Leptospirosis causes abortion, premature birth, and stillbirth in cattle, but the mechanisms remain unclear. Infected cattle shed Leptospira intermittently and present a range of clinical symptoms, making diagnosis difficult. The primary route of Leptospira transmission in any animal is colonization of the renal tubule and excretion by urine, however Leptospira can also colonize the female reproductive tract of cows and can be transmitted by semen. Vaccination against Leptospira in the United States is routine in cattle, but immunity is not guaranteed. The cell wall of Leptospira contains Toll-like receptor agonists including peptidoglycan and lipopolysaccharide. The capacity of Leptospira to initiate an innate inflammatory response from uterine endometrial cells is unknown but may be a cause of reproductive failure. Using cell culture, we tested the capacity of bovine endometrial epithelial cells or human monocytes to elicit an inflammatory response to Leptospira borgpetersenii serovar Hardjo strain TC273. Cells were exposed to either heat-killed Leptospira, Leptospira outer membrane, Escherichia coli lipopolysaccharide, Pam3CSK4 or medium alone for 2 to 24 hours. Exposure of bovine endometrial epithelial cells or human monocytes to heat-killed Leptospira or Leptospira outer membrane did not induce the expression of IL1A, IL1B, IL6 or CXCL8, while exposure to E. coli lipopolysaccharide or Pam3CSK4 increased expression of IL1A, IL1B, IL6 and CXCL8 compared to control cells. This data suggests that Leptospira does not trigger a classical inflammatory response in endometrial cells. Understanding the interaction between Leptospira and the female reproductive tract is important in determining the mechanisms of Leptospirosis associated reproductive failure.
Bovine Endometrial Epithelial Cells Scale Their Pro-inflammatory Response In vitro to Pathogenic Trueperella pyogenes Isolated from the Bovine Uterus in a Strain-Specific Manner
