Molecular characterization of aspergillus fumigatus allergens.

Aspergillus fumigatus (Af) is ubiquitous saprophytic fungus associated with a broad spectrum of diseases in humans. These diseases range from benign colonization of the lung to life threatening diseases such as allergic bronchopulmonary aspergillosis (ABPA) and invasive aspergillosis. Af is the etiologic agent identified in most of the Aspergillus related human diseases and is therefore of particular clinical importance. Af induced obstructive airway diseases may be due to transient exposure to fungal spores resulting in a T helper 2 response. The IgE mediated inflammatory reaction could be due to colonization of bronchial airway epithelium by Af. Early and precise diagnosis of Aspergillus induced respiratory allergy is essential for preventing irreversible lung damages. The major problems in the diagnosis of A. fumigatus induced diseases are due to the lack of standardized and well characterized fungal extracts. The advent of molecular cloning technology and the development of phage surface display technology for cloning genes have facilitated the isolation of more relevant recombinant allergens. Using these techniques, a panel of different Af allergens having distinct IgE binding with various groups of Af sensitized patients have been cloned and characterized. These allergens can be categorized functionally as secreted and cytoplasmic proteins. The distinct IgE binding property of these purified and well characterized recombinant Af allergens may be useful for the differential diagnosis of Af related pulmonary complications.

Immunology of allergic bronchopulmonary aspergillosis.

Allergic bronchopulmonary aspergillosis (ABPA) is a hypersensitivity lung disease caused predominantly by the ubiquitous fungus Aspergillus fumigatus. ABPA is characterized by eosinophilia, fleeting pulmonary infiltrates, central bronchiectasis, elevated serum IgE and Aspergillus specific IgG and IgE. The pathogenetic mechanism implicated in ABPA is not completely understood. The cytokine response detected in ABPA patients is of a CD4+ Th2 type as evidenced by the production of IL-4, IL-5, and very little or no IFN-g on stimulation of T-lymphocytes with Aspergillus antigens. Animal model studies using wild type and gene knockout mice indicate a more precise mechanism of lung injury in antigen exposed animals. IL-4 knockout mice invariably showed a predominant Th1 response. B-cell deficient and IgE knockout mice exposed to A. fumigatus antigens showed airway response similar to wild type mice indicating a lesser role for IgE and other antibodies in the pathogenesis of murine experimental ABPA. RAG negative mice failed to show airway hyperreactivity response, although airway hyperreactivity was induced in naive RAG negative animals when T-cells from wild type Aspergillus immunized mice were transferred. The results of these studies indicate a multi-factorial immunopathogenesis in ABPA, which include T-cells, IgE, eosinophils, mast cells, and various cytokines and chemokines.

Serological investigation of refractory human adult periodontitis.

This study examined the difference between the serum antibody profiles in refractory adult periodontitis patients (group A), and compared to those (group B) who responded well to conventional periodontal treatment. The levels of specific IgG antibody to Actinobacillus actinomycetemcomitans, Bacteroides gingivalis, Fusibacteriumnucleatum, and Eikenella corrodens were assessed in a group of 19 patients (group A) and 11 patients (group B). Specific IgG serum antibody levels were estimated using biotin-avidin linked immunosorbent assay (BALISA). Results indicated that Actinobacillus actinomycetemcomitans, and Bacteroides gingivalis had very high levels of specific circulating antibody in the sera of both groups of patients; whereas, Fusobacterium nucleatum and Eikenella corrodens showed considerable lower levels of antibody than the other two antigens. However, the differences between the two groups with regard to the antibody levels against different bacterial antigens were not statistically significant.

The prevalence of thermophilic actinomycetes in sugar cane related environments and precipitins in the population in Puerto Rico.

Estudios de nuestras relacionadas a la cana de azucar y otras fuentes ambientales demuestran que los dos principales actinomicetos termofilicos aislados en las planicies de la costa Sur de Puerto Rico son Thermoactinomyces candidus y T.vulgaris. Muestras de aires tomadas al momento que hay quema de la cana demuestran la aislacion de un gran numero de actinomicetos termofilicos mientras que los resultados son negativos cuando no hay quema de la cana