Famularo G, Moretti S, Marcellini S, Nucera E, De Simone C
Department of Experimental Medicine, University of L'Aquila, Italy.
J Clin Lab Immunol. 1997;49(1):15-32.
The part played by CD8 lymphocytes in the pathogenesis of human immunodeficiency virus infection (HIV) is much disputed and the relevant issue of the controversy ranges as to whether the functional activity of these cells is beneficial or detrimental to the host. Even though CD8 cells could efficiently suppress HIV replication through both major histocompatibility complex (MHC)-restricted cytotoxic killing of infected cells, particularly during primary infection, and HIV-suppressing soluble factors, there is evidence that tissue-infiltrating CD8 lymphocytes mediate injury in several organs of HIV-infected subjects. Furthermore, CD8 lymphocytes could contribute to the destruction of CD4 cells in vivo. Of note, the virus has the capability to escape the recognition by cytotoxic CD8 cells and the cytotoxic activity of CD8 cells and their counts decline with evolving HIV infection. Several mechanisms are proposed to explain this latter finding, including the direct in vivo infection of CD8 cells by the virus. It is likely that early during the course of HIV infection when viral loads are generally low an efficient CD8 cell response can control HIV replication whereas in subjects with evolving disease, who have very high viral loads, CD8 lymphocytes remove essential components of the immune response and mediate tissue injury.
CD8淋巴细胞在人类免疫缺陷病毒感染（HIV）发病机制中所起的作用备受争议，争议的相关问题涉及这些细胞的功能活性对宿主是有益还是有害。尽管CD8细胞可通过主要组织相容性复合体（MHC）限制的对感染细胞的细胞毒性杀伤（特别是在初次感染期间）以及HIV抑制性可溶性因子有效抑制HIV复制，但有证据表明，组织浸润的CD8淋巴细胞会介导HIV感染受试者多个器官的损伤。此外，CD8淋巴细胞可能在体内导致CD4细胞的破坏。值得注意的是，该病毒有能力逃避细胞毒性CD8细胞的识别，且CD8细胞的细胞毒性活性及其数量会随着HIV感染的进展而下降。有人提出了几种机制来解释后一发现，包括病毒对CD8细胞的直接体内感染。很可能在HIV感染过程的早期，当病毒载量通常较低时，有效的CD8细胞反应可控制HIV复制，而在疾病进展且病毒载量非常高的受试者中，CD8淋巴细胞会清除免疫反应的关键成分并介导组织损伤。
