No abstract

A synthetic 20 amino acid peptide of the ribosomal protein P0 from ticks, when conjugated to keyhole limpet hemocyanin from Megathura crenulata and used as an immunogen against Rhipicephalus microplus and Rhipicephalus sanguineus s.l. species, has shown efficacies of around 90%. There is also experimental evidence of a high efficacy of this conjugate against Amblyomma mixtum and Ixodes ricinus species, which suggest that this antigen could be a good broad-spectrum anti-tick vaccine candidate. In this study, the P0 peptide (pP0) was chemically conjugated to Bm86 as a carrier protein. SDS-PAGE analysis of this conjugate demonstrated that it is highly heterogeneous in size, carrying from 1 to 18 molecules of pP0 per molecule of Bm86. Forty-nine out of the 54 lysine residues and the N-terminal end of Bm86 were found partially linked to pP0 by using LC-MS/MS analysis and the combination of four different softwares. Several post-translational modifications of Bm86 protein were also identified by mass spectrometry. High immunogenicity and efficacy were achieved when dogs and cattle were vaccinated with the pP0–Bm86 conjugate and challenged with R. sanguineus s.l. and R. microplus, respectively. These results encourage the development of this antigen with promising possibilities as an anti-tick vaccine.

No abstract

To date, many technologies have been developed to increase efficiency in aquaculture, but very few successful biotechnology molecules have arrived on the market. In this context, marine biotechnology has an opportunity to develop products to improve the output of fish in aquaculture. Published in vivo studies on the action of the pituitary adenylate cyclase-activating polypeptide (PACAP) in fish are scarce. Recently, our group, for the first time, demonstrated the biological role of this neuropeptide administrated by immersion baths in the growth and development of larval fish. In this work, we have evaluated the effects of recombinant Clarias gariepinus PACAP administration by intraperitoneal injection on growth performance and feeding behavior in juvenile fish. Our results showed the physiological role of this peptide for growth control in fish, including the juvenile stage, and confirm that its biological functions are well conserved in fish, since C. gariepinus PACAP stimulated growth in juvenile tilapia Oreochromis niloticus. In addition, we have observed that the growth-promoting effect of PACAP in juvenile tilapia was correlated with higher GH concentration in serum. With regard to the neuroendocrine regulation of growth control by PACAP, it was demonstrated that PACAP stimulates food intake in juvenile tilapia. In general, PACAP appears to act in the regulation of the growth control in juvenile fish. These findings propose that PACAP is a prominent target with the potential to stimulate fish growth in aquaculture.

The critical role that antibody responses to the V3 loop epitope play in human immunodeficiency virus type 1 (HIV-1) neutralization has caused this peptide to be used in many HIV-1 vaccine candidates. To enhance cross-reactivity toward several V3 sequences, a database of 50 peptides of the V3 region from HIV-1 subtype A was used to design both a consensus peptide and a combinatorial peptide (mixotope) library representative of these sequences. The two immunogens (consensus and mixotope) were incorporated into multiple antigen peptide (MAP) constructions, conjugated to a recombinant surface antigen from hepatitis B virus (HbsAg) carrier protein, and inoculated to mice in combination with a C4 (CD4-binding) peptide MAP construction, also conjugated to HBsAg. The respective responses and cross-reactivity to several V3 loop sequences of both types of immunogens were compared. Mice inoculated with the V3 consensus-MAP-HBsAg + C4-MAP-HBsAg mixture elicited higher antibody responses than those given the V3 mixotope-MAP-HBsAg + C4-MAP-HBsAg mixture. In addition, pooled serum from the first group of immunogens analyzed at dilution 1:100 had higher cross-reactivity against V3 peptides on cellulose membranes than those from mice given the combinatorial immunogen. Fine epitope mapping of both consensus and C4 peptide by the spot synthesis technique showed that sera of the first group strongly recognized both sequences in their entirety, whereas mice immunized with the mixotope library recognized only the N-terminal region of V3. These results seem to suggest that the V3 consensus peptide is superior to the combinatorial strategy in inducing potent and cross-reactive responses to HIV.