P-glycoprotein plays an insignificant role in the presentation of antigenic peptides to CD8+ T cells.
نویسندگان
چکیده
Most antigenic peptides presented to CD8+ T cells are generated from cytosolic precursors and are translocated by TAP into the endoplasmic reticulum, where they associate with MHC class I molecules. TAP-deficient cells exhibit a limited capacity to deliver peptides from cytosolic proteins to class I molecules. One candidate for an alternative peptide transporter is P-glycoprotein, which transports numerous substances, including peptides, across membranes. Elevation of P-glycoprotein expression is partially responsible for the resistance developed by neoplasias to chemotherapeutic drugs. Overexpression of P-glycoprotein has been reported to enhance the expression of class I molecules. Here, we investigated the role of P-glycoprotein in the generation of peptide-MHC complexes. We were unable to detect P-glycoprotein-mediated transport of synthetic peptides into the endoplasmic reticulum of either T2 cells (TAP-deficient) infected with a recombinant vaccinia virus (rVV) expressing P-glycoprotein or drug-resistant cells in which TAP is inactivated by a peptide from the herpes simplex virus ICP47 protein. Expression of rVV-encoded P-glycoprotein in T2 cells was unable to enhance cell surface expression of any of three MHC class I allomorphs tested. rVV-mediated expression of P-glycoprotein enabled T2 cells to produce limited amounts of class I-peptide complexes from cytosolic antigens, but this was not blocked by a drug that inhibits its transporter function, and a similar degree of presentation was mediated by functionally inactive mutated forms of P-glycoprotein. Thus, this was a nonspecific effect that we attributed to diminished membrane integrity resulting from P-glycoprotein overexpression. Taken together, our findings cast serious doubts that P-glycoprotein is a biologically significant transporter of cytosolic peptides.
منابع مشابه
Islet Amyloid Polypeptide is not a Target Antigen for CD8+ T-Cells in Type 2 Diabetes
Background: Type 2 diabetes (T2D) is a chronic metabolic disorder in which beta-cells are destroyed. The islet amyloid polypeptide (IAPP) produced by beta-cells has been reported to influence beta-cell destruction. Objective: To evaluate if IAPP can act as an autoantigen and therefore, to see if CD8 + T-cells specific for this protein might be present in T2D patients. Methods: Peripheral blood ...
متن کاملMHC Class I Antigen Presentation of DRiP-Derived Peptides from a Model Antigen Is Not Dependent on the AAA ATPase p97
CD8(+) T cells are responsible for killing cells of the body that have become infected or oncogenically transformed. In order to do so, effector CD8(+) T cells must recognize their cognate antigenic peptide bound to a MHC class I molecule that has been directly presented by the target cell. Due to the rapid nature of antigen presentation, it is believed that antigenic peptides are derived from ...
متن کاملAn Investigation into the Role of P-Glycoprotein in the Intestinal Absorption of Repaglinide: Assessed by Everted Gut Sac and Caco-2 Cell Line
The present study aimed at exploring the potential of the P-glycoprotein (P-gp) transporters as a barrier to the repaglinide (REG) epithelial permeability. In-vitro intestinal absorption models, the everted gut sac, and Caco-2 cell line, were used to study the possible role of P-gp in intestinal transport of REG. In the everted gut sacs, apparent permeability coefficients showed cargo concentra...
متن کاملAn Investigation into the Role of P-Glycoprotein in the Intestinal Absorption of Repaglinide: Assessed by Everted Gut Sac and Caco-2 Cell Line
The present study aimed at exploring the potential of the P-glycoprotein (P-gp) transporters as a barrier to the repaglinide (REG) epithelial permeability. In-vitro intestinal absorption models, the everted gut sac, and Caco-2 cell line, were used to study the possible role of P-gp in intestinal transport of REG. In the everted gut sacs, apparent permeability coefficients showed cargo concentra...
متن کاملP 28: Bone Marrow-Derived Mesenchymal Stem Cells Reduces Neuroinflammation and Splenic Cytolytic CD8 + T Cells in Mice with Experimental Autoimmune Encephalomyelitis
Introduction: Multiple sclerosis (MS) has been recognized as a common neurodegenerative disease that occurs after an Auto reactive T cells against myelin antigens. Demyelination and inflammation are the main features of this disease. The anti-inflammatory and neuroprotective roles of bone marrow-derived mesenchymal stem cells (BM-MSCs) have been considered as a suitable tre...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Cancer research
دوره 58 20 شماره
صفحات -
تاریخ انتشار 1998