title: Aging correlates with reduction in regulatory-type cytokines and T cells in the gut mucosa.
abstract: Aging is reported to be associated with decline in oral tolerance induction, which is initiated at the intestinal mucosal surface. Herein, we examined the effect of aging in T cells and cytokines at the intestinal mucosa that might be involved in oral tolerance induction. Frequencies of regulatory-type IEL subsets such as TCRγδ(+) and TCRαβ(+)CD8αα(+) were lower in aged mice. Mucosal CD4(+)CD25(+)Foxp3(+) and CD4(+)LAP(+) T cells increased with aging but activated CD44(+)CD4(+) mucosal T cells also augmented. Production of TGF-β and IL-10 in the small intestine of old mice was reduced. Moreover, the ability of mucosal dendritic cells of aged mice to stimulate TGF-β secretion and differentiation of CD4(+)LAP(+) T cells in co-culture studies also declined with aging. Reduction in these regulatory-type cytokines and T cells may help to explain the decline in susceptibility to oral induction during aging. However, not all mucosal regulatory elements were altered by aging and CD4(+)CD25(+)Foxp3(+) T cells were especially resistant to changes. Persistence of some mechanisms of regulation may play a critical role in maintaining mucosal homeostasis during aging.
authors.affiliation: Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Av. Antônio Carlos 6627, 31270-901 Belo Horizonte, MG, Brazil.
authors.forename: Andrezza F
authors.initials: AF
authors.lastname: Santiago
authors.forename: Andréa C
authors.initials: AC
authors.lastname: Alves
authors.forename: Rafael P
authors.initials: RP
authors.lastname: Oliveira
authors.forename: Raphaela M
authors.initials: RM
authors.lastname: Fernandes
authors.forename: Josiely
authors.initials: J
authors.lastname: Paula-Silva
authors.forename: Frankcineia A
authors.initials: FA
authors.lastname: Assis
authors.forename: Cláudia R
authors.initials: CR
authors.lastname: Carvalho
authors.forename: Howard L
authors.initials: HL
authors.lastname: Weiner
authors.forename: Ana Maria C
authors.initials: AM
authors.lastname: Faria
mesh_terms: D000375:Aging / Q000276:immunology*; D000818:Animals; D000938:Antigen-Presenting Cells / Q000276:immunology; D016207:Cytokines / Q000096:biosynthesis* / Q000276:immunology; D005260:Female; D007413:Intestinal Mucosa / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D010641:Phenotype; D011948:Receptors, Antigen, T-Cell / Q000235:genetics / Q000276:immunology; D016176:T-Lymphocyte Subsets / Q000276:immunology / Q000378:metabolism; D050378:T-Lymphocytes, Regulatory / Q000276:immunology* / Q000378:metabolism
chemical_list: D016207:Cytokines; D011948:Receptors, Antigen, T-Cell