Vaccine. 2007 Mar 9; [Epub ahead of print]
Evaluation of protective effect of recombinant dense granule antigens GRA2 and GRA6 formulated in monophosphoryl lipid A (MPL) adjuvant against Toxoplasma chronic infection in mice
Golkar M, Shokrgozar MA, Rafati S, Musset K, Assmar M, Sadaie R, Cesbron-Delauw MF, Mercier C.
CNRS UMR 5163 - Universite Joseph Fourier, UFR de Biologie, Institut Jean Roget, Campus Sante, Domaine de la Merci. BP 170, 38042 Grenoble cedex 09, France; Molecular Parasitology Laboratory, Department of Parasitology, Pasteur Institute of Iran, 69 Pasteur Ave, Tehran 1316943551, Iran.
To investigate the vaccine potential of both the Toxoplasma GRA2 and GRA6 antigens, the full length recombinant proteins were produced in Escherichia coli, formulated in MPL adjuvant, and used alone and in combination ("mix"), to immunize CBA/J mice. Although high ratios of specific IgG2a/IgG1 were measured against both proteins, only spleen cells from GRA2-immunized mice and mix-immunized mice produced high amounts of both IFN-gamma and IL-2 upon induction with Toxoplasma gondii Excretory-Secretory Antigens. Intra peritoneal challenge with Toxoplasma cysts resulted in significant reduction of brain cysts in GRA2- and in mix-vaccinated mice only. This study shows the protective efficacy of recombinant GRA2 against chronic infection by T. gondii and confirms the utility of MPL adjuvant in enabling a vaccine candidate to induce a protective Th1 immune response.
PMID: 17418457 [PubMed - as supplied by publisher]