Beta 2-microglobulin independent presentation of exogenously added foreign peptide and endogenous self-epitope by MHC class I alpha-chain to a cross-reactive CD8+ CTL clone.
Beta 2-microglobulin independent presentation of exogenously added foreign peptide and endogenous self-epitope by MHC class I alpha-chain to a cross-reactive CD8+ CTL clone.
复制标题
β2-微球蛋白独立地将外源添加的外源肽和内源自身表位通过 MHC I 类 α 链呈递给交叉反应性 CD8 CTL 克隆。
DOI：
10.4049/jimmunol.153.9.4070
复制
发表时间：
1994
影响因子：
4.4
通讯作者：
S. Kaufmann
中科院分区：
文献类型：
--
作者：
U. Zügel;B. Schoel;S. Kaufmann
CD8+ T cells recognize antigenic peptides in the context of MHC class I molecules that encompass two distinct polypeptide chains, the MHC-encoded alpha-chain and the non-MHC-encoded beta 2-microglobulin (beta 2-m). The beta 2-m is considered essential for the stability and function of the MHC class I peptide complex and, hence, for peptide presentation to CD8+ T cells. In this study, we describe peptide presentation by macrophages from beta 2-m-deficient mice to a CD8+ CTL clone tht cross-recognizes an H-2Db-restricted peptide of the mycobacterial heat shock protein 60 (hsp60) and a self-peptide presented by IFN-gamma-stressed macrophages. Specific lysis of stressed or hsp60 peptide-pulsed beta 2-m-/- macrophages was inhibited by the nucleoprotein peptide with high affinity to H-2Db. Brefeldin A, a known inhibitor of MHC class I processing, interfered with lysis of IFN-gamma-stressed, but not of hsp60 peptide-pulsed, beta 2-m-/- macrophages. The hsp60 peptide failed to stimulate surface expression of H-2Db in beta 2-m-/- macrophages, and slightly increased MHC class I expression in the transporter mutant cell line RMA-S, as detected by cytofluorometry. We concLude that presentation of endogenously processed cytosolic epitopes and exogenously added foreign peptides by the MHC class I alpha-chain can occur independent from beta 2-m. Presumably, H-2Db peptides, but not H-2Kb peptides, have the capacity to induce and/or stabilize surface expression of a small number of MHC class I alpha-chains, and this low density is sufficient for recognition by CD8+ CTL, although it need not be detected by serologic means.
