scholarly journals Staphylococcus aureus Escapes More Efficiently from the Phagosome of a Cystic Fibrosis Bronchial Epithelial Cell Line than from Its Normal Counterpart

2006 ◽  
Vol 74 (5) ◽  
pp. 2568-2577 ◽  
Author(s):  
Todd M. Jarry ◽  
Ambrose L. Cheung

ABSTRACTStaphylococcus aureusis frequently the initial bacterium isolated from young cystic fibrosis (CF) patients, and yet its role in CF disease progression has not been determined. Recent data from our lab demonstrates thatS. aureuscan invade and replicate within the CF tracheal epithelial cell line (CFT-1). Here we describe the finding that the fate of internalizedS. aureusin CFT-1 cells differs from its complemented counterpart (LCFSN).S. aureusstrain RN6390 was able to replicate within the mutant CFT-1 cells after invasion but not in the complemented LCFSN cells. At 1 h postinvasion,S. aureuscontaining vesicles within both cell lines acquired vacuolar-ATPase, lysosomal markers LAMP 1 and 2, and the lysomotrophic dye LysoTracker to a similar degree. However, at 4 h postinvasion, the percentage ofS. aureuswithin CFT-1 cells associated with these markers decreased significantly compared to LCFSN, where the association approached 100%. Transmission electron microscopic analysis revealed that the majority of bacteria within CFT-1 cells were free in the cytosol at 4 h after invasion, whereas mostS. aureusbacteria internalized by LCFSN cells remained within vesicles. These results demonstrate a fundamental difference in the fate of liveS. aureusafter invasion of CFT-1 versus LCFSN cell lines and may explain the propensity ofS. aureusto cause chronic lung infection in CF patients.

1997 ◽  
Vol 273 (5) ◽  
pp. L913-L920 ◽  
Author(s):  
Xiaosui Jiang ◽  
Warren G. Hill ◽  
Joseph M. Pilewski ◽  
Ora A. Weisz

Altered glycosylation of mucus and membrane glycoconjugates could explain reported differences in binding of bacterial pathogens to cystic fibrosis (CF) versus normal tissue. However, because bacteria can alter cell surface glycoconjugates, it is not possible to assess the role of cystic fibrosis transmembrane conductance regulators (CFTR) in glycosylation in these studies. To address this issue, we have developed quantitative lectin binding assays to compare cell surface glycosylation in well-matched immortalized CF cells and rescued cell lines. The CF airway bronchial epithelial cell line IB3-1 consistently bound more peanut agglutinin (PNA) than its clonal derivative S9, which stably expresses functional wild-type CFTR. Pretreatment with neuraminidase increased PNA binding and abolished the difference between the two cell lines. However, infection of the IB3-1 cells with a replication-deficient recombinant adenovirus encoding CFTR restored CFTR function but did not alter PNA binding to cells. In contrast, treatment with the weak base ammonium chloride increased PNA binding to both cell lines as expected. Our data show that even clonally related CF and rescued cells can exhibit significant differences in carbohydrate processing. Although the differences that we found are consistent with the proposed role for CFTR in modulating intraorganellar pH, our data strongly suggest that they are CFTR independent. These studies add a cautionary note to the interpretation of differences in glycosylation between CF and normal primary tissues and immortalized cells.


1988 ◽  
Vol 106 (3) ◽  
pp. 761-771 ◽  
Author(s):  
P Boukamp ◽  
R T Petrussevska ◽  
D Breitkreutz ◽  
J Hornung ◽  
A Markham ◽  
...  

In contrast to mouse epidermal cells, human skin keratinocytes are rather resistant to transformation in vitro. Immortalization has been achieved by SV40 but has resulted in cell lines with altered differentiation. We have established a spontaneously transformed human epithelial cell line from adult skin, which maintains full epidermal differentiation capacity. This HaCaT cell line is obviously immortal (greater than 140 passages), has a transformed phenotype in vitro (clonogenic on plastic and in agar) but remains nontumorigenic. Despite the altered and unlimited growth potential, HaCaT cells, similar to normal keratinocytes, reform an orderly structured and differentiated epidermal tissue when transplanted onto nude mice. Differentiation-specific keratins (Nos. 1 and 10) and other markers (involucrin and filaggrin) are expressed and regularly located. Thus, HaCaT is the first permanent epithelial cell line from adult human skin that exhibits normal differentiation and provides a promising tool for studying regulation of keratinization in human cells. On karyotyping this line is aneuploid (initially hypodiploid) with unique stable marker chromosomes indicating monoclonal origin. The identity of the HaCaT line with the tissue of origin was proven by DNA fingerprinting using hypervariable minisatellite probes. This is the first demonstration that the DNA fingerprint pattern is unaffected by long-term cultivation, transformation, and multiple chromosomal alterations, thereby offering a unique possibility for unequivocal identification of human cell lines. The characteristics of the HaCaT cell line clearly document that spontaneous transformation of human adult keratinocytes can occur in vitro and is associated with sequential chromosomal alterations, though not obligatorily linked to major defects in differentiation.


2004 ◽  
Vol 286 (4) ◽  
pp. L777-L785 ◽  
Author(s):  
Kei Takamura ◽  
Yasuyuki Nasuhara ◽  
Motoko Kobayashi ◽  
Tomoko Betsuyaku ◽  
Yoko Tanino ◽  
...  

Retinoic acid (RA) is known to accelerate wound healing and induce cell differentiation. All- trans RA (ATRA) exerts its effect by binding retinoic acid receptors, which are members of the nuclear receptor family. We investigated whether RA can alter expression of eotaxin, a potent eosinophil chemoattractant that is regulated by the transcription factors signal transducer and activator of transcription 6 (STAT6) and NF-κB. We examined the effects of RA on eotaxin expression in a human bronchial epithelial cell line BEAS-2B. ATRA and its stereodimer 9- cis retinoic acid (9- cis RA) inhibited IL-4-induced release of eotaxin at 10-6M by 78.0 and 52.0%, respectively ( P < 0.05). ATRA and 9- cis RA also significantly inhibited IL-4-induced eotaxin mRNA expression at 10-6M by 52.3 and 53.5%, respectively ( P < 0.05). In contrast, neither ATRA nor 9- cis RA had any effects on TNF-α-induced eotaxin production. In transfection studies using eotaxin promoter luciferase plasmids, the inhibitory effect of ATRA on IL-4-induced eotaxin production was confirmed at the transcriptional level. Interestingly, ATRA had no effects on IL-4-induced tyrosine phosphorylation, nuclear translocation, or DNA binding activity of STAT6. Activating protein-1 was not involved in ATRA-mediated transrepression of eotaxin with IL-4 stimulation. The mechanism of the inhibitory effect of ATRA on IL-4-induced eotaxin production in human bronchial epithelial cells has not been elucidated but does not appear to be due to an effect on STAT6 activation. These findings raise the possibility that RA may reduce eosinophilic airway inflammation, one of the prominent pathological features of allergic diseases such as bronchial asthma.


Sign in / Sign up

Export Citation Format

Share Document