Immunity in the spleen and blood of mice immunized with irradiated Toxoplasma gondii tachyzoites

Autor(es)

Zorgi, Nahiara Esteves ^{[1, 2]} ; Galisteo, Jr., Andres Jimenez ^[2] ; Sato, Maria Notomi ^[3] ; do Nascimento, Nanci ^[4] ; de Andrade, Jr., Heitor Franco ^{[1, 2, 5]}

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Dept Parasitol, Inst Ciencias Biomed, Ave Prof Lineu Prestes 1374, BR-05508000 Sao Paulo, SP - Brazil

^[2] Univ Sao Paulo, FMUSP, Inst Med Trop Sao Paulo, Lab Protozool, Ave Dr Eneas de Carvalho Aguiar 470, 1 Andar, BR-05403000 Sao Paulo, SP - Brazil

^[3] Univ Sao Paulo, FMUSP, Inst Med Trop Sao Paulo, Dept Dermatol, Ave Dr Eneas de Carvalho Aguiar 470, 3 Andar, BR-05403000 Sao Paulo, SP - Brazil

^[4] IPEN, Lab Biol Mol, Rua Travessa 400, Cidade Univ, BR-05508900 Sao Paulo, SP - Brazil

^[5] Univ Sao Paulo, Dept Pathol, Fac Med, Sao Paulo - Brazil

• Tipo de documento: Artigo Científico
• Fonte: MEDICAL MICROBIOLOGY AND IMMUNOLOGY; v. 205, n. 4, p. 297-314, AUG 2016.
• Citações Web of Science: 5

Resumo

Toxoplasma gondii infection induces a strong and long-lasting immune response that is able to prevent most reinfections but allows tissue cysts. Irradiated, sterilized T. gondii tachyzoites are an interesting vaccine, and they induce immunity that is similar to infection, but without cysts. In this study, we evaluated the cellular immune response in the blood and spleen of mice immunized with this preparation by mouth (v.o.) or intraperitoneally (i.p.) and analyzed the protection after challenge with viable parasites. BALB/c mice were immunized with three i.p. or v.o. doses of irradiated T. gondii tachyzoites. Oral challenge with ten cysts of the ME-49 or VEG strain at 90 days after the last dose resulted in high levels of protection with low parasite burden in the immunized animals. There were higher levels of specific IgG, IgA and IgM antibodies in the serum, and the i.p. immunized mice had higher levels of the high-affinity IgG and IgM antibodies than the orally immunized mice, which had more high-affinity IgA antibodies. B cells (CD19(+)), plasma cells (CD138(+)) and the CD4(+) and CD8(+) T cell populations were increased in both the blood and spleen. Cells from the spleen of the i.p. immunized mice also showed antigen-induced production of interleukin-10 (IL-10), interferon gamma (IFN-gamma) and interleukin 4 (IL-4). The CD4(+) T cells, B cells and likely CD8(+) T cells from the spleens of the i.p. immunized mice proliferated with a specific antigen. The protection was correlated with the spleen and blood CD8(+) T cell, high-affinity IgG and IgM and antigen-induced IL-10 and IL-4 production. Immunization with irradiated T. gondii tachyzoites induces an immune response that is mediated by B cells and CD4(+) and CD8(+) T cells, with increased humoral and cellular immune responses that are necessary for host protection after infection. The vaccine is similar to natural infection, but free of tissue cysts; this immunity restrains infection at challenge and can be an attractive and efficient model for vaccine development in toxoplasmosis. (AU)

• Processo FAPESP: 13/04676-9 - Citometria de fluxo e fluorimetria em doenças causadas por protozoários
• Beneficiário: Heitor Franco de Andrade Junior
• Modalidade de apoio: Auxílio à Pesquisa - Regular