Tetsuo Asai

Increased levels of tumor necrosis factor and interleukin 1 in bronchoalveolar lavage fluids from pigs infected with Mycoplasma hyopneumoniae

We examined the levels of tumor necrosis factor (TNF)-alpha and interleukin-1 (IL-1) in bronchoalveolar lavage fluids (BALF) from pigs experimentally infected with Mycoplasma hyopneumoniae using biological assays with WEHI-164 cells and D10.G4.1 cells, respectively. Increased TNF-alpha and IL-1 in BALF were found in infected pigs with gross and/or microscopic lesions. A time-course study suggested TNF-alpha and IL-1 to be persistently elevated in infected pigs. Their presence in BALF would thus appear to be associated with the development of pneumonic lesions in M. hyopneumoniae infected pigs.

DETECTION OF INTERLEUKIN-6 AND PROSTAGLANDIN E2 IN BRONCHOALVEOLAR LAVAGE FLUIDS OF PIGS EXPERIMENTALLY INFECTED WITH MYCOPLASMA HYOPNEUMONIAE

In this study, interleukin-6 (IL-6) and prostaglandin E2 (PGE2) were detected in the bronchoalveolar lavage fluids (BALF) from pigs experimentally infected with Mycoplasma hyopneumoniae. IL-6 was detected at 2 weeks post-inoculation (PI), and significantly increased levels of PGE2 were observed at 4 weeks PI. In the BALF collected from infected pigs at 4 weeks PI, the levels of IL-6 increased significantly in the pigs with pneumonic lesions. However, increased levels of PGE2 were observed in all the infected pigs.

Cytological and immunological changes in bronchoalveolar lavage fluid and histological observation of lung lesions in pigs immunized with Mycoplasma hyopneumoniae inactivated vaccine prepared from broth culture supernate

We have compared the cytology of bronchoalveolar lavage fluid (BALF) and the pathology of lung lesions in pigs immunized with/without Mycoplasma hyopneumoniae inactivated vaccine prepared from broth culture supernate on experimental infection. Numbers of total cells, macrophages, neutrophils and lymphocytes have decreased in BALF of vaccinated pigs following infection. The mean percentage of lung lesions, inflammatory cell infiltration into the airways and T cells accumulation around the bronchi were reduced in vaccinated pigs. The levels of tumor necrosis factor (TNF)-alpha also decreased in vaccinated pigs. These results suggest that the vaccination may contribute to decrease TNF-alpha production, and therefore, inflammatory cell responses in the lung due to M. hyopneumoniae infection were suppressed, resulting in fewer lung lesions.

Suppressive effect of bronchoalveolar lavage fluid from pigs infected with Mycoplasma hyopneumoniae on chemiluminescence of porcine peripheral neutrophils.

Bronchoalveolar lavage fluid (BALF) from pigs experimentally infected with Mycoplasma hyopneumoniae suppressed the chemiluminescence (CL) response of porcine polymorphonuclear neutrophils (PMN). The suppressive effect was significantly correlated with the concentration of prostaglandin E2 (PGE2) in the BALF. Furthermore, purified human PGE2 suppressed the CL response of porcine PMN. The increased level of PGE2 following infection with M. hyopneumoniae may be responsible for the suppression of PMN function in the airway of infected pigs. The decrease of PMN function may be responsible for exacerbation of mycoplasmal pneumonia by secondary infection with pulmonary bacterial pathogens.