Objective: To investigate the role of CXCL5 in tumor immune of lung cancer and to explore the potential molecular mechanisms. Methods: A total of 62 cases of patients with lung cancer admitted in the First Affiliated Hospital of Henan University from May 2018 to December 2019 were recruited as study object. Another 20 cases of patients with pulmonary infectious diseases and 20 cases of healthy control were selected as control. Enzyme-linked immunosorbent assay (ELISA) was used to determine serum levels of CXCL5 in patients with lung cancer, pulmonary infectious diseases and healthy control. Immunohistochemical staining (IHC) was used to detect the expressions of CXCL5 and PD-1/PD-L1 in tumor and paracarcinoma tissues of patients with lung cancer. Pearson correlation analysis was used to evaluate the correlation between CXCL5 and PD-1 in tumor and paracarcinoma tissues of patients with lung cancer. Lewis cells either expressing CXCL5 or vector plasmids were used to establish C57BL/6J mice model of lung cancer, and all mice were then divided into vehicle and PD-1 antibody treatment groups, 10 mice for each group. The mice survival and tumor growth curves were recorded. IHC was used to evaluate the expressions of CXCL5, PD-1 as well as the proportions of CD8(+) T and Treg cells in xenograft tumor tissues. Results: In patients with lung cancer, the serum level of CXCL5 [(351.7±51.5) ng/L] was significant higher than that in patients with pulmonary infectious diseases and healthy control [(124.7±23.4) ng/L, P<0.001]. The expression levels of CXCL5 (0.136±0.034), CXCR2 (0.255±0.050), PD-1 (0.054±0.012) and PD-L1 (0.350±0.084) in tumor were significant higher than those in paracarcinoma normal tissues [(0.074±0.022), (0.112±0.023), (0.041±0.007) and (0.270±0.043) respectively, P<0.001]. CXCL5 was significant positively correlated with PD-1 in tumor tissues of lung cancer (r=0.643, P<0.001), but not correlated with PD-1 in paracarcinoma tissues(r=0.088, P=0.496). The vector control group, CXCL5 overexpression group, vector control + anti-PD-1 antibody treatment group and CXCL5 overexpression + anti-PD-1 antibody treatment group all successfully formed tumors in mice, while CXCL5 overexpression increased the tumor growth significantly (P<0.01), which was abrogated by the treatment of anti-PD-1 antibody. CXCL5 overexpression decreased the mice survival time significantly (P<0.01), this effect was also abrogated by the treatment of anti-PD-1 antibody. The proportion of CD8(+) T cells in CXCL5 overexpression group [(10.40±2.00)%] was significant lower than that in vector control group [(21.20±3.30)%, P=0.002]. The proportion of CD4(+) Foxp3(+) Treg cells in CXCL5 overexpression group [(38.40±3.70)%] was significant higher than that in vector control group [(23.30±2.25)%, P<0.001]. After the treatment of anti-PD-1 antibody, no significant difference were observed for the proportion of CD8(+) T cells [(34.10±5.00)% and (33.40±4.00)% respectively] and Treg cells [(14.70±3.50)% and (14.50±3.30)% respectively] in xenograft tumor tissues between CXCL5 overexpression+ anti-PD-1 antibody treatment group and vector control + anti-PD-1 antibody treatment group (P>0.05). Conclusion: The expressions of CXCL5 and PD-1/PD-L1 are all increased significantly in the tumor tissues of patients with lung cancer, CXCL5 may inhibit tumor immune of lung cancer via modulating PD-1/PD-L1 signaling.
Animals ; B7-H1 Antigen/metabolism* ; CD8-Positive T-Lymphocytes ; Chemokine CXCL5/metabolism* ; Humans ; Lung Neoplasms/pathology* ; Mice ; Mice, Inbred C57BL ; Programmed Cell Death 1 Receptor/metabolism*

Granulocyte colony stimulating factor (G-CSF) restores neutrophil count in patients with chemotherapy-induced neutropenia. G-CSF can also induce production of epithelial neutrophil activating protein-78 (ENA-78) and interleukin-8 (IL-8), chemotactic factors from neutrophils in vitro. This study was purposed to investigate whether this effect is also observed in vivo. 10 lymphoma patients were selected who received chemotherapy and G-CSF (nartograstim) administration. Blood was obtained before chemotherapy [Time Point 1 (TP1)], at neutropenic phase before G-CSF administration (TP2), and at neutrophil recovery phase after G-CSF (TP3). ENA-78 and IL-8 mRNA in neutrophils were quantified by real-time PCR. Phagocytosis and reactive oxygen species (ROS) generation were examined by flow cytometry. The results showed that ENA-78 and IL-8 mRNA expression at TP2 increased in 5 and 8 patients, respectively. The ENA-78 mRNA expression at TP3 was increased in 3 and decreased in 6 patients, and IL-8 mRNA expression at TP3 decreased in 7 patients. G-CSF did not affect phagocytosis and normalized ROS generation in all of the patient. It is concluded that increase of ENA-78 and IL-8 expression in neutrophils is common in chemotherapy-induced neutropenic patients. G-CSF administration does not significantly increase ENA-78 and IL-8 expression.
Adult ; Aged ; Antineoplastic Combined Chemotherapy Protocols ; adverse effects ; Chemokine CXCL5 ; metabolism ; Female ; Granulocyte-Macrophage Colony-Stimulating Factor ; pharmacology ; Humans ; Interleukin-8 ; metabolism ; Lymphoma ; metabolism ; Male ; Middle Aged ; Neutropenia ; chemically induced ; metabolism ; Neutrophils ; drug effects ; metabolism ; RNA, Messenger ; genetics