Processed antigen binds to newly synthesized mhc class II molecules in antigen-specific B lymphocytes

TY - JOUR

T1 - Processed antigen binds to newly synthesized mhc class II molecules in antigen-specific B lymphocytes

AU - Davidson, Howard W.

AU - Reid, Pamela A.

AU - Lanzavecchia, Antonio

AU - Watts, Colin

N1 - Funding Information: We thank A. Sheppard and N. Fairweather for tetanus toxin, K. Guy for DA6.231 antibody, A. Sette and G. P. Corradin for peptides, and J. Kaufmann, P. Dellabona, S. Demotz, K. Karjalainen, and A. Living stone for helpful discussion and comments on the manuscript. This work was supported by the MRC and the Wellcome Trust. The Base1 Institute for Immunology was founded and is supported by Hoffmann La Roche.

PY - 1991/10/4

Y1 - 1991/10/4

N2 - We describe the direct detection of radiolabeled antigen fragments bound to class II MHC molecules following immunoglobulin-mediated endocytosis and processing of native antigen in B lymphoblastoid cells. Tris-Tricine SDS gels revealed six distinct iodinated processing products that could be detected on class II MHC 1 hr after antigen endocytosis and persisted for at least 20 hr. These physiological processed antigen-class II complexes were remarkably stable, as judged by the fact that class II a(3 dimers, which remain associated in SDS, became labeled with the same set of processed peptides. Using a lectin-binding assay, we show that these physiological processing products bind to the newly maturing population of MHC molecules rather than binding to the preexisting cell surface population; in contrast, an exogenous peptide binds predominantly to the latter population. A direct T cell-independent assay for processed peptide-MHC complex formation should facilitate additional studies on the exogenous antigen processing pathway.

AB - We describe the direct detection of radiolabeled antigen fragments bound to class II MHC molecules following immunoglobulin-mediated endocytosis and processing of native antigen in B lymphoblastoid cells. Tris-Tricine SDS gels revealed six distinct iodinated processing products that could be detected on class II MHC 1 hr after antigen endocytosis and persisted for at least 20 hr. These physiological processed antigen-class II complexes were remarkably stable, as judged by the fact that class II a(3 dimers, which remain associated in SDS, became labeled with the same set of processed peptides. Using a lectin-binding assay, we show that these physiological processing products bind to the newly maturing population of MHC molecules rather than binding to the preexisting cell surface population; in contrast, an exogenous peptide binds predominantly to the latter population. A direct T cell-independent assay for processed peptide-MHC complex formation should facilitate additional studies on the exogenous antigen processing pathway.

UR - https://www.scopus.com/pages/publications/0025939316

U2 - 10.1016/0092-8674(91)90575-J

DO - 10.1016/0092-8674(91)90575-J

M3 - Article

C2 - 1913812

AN - SCOPUS:0025939316

SN - 0092-8674

VL - 67

SP - 105

EP - 116

JO - Cell

JF - Cell

IS - 1

ER -