No abstract

The membrane TNF-α is known to serve as a precursor of the soluble form of TNF-α. Although it has been reported the biological functions of the membrane TNF-α as a ligand, the outside-to-inside (reverse) signal transmitted through membrane TNF-α is poorly understood. Here we report a novel function mediated by outside-to-inside signal via membrane TNF-α into the cells expressing membrane TNF-α. Activation by anti-TNF-α Ab against membrane TNF-α on human T cell leukemia virus (HTLV) I-infected T cell line, MT-2, or PHA-activated normal human CD4+ T cells resulted in the induction of an adhesion molecule, E-selectin (CD62E), on the cells with the peak of 12–24 h, which completely disappeared by 48 h. When wild-type or mutant membrane TNF-α (R78T/S79T) resistant to proteolytic cleavage was introduced into Jurkat or HeLa cells, E-selectin was induced by the treatment with anti-TNF-α Ab with the similar kinetics. Membrane TNF-α-expressing Jurkat cells also up-regulated E-selectin when brought into cell-to-cell contact with TNF receptor-expressing HeLa cells. Northern blot analysis and RT-PCR analysis showed that the membrane TNF-α-mediated E-selectin expression was up-regulated at the level of transcription. These results not only confirmed our previous findings of reverse signaling through membrane TNF-α, but also presented evidence that E-selectin was inducible in cell types different from endothelial cells. It is strongly suggested that membrane TNF-α is a novel proinflammatory cell surface molecule that transmits bipolar signals in local inflammation.

CRISPR/Cas9-mediated beta-globin (HBB) gene correction of sickle cell disease (SCD) patient-derived hematopoietic stem cells (HSCs) in combination with autologous transplantation represents a recent paradigm in gene therapy. Although several Cas9-based HBB-correction approaches have been proposed, functional correction of in vivo erythropoiesis has not been investigated previously. Here, we use a humanized globin-cluster SCD mouse model to study Cas9-AAV6-mediated HBB-correction in functional HSCs within the context of autologous transplantation. We discover that long-term multipotent HSCs can be gene corrected ex vivo and stable hemoglobin-A production can be achieved in vivo from HBB-corrected HSCs following autologous transplantation. We observe a direct correlation between increased HBB-corrected myeloid chimerism and normalized in vivo red blood cell (RBC) features, but even low levels of chimerism resulted in robust hemoglobin-A levels. Moreover, this study offers a platform for gene editing of mouse HSCs for both basic and translational research.

Mannose binding lectin (MBL) deficiency may be associated with increased susceptibility to infection and autoimmune disorders, such as systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA). In the present study, we performed for the first systematic search for mutations in all the four exons of the MBL gene using polymerase chain reaction (PCR)/single-strand conformation polymorphism (SSCP) analysis. Of 49 healthy Japanese individuals studied, only the previously reported mutation at the codon 54 (substitution from Gly to Asp; G54D) was identified. The allele frequencies of G54D in 105 healthy Japanese individuals, 95 SLE patients and 59 RA patients, were 0.233, 0.226 and 0.178, respectively, which were not significantly different. In addition, two polymorhisms at positions of −550 and −221 in the promoter region were not associated with SLE and RA. It is unlikely that MBL deficiency plays a major role in the pathogenesis of SLE and RA in Japanese. Genes and Immunity (2000) 1, 464-466.Keywords: mannose binding lectin; mannose binding protein; Complement; autoimmune diseases; systemic lupus erythematosus; rheumatoid arthritis Mannose binding lectin (MBL), also known as mannose or mannan binding protein, is a member of the collectin family of proteins, characterized by the presence of collagen-like domains and carbohydrate recognition lectin domains. 1 MBL binds to high mannose and Nacetyl-glucosamine oligosaccharides present on the cell surface of yeasts, bacteria and viruses and serves as the initiator of the third pathway of complement system (lectin pathway). 2 MBL is considered to be involved in the innante immunity of host defence that works prior to the establishment of adaptive immune system. Previous studies suggest that homozygous deficiency of MBL is associated with recurrent infections in children 3,4 as well as increased susceptibility and shorter survival of human immunodeficiency virus (HIV) patients. 5,6 Although there are controversies, association of MBL deficiency with chronic hepatitis virus type B (HBV) infection 7 and its progression, 8 and with poor response to interferon in chronic hepatitis virus type C (HCV) 9 has also been reported. In addition MBL deficiency has also been implicated in the pathogenesis of autoimmune diseases. Studies in the UK and Spanish

The bacterial transposon Tn3 encodes a site-specific recombination system. The recombination requires the product oftnpR, a gene previously identified as a repressor ofthe transposase. This recombination is site specific and takes place somewhere within the sequence