Background <p>For lung adenocarcinoma (LUAD), which has the highest mortality rate among cancers, the current known immunotherapy has only achieved limited results. This article aimed to clarify the novel immune escape mechanism in LUAD based on the long non-coding RNA (lncRNA)-microRNA (miRNA) network.</p> Methods <p>By bioinformatics analysis, the expression of B4GALT1-AS1 and miR-144-3p was determined and the binding sites were predicted. RNA immunoprecipitation assay, dual-luciferase assay, and RNA pull-down experiment were employed to validate their binding. Quantitative reverse transcription polymerase chain reaction was utilized to measure the expression levels. LUAD cell proliferation and cell cycle progression were detected by Colony formation assay and cell cycle analysis. Cell migration and invasion were detected by Transwell assay. A co-culture system evaluated the proportion of IFN-γ positive CD8⁺ T cells, the cytotoxicity of CD8⁺ T cells, and cytokines secretion. The expression of programmed death-ligand 1 (PD-L1) was detected by western blot.</p> Results <p>In LUAD, B4GALT1-AS1 was highly expressed, while miR-144-3p was lowly expressed. B4GALT1-AS1 facilitated LC cell proliferation, migration, invasion, inhibited CD8⁺ T cell toxicity, and promoted immune escape. Furthermore, B4GALT1-AS1 functioned as a molecular sponge for miR-144-3p. Rescue experiments revealed that overexpression of B4GALT1-AS1 up-regulated the expression of PD-L1, and overexpression of miR-144-3p partially attenuated the promoting impact of B4GALT1-AS1 overexpression on LUAD cell proliferation, migration, invasion, and immune escape.</p> Conclusion <p>This study demonstrated that the B4GALT1-AS1/miR-144-3p axis suppressed the cytotoxicity of CD8⁺ T cells in LUAD by modulating the expression of PD-L1, which will assist in innovating new immunotherapies.</p>