Abstract: Objective To analyze the expression,tumor immunoinvasion and clinical value of Human leukocyte antigen(HLA) class II antigen DPB1 in Lung adenocarcinoma(LUAD) tissues. Methods Oncomine,TIMER,UALCAN,GEPIA and other databases were used to analyze the expression of HLA-DPB1 in LUAD patients,tumor immunoinvasion and its clinical value. Results HLA-DPB1 was low expressed in LUAD tissues,and its expression level was correlated with the clinicopathological characteristics and tumor protein 53(Tp53) mutation in LUAD patients(P<0.05).Further analysis showed that decreased HLA-DPB1 expression was significantly associated with poorer prognosis in patients with lung adenocarcinoma( P <0.005).The expression level of HLA-DPB1 was related to the purity of LUAD immunoinfiltrate,the level of immune cells(B cells,CD8+T cells,CD4+T cells,macrophages,dendritic cells and neutrophils) and their markers. Conclusion The expression level of HLA-DPB1 in LUAD tissues is decreased,and LUAD patients with elevated HLA-DPB1 expression tend to have a better prognosis.The low expression of HLA-DPB1 is associated with immunoinfiltrating cells in LUAD patients,suggesting that HLA-DPB1 is expected to be a prognostic biomarker and a potential target for immunotherapy in LUAD patients.

Key words: human leukocyte antigen-DPB1, lung adenocarcinoma, prognosis, immune infiltration, biomarker