Impaired T Helper 2 Response to Aeroallergen in Helminth‐Infected Patients with Asthma

Abstract

Helminthic infections have been shown to inhibit allergy skin-prick tests and to modify the course of asthma. We evaluated Dermatophagoides pteronyssinus-specific immune responses in patients with asthma by measuring levels of T helper 2 (Th2) cytokines in peripheral blood mononuclear cell (PBMC) cultures. PBMCs from Schistosoma mansoni-infected patients with asthma living in an area of polyhelminthic endemicity produced lower levels of interleukin (IL)-5 and IL-4 in response to D. pteronyssinus antigen (Ag) 1 than did PBMCs from helminth-free patients with asthma. In contrast, D. pteronyssinus Ag 1-specific production of IL-10 was higher in helminth-infected patients than in helminth-free patients. The addition of recombinant human IL-10 to D. pteronyssinus Ag 1-stimulated cultures of PBMCs from helminth-free patients led to down-modulation of production of IL-5. After helminth-infected patients with asthma received antihelminthic treatment, there was down-modulation of D. pteronyssinus Ag 1-specific production of IL-10 in vitro. S. mansoni-infected patients with asthma produce lower levels of Th2 cytokines than do helminth-free patients with asthma, and this modulation is likely done by IL-10.

Schistosoma mansoni antigen-driven interleukin-10 production in infected asthmatic individuals

“…mansoni infection seems to be protective against asthma (Medeiros et al 2003, Araujo et al 2004. Using mice models of S. mansoni infection it has been demonstrated that this parasite also protects against the development of auto-immune disease such as diabetes, experimental auto-immune encephalopathy, and Crohn's disease (Cooke et al 1999, Elliott et al 2003, La Flamme et al 2003, Sewell et al 2003, Zaccone et al 2003.…”

“…Studies have shown that IL-10 is protective against asthma, and increases in levels during immunotherapy (Akdis et al 1998). The protective role of IL-10 in asthma include the induction of IgG4 (Jeannin et al 1998), down-modulation of Th2 cytokine production (Araujo et al 2004) and the inhibition of histamine and other inflammatory mediators by mast cells (Royer et al 2001).…”

“…Studies have shown that IL-10 is protective against asthma, and increases in levels during immunotherapy (Akdis et al 1998). The protective role of IL-10 in asthma include the induction of IgG4 (Jeannin et al 1998), down-modulation of Th2 cytokine production (Araujo et al 2004) and the inhibition of histamine and other inflammatory mediators by mast cells (Royer et al 2001).Considering the potential of S. mansoni antigens in protecting against allergic diseases, this study aimed to evaluate some parasite antigens regarding their ability to induce IL-10 production. The S. mansoni antigens evaluated were Sm22.6, a soluble protein from the tegument, present in all life cycle of the worm with the exception of egg (Jeffs et al 1991).…”

“…While some environmental factors precipitate the development of asthma, others seem to be protective. This is the case of helminth infections, particularly S. mansoni, which through the modulation of the inflammatory response prevent asthma (Medeiros et al 2003, Araujo et al 2004. Studying the mechanisms behind the protection against allergy, Araujo et al (2004) found that interleukin (IL-10) seems to play an important role in modulating the Th2 inflammatory response involved in the pathology of allergic diseases.…”

“…This is the case of helminth infections, particularly S. mansoni, which through the modulation of the inflammatory response prevent asthma (Medeiros et al 2003, Araujo et al 2004. Studying the mechanisms behind the protection against allergy, Araujo et al (2004) found that interleukin (IL-10) seems to play an important role in modulating the Th2 inflammatory response involved in the pathology of allergic diseases. Supporting this idea, Bigellar et al showed high levels of this cytokine in individuals infected with S. haematobium who did not respond to skin test to aeroallergens (van den Biggelaar et al 2000).…”