Effect of early introduction of microencapsulated diet to larval Atlantic halibut, Hippoglossus hippoglossus L. assessed by microarray analysis.

An experimental microdiet prepared using an internal gelation method was used to partially replace the traditional live feed (Artemia) for larval Atlantic halibut, Hippoglossus hippoglossus L. Three trials were conducted with microdiet introduced at 20, 32, and 43 days post first feeding and larvae were sampled at approximately 2, 13, 23, and 33 days after microdiet introduction in each trial. The success of feeding was assessed by morphometrics and histological analysis of gut contents. Microdiet particles were readily consumed after a period of adaptation and provided an adequate source of nutrients with no significant increase in mortality in the microdiet-fed group compared to the control group. However, growth was limited and there was an increased incidence of malpigmentation of the eye and skin. Subtle changes in underlying digestive and developmental physiology were revealed by microarray analysis of RNA from control and experimental fish given microdiet from day 20 post first feeding. Fifty-eight genes were differentially expressed over the four sampling times in the course of the trial and the 28 genes with annotated functions fell into five major categories: metabolism and biosynthesis, cell division and proliferation, protein trafficking, cell structure, and stress. Interestingly, several of these genes were involved in pigmentation and eye development, in agreement with the phenotypic abnormalities seen in the larvae.

Characterization of recombinant respiratory syncytial viruses with the region responsible for type 2 T-cell responses and pulmonary eosinophilia deleted from the attachment (G) protein.

It is essential that preventative vaccines for respiratory syncytial virus (RSV) elicit balanced T-cell responses. Immune responses dominated by type 2 T cells against RSV antigens are believed to cause exaggerated respiratory tract disease and may also contribute to unwanted inflammation in the airways that predisposes infants to wheeze through adolescence. Here we report on the construction and characterization of recombinant RSV (rRSV) strains with amino acids 151 to 221 or 178 to 219 of the attachment (G) glycoprotein deleted (rA2cpDeltaG150-222 or rA2cpDeltaG177-220, respectively). The central ectodomain was chosen for modification because a peptide spanning amino acids 149 to 200 of G protein has recently been shown to prime several strains of naïve inbred mice for polarized type 2 T-cell responses, and peripheral blood T cells from most human donors recognize epitopes within this region. Quantitative PCR demonstrated that synthesis of nascent rRSV genomes in human lung epithelial cell lines was similar to that for the parent virus (cp-RSV). Plaque assays further indicated that rRSV replication was not sensitive to 37 degrees C, but pinpoint morphology was observed at 39 degrees C. Both rRSV strains replicated in the respiratory tracts of BALB/c mice and elicited serum neutralization and anti-F-protein immunoglobulin G titers that were equivalent to those elicited by cp-RSV and contributed to a 3.9-log(10)-unit reduction in RSV A2 levels 4 days after challenge. Importantly, pulmonary eosinophilia was significantly diminished in BALB/c mice primed with native G protein and challenged with either rA2cpDeltaG150-222 or rA2cpDeltaG177-220. These findings are important for the development of attenuated RSV vaccines.