ABSTRACT
Interaction of retrovirus vectors and endogenous retroviruses present in packaging cell lines and target cells may result in the formation of recombinant viruses. Using sensitive RT-PCR assays, we have investigated human and murine gene therapy packaging cell lines for the incorporation of endogenous retrovirus transcripts into murine leukaemia virus (MLV) vector particles and whether vector genomes are incorporated into human endogenous retrovirus (HERV) particles. VL30 endogenous retrovirus sequences were packaged in particles produced by the murine AM12 packaging system. For every seven MLV-derived -galactosidase beta-Gal vector genomes present in the particles, one copy of VL30 was also packaged. Although human FLY packaging cells expressed HERV transcripts (HERV-K, HuRT, type C, and RTVL-H), none was detectable in the MLV vector particles released from the cells. Non-specific packaging of the MLV gag-pol expression vector transcripts was detected in the FLY virions at a low level (one in 17,000 sequences). In other experiments, gag proteins produced by HERV-K particles present in human teratocarcinoma cells did not appear to package MLV-based vectors that expressed Gal transcripts. These findings indicate that retrovirus vectors interact with human packaging cells to produce retrovirus particles that are far less contaminated by endogenous viral sequences or other types of extraneous particles than murine packaging cells.
Subject(s)
Leukemia Virus, Murine/genetics , Models, Biological , Virus Assembly , Animals , Cell Line , Genetic Vectors , Humans , Mice , Reverse Transcriptase Polymerase Chain ReactionABSTRACT
The primer pheromone is responsible for the "male effects" in goats and produced in the sebaceous glands testosterone-dependently. In the present study, the responses of sebaceous glands obtained from the head and rump regions of castrated goats were examined by our bioassay system after testosterone treatment to demonstrate the presence of regional differences in the pheromone production in male goats. The testosterone treatment resulted in the marked development of sebaceous glands and the induction of pheromone bioactivity in the head region of the goats. On the contrary, this treatment brought neither development of the sebaceous glands nor induction of pheromone bioactivity in the rump region. The treatment increased immunoreactivities to androgen receptors (AR) and 5alpha-reductase in the sebaceous glands of both regions, although the activities were more apparent in the head region than the rump region. These findings suggest that the primer pheromone of male goats is produced specifically in the sebaceous glands of the head region due partly to regional differences in the expression of AR and 5alpha-reductase mediating testosterone bioactivities.
Subject(s)
Goats/metabolism , Pheromones/biosynthesis , Sebaceous Glands/metabolism , Testosterone/pharmacology , 3-Oxo-5-alpha-Steroid 4-Dehydrogenase/biosynthesis , Animals , Head , Immunohistochemistry/veterinary , Male , Orchiectomy/veterinary , Receptors, Androgen/biosynthesis , Receptors, Androgen/drug effects , Sebaceous Glands/drug effects , Sebaceous Glands/pathology , Testosterone/bloodABSTRACT
An efficient Statistical Analysis System computer program for the exact stratification of person-years is described, in order to determine the expected number of deaths or cases of diseases in a cohort for the calculation of standardized mortality ratios or standardized morbidity ratios. A comparison of this program with Macaluso's "Method B" program shows that the speed of the former is considerably faster than that of the latter, when the widths of the categories defined by all of the time factors are identical.
