Gene expression changes are linked to air pollutant exposures in in vitro and animal experiments. However, limited data are available on how these outcomes relate to ambient air pollutant exposures in humans. We performed an exploratory analysis testing whether gene expression levels were associated with air pollution exposures in a Los Angeles area cohort of elderly subjects with coronary artery disease. Candidate genes (35) were selected from published studies of gene expression-pollutant associations. Expression levels were measured weekly in 43 subjects (≤12 weeks) using quantitative PCR. Exposures included gaseous pollutants O3, nitrogen oxides (NOx), and CO; particulate matter (PM) pollutants elemental and black carbon (EC, BC); and size-fractionated PM mass. We measured organic compounds from PM filter extracts, including polycyclic aromatic hydrocarbons (PAHs), and determined the in vitro oxidative potential of particle extracts. Associations between exposures and gene expression levels were analyzed using mixed-effects regression models. We found positive associations of traffic-related pollutants (EC, BC, primary organic carbon, PM0.25-2.5 PAH and/or PM0.25 PAH, and NOx) with NFE2L2, Nrf2-mediated genes (HMOX1, NQO1, and SOD2), CYP1B1, IL1B, and SELP. Findings suggest that NFE2L2 gene expression links associations of traffic-related air pollution with phase I and II enzyme genes at the promoter transcription level.
Epstein-Barr (EB) virus induces a new pyrimidine deoxynucleoside kinase [thymidine kinase (dTk)] activity in Raji B lymphocyte cells after superinfection. This dTk activity is also present in small amounts in the HR-1 virus-producer cell line and in larger amounts in the B95-8 virus-producer line. The dTk activity induced by EB virus coelutes from DEAE-cellulose columns with deoxycytidine kinase (dCk) activity and elutes as a broad peak well separated from the large peaks of cellular dTk and dCk activities. This EB virus-induced pyrimidine deoxynucleoside kinase activity from HR-1 cells differs from cellular kinases in most basic biochemical properties but shares certain properties with the herpes simplex virus dTk.
We describe the application of a novel filamentous phage vector system suitable for efficient screening and production of F(ab) antibody fragments. The vector system can concurrently produce free F(ab) fragments and F(ab) displayed on the surface of M13 bacteriophage via a VHCH1-pVIII fusion protein. When expressed in a supO (nonsuppressor) strain of Escherichia coli free F(ab) can be produced. Antibody F(ab) fragments are secreted into culture medium at concentrations up to 0.3 mg/liter and conveniently subjected to detailed analysis with little or no purification. Higher concentrations of F(ab) (approximately 10 mg/liter) were found to accumulate in the periplasmic space. In this report the vector system is shown to produce correctly folded and assembled F(ab) fragments of chimeric L6, a mAb against a tumor-associated Ag expressed by many human carcinomas.
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