ABSTRACT
Background: We have previously reported that immunization with GRA2 antigen of Toxoplasma gondii induces protective immunity in CBA/J [H2k] and BALB/c mice [H2d]. We aimed to examine whether immunization of a distinct strain of rodent with recombinant dense granule antigens [GRA2] combined with monophosphorryl lipid A [MPL] adjuvant elicits protective immune response against T. gondii
Methods: C57BL/6 [H2b haplotype] mice were immunized with GRA2, formulated in MPL adjuvant
Results: Strong humoral response, predominantly of IgG1 subclass and cellular response, IFN-gamma, was detected at three weeks post immunization. Mice immunized with GRA2 had significantly [p < 0.01] fewer brain cysts than those in the adjuvant group, upon challenge infection. Despite the production of a strong antibody response, IFN-gamma production and brain cyst reduction were not significant when the immunized mice were infected four months after the immunization
Conclusions: We can conclude that GRA2 immunization partially protects against T. gondii infection in C57BL/6 mice, though the potency and longevity of this antigen as a standalone vaccine may vary in distinct genetic backgrounds. This observation further emphasizes the utility of GRA2 for incorporation into a multi-antigenic vaccine against T. gondii
ABSTRACT
Toxoplasmosis is a worldwide-distributed infection which is mostly asymptomatic but can cause serious health problems in congenitally-infected newborns and immunecompromised individuals. Research is under- going both to improve toxoplasma serological tests, which play the main role in laboratory diagnosis of the infection, and develop an effective vaccine to prevent the infection. Some studies showed usefulness of rhoptry protein 1 [ROP1] antigen of Toxoplasma gondii [T. gondii] in serodiagnosis of the infection and induction of protective immunity. The purpose of this study was to produce recombinant ROP1 and evaluate its antigenicity against human in-fected sera. DNA encoding ROP1, amino acids 171 to 574, was obtained from T. goncff/RH strain by polymerase chain reaction amplification and cloned in probaryotic expression plasmid pET-15b. rROPl was expressed in Escherichia coli [E coli] and purified in a single step by immobilized metal ion affinity chromatography. DNA sequencing showed 99% similarity between the cloned sequence and the corresponding sequence in Gene bank. Results indicated the proper antigenicity of rROPl. Sera from Toxoplasma infected individuals specifically recognized rROPl in Western blotting. rROPl is antigenic toward human infected sera and can be used in studies for development of both a Toxoplasma serological test and a protective vaccine
ABSTRACT
X-ray repair cross-complementing group 1 [XRCC1] gene is a DNA repair gene and its non-synonymous single nucleotide polymorphisms [SNP] may influence DNA repair capacity which has been considered as a modifying risk factor for cancer development. A case-control study was conducted to investigate impact of three frequently studied polymorphisms [Arg194Trp, Arg280His and Arg399Gln] on developing differentiated thyroid carcinoma [DTC]. Increased risks for DTC were shown in homozygous [odds ratio [OR]: 3.66, 95% confidence interval [CI]: 0.38-35.60] and in dominant trait [OR: 1.22, 95% CI: 1.64-2.32] of Arg194Trp genotype. Also, for Arg280His genotype, an increased risk for DTC was shown in dominant trait [OR: 1.42, 95% confidence interval [CI]: 0.76-2.68], while a mildly reduction of risk for DTC [OR: 0.77, 95% [CI]: 0.50-1.17] was estimated in dominant Gln genotype of Arg399Gln. Considering combinatory effects of Arg194Trp and Arg280His genotypes on DTC, the calculated OR and 95% CI for being heterozygous for one of Arg194Trp or Arg280His genotypes were 1.57 and 0.90-2.74, respectively. Genotyping of codons 194, 280 and 399 in XRCC1 gene may use in risk assessment of DTC