Splenic Niche Cells from Young Heterochronic Parabionts Have Decreased Capability to Amplify T-cell Proliferation in Vitro

Abstract

Immune system dysfunction during aging is well documented fact. Changes in the adaptive immune system are the most marked, especially in the T-cell compartment. In multiple preliminary studies it has been shown that parabiosis between 2 animals of different age can induce age-related changes in adaptive immune response and T-cell subpopulation composition of younger animal. In present study we evaluated the age-related changes in functions of rapidly renewing (macrophages) and slowly renewing cells (CD11c+ DCs) cells in spleens of young and old parabionts. We observed impaired capacity of splenic adherent cells from younger heterochronic parabionts to co-stimulate proliferation of autologous T-cells in vitro up to the level of old animals. Also we observed negative effect of this splenic cell population on intracellular signaling mechanisms that regulate PHA-activated proliferation of T-cells from young animals: statistically significant decrease of NFκB p65 expression and increased expression of IκBα during early activation events. This fact suggests that splenic macrophages may be involved in the induction of age-related changes of the immune system and they can be prospective target for further investigation.