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Autoimmune regulator (AIRE) is a transcription factor expressed in the thymic medullary epithelial cells (MECs). MECs have been suggested to contribute to tolerance induction by presenting tissue specific antigens to T cells that react to these antigens. AIRE expression in cells other than MECs has not been studied extensively. Here we report four-color flow cytometric and quantitative real-time PCR studies on the expression of AIRE in the lymphoid cells in the thymus and periphery. In the thymus AIRE was expressed in B cells and CD4+CD8+ double positive cells at a low level. In the peripheral blood AIRE was expressed in B cells but not in T cells, and also expressed in CD14+ dendritic cells (DCs)/macrophages and granulocytes at higher levels. AIRE mRNA was expressed higher in B cells than in T cells. Further study is warranted to define the functional role of the AIRE expressed in the lymphoid cells.

Bombyx mori chitinase (Bm-CHI), with a molecular mass of 75 kDa, was investigated on the possibility that it can serve as a biocontrol agent against the adult Japanese pine sawyer (JPS), Monochamus alternatus (Coleoptera: Cerambycidae). Oral ingestion of purified chitinase at concentrations of 3 microM (11.25 microg/50 microl) and 0.3 micoM (1.125 microg/50 microl) caused high mortality in JPS, a significant decrease in bark consumption, and, only in high concentration, a slight reduction of body weight. Fluorescence assays indicated that peritrophic membrane (PM) chitin is degraded by the action of orally ingested Bm-CHI at 3 microM concentration only. Scanning electron micrographs clearly indicated that the beetles that ingested Bm-CHI of the same high concentration had their PM perforated and disrupted, but ultrastructural studies showed that the ingested chitinase did not affect the midgut epithelium. These findings open up the possibility of using insect chitinase as a biopesticidal enzyme. It should have agronomic potential for insect control.