> In article <2e89obINNcpb at dns1.NMSU.Edu>, smori at nmsu.edu (Shahram Mori)
> wrote:
><<more stuff deleted>>
> <Stuff Deleted>
>> IMHO, I think it is clear that both IL-4 and IL-7 can in some cases act
> as an IL-2 indepedant T cell growth factors just like IL-2. IL-4 is not
> the mode of action in this transgenic model though, but they don't discount
> other factors. I would not be surprised if there are even more "TCGF"s than
> these though. If you look at the IL-2 receptor you'll see it has 3
> subunits. Just as oncostatin M, LIF, IL-6 and CNTF have different
> "receptors" but all share gp130 signalling molecule in the receptor
> complex, it would not be far fetched to think that other molecules may
> appropriate an IL-2R subunit. Also it seems that the IL-2beta,IL-2gamma,
> IL-4,IL-7,IL-9, and EPO receptors are in the same family. This too may
> explain overlapping function. Check out "Cytokine receptors and and signal
> transduction" in FASEB Journal Dec. 1992 vol.6, p3387 by Taga and
> Kishimoto, its a pretty good review and tends to highlight the similarities
> between the diferrent cytokine receptors. Anyway, I guess I'm kinda happy
> that IL-2 isn't the ultimate cytokine, that would be too simple and kinda
> boring.
>>>> Allen Black
> Dept. of Microbiology
> Univ. of Birmingham at Alabama
> "I am not a scientist, but I've seen one on T.V."
>This discussion is interesting to me because of the results that we
have found in the examination of cytokine expression in endomyocardial
biopsies from human cardiac transplant recipients. Since they are
immunosuppressed with cyclosporine and steroids, it is unusual to see
much IL-2 production anywhere. But as they approach rejection, it
seems that a subset of samples show a substantial increase in the
expression of IL-4 and IL-10 just prior to the diagnosis of rejection,
which is not what I would expect given some of the tenets of TH1/TH2
paradigm. They behave as if they are potentiating the response
instead, which could happen if there is a shift in the composition or
the type of signal transmitted by the target receptors.
==============================================================================
James F. George, Ph.D. "Back off man, I'm a scientist"
Department of Surgery Bill Murray in Ghostbusters
University of Alabama at Birmingham
205-934-4261 voice
txpljfg at uabcvsr.cvsr.uab.edu
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