Analysis of maternal microchimerism in rhesus monkeys (Macaca mulatta) using real-time quantitative PCR amplification of MHC polymorphisms.
Although pregnancy-associated microchimerism is known to exist in humans, its clinical significance remains unclear. Fetal microchimerism has been documented in rhesus monkeys, but the trafficking and persistence of maternal cells in the monkey fetus and infant have not been fully explored. To investigate the frequency of maternal microchimerism in the rhesus monkey (Macaca mulatta), a real-time polymerase chain reaction (PCR) strategy was developed and validated to target polymorphic major histocompatibility complex (MHC) gene sequences. Informative PCR assays were identified for 19 of 25 dams and their respective offspring. Analyses were performed on tissues (thymus, liver, spleen, lymph nodes, and bone marrow) and peripheral blood mononuclear cells (PBMCs) collected prenatally and postnatally in a subset of animals. Seven of 19 monkeys had detectable maternal microchimerism in at least one compartment (range: 0.001-1.9% chimeric cells). In tissues, maternal microchimerism was found in 2 of 7 fetuses and 3 of 12 juveniles (1-1.5 years of age), and most of the animals that were positive had microchimeric cells in more than one tissue. Maternal microchimerism was detected in PBMCs from all (4 of 4) fetuses. These observations suggest that maternal microchimerism occurs in the rhesus monkey fetus and can be detected in tissues in a subset of offspring after birth.
Blood Systems Research Institute; San Francisco, CA USA.
Sonia
S
Bakkour
Division of Experimental Medicine; Department of Medicine; University of California San Francisco; San Francisco, CA USA.
Chris A R
CA
Baker
California National Primate Research Center; Departments of Pediatrics and Cell Biology and Human Anatomy; University of California Davis; Davis, CA USA.
Alice F
AF
Tarantal
Blood Systems Research Institute; San Francisco, CA USA.
Li
L
Wen
Blood Systems Research Institute; San Francisco, CA USA.
Michael P
MP
Busch
Blood Systems Research Institute; San Francisco, CA USA.
Tzong-Hae
TH
Lee
Division of Experimental Medicine; Department of Medicine; University of California San Francisco; San Francisco, CA USA.
Joseph M
JM
McCune
D000818:Animals; D002678:Chimera / Q000235:genetics*; D005260:Female; D005805:Genes, MHC Class I; D007963:Leukocytes, Mononuclear / Q000378:metabolism; D008253:Macaca mulatta / Q000235:genetics*; D008431:Maternal-Fetal Exchange; D011110:Polymorphism, Genetic; D011247:Pregnancy; D060888:Real-Time Polymerase Chain Reaction; D015203:Reproducibility of Results
major histocompatibility complex; microchimerism; quantitative PCR; rhesus monkey; transplacental transfer