Telomeres, which are caps at the ends of chromosomes are known to get shorter as we age. Shorter telomeres might increase mortality risk. Also, lack of vitamin D and chronic stress both seem to make telomeres shorter. So telomere length really seems to matter. With all that in mind: Exposure to a pathogen causes telomeres to shrink more rapidly.
We experimentally tested whether repeated exposure to an infectious agent, Salmonella enterica, causes telomere attrition in wild-derived house mice (Mus musculus musculus). We repeatedly infected mice with a genetically diverse cocktail of five different S. enterica strains over seven months, and compared changes in telomere length with sham-infected sibling controls. We measured changes in telomere length of white blood cells (WBC) after five infections using a real-time PCR method. Our results show that repeated Salmonella infections cause telomere attrition in WBCs, and particularly for males, which appeared less disease resistant than females. Interestingly, we also found that individuals having long WBC telomeres at early age were relatively disease resistant during later life. Finally, we found evidence that more rapid telomere attrition increases mortality risk, although this trend was not significant.
I have a sore throat as I write this post. Therefore my immune system is getting a little more aged and my white blood cell telomeres are getting shortened. Bummer dudes. Fortunately I only very rarely get sick. But if you live a lifestyle that causes you to get colds and flus every year then think about what steps you can take to cut your frequency of sickness. Every bout with some germ is making you another day older and closer to death.
What we really need: technologies for stem cell manipulation to produce youthful replacement immune system stem cells. That will do more than just reduce deaths of old people from influenza, pneumonia, and other pathogens which kill the elderly. Stronger rejuvenated immune systems will reduce death from cancer and maybe reduce the incidence of auto-immune disorders.
|Share |||Randall Parker, 2008 May 18 03:05 PM Aging Mechanisms|