Peptide Loading Complex in Cancer: From Peptide Translocation, Editing, and Loading into MHC-I to a Potential Therapeutic Target
Omer Qutaiba B. Allela , Abdulkareem Shareef , Hayder Naji Sameer , Ahmed Yaseen , Zainab H. Athab , Mohaned Adil
Current Medical Science ›› : 1 -20.
The peptide-loading complex (PLC) is a pivotal endoplasmic reticulum (ER) protein machinery that facilitates peptide translocation, editing, and loading onto major histocompatibility complex class I (MHC-I) to allow recognition of infected or transformed cells by CD8⁺ cytotoxic T lymphocytes (CTLs). PLC comprises the peptide transporter complex formed of transporters associated with antigen processing (TAP1/2), the adapter protein tapasin, chaperones such as calreticulin (CRT) and ERp57, and β2-microglobulin (β2M), ensuring the proper assembly of MHC-I/peptide complexes for subsequent antigen presentation on the cell surface. In cancer, tumorigenesis often involves structural malfunctions and transcriptional, post-transcriptional, and epigenetic modifications that impair the functioning of PLC proteins. This eventually causes loss of MHC-I cell-surface expression, failure of antigen presentation, and escape from CTL-mediated immunosurveillance. Although malfunctions in antigen-processing machineries are well known, herein we provide an overview of the PLC as a major determinant of tumor immune escape and a potential therapy target. In this regard, recent evidence indicates that individual PLC components not only affect MHC-I/antigen presentation but also influence tumor development and progression, immune evasion, and treatment resistance. Furthermore, we explore existing or evolving therapeutic approaches to recover/reprogram PLC functions such as IFN-γ-induced PLC activation, TAP1 and tapasin gene therapy, epigenetics-based treatments such as DNA methyltransferase inhibitors (DNMTi) and histone deacetylase inhibitors (HDACi), and microRNA targeting strategy.
Peptide-loading complex / MHC-I / Cancer immunotherapy / TAP / Tapasin / Calreticulin / ERp57 / β2-Microglobulin / Antigen processing
| [1] |
Janeway CA Jr, Travers P, Walport M, et al. The major histocompatibility complex and its functions. Immunobiology: The Immune System in Health and Disease. New York: Garland Science; 2001. |
| [2] |
|
| [3] |
|
| [4] |
|
| [5] |
|
| [6] |
|
| [7] |
|
| [8] |
|
| [9] |
|
| [10] |
|
| [11] |
|
| [12] |
|
| [13] |
|
| [14] |
|
| [15] |
|
| [16] |
|
| [17] |
|
| [18] |
|
| [19] |
Ferrington DA, Gregerson DS. Immunoproteasomes. The Proteasomal System in Aging and Disease. Amsterdam: Elsevier; 2012:75–112. |
| [20] |
|
| [21] |
|
| [22] |
|
| [23] |
|
| [24] |
|
| [25] |
|
| [26] |
|
| [27] |
|
| [28] |
|
| [29] |
|
| [30] |
|
| [31] |
|
| [32] |
|
| [33] |
|
| [34] |
|
| [35] |
|
| [36] |
|
| [37] |
|
| [38] |
|
| [39] |
|
| [40] |
|
| [41] |
|
| [42] |
|
| [43] |
|
| [44] |
|
| [45] |
|
| [46] |
|
| [47] |
|
| [48] |
|
| [49] |
|
| [50] |
|
| [51] |
|
| [52] |
|
| [53] |
|
| [54] |
|
| [55] |
|
| [56] |
|
| [57] |
|
| [58] |
|
| [59] |
|
| [60] |
|
| [61] |
|
| [62] |
|
| [63] |
|
| [64] |
|
| [65] |
|
| [66] |
|
| [67] |
|
| [68] |
|
| [69] |
|
| [70] |
|
| [71] |
|
| [72] |
|
| [73] |
|
| [74] |
|
| [75] |
|
| [76] |
|
| [77] |
|
| [78] |
|
| [79] |
|
| [80] |
|
| [81] |
|
| [82] |
|
| [83] |
|
| [84] |
|
| [85] |
|
| [86] |
|
| [87] |
|
| [88] |
|
| [89] |
|
| [90] |
|
| [91] |
|
| [92] |
|
| [93] |
|
| [94] |
|
| [95] |
|
| [96] |
|
| [97] |
|
| [98] |
|
| [99] |
|
| [100] |
|
| [101] |
|
| [102] |
|
| [103] |
|
| [104] |
|
| [105] |
|
| [106] |
|
| [107] |
|
| [108] |
|
| [109] |
|
| [110] |
|
| [111] |
|
| [112] |
|
| [113] |
|
| [114] |
|
| [115] |
|
| [116] |
|
| [117] |
|
| [118] |
|
| [119] |
|
| [120] |
|
| [121] |
|
| [122] |
|
| [123] |
|
| [124] |
|
| [125] |
|
| [126] |
|
| [127] |
|
| [128] |
|
| [129] |
|
| [130] |
|
| [131] |
|
| [132] |
|
| [133] |
|
| [134] |
|
| [135] |
|
| [136] |
|
| [137] |
|
| [138] |
|
| [139] |
|
| [140] |
|
| [141] |
|
| [142] |
|
| [143] |
|
| [144] |
|
| [145] |
|
| [146] |
|
| [147] |
|
| [148] |
|
| [149] |
|
| [150] |
|
| [151] |
|
| [152] |
|
| [153] |
|
| [154] |
|
| [155] |
|
| [156] |
|
| [157] |
|
| [158] |
|
| [159] |
|
| [160] |
Aptsiauri N, Cabrera T, Garcia-Lora A, et al. MHC class I antigens and immune surveillance in transformed cells. International Review of Cytology. Amsterdam: Elsevier; 2007:139–189. |
| [161] |
|
| [162] |
|
| [163] |
|
| [164] |
|
The Author(s), under exclusive licence to the Huazhong University of Science and Technology
/
| 〈 |
|
〉 |