Immunosenescence and its potential modulation: lessons from mouse models.

Evaluation of: Goldmann O, Lehne S, Medina E. Age-related susceptibility to Streptococcus pyogenes infection in mice: underlying immune dysfunction and strategy to enhance immunity. J. Pathol. 220(5), 521-529 (2010). Immunosenescence is a pathophysiological event in the aging process, which probably represents the greatest danger to an individual; diminished immune functions and altered immunoregulation lead to increased susceptibility to infections, autoimmunity and increased frequency of tumors in the elderly. Immunosenescence affects the functions of both innate immune cells (such as neutrophils, macrophages and dendritic cells) and cells involved in adaptive immunity (T and B lymphocytes). A number of methods have been developed to monitor age-related abnormalities in inbred murine strains, including physiologial and immunological tests, and a variety of genetic and epigenetic assays. Various animal models enable investigation of certain aspects of the aging process, and also allow for testing of immune-modulating agents that might 'rejuvenate' the cellular functions altered by aging. Although short-term experiments with targeted compounds to replenish certain cell types or restore cellular functions may present impressive results of 'rejuvenation' of innate immunity (reduced susceptibility to an infectious agent), to date, immunosenescence still remains a phenomenological term with limited etiologic information at the cellular and molecular levels.