HIV-1 Infection and the Aging of the Immune System: Facts, Similarities and Perspectives

During infection with the human immunodeficiency type-1 virus (HIV), the immune system has to cope with the exposure to an unexpected number of different and new antigens that are generated by continuous mutations of the virus. This phenomenon causes a profound derangement of the immune response, which is similar to that defined immunosenescence, a complex remodeling, whereby clonotypical immunity deteriorates, and ancestral and innate immunity is largely preserved. Either in HIV+ patients or in elderly individuals, the lifelong chronic antigenic stress, along with the involution of the thymus, causes the accumulation of memory/effector T cells and the exhaustion of naïve T cells. Furthermore, in both these conditions a chronic inflammatory status exists in the aging process, which has been defined as “inflammaging” and is characterized by an enhanced production of proinflammatory cytokines. In this review, we will underline the similarities that exist between immunological changes present during the physiological aging process and HIV infection.