Sort of a naive bit of free-association from someone with very sketchy
knowledge of apoptosis and of the danger vs. nonself controversy: not
much of a "danger" given that the cell is suiciding and will soon be
out of the way. Which leads to question about (1) time course of
developing identification of danger OR of nonself (does apoptopic
process change identity as self?) in specific case, and (2)
evolutionary pressures for or against reaction to cells already on
their way out...
F. Frank LeFever, Ph.D.
New York Neuropsychology Group
In <78le3k$hja$1 at nnrp1.dejanews.com> obsession1 at my-dejanews.com writes:
>>I believe Polly is doing, or has done, the experiments to address this
>question. I believe she supports the view that apoptotic cells are not
>"dangerous". However, as the paper from Bhardwaj et al used virus to
induce
>apoptosis in monocytes the presentation of exogenous antigen in
apoptotic
>bodies on MHC class I may depend on the method of inducing apoptosis
in the
>antigenic cells, as viral infections are certainly "dangerous"
according to
>Polly's last Nature paper.
>>Chris
>>>In article <36963186.4075003A at uia.ua.ac.be>,
>vigor at uia.ua.ac.be wrote:
>> Hi,
>> I'm a PhD student who is very interested in the field of immunology.
>> Recently, the cross-priming pathway by which acceptor professional
APC
>> (= dendritic cells; DC) acquire antigen from donor cells to elicit
an
>> antigen-specific CTL respons has been studied in detail by the group
of
>> N. Bhardwaj et al. (Nature 1998; 392: 86-89 & J Exp Med 1998; 188:
>> 1359-1368. This group demonstrated that the cross-priming phenomenon
can
>> be explained by the phagocytosis, processing and presentation of
>> antigens derived from apoptotic and not necrotic cells on MHC class
I
>> molecules.
>> Well now, my question is how this theory fits with the "danger"
model of
>> P. Matzinger (Ann Rev Immunol 1994; 12: 991-1045)? According to
>> Matzinger, the DC must become activated through a danger signal
>> (necrosis, viral infection,...) in order to function as a
professional
>> (effector) APC capable of activating virgin T cells. As I understood
>> from this latter model, apoptosis does not represent "danger". Is
>> something wrong with the way I look at these models or is there a
>> distinct discrepancy?
>> Any suggestion?
>>>> Viggo VT
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