dorsal Root ◽  
Transgene Expression ◽  
State Of The Art ◽  
Host Immunity ◽  
Gene Therapies ◽  
Cellular Immune Responses ◽  
Cellular Immune

Adeno-associated viruses (AAV) have emerged as the lead vector in clinical trials and form the basis for several approved gene therapies for human diseases, mainly owing to their ability to sustain robust and long-term in vivo transgene expression, their amenability to genetic engineering of cargo and capsid, as well as their moderate toxicity and immunogenicity. Still, recent reports of fatalities in a clinical trial for a neuromuscular disease, although linked to an exceptionally high vector dose, have raised new caution about the safety of recombinant AAVs. Moreover, concerns linger about the presence of pre-existing anti-AAV antibodies in the human population, which precludes a significant percentage of patients from receiving, and benefitting from, AAV gene therapies. These concerns are exacerbated by observations of cellular immune responses and other adverse events, including detrimental off-target transgene expression in dorsal root ganglia. Here, we provide an update on our knowledge of the immunological and molecular race between AAV (the “hedgehog”) and its human host (the “hare”), together with a compendium of state-of-the-art technologies which provide an advantage to AAV and which, thus, promise safer and more broadly applicable AAV gene therapies in the future.

scholarly journals Impact of Influenza A Virus Shutoff Proteins on Host Immune Responses

Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 629
Author(s):  
Megan M. Dunagan ◽  
Kala Hardy ◽  
Toru Takimoto
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Influenza A Virus ◽  
Influenza A ◽  
Human Populations ◽  
Lymphocyte Migration ◽  
Host Immune Responses ◽  
Mhc Molecules ◽  
The Impact

Influenza A virus (IAV) is a significant human pathogen that causes seasonal epidemics. Although various types of vaccines are available, IAVs still circulate among human populations, possibly due to their ability to circumvent host immune responses. IAV expresses two host shutoff proteins, PA-X and NS1, which antagonize the host innate immune response. By transcriptomic analysis, we previously showed that PA-X is a major contributor for general shutoff, while shutoff active NS1 specifically inhibits the expression of host cytokines, MHC molecules, and genes involved in innate immunity in cultured human cells. So far, the impact of these shutoff proteins in the acquired immune response in vivo has not been determined in detail. In this study, we analyzed the effects of PA-X and NS1 shutoff activities on immune response using recombinant influenza A/California/04/2009 viruses containing mutations affecting the expression of shutoff active PA-X and NS1 in a mouse model. Our data indicate that the virus without shutoff activities induced the strongest T and B cell responses. Both PA-X and NS1 reduced host immune responses, but shutoff active NS1 most effectively suppressed lymphocyte migration to the lungs, antibody production, and the generation of IAV specific CD4+ and CD8+ T cells. NS1 also prevented the generation of protective immunity against a heterologous virus challenge. These data indicate that shutoff active NS1 plays a major role in suppressing host immune responses against IAV infection.

An appraisal of survival strategies

Parasitology ◽  
1984 ◽  
Vol 88 (4) ◽  
pp. 575-577 ◽  
Author(s):  
N. A. Mitchison
Keyword(s):  
Immune System ◽  
Immune Responses ◽  
Survival Strategies ◽  
Host Immune System ◽  
Cellular Immunology ◽  
Host Immune Responses ◽  
Host Defence System ◽  
Bio Engineering

Only a few years ago parasite immunology looked an unattractive subject better left to the dogged specialists. Parasites and hosts had been playing chess together for a million years, and there seemed little prospect of perturbing matters in favour of the host immune system. All that has changed, for three reasons. Firstly, we have learned how to grow at least some parasites in vitro, and prospects of doing so with others are encouraging. Secondly, progress in cellular immunology has revealed the sort of loopholes in the host defence system which parasites are likely to exploit: we are learning the questions which matter about parasites as antigens. Thirdly, and most importantly, molecular genetics is being brought to bear on parasites: we can now see a real, though long-term, prospect of manufacturing practicable vaccines through bio-engineering, and more immediately it gives us the tools needed to probe the host immune responses in the form of cloned antigens.

scholarly journals The Effects of In Vivo Exposure to Copper Oxide Nanoparticles on the Gut Microbiome, Host Immunity, and Susceptibility to a Bacterial Infection in Earthworms

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1337 ◽  
Author(s):  
Elmer Swart ◽  
Jiri Dvorak ◽  
Szabolcs Hernádi ◽  
Tim Goodall ◽  
Peter Kille ◽  
...  
Keyword(s):  
Immune Responses ◽  
Gut Microbiome ◽  
Methodological Approach ◽  
Copper Oxide Nanoparticles ◽  
Mrna Levels ◽  
Immune Genes ◽  
Host Immune Responses ◽  
Earthworm Gut ◽  
Bacterium Bacillus

