You've repeatedly said or implied that Aubrey, Michael, and SENS supporters are unqualified. That's incorrect, and rude. Perhaps what you consider "directness" is coming across as insulting.
Repeatedly said or implied? Once in this thread I stated the fact that de Grey's formal education in biology amounts to a BS in computer science. You seem overly touchy about this fact.
Did you read Reason's rationale or are you just dismissing it? Having 80% of your T-cell population specialized to one specific virus isn't leaving much space for all the other threats you might encounter. I think the point is that you don't need all of them, and the fact that they're there is hurting you more than it helps. So do you think that they are all necessary to keep us safe from CMV, despite the fact that we could deal with CMV just fine with far few such cells all the way up to late life? The proposal is to revert the T-cell population back to a youthful state, not destroy it.
Yes I did. And now I read it again, only out of respect for you, niner. You asked and here it comes. I'll tell it to you straight, only the facts, and I sure hope you won't find them insulting.
Ready?
This is wrong:
"Having 80% of your T-cell population specialized to one specific virus ..".
It looked wrong off the bat but just for you I checked the references. The 80% number comes from this quote from
this mouse study:
A frequent and drastic hallmark of age-related TCR diversity reduction is the appearance of CD8 T cell clonal expansions (TCE), which in some instances can comprise >80% of the total CD8 compartment (6, 7, 9, 12).
As you see, the number refers NOT to the percentage of CMV-specialized T-cells out of the whole T-cell population, but the percentage of
the its CD8 compartment displaced by CD8 T-cell clonal expansions. Again: it's the percentage of the CD8 compartment of the whole T-cell pool that is displaced by TCE.
Then, of the 4 refs supporting that 80% number, only
(7) and
(12) apply to humans (and the other two are the studies of mice; the 80% number belongs to them). The two human refs give different numbers: 37.5% and 50%. The smaller number applies to "normal people over 65". The 50% is based on a mixed cohort, half "normal" and half recruited from a methadone clinic of substance abusers, who were HIV, HVB or HVC sero-positive -- this explains the higher number in (12) vs (7) -- 50% vs 37.5% -- but not 80% !
These clonal CD8 expansions normally occur in
any viral infection --not just CMV-- and they usually resolve some time after the infection is gone, but naturally they persist as long the virus persists. As (12) sais, "The in vivo persistence of expanded CD8 clones in old subjects suggests chronic antigen exposure."
So, to wrap up this part, the fact is that Reason misrepresented the problem. He took the data from a mouse CMV study, exaggerated it and sold as human data. The part he got right was about the clones persisting because of the persisting virus
But then he totally messed up the part about CMV being 'harmless' -- but this was discussed already ad nauseam.
Now the rest of your statement:
the point is that you don't need all of them, and the fact that they're there is hurting you more than it helps. So do you think that they are all necessary to keep us safe from CMV, despite the fact that we could deal with CMV just fine with far few such cells all the way up to late life? The proposal is to revert the T-cell population back to a youthful state, not destroy it.
The fact? Can you please cite a ref for this fact, 'cause all I saw just now was a couple of loose hypotheses based on mouse studies plus a conjecture. And how do you know how many if them you need, if you don't know the viral load -- or do you presume that it remains static? What if it grows and the clones expand in response to this growth?
The point is, the cells are there because the virus is there. It is the fact of life that a persistent infection taxes the immune system and renders it less effective against other pathogens -- and this applies to all chronic infections, not just CMV and not just viral (and btw I just saw that some cancers also cause CD8 clonal expansions). It is also a fact that persistent infections are caused by pathogens that manage to misdirect or disrupt the immune response rendering it ineffective. Still, the only right thing to do is to get rid of the underlying problem -- but the problem here is not the immune system. It is the virus. Get rid of the virus and in a while the clones will be gone.
Edited by xEva, 10 June 2015 - 09:42 AM.