Generally, cationic vector-based intravenous delivery of at a ratio of 4 nitrogen equivalents per DNA phosphate. DNA is hindered by interactions of positively charged comLower levels of transfection were found in the heart, plexes with serum proteins. However, if optimally formuspleen, liver and kidney. Expression was dose-and timelated, cationic vectors can provide reasonable levels of dependent in all tissues examined. In the lung, ␤-galactotransfection in the lung either by intravenous or intrapulsidase staining showed transgene expression in clusters monary routes. We investigated the in vivo transfection of 10 or more pulmonary cells including the alveolar endocapacity of a cationic polymer: linear, 22 kDa polyethylenithelium, squamous and great alveolar epithelial cells (type mine. PEI/DNA complexes were formulated in 5% glucose I and II pneumocytes) and septal cells. These findings indiand delivered into adult mice through the tail vein. Two cate that the complexes pass the capillary barrier in the marker genes were used, ␤-galactosidase and luciferase.lung. Although the delivery mechanism requires eluciHigh levels of luciferase expression (10 7 RLU/mg protein) dation, linear PEI has promise as a vector for intravenous were found in the lung when DNA was complexed with PEI transfer of therapeutic genes.Keywords: cationic polymers; pneumocytes; plasmid DNA; nonviral; gene therapy A number of generations of cationic vectors have been synthetised and tested in a variety of in vivo models and some have been taken to clinical trials. Most of these vectors are either monocationic or polycationic lipids, but there has been more recent interest in cationic polymers. Indeed, we showed that the branched cationic polymer polyethylenimine (PEI) can provide high levels of transfection in vivo. [1][2][3] In particular the lowest molecular weight preparation then commercially available, the 25 kDa preparation from Aldrich, was shown to be a versatile and efficient vector in the mammalian brain. 2 In a more recent study, 3 we chose to examine the effect of formulation procedures (glucose or saline solutions) on the size and in vivo transfection activity of a mixture of linear polymers with a mean MW of 22 kDa (Exgene 500; Euromedex, Souffleweyersheim, France). We found that the complexes formed in glucose were an order of magnitude smaller than those formed in saline and these complexes provided high levels of gene transfer following dilution into a physiological medium, the cerebrospinal fluid. In the light of these findings we chose to examine the effects of injecting complexes of plasmid DNA formulated with 22 kDa PEI in 5% glucose directly into the blood system and to examine transgene expression in a variety of organs.PEI-DNA complexes with different ratios of PEI nitro- gen to DNA phosphate (N/P ratio) were prepared in 5% glucose using a CMV-Luc plasmid 4 and the 22 kDa linear PEI. This PEI is synthesised to a degree of polymerisation of 510 units. Earlier experiments carried out with the branched 25 kDa PEI (Aldri...

CTLA-4 (CD152) is a cell surface receptor that behaves as a negative regulator of the proliferation and the effector function of T cells. We have previously shown that CTLA-4 is also expressed on neoplastic lymphoid and myeloid cells, and it can be targeted to induce apoptosis. In our study, we have extended our analysis and have discovered that surface expression of CTLA-4 is detectable by flow cytometry on 30 of 34 (88%)

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The congenital malformation Split Hand-Foot Malformation (SHFM, or ectrodactyly) is characterized by a medial cleft of hands and feet, and missing central fingers. Five genetically distinct forms are known in humans; the most common (type-I) is linked to deletions of DSS1 and the distalless-related homeogenes DLX5 and DLX6. As Dlx5;Dlx6 double-knockout mice show a SHFM-like phenotype, the human orthologs are believed to be the disease genes. SHFM-IV and Ectrodactyly-Ectodermal dysplasia-Cleft lip (EEC) are caused by mutations in p63, an ectoderm-specific p53-related transcription factor. The similarity in the limb phenotype of different forms of SHFM may underlie the existence of a regulatory cascade involving the disease genes. Here, we show that p63 and Dlx proteins colocalize in the nuclei of the apical ectodermal ridge (AER). In homozygous p63-(null) and p63 EEC (R279H) mutant limbs, the AER fails to stratify and the expression of four Dlx genes is strongly reduced; interestingly, the p63 +/EEC and p63hindlimbs, which develop normally and have a normally stratified AER, show reduced Dlx gene expression. The p63 +/EEC mutation combined with an incomplete loss of Dlx5 and Dlx6 alleles leads to severe limb phenotypes, which are not observed in mice with either mutation alone. In vitro, ⌬Np63␣ induces transcription from the Dlx5 and Dlx6 promoters, an activity abolished by EEC and SHFM-IV mutations, but not by Ankyloblepharon-Ectodermal defects-Cleft lip/palate (AEC) mutations. ChIP analysis shows that p63 is directly associated with the Dlx5 and Dlx6 promoters. Thus, our data strongly implicate p63 and the Dlx5-Dlx6 locus in a pathway relevant in the aetio-pathogenesis of SHFM.

