Lipopolysaccharide (LPS) is a component of outer membrane of Gram-negative bacteria involved in post-partum metritis and endometritis in cattle. LPS causes inflammation of the endometrium. Increased cell proliferation is part of the inflammatory process and has been reported in human epithelial and immune cells and from bovine Endometrial epithelial Cells (bEEC). In this study we investigated possible changes in gene expression in relation with the proliferative response of bEEC after challenge with E. coli-LPS. Following In vitro culture, bEEC from 3 cows were exposed to 0, 2, and 8 μg/ml LPS for 24 hrs. For each time point and LPS dosage, attached cells were counted then frozen. The variation of cells number over time was analyzed by ANOVA (SAS 9.1, proc GLM). RNA was extracted by using the All prep DNA/RNA Universal kit (Qiagen). Samples were analyzed by RNA sequencing performed in SciLife Laboratory in Uppsala and differentially expressed genes (DEG) searched by using Ensemble genes as reference. A significant increase in cell number was observed for cells treated with 8 μg/ml LPS (P≤ 0.001) whereas proliferation with 2μg/ml was more moderate. Major changes in gene expression were observed whatever the dosage used. 2035 DEG were found (Benjamini-Hochberg adjusted P value <0.05) between controls and samples treated with 2μg/ml LPS. No DEG were found between 2 and 8μg/ml LPS treated samples. Gene ontology analysis shown that DEG were associated to Immune response and its regulation (up), response to stress and external stimuli (up), catalytic activity (up), anatomical structure and development especially cell membrane and adhesion (down) cell cycle (down) pathways. Interestingly specific genes in relation with allergy and immuno-tolerance were up and down regulated respectively. Complementary RNAseq analyzes will be performed on additional individuals together with epigenetic studies on associated methylation patterns.