A J Duclos1, E K Haddad, M G Baines. 1. Department of Microbiology and Immunology, McGill University, Montréal, Québec, Canada.
Abstract
PROBLEM: Even though our knowledge of the phenomenon at play at the fetoplacental interface has greatly advanced during the past years, a complete understanding of the reasons why the developing embryo is not rejected by maternal immune effector cells remains largely unknown. METHODS: We have used immunohistochemistry with the macrophage-specific markers F4/80 and MHC II to study the relationship between decidual infiltration and resorption in murine models of embryo loss between days 6 and 10 of gestation. RESULTS: Analysis of day 8 CBA/J x DBA/2 pregnancies has revealed 2 distinct populations of embryos. The majority (69.4%) expressed low levels of F4/80+ cells, but a minority (30.6%) expressed much higher level of the macrophage marker. In FBA/J x BALB/c, most embryos (91.7%) expressed low numbers of F4/80+ cells. As earlier experiments established that products of activated macrophages (TNF-alpha and nitric oxide) were implicated in embryo loss in this model, the activation status of the F4/80+ macrophages was assessed through the cell surface expression of MHC II. Again, a similar association was established: 30.6% of the CBA/J x DBA/2 embryos were infiltrated by significantly more MHC II+ cells than the control CBA/J x BALB/c mating. Finally, when coordinate expression of F4/80, MHC II and CD11b was assessed, it was found that an embryo significantly infiltrated by cells bearing one of the 3 markers was also heavily infiltrated by cells bearing the 2 other markers. CONCLUSIONS: This study has shown that the augmented infiltration of the deciduum with maternal macrophages is an early event which precedes spontaneous abortion of the early embryo.
PROBLEM: Even though our knowledge of the phenomenon at play at the fetoplacental interface has greatly advanced during the past years, a complete understanding of the reasons why the developing embryo is not rejected by maternal immune effector cells remains largely unknown. METHODS: We have used immunohistochemistry with the macrophage-specific markers F4/80 and MHC II to study the relationship between decidual infiltration and resorption in murine models of embryo loss between days 6 and 10 of gestation. RESULTS: Analysis of day 8 CBA/J x DBA/2 pregnancies has revealed 2 distinct populations of embryos. The majority (69.4%) expressed low levels of F4/80+ cells, but a minority (30.6%) expressed much higher level of the macrophage marker. In FBA/J x BALB/c, most embryos (91.7%) expressed low numbers of F4/80+ cells. As earlier experiments established that products of activated macrophages (TNF-alpha and nitric oxide) were implicated in embryo loss in this model, the activation status of the F4/80+ macrophages was assessed through the cell surface expression of MHC II. Again, a similar association was established: 30.6% of the CBA/J x DBA/2 embryos were infiltrated by significantly more MHC II+ cells than the control CBA/J x BALB/c mating. Finally, when coordinate expression of F4/80, MHC II and CD11b was assessed, it was found that an embryo significantly infiltrated by cells bearing one of the 3 markers was also heavily infiltrated by cells bearing the 2 other markers. CONCLUSIONS: This study has shown that the augmented infiltration of the deciduum with maternal macrophages is an early event which precedes spontaneous abortion of the early embryo.
Authors: Cheuk-Lun Lee; Eve Y F Lam; Kevin K W Lam; Hannu Koistinen; Markku Seppälä; Ernest H Y Ng; William S B Yeung; Philip C N Chiu Journal: J Biol Chem Date: 2012-09-12 Impact factor: 5.157
Authors: Thomas M Maynard; Deepak Gopalakrishna; Daniel W Meechan; Elizabeth M Paronett; Jason M Newbern; Anthony-Samuel LaMantia Journal: Hum Mol Genet Date: 2012-10-16 Impact factor: 6.150
Authors: G Chaouat; E Menu; B Mognetti; M Moussa; V Cayol; Y Mostefaoui; S Dubanchet; P Khadel; J L Voluménie; C B Rongiéres; G L Delage Journal: Infect Dis Obstet Gynecol Date: 1997