TY - JOUR
T1 - Endogenous MHC-related protein 1 is transiently expressed on the plasma membrane in a conformation that activates mucosal-associated invariant T cells
AU - Chua, Wei Jen
AU - Kim, Sojung
AU - Myers, Nancy
AU - Huang, Shouxiong
AU - Yu, Lawrence
AU - Fremont, Daved H.
AU - Diamond, Michael S.
AU - Hansen, Ted H.
PY - 2011/4/15
Y1 - 2011/4/15
N2 - The development of mucosal-associated invariant T (MAIT) cells is dependent upon the class Ib molecule MHC-related protein 1 (MR1), commensal bacteria, and a thymus. Furthermore, recent studies have implicated MR1 presentation to MAIT cells in bacteria recognition, although the mechanism remains undefined. Surprisingly, however, surface expression of MR1 has been difficult to detect serologically, despite ubiquitous detection of MR1 transcripts and intracellular protein. In this article, we define a unique mAb capable of stabilizing endogenous mouse MR1 at the cell surface, resulting in enhanced mouse MAIT cell activation. Our results demonstrated that under basal conditions, endogenous MR1 transiently visits the cell surface, thus reconciling the aforementioned serologic and functional studies. Furthermore, using this approach, double-positive thymocytes, macrophages, and dendritic cells were identified as potential APCs for MAIT cell development and activation. Based on this pattern of MR1 expression, it is intriguing to speculate that constitutive expression of MR1 may be detrimental for maintenance of immune homeostasis in the gut and/or detection of pathogenic bacteria in mucosal tissues.
AB - The development of mucosal-associated invariant T (MAIT) cells is dependent upon the class Ib molecule MHC-related protein 1 (MR1), commensal bacteria, and a thymus. Furthermore, recent studies have implicated MR1 presentation to MAIT cells in bacteria recognition, although the mechanism remains undefined. Surprisingly, however, surface expression of MR1 has been difficult to detect serologically, despite ubiquitous detection of MR1 transcripts and intracellular protein. In this article, we define a unique mAb capable of stabilizing endogenous mouse MR1 at the cell surface, resulting in enhanced mouse MAIT cell activation. Our results demonstrated that under basal conditions, endogenous MR1 transiently visits the cell surface, thus reconciling the aforementioned serologic and functional studies. Furthermore, using this approach, double-positive thymocytes, macrophages, and dendritic cells were identified as potential APCs for MAIT cell development and activation. Based on this pattern of MR1 expression, it is intriguing to speculate that constitutive expression of MR1 may be detrimental for maintenance of immune homeostasis in the gut and/or detection of pathogenic bacteria in mucosal tissues.
UR - http://www.scopus.com/inward/record.url?scp=79954985832&partnerID=8YFLogxK
U2 - 10.4049/jimmunol.1003254
DO - 10.4049/jimmunol.1003254
M3 - Article
C2 - 21402896
AN - SCOPUS:79954985832
SN - 0022-1767
VL - 186
SP - 4744
EP - 4750
JO - Journal of Immunology
JF - Journal of Immunology
IS - 8
ER -