D3017: Tissue distribution of the German cockroach (Blattella germanica L.) allergen Bla g 5

German cockroaches (Blattella germanica L.) are common household pests and a major source of indoor allergens known to cause of asthma morbidity. They are difficult to manage for several reasons. They are extreme omnivores, domesticated and thrive in our homes, and have developed resistance to insecticides, specifically pyrethroids. There have been >10 German cockroach produced allergens identified from various tissues including whole-body extracts, digestive tract, Malpighian tubules, ovaries, ootheca, male reproductive accessory glands, exuviae and feces. One German cockroach allergen which displays high immunoglobulin E (IgE) prevalence (70%) but has been relatively understudied is Bla g 5.

The allergen Bla g 5 is believed to be a glutathione S-transferases (GST) based on sequence homology to GSTs of other insects and an ability to bind glutathione. Glutathione S-transferases serve as important detoxification enzymes in insects, and German cockroaches have been shown to have increased expression following exposure to insecticides. Because GSTs are linked to insecticide resistance in German cockroach it is also important to know the tissue distribution so that we can understand how this allergen enters the indoor environment and how insecticide use may affect production/excretion. Therefore, this study will determine where Bla g 5 is distributed in B.germanica, largely following the procedures outlined by Gore and Schal. Primarily, we will dissect and separate the cockroach into different tissues. We can then use enzyme-linked immunosorbent assays (ELISA) to determine which tissues contain Bla g 5.