Cationic lipids enhance cytokine and cell influx levels in the lung following administration of plasmid: cationic lipid complexes.

Administration of plasmid/lipid complexes to the lung airways may be associated, in addition to expression of transgene, with a range of other responses. We report here the induction of cytokines and cellular influx in the lung airway following intratracheal administration of an N-[1-(2-3-dioleyloxy)propyl]-N,N,N-trimethylammonium chloride/cholesterol/plasmid positively charged complex in mice. We show that 1) the appearance of the Th1-associated cytokines IFN-gamma and IL-12 in bronchoalveolar lavage fluid is caused by unmethylated CpG dinucleotide sequences present within the plasmid, and is enhanced by the lipid formulation; 2) cationic lipids by themselves do not induce IL-12 or IL-12p40; 3) TNF-alpha is rapidly induced by cationic lipids and plasmid/lipid complex, but not by plasmid alone; 4) an acute cellular influx is induced by cationic lipid alone and by a plasmid/lipid complex, but to a much lesser extent by plasmid alone; and 5) plasmid methylation does not influence the degree of inflammatory cell influx. The induction of the innate immune responses by plasmid/lipid complexes may be advantageous to gene therapy of lung diseases. In particular, induction of the Th1 cell-promoting cytokines by plasmid/lipid complexes could, in conjunction with an expressed transgene, be used to modulate immune responses in the lung airways in disease conditions that are deficient in Th1 cell responses or that have a dominant Th2 phenotype. Alternatively, the elimination of immunostimulatory sequences in plasmids may improve the tolerability and/or efficacy of nonviral gene therapy, especially for diseases requiring chronic administration.

Rapid isolation of serum albumin using microporous PVC/silica cartridges.

A protocol has been developed for rapid isolation of albumin from rabbit or bovine serum. It is based on the use of microporous plastic silica sheets that have been fabricated into rapid flow-through devices called ACTI-MOD cartridges. In the first step, the untreated silica plastic matrix binds a major portion of the non-albumin protein. A second step, using an ACTI-MOD anion-exchange quaternary amine, further purifies and concentrates the albumin. At this stage, the albumin appears to be at least ninety-nine per cent pure based on sodium dodecyl sulfate gel electrophoresis.

Protein recovery from the all-agarose ProSieve gel system.

Electrophoresis in polyacrylamide gels is one of the most powerful tools used for the analysis of proteins. However, this technique is not widely used for protein purification for a variety of reasons such as the following: less than quantitative recoveries; involved, time-consuming methodologies; and impurities in the protein preparations from gel-polymerization by-products that can modify the proteins and interfere with subsequent experiments. As an alternative, we have developed a simple and quantitative recovery procedure for proteins separated by electrophoresis in the all-agarose ProSieve gel system. Using this procedure, greater than 90% of each protein examined was recovered, and these proteins were unaffected by the recovery procedure.

An improved microchromatographic procedure for separating HbA2 from HbS for the purpose of quantitation.

A microchromatographic method for separating hemoglobin A2 from hemoglobin S and their subsequent quantitation on DEAE-cellulose has been improved. The new procedure is more versatile, since the same system can be used when hemoglobin S is present or absent in the sample without changing to a longer column or another buffer system. Also, the technic is less sensitive to small changes in pH of buffers or resin than are other procedures.

Cytochrome c-specific protein methylase III from Neurospora crassa.

A protein methylase III responsible for specifically methylating the cytochrome c in Neurospora crassa was partially characterized by using unmethylated horse heart cytochrome c as a substrate. This enzyme utilizes S-adenosyl-L-methionine as the methyl donor. An analysis of the distribution of [14C]methyl groups in the peptides obtained by chymotrypsin digestion of the enzymically methylated cytochrome c showed that all of the radioactivity could be recovered within a single peak after chromatography. This indicates that the enzyme methylates a specific amino acid sequence within cytochrome c. On hydrolysis of the radioactive chymotryptic peptide, Me-14C-labelled epsilon -N-mono-methyl-lysine, epsilon-N-dimethyl-lysine and epsilon-N-trimethyl-lysine were identified. The enzyme can easily be extracted from the N. crassa mycelial pads and was purified approx. 30-fold.

Connective tissue synthesis by cultured scleroderma fibroblasts. II. Incorporation of 3h-glucosamine and synthesis of glycosaminoglycans.

Fibroblasts from normal and scleroderma skin, grown tissue culture, were incubated with 3H-glucosamine for 24 hours. No definite trends could be established in 3H-glucosamin incorporation or glycosaminoglycan synthesis. Over 90% of the total 3H activity as well as the glycosaminoglycans synthesized were secreted into the medium. Characterization of glycosaminoglycans showed that in both the medium and cells, hyaluronic acid ins the major glycosaminoglycan in normal and scleroderma fibroblasts. In the medium, hyaluronic acid represented 87% of the total glycosaminoglycans; it was slightly decreased in the cells. Fibroblasts were compared from the upper and lower areas of the affected dermis and an uninvolved dermal area of the same scleroderma patients.