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Iron cofactor for tuberculosis
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| ironjustice@aol.com 2006-06-15, 4:26 pm |
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ID: 24091.0, MPI f=FCr Infektionsbiologie / Department of Immunology
Correction of the iron overload defect in beta-2-microglobulin knockout
mice by lactoferrin abolishes their increased susceptibility to
tuberculosis
Authors: Schaible, Ulrich E.; Collins, Helen L.; Priem, Friedrich;
Kaufmann, Stefan H. E.
Document type: Article
Language: English
External Publication Status: published
Review Status: Peer-review
Issue / Number: 11
Free Keywords: mycobacteria; MHC; innate immunity; macrophages;
endosomes
Title of Journal: Journal of Experimental Medicine
Comment of the Author/Creator: Date: 2002, DEC 2
Abstract / Description: As a resident of early endosomal phagosomes,
Mycobacterium tuberculosis is connected to the iron uptake system of
the host macrophage. beta-2-microglobulin (beta2m) knockout (KO) mice
are more susceptible to tuberculosis than wild-type mice, which is
generally taken as a proof for the role of major histocompatibility
complex class I (MHC-I)-restricted CD8 T cells in protection against M.
tuberculosis. However, beta2m associates with a number of MHC-I-like
proteins, including HFE. This protein regulates transferrin receptor
mediated iron uptake and mutations in its gene cause hereditary iron
overload (hemochromatosis). Accordingly, beta2m-deficient mice suffer
from tissue iron overload. Here, we show that modulating the
extracellular iron pool in beta2m-KO mice by lactoferrin treatment
significantly reduces the burden of M. tuberculosis to numbers
comparable to those observed in MHC class I-KO mice. In parallel, the
generation of nitric oxide impaired in beta2m- KO mice was rescued.
Conversely, iron overload in the immunocompetent host exacerbated
disease. Consistent with this, iron deprivation in infected resting
macrophages was detrimental for intracellular mycobacteria. Our data
establish: (a) defective iron metabolism explains the increased
susceptibility of beta2m-KO mice over MHC-I-KO mice, and (b) iron
overload represents an exacerbating cofactor for tuberculosis.
Volume: 196
Date of Publication (YYYY-MM-DD): 2002-12-02
Start Page: 1507
End Page: 1513
Audience: Experts Only
Journal Abbrev.: J. Exp. Med.
Communicated by: Hilmar F=FCnning
Affiliations:
MPI f=FCr Infektionsbiologie/Department of Immunology
External Affiliations:
Humboldt Univ, Charite, Inst Lab Med & Pathochem, D-10177 Berlin,
Germany
Identifiers:
ISI:000179682000011 [ID No:1]
ISSN:0022-1007 [ID No:2]
Who loves ya.
Tom
Jesus Was A Vegetarian!
http://jesuswasavegetarian.7h.com
Man Is A Herbivore!
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DEAD PEOPLE WALKING=20
http://tinyurl.com/zk9fk
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| babawali.worldd.com 2006-06-15, 4:26 pm |
| "overload", this is the issue. Only a nimority of a population have
overload problems, overload is not the normal status. Round pegs in
square holes only makes sawdust.
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| GMCarter 2006-06-15, 9:25 pm |
| On 15 Jun 2006 15:24:10 GMT, babawali.worldd.com wrote:
>"overload", this is the issue. Only a nimority of a population have
>overload problems, overload is not the normal status. Round pegs in
>square holes only makes sawdust.
Although in this case I think there is a legitimate argument. In
Africa, there has been a tradition of providing iron and iodine
supplements. This may have the unfortunate effect of increasing
susceptibility to become infected by TB and worsening the outcome,
particularly among men. This may also be exacerbated, I would imagine,
if the beer there is high in iron?
Anyway, it is a concern in some places. However, it doesn't mean iron
is the root of all Evil nor that iron deficiency doesn't occur.
George M. Carter
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