Bovine fetal microchimerism in normal and embryo transfer pregnancies and its implications for biotechnology applications in cattle

Fetal cells and DNA have been detected in the maternal circulation during and after pregnancy in a few mammalian species. The incidence of similar microchimerism in cattle could have repercussion for the application of modern biotechnologies such as the transfer of transgenic embryos. To determine if feto-maternal leakage can occur in pregnant cows, we have analyzed maternal blood samples for the presence of fetal DNA during gestation and post-partum periods. Y chromosome-specific DNA was detected in up to 73% of blood samples from naturally mated heifers carrying conventional bull calves and a transgene-specific sequence in up to 50% of recipient cows carrying transgenic fetuses. These findings document for the first time that transplacental leakage of fetal DNA into the maternal circulation can occur in cattle despite the epitheliochorial placenta of ruminants, with potential implications for the utilization of recipient cows in the food chain.     

性别与自身免疫性疾病

自身免疫性疾病在人群中感染率5-10%,具有明显的性别差异,女性患者显著高于男性,具体机制仍未研究清楚。研究发现,除了机体自身的遗传易感体质外,雌激素,微嵌合体和性染色体都与自身免疫性疾病发病有关。     

Male-origin microchimerism and endometrial cancer: A prospective case-cohort study

BackgroundMany women carry male cells of presumed fetal origin–so-called male-origin microchimerism (MOM)–in their circulation and tissues. Studies have found reduced risks of hormone dependent cancers, including breast and ovarian cancer, among MOM-positive women. The aim of this study was to investigate the association between MOM and endometrial cancer.MethodsWe designed a prospective case-cohort study including 76 cases and 505 controls from the Diet, Cancer and Health cohort aged 50–64 years and cancer-free at enrolment in 1993–1997. We analyzed blood samples for the presence of Y-chromosome (DYS14). We examined the association between MOM and endometrial cancer in weighted Cox regression models. As a negative control outcome, we studied the association between MOM and injuries to test for spurious associations.ResultsWe detected MOM in 65.9% controls and 54.0% cases. While we observed no overall association between MOM and endometrial cancer (HR=0.73, 95% CI: 0.47–1.15), we found a borderline significantly reduced rate of Type 1 endometrial cancer (HR=0.66, 95% CI: 0.39–1.00), but not other types of endometrial cancers (HR=1.00, 95% CI: 0.35–2.90). The reduced rate was not modified by hormonal exposure (P = 0.79). We found no association between MOM and risk of injuries (HR=0.96, 95% CI: 95% CI: 0.78–1.21).ConclusionsOur study suggests that MOM is inversely associated with Type 1 endometrial cancer, without evidence of an interaction with hormonal exposure. We encourage future research to confirm our findings.     

性别与自身免疫性疾病

自身免疫性疾病在人群中感染率5-10％,具有明显的性别差异,女性患者显著高于男性,具体机制仍未研究清楚。研究发现。除了机体自身的遗传易感体质外,雌激素,微嵌合体和性染色体都与自身免疫性疾病发病有关。     

Fetal cells in mother rats contribute to the remodeling of liver and kidney after injury

Fetal microchimerism indicates a mixture of cells of maternal and fetal origin seen in maternal tissues during and after pregnancy. Controversy exists about whether persistent fetal microchimerism is related with some autoimmune disorders occurring during and after pregnancy. In the current experiment, an animal model in which EGFP positive cells were taken as fetal-origin cells was designed to detect the fetal microchimerism in various maternal organs. Ethanol drinking and gentamicin injection were adopted to induce liver and kidney injury simultaneously. EGFP positive cells were engrafted not only in the maternal circulation and bone marrow, but also in the liver and kidney as hepatocytes and tubular cells, respectively. These results indicate that fetal cells are engrafted to maternal hematopoietic system without apparent injury and they also contribute to the repairing process of maternal liver and kidney.     

The postnatal maternal environment affects autoimmune disease susceptibility in A/J mice

The postnatal maternal environment is known to increase susceptibility to a number of autoimmune diseases. Here we asked whether the postnatal maternal environment could influence autoimmune disease development to day 3 thymectomy (d3tx)-induced autoimmune ovarian disease (AOD) and experimental allergic encephalomyelitis (EAE) in cross-fostered A/J and B6 mice. A/J pups foster-nursed by B6 mothers exhibit an increase in autoimmune disease development while cross-fostering B6 pups on A/J mothers did not alter their susceptibility. The increase in AOD incidence seen in foster-nursed d3tx A/J mice correlated with a decrease in the total number of CD4⁺ T cells in the lymph nodes of these animals. Analysis of the cellular composition in the milk revealed that B6 mice shed significantly more maternally derived lymphocytes into their milk compared to A/J mothers. These data suggest that there are maternally derived postnatal factors that influence the development of autoimmune disease in A/J mice.