Study links immune responses to environmental exposures early in life

Washington, DC, Nov. 24: Environmental exposures – such as obstetric factors, farm dust, and air pollution – can lead to a change in the immune response in adolescents.

The research of the University of Eastern Finland was published in the journal Pediatric Allergy and Immunology.

There is strong evidence that different exposures early in life can alter the risk of allergic diseases. One of these shows is agriculture. It has been shown that exposure to the agricultural environment during childhood, and even before birth, decreases the risk of allergic diseases.

On the other hand, being born by caesarean section is recognized as a risk factor. The roles of other obstetric factors are less studied. Another harmful exposure is air pollution, especially particle exposure, which increases the prevalence of asthma and exacerbations in children. However, the underlying mechanisms are unclear, delaying the development of asthma prevention strategies.

Previous studies have shown that immunological development and maturation already begin during pregnancy and infancy. Therefore, exposure to this critical point of immune development can alter immune responses and cells, and thus affect the risk of allergies and other immune diseases.

The study explored how different exposures during pregnancy, birth, or childhood modulate immune responses related to asthma in children. The study involved three different exposures: a protection against asthma (agriculture) and two predisposing to asthma (caesarean section and air pollution).

"We investigated whether circulating dendritic cells were associated with agriculture, asthma or atopy, whether obstetric factors affected the immune response in adolescents born from caesarean section and whether Farm dust and urban air particles had immunomodulatory effects on children's circulating immune cells "Maria-Viola Martikainen.

The environmental exposures studied were associated with immune responses related to asthma. The inverse association between on-farm exposure and one of the subsets studied and the association between this subset and asthma in farm children suggest that this subset plays a role in the immunoregulation related to the exploitation.

In contrast, the absence of natural birth processes during delivery and intensive neonatal treatment appeared to result in long-lasting alterations of the immune response. The observed stimulatory effects of farm dust and the inhibitory effects of particulate matter on immune responses indicate that these exposures may alter responses to respiratory pathogens and allergens, and partly explain the differences in asthma prevalence between the studied environments.

The study demonstrated associations between various early-life exposures and immune responses, both ex vivo and in vitro. Some changes in immune responses appeared to be observable until adolescence. The study revealed some of the potential immunological mechanisms behind different exposures and advanced knowledge of immune mechanisms that protect against asthma or predispose to asthma.