Do immune responses to inhaled skin flakes modulate the expression of allergic disease?

Abstract

We examine the nature of the immune responses to inhaled skin particles and query whether early exposure could play a role in providing protection against the development of allergic disease. Currently, the main hypothesis used to explain environmental modulation of allergic diseases, the 'hygiene hypothesis', is linked exclusively to microbial exposures acting upon the innate immune system. However, many of the exposures sustaining this hypothesis also involve co-exposure to skin flakes from humans or animals. Such skin flakes contain a complex mixture of antigens, glycolipids and small peptides that may induce immune responses. Should these responses prove relevant to the modulation of allergic diseases, it provides new opportunities to better understand the epidemic of allergic disease and to develop new interventions for its prevention.

Exploring the feasibility of bioaerosol analysis as a novel fingerprinting technique

“…They are generated from viable organisms then released into the air spontaneously, as a consequence of environmental conditions, or some other mechanical disturbance. The existence of aerosolized skin in airborne particulate matter has been recognized for more than three decades [11, 12], and it continues to be investigated and better understood in more recent years [8, 13]. …”

“…This type of debris is a also major constituent of house dust which is constantly re-aerosolized allowing the skin flakes to re-circulate in the air mass [13]. Bahadori and coworkers reported mean concentrations of such dust in the breathing zone (44 ± 3μgm −3 ) is more than twice that in the ambient air [14].…”

Animal fur and asthma: an indoor farmyard phenomenon?

“…An intriguing alternative has been suggested by TOVEY et al [20]. These authors suggest that many of the protective effects associated with the hygiene hypothesis involve intensive exposure to animal or human dander (kids, cats and cows), and that house dust contains large quantities of human skin flakes capable of being inhaled.…”

“…These contain potentially immunoactive constituents including a variety of antigens, glycolipids and small peptides. Feather bedding is a potent source of airborne feather fragments [20] and may provide exposure to a complex array of keratin xenoantigens. Thus, it is conceivable that the intriguing protective effect of animal furs ( perhaps in a low house dust mite environment) may arise in the same way and is certainly worthy of further investigation.…”

The bell tolls for the relationship between house dust mite exposure and asthma in childhood

“…A number of other important analyses of the data from this CAPS cohort include: examining the time course of atopy, eczema and asthma/rhinitis during early childhood [14]; describing seasonal and climatic variation in house dust mite allergen levels [15]; exploring changes in immunological profiles during the first 5 yrs of life [16]; assessing the impact of duration of breast feeding and other infant feeding practices [17]; possession of cats and dogs; and levels of fatty acids in the blood and the diet on the incidence of allergic disease during early childhood [18]; and describing the incidence of snoring in children with rhinitis [19]. In the group, there was also a lot of creative thinking about alternative explanations to the ''hygiene hypothesis'', which has produced a number of new research questions [20]. It was a very rewarding experience to undertake research as a postdoctorate in a new and creative environment, and I am now in the process of developing plans for future research projects in Sweden.…”