Details

Autor(en) / Beteiligte

• Drake, James R
• Lewis, Timothy A
• Condon, Krista B
• Mitchell, Richard N
• Webster, Paul

Titel

Involvement of MIIC-Like Late Endosomes in B Cell Receptor-Mediated Antigen Processing in Murine B Cells

Ist Teil von

• The Journal of immunology (1950), 1999-01, Vol.162 (2), p.1150-1155

Ort / Verlag

United States: Am Assoc Immnol

Erscheinungsjahr

1999

Link zum Volltext

Quelle

EZB Electronic Journals Library

Beschreibungen/Notizen

• Currently, the involvement of classical vs novel endocytic compartments in the phenomenon of B cell receptor (BCR)-mediated Ag processing is a matter of considerable debate. In murine B cells, class II vesicles (CIIV) represent a novel endocytic compartment involved in BCR-mediated Ag processing and class II peptide loading. Alternatively, in human B cells, the MHC class II-enriched compartment (MIIC) represents a lysosome (L)-like endocytic compartment that appears to be involved in this process. Presently, the relationship between CIIV, MIIC, and classical endosomes and L remains to be determined. Using density gradient centrifugation, a subcellular compartment morphologically and immunologically similar to human MIIC has been identified, isolated, and characterized in murine B cells. These MIIC-like vesicles represent a population of class II-positive late endosomes (LE) and are distinct from CIIV. MIIC-like LE are uniquely marked by the thiol protease cathepsin B, and along with mature L, appear to be the major repository of DM molecules in these cells. Importantly, both MIIC-like LE and CIIV isolated from Ag-pulsed B cells contain BCR-internalized Ag as well as antigenic peptide-class II complexes.