infection specifically suppresses the expression of a host lncRNA to facilitate parasite propagation by modulating host cell mitochondrial function and autophagy.

is one of the most common pathogens causing reproductive failure in ruminants (e.g., cattle and goats) worldwide. However, due to a poor understanding of the pathogenic mechanisms of infection, no effective drugs and vaccines are currently available. Long non-coding RNAs (lncRNAs) have been reported to be important regulators involved in a great number of physiological and pathological processes. Our previous study found that infection induced significantly aberrant expression of lncRNA profiles in caprine endometrial epithelial cells (EECs). In the present study, we found that infection specifically suppressed the expression of a novel lncRNA, , and knockdown of with small interfering RNA significantly promoted the propagation of in caprine EECs. Rapid amplification of cDNA ends analysis generated six splice variants of , with lengths ranging from 592 to 694 nt. Transfection of the full length of each variant markedly inhibited the propagation of in caprine EECs. Further study suggested that acted as a sponge of Chi-miR-93-5p to promote the expression of , and the /Chi-miR-93-5p/ axis significantly delayed the growth of in caprine EECs by regulating host cell mitochondrial function and autophagy. Our findings provide a novel insight to understand the interactions between and host cells.IMPORTANCEThe uterus is an indispensable reproductive organ for embryo implantation and fetal growth. The endometrium is more vulnerable to infection by pathogenic microorganisms resulting in an increased risk of miscarriage. is one of the most common pathogens causing miscarriage in ruminants and is able to naturally inhabit the uterus, with tissue cysts found in the endometrium. Recent advances in research have revealed aberrant expression of long non-coding RNA (lncRNA) profiles in infected caprine endometrial epithelial cells. In the present study, , but not which has similar morphological and biological features to , specifically suppresses the expression of a host lncRNA, , to impair host's defense through the competitive endogenous RNA mechanism to modulate the host cell mitochondrial function and autophagy to facilitate parasite propagation. The findings suggest a novel immune evasion strategy of to facilitate intracellular propagation and provide an alternative path to develop control strategies against neosporosis.