Th1 and Th2 immune response to P30 and ROP18 peptides in human toxoplasmosis.

[congenital toxoplasmosis]

We determined the specific lymphocyte proliferative response and cytokine profile production regarding Toxoplasma P 30 (2017 from virulent and non-virulent strain ) and ROP 18 protein-derived peptides (from clonal lineages I , II and III ) in 19 patients having ocular toxoplasmosis , five suffering chronic asymptomatic infection , nine with congenital toxoplasmosis and eight Toxoplasma negative people . A Beckman Coulter FC 500 flow cytometer was used for determining antigen-specific T cells (CD 3 + CD 4 + or CD 3 + CD 8 + cells ) in peripheral blood culture . IFN γ and IL 10 levels were determined in culture supernatants . Specific CD 4 + and CD 8 + T cell response to total antigen and P 30 - and ROP 18 -derived peptides was observed in infected people . Ocular toxoplasmosis patients had a preferential Th 2 response after antigenic stimulation . Non-virulent peptide 2017 was able to shift response toward Th 1 in congenitally infected children and virulent peptide 2017 induced a Th 2 response in chronically infected , asymptomatic people . An immune response in human toxoplasmosis after ex vivo antigenic stimulation was Th 1 - or Th 2 -skewed , depending on a patient 's clinical condition . Colombian ocular toxoplasmosis patients ' immune response was Th 2 -skewed , regardless of the nature of antigen stimulus .