Type 2 porcine reproductive and respiratory syndrome virus infection increases apoptosis at the maternal-fetal interface in late gestation pregnant gilts

• Author(s) / Creator(s)

  • Novakovic, Predrag
  • Harding, John C. S.
  • Al-Dissi, Ahmad N.
  • Detmer, Susan E.

• The pathogenesis of fetal death associated with porcine reproductive and respiratory syndrome
  (PRRS) is hypothesized to be a consequence of PRRS virus-induced apoptosis at
  the maternal-fetal interface (MFI). The objectives of this study were to evaluate distribution
  and degree of apoptosis in the uterine and fetal placental tissues during the experimental
  type 2 PRRS virus (PRRSV) infection and determine associations between apoptosis at the
  MFI, PRRSV RNA concentration and antigen staining intensity, PRRSV-induced microscopic
  lesions, and fetal preservation status. A total of 114 naïve, high-health pregnant gilts
  were inoculated with type 2 PRRSV on gestation day 85±1 with euthanasia 21 days later; 19
  sham-inoculated gilts served as controls. Two hundred and fifty samples of uterine tissue
  with fetal placenta were selected based on negative, low PRRSV RNA, and high PRRSV
  RNA concentration (0, < or > 2.7 log10 copies/mg, respectively). TUNEL assay was used to
  detect apoptosis in the endometrium and at the MFI. PRRSV RNA concentration and numbers
  of PRRSV immunopositive cells in uterine and placental tissue were positively associated
  with the severity of apoptosis in the endometrium and the MFI (P<0.001, P<0.05 and
  P<0.001, respectively). The number of TUNEL positive cells at the MFI was also positively
  associated with the severity (P<0.001) of vasculitis, but not total numbers of inflammatory
  cells in the endometrium. Increased numbers of TUNEL positive cells at the MFI were associated
  with PRRSV load in the fetal thymus, and greater odds of meconium staining of the
  fetus at 21 days post infection (P<0.001 for both). These findings suggest an important role
  of apoptosis in the pathogenesis of uterine epithelial and trophoblastic cell death at the MFI.
  Moreover, apoptosis at the MFI is significantly associated with fetal demise during in utero
  type 2 PRRSV infection.

• Date created

  2017-03-01

• Subjects / Keywords

  • Porcine reproductive and respiratory syndrome
  • PRRS Virus
  • Pork industry

• Type of Item

  Article (Published)

• DOI

  https://doi.org/10.7939/r3-q12w-dv87

• License

  Attribution-NonCommercial 4.0 International