Search results for "Acquired immune system"

Successive Losses of Central Immune Genes Characterize the Gadiformes' Alternate Immunity.

2016

Great genetic variability among teleost immunomes, with gene losses and expansions of central adaptive and innate components, has been discovered through genome sequencing over the last few years. Here, we demonstrate that the innate Myxovirus resistance gene (Mx) is lost from the ancestor of Gadiformes and the closely related Stylephorus chordatus, thus predating the loss of Major Histocompatibility Complex class II (MHCII) in Gadiformes. Although the functional implication of Mx loss is still unknown, we demonstrate that this loss is one of several ancient events appearing in successive order throughout the evolution of teleost immunity. In particular, we find that the loss of Toll-like r…

Host infection history modifies co-infection success of multiple parasite genotypes.

2015

Co-infections by multiple parasite genotypes are common and have important implications for host-parasite ecology and evolution through within-host interactions. Typically, these infections take place sequentially, and therefore, the outcome of co-infection may be shaped by host immune responses triggered by previous infections. For example, in vertebrates, specific immune responses play a central role in protection against disease over the course of life, but co-infection research has mostly focused on previously uninfected individuals. Here, we investigated whether sequential exposure and activation of host resistance in rainbow trout Oncorhynchus mykiss affects infection success and inte…

NO Signalling in Plant Immunity

2016

The importance of nitric oxide (NO) in innate and adaptive immunity in mammals is well recognised. NO exerts antimicrobial properties against invaders but also displays immunoregulatory functions in which S-nitrosylation represents a signalling process of major importance. Over the last two decades, a growing body of evidence suggests that NO is also a major component of plant immunity. Our understanding of its role in plant defence has been enriched by the identification and functional analysis of S-nitrosylated proteins. The recent identification of new S-nitrosylated proteins including the chaperone-like enzyme cell division cycle 48 (CDC48), histone deacetylases (HDACs) and calmodulin (…

2013

Vertebrate hosts often defend themselves against several co-infecting parasite genotypes simultaneously. This has important implications for the ecological dynamics and the evolution of host defence systems and parasite strategies. For example, it can drive the specificity of the adaptive immune system towards high genotype-specificity or cross-reactivity against several parasite genotypes depending on the sequence and probability of re-infections. However, to date, there is very little evidence on these interactions outside mammalian disease literature. In this study we asked whether genotype-specific or cross-reactive responses dominate in the adaptive immune system of a fish host towards…

Cognate HLA absence in trans diminishes human NK cell education

2016

NK cells are innate lymphocytes with protective functions against viral infections and tumor formation. Human NK cells carry inhibitory killer cell Ig-like receptors (KIRs), which recognize distinct HLAs. NK cells with KIRs for self-HLA molecules acquire superior cytotoxicity against HLA– tumor cells during education for improved missing-self recognition. Here, we reconstituted mice with human hematopoietic cells from donors with homozygous KIR ligands or with a mix of hematopoietic cells from these homozygous donors, allowing assessment of the resulting KIR repertoire and NK cell education. We found that co-reconstitution with 2 KIR ligand–mismatched compartments did not alter the frequenc…

Different Innate and Adaptive Immune Responses to SARS-CoV-2 Infection of Asymptomatic, Mild, and Severe Cases

2020

Abstract Background SARS-CoV-2 is a novel coronavirus, not encountered before by humans. The wide spectrum of clinical expression of SARS-CoV-2 illness suggests that individual immune responses to SARS-CoV-2 play a crucial role in determining the clinical course after first infection. Immunological studies have focussed on patients with moderate to severe disease, demonstrating excessive inflammation in tissues and organ damage. We have studied the individual response to SARS-CoV-2 of asympromatic, mild and severe COVID-19 patients in order to investigate the role of innnate and adaptive immunity in determining the clinical course after first infection. Methods To understand the basis of th…

Triggering of Toll-like Receptors in Old Individuals. Relevance for Vaccination

2019

Aging is characterized by a general decline in a range of physiological functions, with a consequent increase in the risk of developing a variety of chronic diseases and geriatric syndromes. Additionally, increasing age is accompanied by a progressive decline in both innate and acquired immune system, referred to as immunosenescence. This impaired ability to mount an efficient immune response after exposure to microorganisms or vaccines represents a major challenge in acquiring protection against pathogens in aging. Therefore, there is still a great need for vaccines that are tailored to optimally stimulate the aged immune system, thus promoting more successful aging. Various strategies ca…

Selective autophagy restricts IL-9 secretion from TH9 cells: relevance in cancer growth

2018

IF 3.530; International audience

Role of food nutrients and supplementation in fighting against viral infections and boosting immunity: A review

2021

Background The viral infections can be highly contagious and easily transmissible, which even can lead to a pandemic, like the recent COVID-19 outbreak, causing massive deaths worldwide. While, still the best practical way to prevent the transmission of viruses is to practice self-sanitation and follow social distancing principles, enhancing the individual's immunity through the consumption of proper foods containing balanced nutrients can have significant result against viral infections. Foods containing nutrients such as vitamins, minerals, fatty acids, few polysaccharides, and some non-nutrients (i.e. polyphenols) have shown therapeutic potential against the function of viruses and can i…

Tumor-Derived Prostaglandin E2 Promotes p50 NF-κB-Dependent Differentiation of Monocytic MDSCs

2020

Abstract Myeloid-derived suppressor cells (MDSC) include immature monocytic (M-MDSC) and granulocytic (PMN-MDSC) cells that share the ability to suppress adaptive immunity and to hinder the effectiveness of anticancer treatments. Of note, in response to IFNγ, M-MDSCs release the tumor-promoting and immunosuppressive molecule nitric oxide (NO), whereas macrophages largely express antitumor properties. Investigating these opposing activities, we found that tumor-derived prostaglandin E2 (PGE2) induces nuclear accumulation of p50 NF-κB in M-MDSCs, diverting their response to IFNγ toward NO-mediated immunosuppression and reducing TNFα expression. At the genome level, p50 NF-κB promoted binding …