[Maternal-fetal cytomegalovirus infection : experience in Liege and new antenatal screening and care strategy].

Summmary : In Belgium, as in most developed countries, routine antenatal screening for cytomegalovirus (CMV) remains controversial and is not recommended. However, 1-2 % of seronegative pregnant women will develop a primary infection during pregnancy and, with a prevalence of 0.7 % of live births, CMV is the leading cause of congenital infection.

The histone methyltransferase activity of MLL1 is dispensable for hematopoiesis and leukemogenesis.

Despite correlations between histone methyltransferase (HMT) activity and gene regulation, direct evidence that HMT activity is responsible for gene activation is sparse. We address the role of the HMT activity for MLL1, a histone H3 lysine 4 (H3K4) methyltransferase critical for maintaining hematopoietic stem cells (HSCs). Here, we show that the SET domain, and thus HMT activity of MLL1, is dispensable for maintaining HSCs and supporting leukemogenesis driven by the MLL-AF9 fusion oncoprotein.

An MLL-dependent network sustains hematopoiesis.

The histone methyltransferase Mixed Lineage Leukemia (MLL) is essential to maintain hematopoietic stem cells and is a leukemia protooncogene. Although clustered homeobox genes are well-characterized targets of MLL and MLL fusion oncoproteins, the range of Mll-regulated genes in normal hematopoietic cells remains unknown. Here, we identify and characterize part of the Mll-dependent transcriptional network in hematopoietic stem cells with an integrated approach by using conditional loss-of-function models, genomewide expression analyses, chromatin immunoprecipitation, and functional rescue assays.

Developmentally induced Mll1 loss reveals defects in postnatal haematopoiesis.

The mixed lineage leukemia (MLL) gene is disrupted by chromosomal translocations in acute leukemia, producing a fusion oncogene with altered properties relative to the wild-type gene. Murine loss-of-function studies have shown an essential role for Mll in developing the haematopoietic system, yet studies using different conditional knockout models have yielded conflicting results regarding the requirement for Mll during adult steady-state haematopoiesis. In this study, we used a loxP-flanked Mll allele (Mll(F)) and a developmentally regulated, haematopoietic-specific VavCre transgene to reassess the consequences of Mll loss in the haematopoietic lineage, without the need for inducers of Cre recombinase.

Primary chicken tracheal cell culture system for the study of infection with avian respiratory viruses.

A major route of infection of avian influenza virus (AIV) and Newcastle disease virus (NDV) in chickens is through cells of the respiratory epithelium. Here we describe the development of a method for culture of tracheal epithelial cells from chicken embryos as well as their use in studies of infection with avian respiratory viruses such as low-pathogenicity AIV and lentogenic NDV. Positive immunostaining for cytokeratin, the presence of cilia and microvilli, and microarray analysis of transcribed RNA demonstrated that the isolated cells were epithelial in nature.