Cruz, R

Cruz, R. the production of spontaneous IL-10. Among infectious brokers, helminth parasites are regarded as master manipulators of the host immune response, being associated with chronic but generally asymptomatic infections. Although helminth infections induce strong Th2 responses, parasitic worms may survive in their mammalian hosts by switching off inflammatory immune responses and inducing a tolerant response to parasite antigens (38). Atopy, characterized by raised immunoglobulin E (IgE) levels, is considered a major mediator of allergic diseases such as asthma, rhinoconjunctivitis, and eczema. The interaction of an environmental allergen with the innate immune system, uptake by antigen-presenting cells, and subsequent T-cell priming lead to the activation of Th2 cytokines, such as interleukin-4 (IL-4), IL-5, and IL-13. These cytokines stimulate IgE production and increased numbers of eosinophils and mast cells, which together may cause allergic inflammation in the respiratory NPI64 tract (37). The hygiene hypothesis has tried to explain the temporal styles of increased allergic disease prevalence over recent decades in industrialized countries by alterations in the host response to environmental allergens caused by decreased exposure to child years infections through improvements in hygiene and greater access to antibiotics and vaccines (32). Such improved hygiene has been considered to alter the balance between type 1 (Th1) and type 2 (Th2) immune responses due to a failure of immune regulation resulting in allergy-mediating Th2 responses (22). Exposure to pathogens and their products, and to helminths in particular, has been shown to protect against the development of autoimmune and allergic diseases in experimental animal models (7, 8, 10, 23, 25, 26, 28), and some evidence in support of this has been observed in human populations (3, 8, 10, 23, 29, 30, 31). We previously exhibited that children living in circumstances of poor hygiene without access to sanitation or clean water during the first 3 years of life have elevated spontaneous production of IL-10 up to 8 years later in life (13). In the present study, we compared cytokine profiles from whole-blood NPI64 cultures and antibody responses among children stratified by intestinal helminth contamination status, decided at two individual time points in childhood. MATERIALS AND METHODS Study populace and data collection. This study was conducted in the city of Salvador in northeastern NPI64 Brazil, which has a populace of 2.5 million. The prevalence of wheezing in this city in the past 12 months in school children aged 12 to 13 years was reported to be very high (27.1%) (29). The design Rabbit Polyclonal to T3JAM of this study has been reported elsewhere (6, 13, 29). In short, the study populace included 1,445 children recruited in infancy for any prospective study measuring the impact of a citywide sanitation program on child years morbidity (5). Data were collected from children given birth to between 1994 and 2001 who lived in sentinel neighborhoods in the city. Standardized questionnaires were administered to the children’s guardians between 1997 and 2003 (baseline) to collect data on demographic and interpersonal variables as well as on the home environment. In 2000, stool samples were collected to detect intestinal helminth contamination (33). The children were surveyed again in 2005 to collect data on the same variables and to obtain stool and blood samples. Of the 1,445 children included in the study, we assayed 1,006 for gamma interferon (IFN-), 1,356 for IL-10, 1,289 for IL-13, and 1,243 for IL-5. For the present analysis, we used data on 1,060 children who had information for.