Complete protection against lethal Toxoplasma gondii infection in mice immunized with a plasmid encoding the SAG1 gene.

نویسندگان

  • H V Nielsen
  • S L Lauemøller
  • L Christiansen
  • S Buus
  • A Fomsgaard
  • E Petersen
چکیده

Infection with the protozoan parasite Toxoplasma gondii is transmitted to humans from infected animals by tissue cysts and oocysts excreted by cats. Immunization with inactivated parasites or recombinant proteins has at best shown partial protection. We constructed a plasmid expressing the SAG1 surface antigen of T. gondii, p1tPASAG1, and showed that animals immunized with the plasmid produce anti-SAG1 antibodies which recognize the native SAG1. Mice immunized with p1tPASAG1 showed 80 to 100% protection against challenge with the non-cyst-producing, virulent RH isolate, compared to an 80% mortality in mice immunized with empty plasmid, which is the greatest efficacy of any vaccine against T. gondii produced so far. The SAG1 molecule was analyzed for potential cytotoxic T-lymphocyte (CTL) epitopes, and four peptides with the best fit were synthesized. The ability of the peptides to stimulate gamma interferon production by CD8(+) T cells from p1tPASAG1-immunized mice was tested in an ELISPOT assay, and one new CTL epitope was identified. Adoptive transfer of CD8(+) T cells from p1tPASAG1-immunized to naïve mice showed partial protection. In conclusion, DNA vaccination with p1tPASAG1 gave effective protection in mice against T. gondii infection and the protection could be adoptively transferred by purified CD8(+) T cells.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

The MIC3 gene of Toxoplasma gondii is a novel potent vaccine candidate against toxoplasmosis.

Infection with the intracellular protozoan parasite Toxoplasma gondii causes serious public health problems and is of great economic importance worldwide. The micronemal protein MIC3, which is a potent adhesin of T. gondii, could be a significant candidate vaccine against toxoplasmosis. In this study, all CBA/J mice intramuscularly vaccinated with a plasmid encoding the immature form of the MIC...

متن کامل

Construction, Expression and Preliminary Immunological Evaluation of a DNA Plasmid Encoding the GRA2 Protein of Toxoplasma gondii

Toxoplasmosis is a worldwide infection which is commonly asymptomatic but can cause serious medical problems in immunocompromised individuals and fetus. The infection also causes considerable economic loss because of abortion in livestock, mostly in sheep and goats. DNA vaccination may be a powerful approach against intracellular parasites such as Toxoplasma gondii. The goal of this study was t...

متن کامل

Immunization with a DNA plasmid encoding the SAG1 (P30) protein of Toxoplasma gondii is immunogenic and protective in rodents.

Immunization with DNA can induce humoral and cell-mediated immune responses, both of which are important in conferring immunity to Toxoplasma gondii. The efficacy of genetic vaccination with a cDNA encoding the T. gondii SAG1 (P30) surface antigen was evaluated. Sera of immunized mice showed recognition of T. gondii tachyzoites by immunofluorescence and exhibited high titers of antibody to SAG1...

متن کامل

Cloning and sequencing of Toxoplasma gondii major surface antigen (SAG1) gene

  Genetic typing methods of T. gondii strains have been extensively perfected in recent years. From a technical point of view, many tools usable for genetic studied on single-copy loci have been used: RFLP, PCR-RFLP, sequencing, RAPD-PCR and isoenzyme analysis. We described the cloning and sequence analysis of the gene which encodes the major surface antigen (SAG1 or P30) of T. gondii. SAG1 is ...

متن کامل

Assessment of DNA vaccine encoding Toxoplasma gondii microneme complete gene and IL-12 as adjuvant in BALB/c mice

Objective(s): Toxoplasma gondii is an obligate intracellular protozoan parasite that causes toxoplasmosis in humans and animals. Micronemes (MICs) are effective candidates for DNA vaccine. Materials and Methods: In this study, we evaluated the immune response of BALB/c mice against MIC3 gene of Toxoplasma gondii and interleukin 12 (IL-12...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:
  • Infection and immunity

دوره 67 12  شماره 

صفحات  -

تاریخ انتشار 1999