Nanomaterials (NMs) can interact with the innate immunity of organisms. It remains, however, unclear whether these interactions can compromise the immune functioning of the host when faced with a disease threat. Co-exposure with pathogens is thus a powerful approach to assess the immuno-safety of NMs. In this paper, we studied the impacts of in vivo exposure to a biocidal NM on the gut microbiome, host immune responses, and susceptibility of the host to a bacterial challenge in an earthworm. Eisenia fetida were exposed to CuO-nanoparticles in soil for 28 days, after which the earthworms were challenged with the soil bacterium Bacillus subtilis. Immune responses were monitored by measuring mRNA levels of known earthworm immune genes. Effects of treatments on the gut microbiome were also assessed to link microbiome changes to immune responses. Treatments caused a shift in the earthworm gut microbiome. Despite these effects, no impacts of treatment on the expression of earthworm immune markers were recorded. The methodological approach applied in this paper provides a useful framework for improved assessment of immuno-safety of NMs. In addition, we highlight the need to investigate time as a factor in earthworm immune responses to NM exposure.

scholarly journals Seroprevalence of Antibodies against Pkn1, a Novel Potential Immunogen, inChlamydia trachomatis-InfectedMacaca nemestrinaand Human Patients

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Achchhe L. Patel ◽  
Prashant K. Mishra ◽  
Divya Sachdev ◽  
Uma Chaudhary ◽  
Dorothy L. Patton ◽  
...  
Keyword(s):  
Immune Responses ◽  
Genital Tract ◽  
Protein A ◽  
Macaca Nemestrina ◽  
Sexually Transmitted ◽  
Host Immune Responses ◽  
Bioinformatic Tools ◽  
Genital Tract Infections ◽  
Tract Infections

Chlamydia trachomatis(CT) is an important cause of sexually transmitted genital tract infections (STIs) and trachoma. Despite major research into chlamydial pathogenesis and host immune responses, immunoprotection has been hampered by the incomplete understanding of protective immunity in the genital tract. Characterized vaccine candidates have shown variable efficacy ranging from no protection to partial protectionin vivo. It is therefore a research priority to identify novel chlamydial antigens that may elicit protective immune responses against CT infection. In the present study we assessed the seroprevalence of antibodies against protein kinase1 (Pkn1), DNA ligaseA (LigA), and major outer membrane protein A (OmpA) following natural CT infection in humans and in experimentally induced CT infection inMacaca nemestrina. Antigenic stretches of Pkn1, LigA, and OmpA were identified using bioinformatic tools.Pkn1,LigA, andOmpAgenes were cloned in bacterial expression vector and purified by affinity chromatography. Our results demonstrate significantly high seroprevalence of antibodies against purified Pkn1 and OmpA in sera obtained from the macaque animal model and human patients infected with CT. In contrast no significant seroreactivity was observed for LigA. The seroprevalence of antibodies against Pkn1 suggest that nonsurface chlamydial proteins could also be important for developing vaccines forC. trachomatis.

scholarly journals Application of the ERK signaling pathway inhibitor PD98059 in long-term in vivo experiments

2015 ◽  
Vol 14 (4) ◽  
pp. 18325-18333 ◽  
Author(s):  
X.Y. Chen ◽  
H.Z. Cai ◽  
X.Y. Wang ◽  
Q.Y. Chen ◽  
H. Yang ◽  
...  
Keyword(s):  
Signaling Pathway ◽  
Erk Signaling ◽  
In Vivo Experiments

scholarly journals Reduction of Retrovirus-Induced Immunosuppression by In Vivo Modulation of T Cells during Acute Infection

2004 ◽  
Vol 78 (21) ◽  
pp. 11641-11647 ◽  
Author(s):  
Hong He ◽  
Ronald J. Messer ◽  
Shimon Sakaguchi ◽  
Guojun Yang ◽  
Shelly J. Robertson ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Immune Responses ◽  
Acute Infection ◽  
Tumor Necrosis Factor Receptor ◽  
Cell Responses ◽  
Th1 Immune Responses ◽  
Necrosis Factor

ABSTRACT Chronic infection with Friend retrovirus is associated with suppressed antitumor immune responses. In the present study we investigated whether modulation of T-cell responses during acute infection would restore antitumor immunity in persistently infected mice. T-cell modulation was done by treatments with DTA-1 anti- glucocorticoid-induced tumor necrosis factor receptor monoclonal antibodies. The DTA-1 monoclonal antibody is nondepleting and delivers costimulatory signals that both enhance the activation of effector T cells and inhibit suppression by regulatory T cells. DTA-1 therapy produced faster Th1 immune responses, significant reductions in both acute virus loads and pathology and, most importantly, long-term improvement of CD8+ T-cell-mediated antitumor responses.

scholarly journals Roles of Host Immunity in Viral Myocarditis and Dilated Cardiomyopathy

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Lifang Zhao ◽  
Zhaoying Fu
Keyword(s):  
Innate Immunity ◽  
T Cell ◽  
Immune Responses ◽  
Viral Infection ◽  
Dilated Cardiomyopathy ◽  
Viral Myocarditis ◽  
Host Immunity ◽  
Host Immune Responses ◽  
Direct Damage ◽  
Working Together

The pathogenesis of viral myocarditis includes both the direct damage mediated by viral infection and the indirect lesion resulted from host immune responses. Myocarditis can progress into dilated cardiomyopathy that is also associated with immunopathogenesis. T cell-mediated autoimmunity, antibody-mediated autoimmunity (autoantibodies), and innate immunity, working together, contribute to the development of myocarditis and dilated cardiomyopathy.

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