title: Complexity of anti-immunosenescence strategies in humans.
abstract: Immunosenescence is characterized by three main aspects: (i) the shrinkage of the T cell repertoire and the accumulation of oligoclonal expansions (megaclones) of memory/effector cells directed toward ubiquitary infectious agents; (ii) the involution of the thymus and the exhaustion of naïve T cells; and (iii) a chronic inflammatory status called inflamm-aging. We present here possible strategies to counteract these main aspects of immunosenescence in humans with particular attention to the reduction of antigenic load by pathogens, such as CMV, and the normalization of intestinal microflora, the possible utilization of IL-7 to reverse thymic involution, the purging of megaclones, the forced expression of CD28 on T lymphocytes, the reduction of inflamm-aging and the administration of nutrients such as vitamin D. Possible drawbacks of all these strategies are discussed. Finally, the complexity of a rejuvenation approach is stressed, with particular attention to the inhibitory role played by the "old microenvironment" on the performance of progenitor cells, the best candidate to counteract the decline in regenerative potential characteristic of organs and tissues from old organisms.
authors.affiliation: Department of Experimental Pathology, University of Bologna, Bologna, Italy.
authors.forename: Miriam
authors.initials: M
authors.lastname: Capri
authors.forename: Daniela
authors.initials: D
authors.lastname: Monti
authors.forename: Stefano
authors.initials: S
authors.lastname: Salvioli
authors.forename: Francesco
authors.initials: F
authors.lastname: Lescai
authors.forename: Michela
authors.initials: M
authors.lastname: Pierini
authors.forename: Serena
authors.initials: S
authors.lastname: Altilia
authors.forename: Federica
authors.initials: F
authors.lastname: Sevini
authors.forename: Silvana
authors.initials: S
authors.lastname: Valensin
authors.forename: Rita
authors.initials: R
authors.lastname: Ostan
authors.forename: Laura
authors.initials: L
authors.lastname: Bucci
authors.forename: Claudio
authors.initials: C
authors.lastname: Franceschi
mesh_terms: D000375:Aging / Q000276:immunology*; D000941:Antigens / Q000276:immunology; D005075:Biological Evolution; D003587:Cytomegalovirus / Q000276:immunology; D003586:Cytomegalovirus Infections / Q000276:immunology; D006801:Humans; D007107:Immune System / Q000254:growth & development*; D007249:Inflammation / Q000276:immunology*; D013601:T-Lymphocytes / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology*
chemical_list: D000941:Antigens