Search results for "Immune system"
showing 10 items of 2885 documents
Prediction of pneumococcal conjugate vaccine effectiveness against invasive pneumococcal disease using opsonophagocytic activity and antibody concent…
2011
ABSTRACT We compared the abilities of two serological readouts, antipolysaccharide IgG antibody concentrations and opsonophagocytic activity (OPA) titers, to predict the clinical effectiveness of the 7-valent pneumococcal conjugate vaccine (7vCRM) against invasive pneumococcal disease (IPD). We also assessed the accuracy of the previously established thresholds for GlaxoSmithKline's enzyme-linked immunosorbent assay with 22F adsorption (22F-ELISA) (≥0.2 μg/ml) and OPA assay (titer, ≥8) in predicting effectiveness. We showed that following a 3-dose 7vCRM primary vaccination, the serological response rates as determined using thresholds of ≥0.2 μg/ml IgG and an OPA titer of ≥8 corresponded we…
Tumornekrosefaktor und Interferon als prognostische Marker der HIV-Infektion
1991
Peripheral blood cells were obtained from patients at different stages of their human immunodeficiency virus (HIV) infection. It was found that the capacity to generate interferon alpha was reduced already at Walter Reed stage 2 (WR) while the interferon gamma capacity remained largely unaffected until WR stage 4. Endogenous tumor necrosis factor (TNF) alpha production increased as the HIV disease progressed. The data obtained add to our knowledge on destruction of the immune system by the HIV. Moreover TNF and acid labile interferon alpha might contribute to HIV replication and disease progression. Nevertheless the tests performed are too time-consuming to be introduced into routine analys…
Recent Advances on the Innate Immune Response to Coxiella burnetii.
2021
Coxiella burnetii is an obligate intracellular Gram-negative bacterium and the causative agent of a worldwide zoonosis known as Q fever. The pathogen invades monocytes and macrophages, replicating within acidic phagolysosomes and evading host defenses through different immune evasion strategies that are mainly associated with the structure of its lipopolysaccharide. The main transmission routes are aerosols and ingestion of fomites from infected animals. The innate immune system provides the first host defense against the microorganism, and it is crucial to direct the infection towards a self-limiting respiratory disease or the chronic form. This review reports the advances in understanding…
Enterovirus and Encephalitis
2020
Enterovirus-induced infection of the central nervous system (CNS) results in acute inflammation of the brain (encephalitis) and constitutes a significant global burden to human health. These viruses are thought to be highly cytolytic, therefore normal brain function could be greatly compromised following enteroviral infection of the CNS. A further layer of complexity is added by evidence showing that some enteroviruses may establish a persistent infection within the CNS and eventually lead to pathogenesis of certain neurodegenerative disorders. Interestingly, enterovirus encephalitis is particularly common among young children, suggesting a potential causal link between the development of t…
Visceral leishmaniasis: host-parasite interactions and clinical presentation in the immunocompetent and in the immunocompromised host.
2013
SummaryVisceral leishmaniases are vector-borne parasitic diseases caused by protozoa belonging to the genus Leishmania. The heterogeneity of clinical manifestations and epidemiological characteristics of the disease reflect the complex interplay between the infecting Leishmania species and the genetic and immunologic characteristics of the infected host. The clinical presentation of visceral leishmaniasis depends strictly on the immunocompetency of the host and ranges from asymptomatic to severe forms. Conditions of depression of the immune system, such as HIV infection or immunosuppressive treatments, impair the capability of the immune response to resolve the infection and allow reactivat…
Time course of mycobacterial infection of dendritic cells in the lungs of intranasally infected mice
2004
Summary Setting : Dendritic cells (DC) could regulate between the protective and pathogenic immune responses following tuberculous infection. In this paper we investigated if their early infection in the lungs represents a plausible alternative to cross-priming with mycobacterial antigens acquired from infected macrophages. Objective : To determine the extent and time course of infection of lung DCs following intranasal inoculation of BALB/c mice with green fluorescent protein (GFP) tagged Bacillus Calmette-Guerin (BCG). Results : A fraction of GFP-BCG infected lung cells were classified as monocytic DCs with the CD11c + IA + 33D1 + CD8a − phenotype. These cells represented 5–18% of the tot…
Early Development of the Gut Microbiota and Immune Health
2014
In recent years, the increase in human microbiome research brought about by the rapidly evolving “omic” technologies has established that the balance among the microbial groups present in the human gut, and their multipronged interactions with the host, are crucial for health. On the other hand, epidemiological and experimental support has also grown for the ‘early programming hypothesis’, according to which factors that act in utero and early in life program the risks for adverse health outcomes later on. The microbiota of the gut develops during infancy, in close interaction with immune development, and with extensive variability across individuals. It follows that the specific process of…
Evolution of SARS-CoV-2 immune responses in nursing home residents following full dose of the Comirnaty® COVID-19 vaccine
2021
ABSTRACTObjectivesThere is scarce information as to the durability of immune responses elicited by the Comirnaty® COVID-19 vaccine in nursing home residents. Here, we assessed SARS-CoV-2-Spike (S)-targeted antibody and functional T cell responses at around 6 months after complete vaccination.MethodsThe sample comprised 46 residents (34 females; age, 60-100 years), of whom 10 had COVID-19 prior to vaccination. Baseline (median of 17.5 days after vaccination) and follow-up (median, 195 days) plasma specimens were available for quantitation of SARS-CoV-2-S antibodies and enumeration of SARS-CoV-2-S-reactive IFN-γ CD4+ and CD8+ T cells by flow cytometry.ResultsIn total, 44/45 participants had d…
Immune evasion, immunopathology and the regulation of the immune system.
2013
21 pages; International audience; Costs and benefits of the immune response have attracted considerable attention in the last years among evolutionary biologists. Given the cost of parasitism, natural selection should favor individuals with the most effective immune defenses. Nevertheless, there exists huge variation in the expression of immune effectors among individuals. To explain this apparent paradox, it has been suggested that an over-reactive immune system might be too costly, both in terms of metabolic resources and risks of immune-mediated diseases, setting a limit to the investment into immune defenses. Here, we argue that this view neglects one important aspect of the interaction…
Social evolution of innate immunity evasion in a virus
2019
Antiviral immunity has been studied extensively from the perspective of virus−cell interactions, yet the role of virus−virus interactions remains poorly addressed. Here, we demonstrate that viral escape from interferon (IFN)-based innate immunity is a social process in which IFN-stimulating viruses determine the fitness of neighbouring viruses. We propose a general and simple social evolution framework to analyse how natural selection acts on IFN shutdown and validate it in cell cultures and mice infected with vesicular stomatitis virus. Furthermore, we find that IFN shutdown is costly because it reduces short-term viral progeny production, thus fulfilling the definition of an altruistic tr…