Toxoplasma gondii infection blocks the development of allergic airway inflammation in BALB/c mice

FENOY I; GIOVANNONI M; BATALLA E; MARTÍN V; FRANK FM; PIAZZON I; GOLDMAN A

CLINICAL AND EXPERIMENTAL IMMUNOLOGY

WILEY-BLACKWELL PUBLISHING, INC

Año: 2008 vol. 155 p. 275 - 284

0009-9104

There is a link between increased allergy and a reduction of some infectionsin western countries. Epidemiological data also show that respiratory allergyis less frequent in people exposed to orofaecal and foodborne microbes suchas Toxoplasma gondii. Infection with T. gondii induces a strong cell-mediatedimmunity with a highly polarized T helper type 1 (Th1) response in earlystages of infection. Using a well-known murine model of allergic lunginflammation, we sought to investigate whether T. gondii infection couldmodulate the susceptibility to develop respiratory allergies. Both acute andchronic infection with T. gondii before allergic sensitization resulted in adiminished allergic inflammation, as shown by a decrease in bronchoalveo-lar lavage (BAL) eosinophilia, mononuclear and eosinophil cell infiltrationaround airways and vessels and goblet cell hyperplasia. Low allergen-specificimmunoglobulin (Ig)E and IgG1 and high levels of allergen-specific IgG2aserum antibodies were detected. A decreased interleukin (IL)-4 and IL-5production by lymph node cells was observed, while no antigen-specificinterferon-g increase was detected. Higher levels of the regulatory cytokineIL-10 were found in BAL from infected mice. These results show that bothacute and chronic parasite infection substantially blocked development ofairway inflammation in adult BALB/c mice. Our results support the hypoth-esis that T. gondii infection contributes to protection against allergy inhumans.