Split hand/foot malformation type I (SHFM1) disease locus maps to chromosome 7q21.3-q22, a region that includes the distal-less-related (dll) genes DLX5 and DLX6. However, incomplete penetrance, variable expressivity, segregation distortion, and syndromic association with other anomalies have so far prevented the identification of the SHFM1 gene(s) in man. Here we show that the targeted double inactivation of Dlx5 and Dlx6 in the mouse causes in homozygous mutant animals bilateral ectrodactyly with a severe defect of the central ray of the hindlimbs, a malformation typical of SHFM1. This is the first evidence that the role of dll/Dlx genes in appendage development is conserved from insects to mammals and proves their involvement in SHFM1.

In the mouse embryo, Dlx5 is expressed in the otic placode and vesicle, and later in the semicircular canals of the inner ear. In mice homozygous for a null Dlx5/LacZ allele, a severe dysmorphogenesis of the vestibular region is observed, characterized by the absence of semicircular canals and the shortening of the endolymphatic duct. Minor defects are observed in the cochlea, although Dlx5 is not expressed in this region. Cristae formation is severely impaired; however, sensory epithelial cells, recognized by calretinin immunostaining, are present in the vestibular epithelium of Dlx5(-/-) mice. The maculae of utricle and saccule are present but cells appear sparse and misplaced. The abnormal morphogenesis of the semicircular canals is accompanied by an altered distribution of proliferating and apoptotic cells. In the Dlx5(-/-) embryos, no changes in expression of Nkx5.1(Hmx3), Pax2, and Lfng have been seen, while expression of bone morphogenetic protein-4 (Bmp4) was drastically reduced. Notably, BMP4 has been shown to play a fundamental role in vestibular morphogenesis of the chick embryo. We propose that development of the semicircular canals and the vestibular inner ear requires the independent control of several homeobox genes, which appear to exert their function via tight regulation of BPM4 expression and the regional organization of cell differentiation, proliferation, and apoptosis.

Chronic lung infections by Pseudomonas aeruginosa strains are a major cause of morbidity and mortality in cystic fibrosis (CF) patients. Although there is no clear evidence for a primary defect in the immune system of CF patients, the host is generally unable to clear P. aeruginosa from the airways. PTX3 is a soluble pattern recognition receptor that plays nonredundant roles in the innate immune response to fungi, bacteria, and viruses. In particular, PTX3 deficiency is associated with increased susceptibility to P. aeruginosa lung infection. To address the potential therapeutic effect of PTX3 in P. aeruginosa lung infection, we established persistent and progressive infections in mice with the RP73 clinical strain RP73 isolated from a CF patient and treated them with recombinant human PTX3. The results indicated that PTX3 has a potential therapeutic effect in P. aeruginosa chronic lung infection by reducing lung colonization, proinflammatory cytokine levels (CXCL1, CXCL2, CCL2, and IL-1β), and leukocyte recruitment in the airways. In models of acute infections and in in vitro assays, the prophagocytic effect of PTX3 was maintained in C1q-deficient mice and was lost in C3- and Fc common γ-chain–deficient mice, suggesting that facilitated recognition and phagocytosis of pathogens through the interplay between complement and FcγRs are involved in the therapeutic effect mediated by PTX3. These data suggested that PTX3 is a potential therapeutic tool in chronic P. aeruginosa lung infections, such as those seen in CF patients.

Intravenous administration could become a delivery route of choice for prophylactic and curative gene therapies on condition that genes cross the capillary barrier and reach target tissues without being degraded. We investigated the kinetics and process of transgene delivery through mouse lung capillaries following DNA complexation with linear polyethylenimine (L-PEI) and intravenous injection. Using digoxin-labeled DNA we followed the cellular localization of DNA at different times after injection and correlated these findings with cell markers and transgene expression. At 2 h after injection some DNA was still localized on the interior of the capillary lumen, but other complexes had already crossed the barrier and resulted in gene expression. At 24 h after injection most