Autoantibody to heat shock protein Hsp40 in sera of lung cancer patients.
Heat shock protein Hsp40 is a stress protein with chaperone activity and has a cooperative function with Hsp70 in mammalian cells. We examined the possible expression of Hsp40 in lung tumor tissues using immunoblotting and immunohistochemistry, and established an enzyme-linked immunosorbent assay (ELISA) method to detect IgG antibody to Hsp40 in the serum using purified human Hsp40. Sera were obtained from 130 normal subjects and 50 patients with lung cancer. Lung tumor tissues and cells specifically overexpressed Hsp40, and no such expression was detected in normal lung tissues. Compared with normal sera, significantly higher levels of autoantibody to Hsp40 were present in patients with lung cancer. The present study is the first to demonstrate overexpression of Hsp40 in human tumor tissue and the associated presence of autoantibody to Hsp40 in the serum. These results suggest that overexpression of Hsp40 in tumor cells may be recognized as a self-antigen.
Oka
M
M
Division of Molecular and Clinical Microbiology, Department of Molecular Microbiology and Immunology, Nagasaki University Graduate School of Medical Sciences, Nagasaki 852-8523, Japan. okamikio@net.nagasaki-u.ac.jp
Sato
S
S
Soda
H
H
Fukuda
M
M
Kawabata
S
S
Nakatomi
K
K
Shiozawa
K
K
Nakamura
Y
Y
Ohtsuka
K
K
Kohno
S
S
D000230:Adenocarcinoma / Q000473:pathology; D001323:Autoantibodies / Q000097:blood*; D018288:Carcinoma, Small Cell / Q000473:pathology; D002294:Carcinoma, Squamous Cell / Q000473:pathology; D004797:Enzyme-Linked Immunosorbent Assay; D050956:HSP40 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000032:analysis* / Q000276:immunology*; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007150:Immunohistochemistry; D008168:Lung / Q000276:immunology / Q000473:pathology; D008175:Lung Neoplasms / Q000097:blood / Q000276:immunology* / Q000473:pathology*; D012016:Reference Values
D001323:Autoantibodies; C494647:DNAJB1 protein, human; D050956:HSP40 Heat-Shock Proteins; D006360:Heat-Shock Proteins; D007074:Immunoglobulin G