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Título:
Toxoplasma Gondii AND PROTECTION AGAINST ALLERGIC SENSITIZATION
Autor/es:
BATALLA, E; MARTIN V; ROMERO Y; PIAZZÓN I; GOLDMAN A
Lugar:
Ciudad de Córdoba, Argentina.
Reunión:
Congreso; VII Congreso Latinoamericano de Inmunología, ALAI; 2005
Institución organizadora:
ALAI
Resumen:
Respiratory allergy is less frequent in people exposed to orofecal and foodborne microbes such as Toxoplasma gondii and hepatitis A virus (BMJ 2000,320:412), but not to viruses transmitted through other routes. Infection with T. gondii induces a strong cell-mediated immunity with a highly polarized Th1 response in early stages of infection (J.Immunol.1994,153:2533). We hypothesized that T. gondii infection diminishes the development of respiratory allergy. One week before allergic sensitization (day 7), adult BALB/c mice were orally infected with T. gondii (15 oocysts). They were then sensitized with two i.p. injections of OVA (days 0 and 7) before aerosol challenge (days 14-16). We evaluated allergic airway inflammation (AI) (differential count in bronchoalveolar lavage (BAL) and lung histology), serum IgE, and IgG1 OVA-specific antibodies, and IL-4 (Th2) secreted by OVA-stimulated thoracic lymph node cells. Infection was confirmed by measuring T. gondii specific antibodies.
Group
IL-4 (pg/ml)
BAL eos
(%)
IgE
(ng/ml)
IgG1
(µg/ml)
T. gondii /OVA
18,2±0,3*
6,9±3,4*
971,0±322,6*
50,6±12,2*
sham /OVA
707,2±93,7
67,9±7,4
3244,1±390,6
298,3±25,9
T. gondii /sham
<15,5
2,8±1,2
<78
<5,3x10-4
sham /sham
ND
0
<78
<5,3x10-4
X±SEM. *p<0,05 vs sham/OVA sensitized group. Histopathology showed a diminished allergic airway inflammation and goblet cell hyperplasia in OVA-sensitized mice previously infected with T. gondii. Parasite infection substantially blocked development of AI in adult BALB/c mice.