Rejuvenating the old immune system
By comparing the immune responses of both, young and old mice, to bacterial infection they found that the number of macrophages, one of the major cell populations involved in the elimination of infecting bacteria, decreases rapidly in aged mice. This decline in the number of fighters and the associated weakness of the immune defense may be responsible for the age-associated increase in susceptibility to infections. The HZI researchers have succeeded to enhance the resistance to an infection in aged mice by treating them with a macrophage-specific growth factor. This treatment increases the amount of macrophages in aged mice and improves their capacity to fight the infection. This study has been published in the current issue of the scientific magazine "Journal of Pathology".