CD91: a receptor for heat shock protein gp96

RJ Binder, DK Han, PK Srivastava - Nature immunology, 2000 - nature.com
RJ Binder, DK Han, PK Srivastava
Nature immunology, 2000nature.com
Antigen presenting cells (APCs) can take up exogenous antigenic peptides chaperoned by
heat shock protein gp96 and re-present them through the endogenous pathway on their
major histocompatibility class I molecules. The high efficiency of this process has been
attributed previously to a receptor for gp96 on APCs. The CD91 molecule (also called α 2-
macroglobulin receptor or the low density lipoprotein–related protein) is shown here to be a
cell surface receptor for the heat shock protein gp96. CD91 binds gp96 directly, rather than …
Abstract
Antigen presenting cells (APCs) can take up exogenous antigenic peptides chaperoned by heat shock protein gp96 and re-present them through the endogenous pathway on their major histocompatibility class I molecules. The high efficiency of this process has been attributed previously to a receptor for gp96 on APCs. The CD91 molecule (also called α 2-macroglobulin receptor or the low density lipoprotein–related protein) is shown here to be a cell surface receptor for the heat shock protein gp96. CD91 binds gp96 directly, rather than through another ligand for CD91. The previously known CD91 ligand, α 2-macroglobulin, inhibits re-presentation of gp96-chaperoned antigenic peptides by macrophages, as do antibodies to CD91. As gp96 is exclusively intracellular and is released as a result of necrotic but not apoptotic cell death, we propose that CD91 acts as a sensor for necrotic cell death.
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