Toxicology, biodistribution and shedding profile of a recombinant measles vaccine vector expressing HIV-1 antigens, in cynomolgus macaques.

As a new human immunodeficiency virus type 1 (HIV-1) vaccine approach, the live-attenuated measles virus (MV) Schwarz vaccine strain was genetically engineered to express the F4 antigen (MV1-F4). F4 is a fusion protein comprising HIV-1 antigens p17 and p24, reverse transcriptase and Nef. This study assessed the toxicity, biodistribution and shedding profiles of MV1-F4. Cynomolgus macaques were intramuscularly immunized one or three times with the highest dose of MV1-F4 intended for clinical use, the reference (Schwarz) measles vaccine or saline, and monitored clinically for 11 or 85 days. Toxicological parameters included local and systemic clinical signs, organ weights, haematology, clinical and gross pathology and histopathology. Both vaccines were well tolerated, with no morbidity, clinical signs or gross pathological findings observed. Mean spleen weights were increased after three doses of either vaccine, which corresponded with increased numbers and/or sizes of germinal centers. This was likely a result of the immune response to the vaccines. Either vaccine virus replicated preferentially in secondary lymphoid organs and to a lesser extent in epithelium-rich tissues (e.g., intestine, urinary bladder and trachea) and the liver. At the expected peak of viremia, viral RNA was detected in some biological fluid samples from few animals immunized with either vaccine, but none of these samples contained infectious virus. In conclusion, no shedding of infectious viral particles was identified in cynomolgus monkeys after injection of MV1-F4 or Schwarz measles vaccines. Furthermore, no toxic effect in relation to the MV vaccination was found with these vaccines in this study.

Deletion of open reading frames 9, 10 and 11 from the avian adenovirus CELO genome: effect on biodistribution and humoral responses.

In this study, the in vivo effect of the 3.6 kbp deletion of the three open reading frames (ORF) 9, 10 and 11 found at the right end of the CELO genome was examined. Groups of chickens were inoculated oronasally with 10(5)-10(7) p.f.u. per animal of wild-type virus and two recombinant CELO strains (rCELO) expressing luciferase and secreted alkaline phosphatase (SEAP). The tissue biodistribution, assessed by PCR, was similar for both wild-type and recombinant viruses. The infectious viral particle titre was determined by a p.f.u. counting method and the antibody responses to the CELO vector and the SEAP antigen were evaluated by ELISA. Infectious particle titres in tissues from chickens inoculated with the wild-type CELO virus increased up to 6 days post-inoculation, and declined until 11 days while titres in organs from chickens inoculated with the rCELO strain were low and only detectable at 4 days post-inoculation. Moreover, although anti-CELO antibody levels were three times lower in sera from chickens inoculated with rCELO, antibodies directed to the heterologous SEAP antigen were detected. Based on these results, no differences in tropism were observed, but the level of production of viral particles and the humoral responses appeared to decrease. Viruses replicate less efficiently with a deletion performed at the right end of the CELO genome. Nevertheless, the presence of antibodies directed to heterologous antigens makes the CELO virus an advantageous candidate for avian vaccination.

Oltipraz regulates different categories of genes relevant to chemoprevention in human hepatocytes.

Numerous chemical compounds are cytotoxic or carcinogenic to human beings and attention is now focusing on preventative strategies. One agent, oltipraz (OPZ), regarded as one of the most promising chemoprotectors, has been shown to be a potent inducer of phase II enzymes involved in the detoxification of carcinogens, including aflatoxins. However, little is known about its effects on global gene expression in human cells. Thus, we used microarrays and reverse transcription-quantitative polymerase chain reaction to test the effects of OPZ on the overall pattern of mRNA expression of multiple metabolic pathways in human hepatocytes in primary culture. Our results show for the first time that OPZ significantly alters the expression of human genes within different functional categories (detoxification of xenobiotics, antioxidant defences, xenobiotic transport, cell cycle and stress responses), at both the mRNA and protein levels, some of which are highly relevant to chemoprevention. Amongst these genes, several have never been described as being regulated by OPZ before. We also demonstrate variations in response to OPZ, depending on the individual from whom the cells were derived, that might potentially contribute to differences in efficacy of chemopreventive treatments between individuals. Moreover, comparison of our results with those obtained in rodents demonstrates species differences in response to OPZ for some genes, underlying the importance of studies on human cells to predict the effects of chemopreventive agents.