Recombinant Rhipicephalus appendiculatus gut (Ra86) and salivary gland cement (Trp64) proteins as candidate antigens for inclusion in tick vaccines: protective effetcs of Ra86 on infestation with adult R. appendiculatus.
Saimo, M. ; Odongo, D.O. ; Mwaura, S. ; Vlak, J.M. ; Musoke, A.J. ; Lubega, G.W. ; Bishop, R.P. ; Oers, M.M. van - \ 2011
Vaccine: Development and Therapy 1 (2011). - ISSN 2230-2298 - p. 15 - 23.
Rhipicephalus appendiculatus gut protein Ra86 (variants Ra85A and Ra92A) and the salivary gland cement protein (Trp64) were expressed in the baculovirus-insect cell system. The recombinant gut proteins expressed as soluble proteins and the recombinant cement protein, as insoluble inclusion bodies, were used to immunize rabbits, which were then challenged with larval, nymphal, and adult stages of R. appendiculatus ticks. High tick mortality (23.3%) occurred on adult ticks that fed on rabbits vaccinated with the gut proteins, compared with 1.9% mortality in ticks that fed on unvaccinated naïve control rabbits. The mean weight of engorged female ticks was significantly reduced by 31.5% in rabbits vaccinated with the Ra86 recombinant protein compared with controls, as was egg production. Marked effects on these parameters were also observed in adult ticks as a result from vaccination using Trp64, but these were not statistically significant. For both antigens, there was no demonstrable effect on larval or nymphal ticks. This study demonstrates for the first time the protective efficacy of a homolog of Boophilus microplus Bm86 in reducing tick infestation by the adult stage of the three-host tick R. appendiculatus. The results demonstrate the potential of Ra86 for vaccine development against this tick and for the control of East Coast fever.
Novel baculovirus-derived p67 subunit vaccines efficacious against East Coast fever in cattle
Kaba, S.A. ; Musoke, A.J. ; Schaap, D. ; Schetters, T. ; Rowlands, J. ; Vermeulen, A.J. ; Nene, V. ; Vlak, J.M. ; Oers, M.M. van - \ 2005
Vaccine 23 (2005)21. - ISSN 0264-410X - p. 2791 - 2800.
theileria-parva sporozoites - neutralizing epitopes - monoclonal-antibody - surface-antigen - protection - protein - stocks - immunogenicity - immunization - leukocytes
Two novel baculovirus-derived recombinant Theileria parva p67 constructs were tested for their vaccine potential against East Coast fever. Boran calves were immunized with a his-GFP-p67 fusion protein (GFP:p67¿SS) or with GP64:p67C, a protein fusion between a C-terminal domain of p67 and the baculovirus envelope protein GP64. Both GFP:p67¿SS and GP64:p67C induced antibodies with high ELISA titers that neutralized T. parva sporozoites with high efficiency. Upon challenge, a correlation was observed between the in vitro neutralizing capacity and the reduction in severe ECF for individual animals. A protection level upto 85% was obtained. This level of protection was achieved with only two inoculations of 100 ¿g per dose, which is a major improvement over previous recombinant p67 products
|Development of novel and effective subunit vaccines against East Coast Fever based on insect cell-derived T. parva sporozoite surface protein P67
Kaba, S.A. ; Musoke, A.J. ; Schaap, D. ; Vlak, J.M. - \ 2004
In: Book of Abstracts, SIP 2004, Helsinki, 1-6 August 2004. - Helsinki : - p. 87 - 88.
Improved immunogenicity of novel baculovirus-derived Theileria parva p67 subunit antigens
Kaba, S.A. ; Schaap, D. ; Roode, E.C. ; Nene, V. ; Musoke, A.J. ; Vlak, J.M. ; Oers, M.M. van - \ 2004
Veterinary Parasitology 121 (2004)1-2. - ISSN 0304-4017 - p. 53 - 64.
sporozoite-neutralizing epitopes - vaccine antigen - antibody-responses - salmonella-dublin - surface-antigen - cattle - protein - virus - protection - adjuvants
East Coast fever (ECF) in cattle is caused by the tick-borne protozoan parasite Theileria parva. The major sporozoite surface antigen of T parva (p67) is an important candidate for inclusion in a subunit vaccine. Recently, we reported the expression and production of different parts of p67 as fusions to either GFP or to the baculovirus GP64 envelope glycoprotein in insect cells, which resulted in stable proteins recognized by a monoclonal specific for native p67. The immunogenicity of these fusion proteins was examined in out-bred mice and cattle. In mice, the full length p67 molecule without its signal peptide and transmembrane region, but fused to GFP (GFP:p67 DeltaSS) was the best immunogen followed by the C-terminus of p67 fused to GP64 (GP64:p67C). These two immunogens also provoked a high level of sero-conversion in cattle when formulated in a water-in-oil or saponin-derived adjuvant with only 100 mug of protein and a single booster. The vaccine-elicited antibodies efficiently inhibited the infectivity of T parva sporozoites in in vitro neutralization assays. This study demonstrated that these new baculovirus-derived p67 vaccines were highly immunogenic, and that in combination with a suitable adjuvant, they have a clear potential to induce protective immunity in cattle. (C) 2004 Elsevier B.V. All rights reserved.
Baculovirus surface display of Theileria parva p67 antigen preserves the conformation of sporozoite-neutralizing epitopes
Kaba, S.A. ; Hemmes, J.C. ; Lent, J.W.M. van; Vlak, J.M. ; Nene, V. ; Musoke, A.J. ; Oers, M.M. van - \ 2003
Protein Engineering 16 (2003)1. - ISSN 0269-2139 - p. 73 - 78.
nuclear polyhedrosis-virus - green fluorescent protein - envelope fusion protein - vaccine development - foreign proteins - gp64 - responses - cattle
Theileria parva is an intracellular protozoan parasite that causes East Coast fever, a severe lymphoproliferative disease in cattle. Previous attempts to produce recombinant sporozoite surface antigen (p67) in bacterial or insect cells for vaccine purposes have not resulted in a correctly folded protein. Here, we report the expression of N- and C-terminal domains of p67 fused to the baculovirus envelope glycoprotein GP64 by cloning the appropriate p67 cDNA segments between the signal sequence and the major portion of GP64. To further advance the generation of such recombinants, existing surface display techniques were combined with bacmid technology. Chimeric proteins were present on the surface of budded viruses as judged by immunogold labelling and were exposed on the surface of insect cells, as concluded from immunofluorescence studies of infected, non-fixed insect cells. In non-denaturing dot blot experiments, a strong reaction was obtained between monoclonal TpM12 and baculovirus particles displaying the p67N-GP64 chimeric protein. This antibody, raised against native p67, also specifically recognized the surface of recombinant-infected cells. Apparently, a more native conformation was achieved than when p67 was expressed in E.coli or in conventional baculovirus expression systems. The baculovirus surface expression system, therefore, provides an improved way of expressing this T.parva sporozoite surface protein.