title: T cell mediated immune responses to Toxoplasma gondii in pregnant women with primary toxoplasmosis.
abstract: The aim of this study was to investigate T cell immunity to Toxoplasma gondii (Tg) in pregnant women with primary toxoplasmosis. This issue has never been addressed before in humans and available information derives from murine models. Peripheral blood mononuclear cells (PBMC) from pregnant women with primary Tg infection were stimulated with Tg tachyzoites, excretory-secretory antigens (ESA) or recombinant surface antigen-1 (rSAG-1), and tested for proliferation, immunophenotype, cytokine production and antigen specific cytotoxic activity. Pregnant women with primary toxoplasmosis displayed a significant decrease of the CD4/CD8 T cell ratio and a significant increase of circulating T cell receptor (TCR) gammadelta+ cells as compared to their uninfected counterparts. T cells from Tg infected pregnant women proliferated to Tg tachyzoites, ESA or rSAG-1. Most tachyzoite and ESA specific T cell blasts were CD4+, whereas SAG-1 specific blasts were CD4+ and CD8+. ESA and tachyzoite specific T cell blasts displayed a Th1 or Th0 cytokine profile with overexpression of IFN-gamma. This pattern was unchanged upon in vitro exposure of T cells to progesterone, tested at a concentration close to that reached in vivo at the maternal-fetal interface. Finally, tachyzoite or ESA specific T cell blasts lysed, through a granule exocytosis dependent mechanism, autologous lymphoblastoid cell lines presenting Tg antigens. In conclusion, pregnant women with primary toxoplasmosis mounted in vitro Tg-specific Th1/Th0 responses whose impact on neonatal infection warrants further investigation.
authors.affiliation: Laboratory of Oncology, Department of Experimental and Laboratory Medicine, G. Gaslini Scientific Institute, Largo G. Gaslini 5, 16148 Genoa, Italy. ignaziaprigione@ospedale-gaslini.ge.it
authors.forename: Ignazia
authors.initials: I
authors.lastname: Prigione
authors.forename: Sabrina
authors.initials: S
authors.lastname: Chiesa
authors.forename: Paola
authors.initials: P
authors.lastname: Taverna
authors.forename: Roberto
authors.initials: R
authors.lastname: Ceccarelli
authors.forename: Rosanna
authors.initials: R
authors.lastname: Frulio
authors.forename: Fabio
authors.initials: F
authors.lastname: Morandi
authors.forename: Paola
authors.initials: P
authors.lastname: Bocca
authors.forename: Marie-France
authors.initials: MF
authors.lastname: Cesbron-Delauw
authors.forename: Vito
authors.initials: V
authors.lastname: Pistoia
mesh_terms: D000818:Animals; D000953:Antigens, Protozoan / Q000235:genetics / Q000276:immunology; D016516:CD4-CD8 Ratio; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism; D005260:Female; D006801:Humans; D016130:Immunophenotyping; D008213:Lymphocyte Activation; D011247:Pregnancy; D015597:Pregnancy Complications, Parasitic / Q000276:immunology* / Q000469:parasitology; D015800:Protozoan Proteins / Q000235:genetics / Q000276:immunology; D011994:Recombinant Proteins / Q000276:immunology; D013601:T-Lymphocytes / Q000276:immunology*; D014122:Toxoplasma / Q000276:immunology*; D014123:Toxoplasmosis / Q000276:immunology* / Q000469:parasitology
chemical_list: D000953:Antigens, Protozoan; D016207:Cytokines; D015800:Protozoan Proteins; D011994:Recombinant Proteins; C047168:SAG1 antigen, Toxoplasma