Experimental reinfection of BALB/c mice with different recombinant type I/III strains of Toxoplasma gondii: involvement of IFN-gamma and IL-10.
To assess reinfection of BALB/c mice with different Toxoplasma gondii strains, the animals were prime infected with the non-virulent D8 strain and challenged with virulent recombinant strains. Thirty days after challenge, brain cysts were obtained from surviving BALB/c mice and inoculated in Swiss mice to obtain tachyzoites for DNA extraction and PCR-RFLP analysis to distinguish the different T. gondii strains present in possible co-infections. Anti-Toxoplasma immune responses were evaluated in D8-primed BALB/c mice by detecting IFN-gamma and IL-10 produced by T cells and measuring immunoglobulin levels in serum samples. PCR-RFLP demonstrated that BALB/c mice were reinfected with the EGS strain at 45 days post prime infection (dpi) and with the EGS and CH3 strains at 180 dpi. High levels of IFN-gamma were detected after D8 infection, with no significant difference between 45 and 180-day intervals. However, higher IL-10 levels and higher plasmatic IgG1 and IgA were detected from samples obtained 180 days after infection. BALB/c mice were susceptible to reinfection with different recombinant T. gondii strains and this susceptibility correlated with enhancement of IL-10 production.
Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brasil.
Geane Peroni
GP
Brandão
Maria Norma
MN
Melo
Ricardo Tostes
RT
Gazzinelli
Braulia Costa
BC
Caetano
Adriana Melo
AM
Ferreira
Letícia Azevedo
LA
Silva
Ricardo Wagner Almeida
RW
Vitor
D000818:Animals; D016054:DNA, Protozoan / Q000235:genetics; D005838:Genotype; D007136:Immunoglobulins / Q000097:blood; D007371:Interferon-gamma / Q000276:immunology*; D016753:Interleukin-10 / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D016133:Polymerase Chain Reaction; D012150:Polymorphism, Restriction Fragment Length; D013997:Time Factors; D014122:Toxoplasma / Q000145:classification / Q000235:genetics* / Q000276:immunology; D014124:Toxoplasmosis, Animal / Q000276:immunology / Q000469:parasitology*
D016054:DNA, Protozoan; D007136:Immunoglobulins; D016753:Interleukin-10; D007371:Interferon-gamma