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Biomedical subjects

D Portetelle

Publications and source records attributed to D Portetelle.

At least 145 records · Page 8Linked to original sources
PubMed1979

Humoral antibody response to bovine leukemia virus infection in cattle and sheep.

In this study, 345 cattle from 7 herds with a history of lymphosarcoma were tested for antibody to BLV antigens by three serological methods, namely immunodiffusion using a bovine leukemia virus glycoprotein with a molecular weight of 60,000 as antigen, and radioimmunoassay using a bovine leukemia virus glycoprotein with a molecular weight of 60,000 and a bovine leukemia virus protein with a molecular weight of 24,000 as antigen. The three tests under comparison agreed for 335 animals, 240 being negative in the three tests, and 95 being positive. Results were variable in ten cases only. Glycoprotein with a molecular weight of 60,000 antibody titers were systematically higher than were protein with a molecular weight of 24,000 antibody titers in bovine sera and milk, as well as in sera of experimentally infected sheep. In the latter case, antibodies to bovine leukemia virus antigens reached maximal values at the animal death in the tumor phase of the disease. Ratios of serum antiglycoprotein titer to milk titer varied between 4 and 117, showing that, if milk pools are to be used in surveys of bovine leukemia virus infection, use of very sensitive techniques of detection is mandatory.

Animals↗
PubMed1978

Detection of complement-dependent lytic antibodies in sera from bovine leukemia virus-infected animals.

Cattle and sheep infected by Bovine Leukemia Virus (BLV) harbor complement-dependent cytotoxic IgG1 antibodies. These antibodies lyse BLV producing cells but are inactive against noncultured tumorous lymphocytes of animals with persistent lymphocytosis. The target structure in the cell membrane contains antigenic determinants of BLV gp 60. The level of cytotoxic activity increases with progression of the disease towards the tumor phase. Sheep vaccinated with inactivated BLV have no cytotoxic activity in the serum but seem to resist infectious BLV challenge. Such cytotoxic activities do not protect the host against tumor growth but strongly control viremia and thus limit BLV spread within bovine and ovine populations.

Animals↗
PubMed1977

Frog oocytes synthesize and completely process the precursor polypeptide to virion structural proteins after microinjection of avian myeloblastosis virus RNA.

After microinjection of Xenopus laevis oocytes with RNA from avian myeloblastosis virus, viral structural proteins p27, p19, p15, and p12 are formed by a sequence of posttranslational cleavages of a high-molecular-weight precursor polypeptide. The 60-70S RNA aggregate or its 30-40S RNA subunits obtained by heat or formamide treatment possess the same ability to serve as template in X. laevis oocytes. The processing pattern of virus-specific precursor polypeptides is the same in X. laevis oocytes as in chick embryo fibroblasts infected with avian myeloblastosis virus, but the processing takes place at a much slower rate.

Animals↗