Cellular sources of interleukin 16 in benign and malignant pleural effusions

• Published in: Chinese medical journal Vol. 124; no. 24; pp. 4160 - 4165
• Main Authors: Li, Jian-Jun, Wei, Wei, Shi, Huan-Zhong, Li, Ying-Xin, Mo, Wu-Ning
• Format: Journal Article
• Language: English
• Published: China Department of AIDS/STD, Guangxi Center for Disease Control and Prevention, Nanning, Guangxi 530028, China%First Affiliated Hospital to Guangxi College of Traditional Chinese Medicine, Nanning, Guangxi530028, China%Department of Respiratory Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology,Wuhan, Hubei 430022, China%Laboratory Center, Pharmaceutical College of Guangxi Medical University, Nanning, Guangxi 530021, China(%Laboratory Center, First Affiliated Hospital, Guangxi Medical University, Nanning, Guangxi 530021, China 20-12-2011
• Subjects: Adult; Aged; Aged, 80 and over; Antigens, CD19 - metabolism; CD19; CD4-Positive T-Lymphocytes - metabolism; CD8-Positive T-Lymphocytes - metabolism; Cells, Cultured; Centrifugation, Density Gradient; ELISA法; Enzyme-Linked Immunosorbent Assay; Female; Flow Cytometry; Humans; IL-16; Immunohistochemistry; Interleukin-16 - metabolism; Lipopolysaccharide Receptors - metabolism; Male; Middle Aged; Pleural Effusion, Malignant - metabolism; T-Lymphocytes - metabolism; Young Adult; 免疫组化法; 白细胞介素; 细胞分泌; 细胞来源; 胸腔积液; flow cytometry; immunohistochemistry; interleukin 16; pleural disease
• ISSN: 0366-6999; 2542-5641
• DOI: 10.3760/cma.j.issn.0366-6999.2011.24.008

Background Interleukin 16 （IL-16） can be detected by ELISA in pleural effusion （PE） and its concentration is higher than in serum. This study investigated the cellular sources of IL-16 in PE.
Methods The samples of PE were collected from 34 patients who were newly diagnosed having PE in the pleural cavity We performed cell culture to purify the pleural mesothelial cells （PMC）, Wright staining to count the purity and immunocytochemical stain to identify the cultured cells. The intracellular IL-16 expression was detected by flow cytometry （FCM）. The different cells in PE were first separated by magnetic cell sorting （MCAS） then the separated cells were cultured in RPMI1640 with 10% fetal calf serum （FCS）. We extracted the supernatant and detected IL-16 concentration by ELISA. The IL-16 protein was detected by immunohistochemistry and double immunofluorescence staining. Results The percentages of cells which secreted IL-16 were： CD3^＋CD8^- cells （（74.27±15.56）%, n=34）; CD3^＋CD8^＋ cells （（69.86±18.55）%, n=34）; CD19^＋ cells （（45.30±18.77）%, n=15）; CD14^＋ cells （（16.91＋16.69）%, n=15）; and PMC （（2.05±1.85）%, n=7）. The concentrations of IL-16 in the supernatant from cultured cells were： CD4^＋ cells （（102.50±42.51） ng/L, n=5）; CD8^＋ cells （（92.58±18.34） ng/L, n=5）; CD19^＋ cells （（79.85±5.62） ng/L, n=5）; CD14^＋ cells （（58.51±25.38） ng/L, n=5）; and PMC （（18.14±8.37） ng/L, n=5）. In lymphocytes, monocytes/macrophages and PMC, we could observe the cells that expressed IL-16 protein. In paraffin-embedded sections, we also could observe by immunohistochemistry the CD4^＋I L-16^＋ cells, CD8^＋IL-16^＋ cells, CD19^＋IL-16^＋ cells, and CD14^＋IL-16^＋ cells.
Conclusions IL-16 in PE is mainly secreted by T lymphocytes, including CD3^＋CD8^- cells and CD^3＋CD^8＋ cells. CD19^＋ cells and CD14^＋ cells can also secrete IL-16, but the percentage of PMC that can secrete IL-16 is very low.