Cargando…

Efficient cell surface expression of class II MHC molecules in the absence of associated invariant chain

The intracytoplasmic forms of class II (or Ia) major histocompatibility complex heterodimers are associated with a third glycoprotein, termed the invariant chain (Ii). This specific interaction has led to the view that Ii plays a necessary role in the assembly, intracellular transport, and/or membra...

Descripción completa

Detalles Bibliográficos
Formato: Texto
Lenguaje:English
Publicado: The Rockefeller University Press 1986
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2188439/
https://www.ncbi.nlm.nih.gov/pubmed/3464691
_version_ 1782146408606859264
collection PubMed
description The intracytoplasmic forms of class II (or Ia) major histocompatibility complex heterodimers are associated with a third glycoprotein, termed the invariant chain (Ii). This specific interaction has led to the view that Ii plays a necessary role in the assembly, intracellular transport, and/or membrane insertion of Ia molecules. To test this hypothesis directly, we have transfected complementary DNA clones that encode murine class II alpha and beta chains into cells that do not express any endogenous Ii messenger RNA (mRNA) (COS-7 and BALB/c 3T3 cells). After DNA-mediated gene transfer, significant cell surface expression of Ia was observed in transient expression assays using COS- 7 cells and a stable expression system using BALB/c 3T3 cells. Furthermore, the total levels of class II alpha and beta mRNA were similar in Ii- cells (transfected BALB/c 3T3) and in Ii+ cells (B cell hybridoma) that expressed nearly identical amounts of surface Ia, suggesting that the efficiency of Ia expression was equivalent in the two cell types and, therefore, independent of Ii. These results indicate that the physiologic role for Ii is not simply to mediate membrane expression of Ia molecules, and that alternative hypotheses concerning the true function of this molecule need to be considered.
format Text
id pubmed-2188439
institution National Center for Biotechnology Information
language English
publishDate 1986
publisher The Rockefeller University Press
record_format MEDLINE/PubMed
spelling pubmed-21884392008-04-17 Efficient cell surface expression of class II MHC molecules in the absence of associated invariant chain J Exp Med Articles The intracytoplasmic forms of class II (or Ia) major histocompatibility complex heterodimers are associated with a third glycoprotein, termed the invariant chain (Ii). This specific interaction has led to the view that Ii plays a necessary role in the assembly, intracellular transport, and/or membrane insertion of Ia molecules. To test this hypothesis directly, we have transfected complementary DNA clones that encode murine class II alpha and beta chains into cells that do not express any endogenous Ii messenger RNA (mRNA) (COS-7 and BALB/c 3T3 cells). After DNA-mediated gene transfer, significant cell surface expression of Ia was observed in transient expression assays using COS- 7 cells and a stable expression system using BALB/c 3T3 cells. Furthermore, the total levels of class II alpha and beta mRNA were similar in Ii- cells (transfected BALB/c 3T3) and in Ii+ cells (B cell hybridoma) that expressed nearly identical amounts of surface Ia, suggesting that the efficiency of Ia expression was equivalent in the two cell types and, therefore, independent of Ii. These results indicate that the physiologic role for Ii is not simply to mediate membrane expression of Ia molecules, and that alternative hypotheses concerning the true function of this molecule need to be considered. The Rockefeller University Press 1986-11-01 /pmc/articles/PMC2188439/ /pubmed/3464691 Text en This article is distributed under the terms of an Attribution–Noncommercial–Share Alike–No Mirror Sites license for the first six months after the publication date (see http://www.rupress.org/terms). After six months it is available under a Creative Commons License (Attribution–Noncommercial–Share Alike 4.0 Unported license, as described at http://creativecommons.org/licenses/by-nc-sa/4.0/).
spellingShingle Articles
Efficient cell surface expression of class II MHC molecules in the absence of associated invariant chain
title Efficient cell surface expression of class II MHC molecules in the absence of associated invariant chain
title_full Efficient cell surface expression of class II MHC molecules in the absence of associated invariant chain
title_fullStr Efficient cell surface expression of class II MHC molecules in the absence of associated invariant chain
title_full_unstemmed Efficient cell surface expression of class II MHC molecules in the absence of associated invariant chain
title_short Efficient cell surface expression of class II MHC molecules in the absence of associated invariant chain
title_sort efficient cell surface expression of class ii mhc molecules in the absence of associated invariant chain
topic Articles
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2188439/
https://www.ncbi.nlm.nih.gov/pubmed/3464691