Submitted June 27, 2007
Returned for revision July 30, 2007
Accepted January 21, 2008
Pregnancy
Murine Maternal Cell Microchimerism: Analysis Using Real-Time PCR and In Vivo Imaging
Eric C. Su ,
Kirby L. Johnson ,
Hocine Tighiouart ,
and
Diana W. Bianchi *
* To whom correspondence should be addressed. E-mail: dbianchi{at}tufts-nemc.org.
Abstract
In humans, maternal cells are present in the affected tissues of children with inflammatory myopathy, scleroderma, and neonatal lupus. It is unknown if maternal cell microchimerism (MCM) contributes to the pathology of disease. We sought to understand the factors that affect MCM to serve as a baseline for future mechanistic studies. Using a mouse model, we bred female mice transgenic for the luciferase (Luc) reporter gene to wild type (WT) males. The WT offspring were sacrificed at various postnatal ages. DNA was extracted from multiple organs and real-time PCR amplification was used to quantify Luc transgene as a marker for maternally derived cells. Sensitivity was 1 to 2 transgenic cells per 100,000 WT cells. MCM was noted in 85% of mice and 45% of tissues assayed. The average quantity of MCM was 158 maternal cells per 100,000 neonatal cells. The organs displaying the highest frequency and quantity of MCM were heart and lung (P < 0.001). Postnatal age up to 21 days did not appear to affect levels of MCM (P = 0.47), whereas increasing parity may increase levels of MCM. The data show that MCM is a common occurrence in healthy newborn mice, is present in their major organs, and that there are organ specific differences. This may represent differential migration of maternal cells, or varying receptivity of specific fetal organs to microchimerism. Pregnancy history appears to play a role in maternal cell trafficking. The role of MCM in pregnancy and disease pathogenesis remains to be elucidated.
Key words:
Pregnancy •
maternal cell microchimerism •
materno-fetal trafficking •
real-time PCR
