So far within this thread, the overwhelming number of postings appear to be assuming that this Japanese research is legitimate and so far, there appears to be absolutely no additional corroborating evidence to substantiate it beyond the initial Russian article. I can only guess that this article strikes a chord with many people that would like individual longevity to be possible.
Even if we do assume truth value behind the article, stating that the immune system becomes severely compromised when C1q activity is suspended immediately indicates that this is not the correct path to be following to eventually achieve significant increases in longevity.
This avenue of research is a dead end.

On the contrary, with increased longevity, one of the additional "enhancements" (if I can use that term) is a corresponding ramping up of the body's immune system. Diseases that normally resulted in high fatality levels such as the black death, cholera, etc, are within these increased longevity/enhanced immune system individuals, handled in a much more efficient manner and their overall impact on bodily functions reduced considerably. Consequently, recovery from such diseases for these individuals is always 100%.

From article:

But there is also a different side to the story. By casting the protein “into sleep” and slowing the ageing process, scientists also block the body’s entire immune system. So far, a way of stopping the ageing and keeping the immune system working has not been found. But the researchers say they are hard at work, so who knows? Perhaps one day before too long we might be able to stay young – and healthy at the same time.

So the solution is easy. Construct a clean-room cryogenic chamber, put this human to sleep, use this protein technique first-off, and revive him once there's a true means to stop aging while living.

You wake up to Star Trek... I'd risk it if someone had already successfully done a year in a chamber and been revived virtually the same age.

i still wonder what the effects of gravity would be on a human body over hundreds of years..