Cutting edge: heat shock protein gp96 induces maturation and migration of CD11c+ cells in vivo.

Immunization of mice with the heat shock protein (HSP) gp96 but not control proteins leads to 5- to 7-fold enlargement of draining lymph nodes (LNs) resulting from accumulation of large numbers of mature CD11c(+) cells, but not T or B lymphocytes in them. The increase in size and cellularity is time-dependent; the draining LNs reach their peak size between 12 and 24 h after injection and regress to their normal size between 48 and 72 h after injection. The increment is elicited specifically in the draining LN but not in other LNs. This observation uncovers a novel aspect of HSP-APC interaction and adds to the mechanistic explanation for the unusually high immunogenicity of HSP-peptide complexes.