Helper T cells are stimulated to fight infections or diseases upon recognition of peptides from antigens that are processed and presented by the proteins of Major Histocompatibility Complex (MHC) Class II molecules. Degradation of a full protein into small peptide fragments is a lengthy process consisting of many steps and chaperones. Malfunctions during any step of antigen processing could lead to the development of self-reactive T cells or defective immune response to pathogens. Although much has been accomplished regarding how antigens are processed and presented to T cells, many questions still remain unanswered, preventing the design of therapeutics for direct intervention with antigen processing. Here, we review published work on the discovery and function of a MHC class II molecular chaperone, HLA-DO, in human, and its mouse analog H2-O, herein called DO. While DO was originally discovered decades ago, elucidating its function has proven challenging. DO was discovered in association with another chaperone HLA-DM (DM) but unlike DM, its distribution is more tissue specific, and its function more subtle.
Keywords: HLA-DO, HLA-DR antigens, MHC class II antigen processing, models for HLA-DO function, HLA-DM
Citation: Poluektov YO, Kim A and Sadegh-Nasseri S (2013) HLA-DO and its role in MHC class II antigen presentation. Front. Immunol. 4:260. doi: 10.3389/fimmu.2013.00260
Received: 31 July 2013; Accepted: 15 August 2013;
Published online: 29 August 2013.
Edited by:Laura Santambrogio, Albert Einstein College of Medicine, USA
Reviewed by:Edda Fiebiger, Children’s Hospital Boston and Harvard Medical School, USA
Copyright: © 2013 Poluektov, Kim and Sadegh-Nasseri. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
*Correspondence: Scheherazade Sadegh-Nasseri, Johns Hopkins University School of Medicine, 720 Rutland Avenue, Ross Building, Room 664C, Baltimore, MD 21205, USA e-mail: email@example.com