Expression of Ig-like transcript 4 inhibitory receptor in human non-small cell lung cancer.
BACKGROUND
Human Ig-like transcript 4 (ILT-4) is a member of the inhibitory receptor family for immune function. Little is known about the expression levels of ILT-4 in tumor cells.


METHODS
We have studied the expression levels of ILT-4 both in vitro in cancer cell lines and in vivo in tumor tissues from 70 patients with non-small cell lung cancer (NSCLC) by reverse transcriptase-polymerase chain reaction, fluorescence-activated cell sorting, and immunohistochemical analysis.


RESULTS
Three cancer cell lines (H1299, A549, and U1810) express ILT-4 messenger RNA, and only two cell lines (H1299 and A549) express ILT-4 protein on the cell surface. Approximately 37.1% of 70 tumor tissue samples express ILT-4, which is localized in the cell membrane and cytoplasm. In addition, tumor cells and stromal and plasma cells also express ILT-4. The number of infiltrating lymphoid cells in the tumor tissues that express B7-H3 was much lower than those that did not, but there is no significant correlation between ILT-4 expression and disease progression including nodal metastasis.


CONCLUSIONS
These findings suggest that ILT-4 is frequently expressed in both tumor and stromal cells of NSCLC, and it might play an important role in regulation of the host immune system.
Sun
Yuping
Y
Jinan Central Hospital, Shandong University, Jinan, People's Republic of China. Electronic address: sunyupingsyp@hotmail.com.
Liu
Jie
J
Jinan Central Hospital, Shandong University, Jinan, People's Republic of China.
Gao
Ping
P
Jinan Central Hospital, Shandong University, Jinan, People's Republic of China.
Wang
Yunshan
Y
Jinan Central Hospital, Shandong University, Jinan, People's Republic of China.
Liu
Chuanyong
C
Jinan Central Hospital, Shandong University, Jinan, People's Republic of China.
D000368:Aged; D002289:Carcinoma, Non-Small-Cell Lung / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D045744:Cell Line, Tumor; D015331:Cohort Studies; D005260:Female; D006801:Humans; D017493:Leukocyte Common Antigens / Q000378:metabolism; D008175:Lung Neoplasms / Q000276:immunology / Q000378:metabolism* / Q000473:pathology; D016246:Lymphocytes, Tumor-Infiltrating / Q000502:physiology; D008297:Male; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism*; D008875:Middle Aged; D009367:Neoplasm Staging; D012333:RNA, Messenger / Q000378:metabolism; D011971:Receptors, Immunologic / Q000235:genetics / Q000378:metabolism*
C491341:LILRB2 protein, human; D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D011971:Receptors, Immunologic; D017493:Leukocyte Common Antigens