Air Date: 11-2-2012| Episode: 262
This week on IAQ Radio we delve into the connection between house dust and asthma with Dr. Donald Cook of the National Institute of Health…
This week on IAQ Radio we delve into the connection between house dust and asthma with Dr. Donald Cook of the National Institute of Health. Dr. Cook’s recent research indicates that a specific component of bacteria found in common house dust activates the immune system so people are more likely to develop allergies to real allergens. Donald N. Cook, Ph.D., is the head of the Immunogenetics Group; he earned his Ph.D. in microbiology and immunology at McGill University in Montreal, Canada. He has published 43 peer-reviewed articles in leading biomedical journals as well as several book chapters. Cook served as a principal scientist at Schering-Plough Research Institute and as an assistant professor in the Division of Pulmonary and Critical Care Medicine at Duke University before joining NIEHS in 2005.
The Magellan of flagellin
Donald Cook Ph.D, who heads the National Institute of Environmental Health Sciences’ Immunogenetics Group, was today’s guest on IAQradio. According to Dr. Cook: Flagella are a whip- like appendages which provide some types of bacteria with the ability to swim. Flagellin is the main protein component of flagella. Flagellin from bacteria acts as an adjuvant promoting allergic sensitization to inhaled allergens. Dr. Cook and his colleagues are studying this hypothesis in mice. Flashbacks to previous episodes with Dr. James Sublett, MD and Dr. John Ouellette, MD helped set the stage:
Nuggets mined from today’s episode:
Dr Sublette- Asthma is a chronic illness that often begins in childhood consisting of 3 components: bronchospasm constricting of airway muscles, inflammation and increased mucus production.
Dr. Ouellette- Allergy is an immune response triggered by IGE antibody, aka “Evil Antibody IGE”. Predisposed people produce more antibody IGE. Microbes use their inherent weapons of mass destruction to battle each over available resources. Endotoxin is a large molecule likely responsible for litigation in the Broward County Courthouse and elsewhere
•Adaptive immune response is a specialized and adaptive response that suppresses the growth of pathogens.
•An adjuvant enhances some types of immune responses.
•There are many sources of bacteria that are found in house dust including plants, kids, food and pets. Wet areas such as showers and drains are sources of microbial growth.
•By weight, 8% of bacteria may be flagellin.
•Mammalian cells recognize microbial products such as endotoxin and flagellin.
•Viral infection, endotoxin, flagellin can exacerbate asthma in people who already have it, and might also contribute to the initiation of asthma.
•House dust from low income housing tends to have higher levels of some allergens.
•Maintaining a clean home environment might reduce the prevalence of asthma.
•Hygiene hypothesis- the absence of early childhood exposure to infectious agents might increase susceptibility to allergic disease in some individuals by suppression some aspects of the immune system.
The word flagella brought back vivid memories of 6th grade health class, where as preteens we watched a sex education film in which human seminal fluid was viewed under high microscopy. Perhaps I could contribute something to important health research? I began to mentally connect the dots. Human seminal fluid has flagella and contains proteins; could spent human seminal fluid be a cause of asthma, unlikely according to Dr. Cook. Oh well.
Today’s Music: “Allergies” by Paul Simon
Z-Man signing off