Since its creation, our laboratory conducted intensive experiments on determination of mechanisms of immune system aging. It was observed that interactions of immune and neuro-endocrine system are impaired during aging. During experimental and clinical investigations the role of impaired function of epiphysis in thymus and bone marrow aging. Also there were investigated age-associated changes in the functional state of bone tissue. Connection of changes in immune system and in state of bone tissue were observed in aged mice and women in postmenopausal period of life. On the model of heterochronic parabiosis it was observed that exposure of old systemic environment to young systemic environment causes age-associated changes in the immune and several other systems of young organism without signs of correction of aging in old organism. Currently we test the role of changes in peripheral lymphoid niche in age-associated dysfunction of immune system.