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Mammalian Immune System (mammalian + immune_system)

Distribution by Scientific Domains

Life Sciences	60%
Medical Sciences	40%

Selected Abstracts

The gut, immunoregulation and micro-organisms from man's evolutionary past

NUTRITION BULLETIN, Issue 2 2010
G. A. W. Rook
Summary Man has moved rapidly from the hunter-gatherer environment to the living conditions of the rich industrialised countries. The hygiene hypothesis suggests that the resulting changed and reduced pattern of exposure to certain critical micro-organisms, mostly derived from mud, animals and faeces, has led to disordered regulation of the immune system and, hence, to increases in chronic inflammatory disorders such as allergies, inflammatory bowel diseases and autoimmunity. Epidemiology, backed up by laboratory models, indicates that the relevant organisms are those that have very long associations with the mammalian immune system, traceable back to the Palaeolithic or earlier. Often, these organisms have been present as commensals (notably in the intestinal microbiota), environmental ,pseudocommensals', sub-clinical infections or asymptomatic carrier states, and the mammalian immune system is in a state of ,evolved dependence' on their continued presence. Several of these ,Old Friends', often operating primarily in the gut, act as modulators of dendritic cells and T cells, leading to the establishment of immunoregulatory circuits. Clinical trials are in progress to test living helminths (Trichuris suis and Necator americanus) in allergies, inflammatory bowel disease and multiple sclerosis. We can anticipate rapid increases in the use of these and other organisms or their components in novel types of therapy with applications in several branches of medicine. Probiotics tested in clinical trials targeting chronic inflammatory disorders have so far given unconvincing results, but if strains for these indications are selected on the basis of their ability to induce immunoregulation, and not merely imposed by companies that have intellectual property rights, we can anticipate rapid progress. [source]

Expression of helminth genes in Leishmania: an experimental transfection system to test immunological function

PARASITE IMMUNOLOGY, Issue 4 2008
R. M. MAIZELS
SUMMARY Functional analysis of genes from parasitic helminths requires, at the present time, heterologous expression. We have adapted the well-characterized system of transfection in Leishmania protozoal parasites, as a means of analysing the effect of single filarial genes on the mammalian immune system. For example, testing the function of the Brugia malayi abundant larval transcript (ALT) gene-transfected Leishmania mexicana were found to be significantly more virulent in macrophages in vitro. The course of infection in vivo is also aggravated by expression of the ALT gene. Examples are also given of transgenes which reduced in vitro growth within macrophages, as well as others which exert no effect on the protozoal parasitism. Thus, Leishmania transfection provides a tractable system to analyse helminth gene function within the context of the host immune system. [source]

How to kill a mocking bug?

CELLULAR MICROBIOLOGY, Issue 4 2006
Vitor B. Pinheiro
Summary All metazoans have evolved means to protect themselves from threats present in the environment: injuries, viruses, fungi, bacteria and other parasites. Insect protection includes innate physical barriers and both cellular and humoral responses. The insect innate immune response, best characterized in Drosophila melanogaster, is a rapid broad response, triggered by pathogen-associated molecular patterns (PAMPs) recognition, which produces a limited range of effectors that does not alter upon continued pathogen exposure and lacks immunological memory. The Drosophila response, particularly its humoral response, has been investigated by both low and high-throughput methods. Three signalling pathways conserved between insects and mammals have been implicated in this response: Toll (equivalent to mammalian TLR), Imd (equivalent to TNF,) and Hop (equivalent to JAK/STAT). This review provides an entry point to the insect immune system literature outlining the main themes in D. melanogaster bacterial pathogen detection and humoral and cellular immune responses. The Drosophila immune response is compared with other insects and the mammalian immune system. [source]

Comparative and developmental study of the immune system in Xenopus

DEVELOPMENTAL DYNAMICS, Issue 6 2009
Jacques Robert
Abstract Xenopus laevis is the model of choice for evolutionary, comparative, and developmental studies of immunity, and invaluable research tools including MHC-defined clones, inbred strains, cell lines, and monoclonal antibodies are available for these studies. Recent efforts to use Silurana (Xenopus) tropicalis for genetic analyses have led to the sequencing of the whole genome. Ongoing genome mapping and mutagenesis studies will provide a new dimension to the study of immunity. Here we review what is known about the immune system of X. laevis integrated with available genomic information from S. tropicalis. This review provides compelling evidence for the high degree of similarity and evolutionary conservation between Xenopus and mammalian immune systems. We propose to build a powerful and innovative comparative biomedical model based on modern genetic technologies that takes take advantage of X. laevis and S. tropicalis, as well as the whole Xenopus genus. Developmental Dynamics 238:1249,1270, 2009. © 2009 Wiley-Liss, Inc. [source]

Immunity to vacuolar pathogens: What can we learn from Legionella?

CELLULAR MICROBIOLOGY, Issue 11 2004
Annie L. Neild
Summary Intracellular pathogens can manipulate host cellular pathways to create specialized organelles. These pathogen-modified vacuoles permit the survival and replication of bacterial and protozoan microorganisms inside of the host cell. By establishing an atypical organelle, intracellular pathogens present unique challenges to the host immune system. To understand pathogenesis, it is important to not only investigate how these organisms create unique subcellular compartments, but to also determine how mammalian immune systems have evolved to detect and respond to pathogens sequestered in specialized vacuoles. Recent studies have identified genes in the respiratory pathogen Legionella pneumophila that are essential for establishing a unique endoplasmic reticulum-derived organelle inside of mammalian macrophages, making this pathogen an attractive model system for investigations on host immune responses that are specific for bacteria that establish vacuoles disconnected from the endocytic pathway. This review will focus on the host immune response to Legionella and highlight areas of Legionella research that should help elucidate host strategies to combat infections by intracellular pathogens. [source]