Helminth infection can block TLR4 induction in TNBS-induced colitis (colitis allergy lymphocytes colon antibodies)
Different species of helminths may have different effects on
innate/sympathetic response at different parts of their lifecycle. The
presence of phosphorylcholine in ES-62 suggests to me the involvement of
the cholinergic nervous system, which balances out sympathetic flow.
J Gastroenterol Hepatol. 2009 Nov;24(11):1775-80.
*
Preventive effects of Schistosoma japoni*** ova on
trinitrobenzenesulfonic acid-induced colitis and bacterial translocation
in mice.
Zhao Y, Zhang S, Jiang L, Jiang J, Liu H.
ZhongShan Hospital, Fudan University, Gastroenterology, Shanghai, China.
AIMS: To evaluate the preventive effects of Schistosoma japoni*** ova on
trinitrobenzenesulfonic acid (TNBS)-induced colitis and bacterial
translocation in mice. METHODS: BALB/c mice were randomly divided into
three groups: control group; TNBS(+)Ova(-) group; and TNBS(+)Ova(+)
group. Mice of the TNBS(+)Ova(+) group were exposed to 10 000
freeze-killed S. japoni*** ova by i.p. injection on day 1 and day 11. On
day 15, mice were challenged with TNBS to induce colitis. The following
variables were assessed: colon pathological changes; serum expression of
tumor necrosis factor-alpha (TNF-alpha), gamma-interferon (IFN-gamma)
and interleukin-10 (IL-10); expression of Toll-like receptor 4 (TLR4) in
colon; IFN-gamma, IL-10 and TLR4 mRNA expression in colon; and the
bacterial translocation rate. RESULTS: Compared to TNBS(+)Ova(-) group,
the colonic inflammation in the TNBS(+)Ova(+) group were relieved. A
highly significant elevation of IFN-gamma and TNF-alpha were observed in
the TNBS-induced colitis group. After exposure to the eggs, IFN-gamma
was significantly decreased, while TNF-alpha was similar to that of the
TNBS(+)ova(-) group. No obvious variation was seen in IL-10 expression
in TNBS-induced colitis, compared to the controls. Exposure to the eggs
led to a significant upregulation of IL-10 expression. TLR4 expression
was elevated after injected with TNBS and was downregulated in the eggs
group. Less intestinal bacterial translocation frequency was observed
when exposed to eggs. CONCLUSION: S. japoni*** ova can prevent the
TNBS-induced colitis and reduce the bacterial translocation frequency in
mice. The mechanisms were supposed to be due to the regulation of
T-helper cell 1/2 balance and TLR4 expression.
PMID: 20136961
Adv Exp Med Biol. 2009;666:88-94. Related Citations, LinkOut
Immunomodulatory activity and the****utic potential of the filarial
nematode secreted product, ES-62.
Harnett W, Harnett MM.
Strathclyde Institute of Pharmacy and Biomedical Sciences, University of
Strathclyde, Glasgow, UK.
ES-62 is a protein that is actively secreted by filarial nematodes
during parasitism of the vertebrate host. The molecule is able to
directly interact with a number of cells of the immune system including
B-lymphocytes, dendritic cells, macrophages and mast cells. Interaction
appears to be dependent on complexing with TLR4 and results in
modulation of the activity of a number of signal transduction molecules
including MAP kinases, PI-3 kinase and NF-kappaB. Immunomodulatory
activity of ES-62 appears to be largely due to the presence of
phosphorylcholine (PC) moieties covalently attached to N-type glycans.
The net effect of ES-62's interaction with the immune system is the
generation of an anti-inflammatory immunological phenotype. As a
consequence of this, ES-62 demonstrates striking drug-like activity in
models of disease associated with aberrant inflammation, in particular
those associated with autoimmunity and allergy.
Publication Types:
* Review
PMID: 20054977
In schistosomiasis, a major human parasitic disease caused by helminths,
different life-stages of the parasite contribute to the developing host
immune response. To increase our understanding of the mechanisms that
play a role in shaping the host immune responses, we have investigated
the effects of schistosome glycoconjugates on the phenotype of dendritic
cells (DCs), which form a crucial link between the innate and the
adaptive immunity; Schistosoma mansoni worm glycolipids induce DC
activation as indicated by upregulation of the maturation markers CD80,
CD86 and MHC-II, as well as the production of the cytokines
interleukin-12 p40 (IL-12 p40), IL-10, IL-1beta, IL-6, IL-8 and tumor
necrosis factor-alpha (TNF-alpha). Co-culture of glycolipid-primed DCs
with naive T cells results in skewing of the T cell response towards a
Th1 profile. Remarkably, the DC activation is dependent on fucosylated
glycan moieties of the glycolipids. On the DCs, the C-type lectin
DC-SIGN and TLR4 are both critically involved in the induced activation,
as was demonstrated by using monoclonal antibodies that block
interaction of these receptors with the glycolipids. Furthermore,
whereas the worm glycolipids were not able to activate HEK 293 cells
expressing TLR4, they did show TLR4 activation after introduction of
DC-SIGN in the HEK 293-TLR4 cells. Our data provide evidence for a novel
function of DC-SIGN as an essential co-receptor for TLR4-induced
activation of human DCs. This mechanism of TLR4 activation by worm
glycolipids may contribute to eliciting Th1 immune responses in
schistosome infection [PMID 20170964]
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