Derhovanessian Evelyna, Larbi Anis, Pawelec Graham
Center for Medical Research, ZMF, University of Tübingen Medical School, Tübingen, Germany.
Curr Opin Immunol. 2009 Aug;21(4):440-5. doi: 10.1016/j.coi.2009.05.012. Epub 2009 Jun 15.
Age-associated failing systemic immunity, loosely termed 'immunosenescence', is thought to contribute to the increased incidence and severity of infectious disease in old people. It would therefore be of great practical as well as academic interest to accurately identify which of the multitude of alterations to immune parameters thus far reported are causally related to a person's clinically unfavourable health status, in order to identify the mechanisms of immune ageing and intervene to restore appropriate immunity. This is an enormous current challenge, as it requires longitudinal studies in a very long-lived species. Circumstantial evidence and longitudinal studies limited to the very elderly have begun to reveal 'immune signatures' or biomarkers of immune ageing consisting not of a single parameter, but clusters of parameters increasingly recognized as an 'immune risk profile', or IRP. Although hinted at many years ago, a marked impact of usually asymptomatic infection with the persistent beta-herpesvirus Cytomegalovirus (CMV) on markers of immunosenescence is now becoming incontrovertible. The fascinating cohabitation of CMV with the human immune system, which commits a very significant fraction of its entire resources to CMV-immunosurveillance, may suggest an early-life benefit from infection, which becomes deleterious for the majority of the population only in later life or under pathological conditions.
与年龄相关的全身免疫功能衰退，笼统地称为“免疫衰老”，被认为是导致老年人传染病发病率和严重程度增加的原因。因此，准确识别迄今为止报道的众多免疫参数改变中哪些与个体临床不良健康状况存在因果关系，从而确定免疫衰老的机制并进行干预以恢复适当的免疫力，具有重大的实践意义和学术价值。这是当前一项巨大的挑战，因为它需要对寿命很长的物种进行纵向研究。间接证据以及仅限于老年人的纵向研究已开始揭示免疫衰老的“免疫特征”或生物标志物，这些标志物并非由单一参数组成，而是由越来越被认可为“免疫风险概况”（IRP）的参数簇构成。尽管多年前就有所暗示，但持续感染通常无症状的β疱疹病毒巨细胞病毒（CMV）对免疫衰老标志物的显著影响现在已变得无可争议。CMV与人类免疫系统的奇妙共存，免疫系统将其全部资源的很大一部分用于CMV免疫监视，这可能表明感染在生命早期有好处，但仅在晚年或病理条件下才对大多数人有害。
