Saturday, November 3, 2007

Acute Stress at the Time of Vaccination

Someone in class brought up Professor Dhabhar's lecture from Human Biology last year. Since I actually work in his immunology lab, I thought I would bring up the article that he was talking about.

"Short Term Stress Experienced at the Time of Immunization Induces a Long-Lasting Increase in Immunological Memory" Dhabhar and Vaswanathan

The experiment was done on mice. Researchers acutely stressed the mouse by placing them in restraints for 2.5 hours - mimicking a "collapsed" tunnel which is stressful for burrowing rodents.

"One group was not immunized but was exposed to keyhole limpet hemocyanin (KLH) on the pinna for the first time in parallel with the recall phase of the following two groups (nonimmunized control). The second group of animals remained in their home cages before primary immunization as the nonstressed immunized controls and were reexposed to KLH on the pinnae 9 mo later, also under resting conditions. The third group was stressed before primary immunization and reexposed to KLH on the pinnae 9 mo later under resting conditions. This was the only group that was acutely stressed, and stress was administered only once for 2.5 h before primary immunization."

These results show that acute psychophysiological stress exerts adjuvant-like effects on the immune system. Animals acutely stressed before immunization showed increased numbers of activated-effector (CD62Llow and CD44hi) and Tcm-like (CD45RA–CD62L+) Th cells during the early phase of the primary immune response

The only stress manipulation that was performed in these experiments occurred 9 mo before the recall CMI response was measured. Interestingly, acutely stressed animals mounted a significantly larger recall response that was marked by a robust increase in macrophages and lymphocytes infiltrating the novel site of antigen reexposure.

I guess maybe we should stress out babies before vaccination. Although I'm pretty sure that if Bob were there, he'd stress out his babies enough trying to explain to them what a vaccination is, what types there are, and how they were discovered... etc.

Woohoo! <3 Immunology!

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