摘要：Within its intermediate host, such as man, the protozoan parasite Toxoplasma gondii
interconverts between tachyzoites and bradyzoites. The replicative tachyzoite stage is thought to be
responsible for acute/active infection and expresses immunodominant antigens thereby inducing a strong
cellular immune response, which vice versa triggers the differentiation process into dormant and immunologically
weak cyst stages. The immunodominance of tachyzoites is also responsible for the induction of a
strong humoral immune response leading to the formation of antibodies specifically directed against
tachyzoite antigens. In contrast, the bradyzoite stage which is associated with inactive/chronic infection,
seems not to be a strong inducer of specific antibodies. However, since the humoral antibody response is also
directed against antigens that are expressed in both stages, serodiagnosis cannot always adequately
discriminate between active and inactive/chronic infection. This short review focuses on the impact of stage
differentiation and discusses the potential of stage-specifically expressed antigens that might be useful in a
recombinant form in order to improve future serodiagnostical approaches.
