Why fat angers the immune system - TLR4
JRStern
http://www.newscientist.com/article/dn18101-why-fat-angers-the-immune-system.html
11:44 04 November 2009 by Deborah MacKenzie
Magazine issue 2733. Subscribe and get 4 free issues.
Overweight people get heart disease and diabetes � and more severe
swine flu � because their fat triggers inflammation, an immune
response meant to fight infection. Now the protein responsible for
this sequence of events may have been found.
Jerrold Olefsky and colleagues at the University of California, San
Diego, killed the bone marrow cells in mice that make immune cells
called macrophages. Then they injected the mice with macrophages
lacking a surface protein called TLR4.
When the team fed the mice high-fat diet, all grew obese, as did a
group of normal mice. But unlike the normal mice, those with altered
macrophages showed no signs of inflammation, such as changes in
insulin production, high levels of immune chemicals, and macrophages
in their belly fat.
Olefsky concludes that TLR4 mediates the immune system's response to
fat. He says that some fatty acids look like the bacterial invaders
that TLR4 senses, prompting normal macrophages to mistake fatty acids
for the enemy and turn on inflammation. His team is now testing drugs
that block TLR4. One day these might help people dodge some of the
health effects of being overweight.
Journal reference: Cell Metabolism, vol 10, p 419
JRStern
>The method of INDUCING obesity triggers inflammation, yes, but that
>doesn't prove that obesity causes inflammation.
The claim is that fat *cells* produce inflammatory compounds in
general, and in this case, trigger macrophages - and the entire
cascade entailed.
J.
JRStern
>x-no-archive: yes
>
>JRStern wrote:
>
>> The claim is that fat *cells* produce inflammatory compounds in
>> general, and in this case, trigger macrophages - and the entire
>> cascade entailed.
>
>Yes, but something triggers the event, and researchers keep stopping
>their investigation once they find what they're looking for to support a
>presupposition, without digging deeper.
>
>In fact, many fats are anti inflammatory, whereas any diet that induces
>high insulin levels (including overeating any type diet) triggers
>inflammation.
Lots of things may trigger inflammation - infection, diet, fats,
calories, insulin, injury. There are multiple immune systems,
multiple inflammatory pathways.
How many of these are involved in psoriasis, who knows.
Probably several, at least.
J.
zzznot
news:7le8p0F...@mid.individual.net...
> x-no-archive: yes
>
>> How many of these are involved in psoriasis, who knows.
>
> by HPA axis function in particular. I'm always open to learning.
Lordy, I wondered if you would ask that. I haven't the foggiest. I thought
I was doing my part just by being a patient.
Clinical, epidemiological, molecular, genetic, dietary, bacteriological,
environmental, psychological, ... ow my head.
I'm sure everything is interlocked to one degree or another but that might
work both ways, so that stuff governed mostly by HPA function could still be
modified through other pathways.
J.
zzznot
> x-no-archive: yes
>
> zzznot wrote:
>
>> Lordy, I wondered if you would ask that. I haven't the foggiest. I
>> thought I was doing my part just by being a patient.
>>
>> Clinical, epidemiological, molecular, genetic, dietary, bacteriological,
>> environmental, psychological, ... ow my head.
>>
>> I'm sure everything is interlocked to one degree or another but that
>> might work both ways, so that stuff governed mostly by HPA function could
>> still be modified through other pathways.
>
> authoritative statement without having any idea what you were talking
> about or that the above was a total non answer, did you? :-)
Are you claiming it's all driven off the HPA axis,
and do you have any more idea than me what you're talking about?
J.