Effects of Bordetella pertussis infection on human respiratory epithelium in vivo and in vitro

Abstract

Bordetella pertussis infection probably involves attachment to and destruction of ciliated epithelial cells, but most previous studies have used animal tissue. During an epidemic, nasal epithelial biopsy specimens of 15 children (aged 1 month to 3 1/2 years) with whooping cough were examined for ciliary beat frequency, percent ciliation of the epithelium, and ciliary and epithelial cell ultrastructure. In addition, the in vitro effects of filtrates from a 24-h broth culture and of tracheal cytotoxin derived from B. pertussis on human nasal tissue organ culture were measured. B. pertussis was cultured from nasal swabs from 12 children. The mean ciliary beat frequency of their nasal biopsy specimens, 11.3 Hz (range, 10.4 to 13.0 Hz) was similar to that found in biopsy specimens from 10 normal children (mean, 12.5 Hz; range, 11.8 to 13.5 Hz). The abnormalities of the epithelium observed in 14 of 15 patients were a reduction in the number of ciliated cells, an increase in the number of cells with sparse ciliation, an increase in the number of dead cells, and extrusion of cells from the epithelial surface. In vitro, neither culture filtrate nor tracheal cytotoxin had any acute effect on ciliary function, but culture filtrate and tracheal cytotoxin (1 and 5 microM, respectively) caused extrusion of cells from the epithelial surface of turbinate tissue, loss of ciliated cells, an increased frequency of sparsely ciliated cells, and toxic changes in some cells. These changes were dose dependent and progressive, and between 36 and 90 h ciliary beating ceased. The observations made with patient tissue confirm that B. pertussis infection damages ciliated epithelium, and the in vitro experiments suggest that tracheal cytotoxin may be responsible for the abnormalities observed in vivo.

Role ofBordetella pertussisVirulence Factors in Adherence to Epithelial Cell Lines Derived from the Human Respiratory Tract

“…Since we observed no effect on the viability of the cells, we conclude that neither virulence factor has a toxic effect on respiratory tract epithelial cells. This observation is supported by an earlier report describing that tracheal cytotoxin instead of PT is the toxic virulence factor for primary human ciliated bronchial epithelium (52).…”

“…Some of these factors, including pertussis toxin (PT), adenylate cyclase, tracheal cytotoxin, dermonecrotic toxin, and lipopolysaccharide, exert a toxic effect. Other virulence factors, such as filamentous hemagglutinin (FHA), fimbriae, pertactin (Prn), and PT, have been reported to mediate the adherence of B. pertussis to various mammalian cells, including human epithelial cells (11,14,47,49,52) and human monocytes (17,36). However, most of these studies pertain to the role of one or more of these virulence factors in the binding of B. pertussis to cells (4,12,13,28,32,38,47,49,51); a comparative study of the most relevant adhesion factors was lacking until now.…”

Effect of tracheal cytotoxin from Bordetella pertussis on human neutrophil function in vitro

“…TCT cytotoxicity has been previously documented in both hamster tracheal (6) and human nasal (28) organ cultures incubated with 10-6 M TCT. We have shown that TCT at 10-11 M is able to significantly inhibit important human neutrophil functions in vitro, and TCT is thus more potent in this biological assay system than in those previously described (6,28). The concentrations of TCT present in the airways of patients infected with B. pertiussis are not known, although in vitro studies have shown that under optimal conditions, 10-6 M TCT may be elaborated in broth culture (6).…”

Viability of cultured periodontal pocket epithelium cells and Porphyromonas gingivalis association

“…1999), although, for the latter, host cell death was contact dependent as EPEC is a non‐invasive pathogen. Bordetella pertussis infection increased the number of dead respiratory epithelial cells in vitro progressively and dose dependently (Wilson et al . 1991).…”