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CEACAM engagement by human pathogens enhances cell adhesion and counteracts bacteria-induced detachment of epithelial cells.

Muenzner P, Rohde M, Kneitz S, Hauck CR - J. Cell Biol. (2005)

Bottom Line: Blockage of CD105 expression by antisense oligonucleotides abolished infection-induced cell adhesion.The CD105-mediated increase in cell adhesion was dependent on the presence and function of integrin beta1.CD105 expression did not elevate cellular integrin levels but caused a dramatic increase in the ECM-binding capacity of the cells, suggesting that CD105 affects integrin activity.

View Article: PubMed Central - PubMed

Affiliation: Zentrum für Infektionsforschung, Universität Würzburg, 97070 Würzburg, Germany.

ABSTRACT
Exfoliation, which is the detachment of infected epithelial cells, is an innate defense mechanism to prevent bacterial colonization. Indeed, infection with Neisseria gonorrhoeae induced epithelial detachment from an extracellular matrix (ECM) substrate in vitro. Surprisingly, variants of N. gonorrhoeae that bind to human carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) failed to induce detachment and, instead, promoted enhanced host cell adhesion to the ECM. Microarray analysis revealed that CEACAM engagement by several human pathogens triggers expression of CD105. Blockage of CD105 expression by antisense oligonucleotides abolished infection-induced cell adhesion. The expression of full-length CD105 promoted cell adhesion to the ECM and was sufficient to prevent infection-induced detachment. The CD105-mediated increase in cell adhesion was dependent on the presence and function of integrin beta1. CD105 expression did not elevate cellular integrin levels but caused a dramatic increase in the ECM-binding capacity of the cells, suggesting that CD105 affects integrin activity. The exploitation of CEACAMs to trigger CD105 expression and to counteract infection-induced cell detachment represents an intriguing adaptation of pathogens that are specialized to colonize the human mucosa.

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CD105 up-regulation is necessary to mediate increased cell adhesion. (A) 293T cells were cotransfected with the empty vector (pcDNA) or CEACAM1 and 400 nM of either CD105 antisense oligonucleotide (AS ODN) or a scrambled control oligonucleotide (SC ODN), respectively. After 8 h of infection with Ngo OpaCEA, CEACAM1 and CD105 expression were determined by flow cytometry. Bars represent the percentage of CEACAM1- or CD105-positive cells of a representative experiment repeated three times with similar results. (B) 293T cells were treated as in A using the indicated amounts of antisense or scrambled control oligonucleotides, respectively. After 8 h of infection with Ngo OpaCEA, cells were used in adhesion assays. Error bars represent means ± SD of eight samples. Statistical significance was determined by a two-tailed t test. Collagen-plated samples that differed significantly (P < 0.001) from the infected CEACAM1-expressing cells in the absence of oligonucleotides are marked by an asterisk.
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fig5: CD105 up-regulation is necessary to mediate increased cell adhesion. (A) 293T cells were cotransfected with the empty vector (pcDNA) or CEACAM1 and 400 nM of either CD105 antisense oligonucleotide (AS ODN) or a scrambled control oligonucleotide (SC ODN), respectively. After 8 h of infection with Ngo OpaCEA, CEACAM1 and CD105 expression were determined by flow cytometry. Bars represent the percentage of CEACAM1- or CD105-positive cells of a representative experiment repeated three times with similar results. (B) 293T cells were treated as in A using the indicated amounts of antisense or scrambled control oligonucleotides, respectively. After 8 h of infection with Ngo OpaCEA, cells were used in adhesion assays. Error bars represent means ± SD of eight samples. Statistical significance was determined by a two-tailed t test. Collagen-plated samples that differed significantly (P < 0.001) from the infected CEACAM1-expressing cells in the absence of oligonucleotides are marked by an asterisk.

Mentions: To investigate whether the observed up-regulation of CD105 could be required for bacteria-induced cell adhesion, 293T cells were cotransfected with CEACAM1 cDNA, and an antisense oligonucleotide was directed against CD105. The antisense oligonucleotide was complementary to sequences spanning the AUG start codon on the CD105 mRNA and has been shown to specifically suppress CD105 expression in human vascular endothelial cells (Li et al., 2000). In contrast to untreated cells or to cells receiving a scrambled control oligonucleotide, CEACAM1-expressing 293T cells that were treated with the CD105 antisense oligonucleotide did not exhibit CD105 up-regulation upon infection with CEACAM-binding gonococci (Fig. 5 A and Fig. S4, available at http://www.jcb.org/cgi/content/full/jcb.200412151/DC1). Importantly, the blockage of CD105 up-regulation by antisense oligonucleotide treatment also abolished increased cell adhesion in response to OpaCEA gonococci in a dose-dependent manner (Fig. 5 B). The cotransfection of 293T cells with the scrambled control oligonucleotide had no effect on bacteria-induced cell adhesion (Fig. 5 B). These results suggested that CD105 up-regulation is necessary to promote cell adhesion upon bacterial engagement of CEACAMs.


CEACAM engagement by human pathogens enhances cell adhesion and counteracts bacteria-induced detachment of epithelial cells.

Muenzner P, Rohde M, Kneitz S, Hauck CR - J. Cell Biol. (2005)

CD105 up-regulation is necessary to mediate increased cell adhesion. (A) 293T cells were cotransfected with the empty vector (pcDNA) or CEACAM1 and 400 nM of either CD105 antisense oligonucleotide (AS ODN) or a scrambled control oligonucleotide (SC ODN), respectively. After 8 h of infection with Ngo OpaCEA, CEACAM1 and CD105 expression were determined by flow cytometry. Bars represent the percentage of CEACAM1- or CD105-positive cells of a representative experiment repeated three times with similar results. (B) 293T cells were treated as in A using the indicated amounts of antisense or scrambled control oligonucleotides, respectively. After 8 h of infection with Ngo OpaCEA, cells were used in adhesion assays. Error bars represent means ± SD of eight samples. Statistical significance was determined by a two-tailed t test. Collagen-plated samples that differed significantly (P < 0.001) from the infected CEACAM1-expressing cells in the absence of oligonucleotides are marked by an asterisk.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2171332&req=5

fig5: CD105 up-regulation is necessary to mediate increased cell adhesion. (A) 293T cells were cotransfected with the empty vector (pcDNA) or CEACAM1 and 400 nM of either CD105 antisense oligonucleotide (AS ODN) or a scrambled control oligonucleotide (SC ODN), respectively. After 8 h of infection with Ngo OpaCEA, CEACAM1 and CD105 expression were determined by flow cytometry. Bars represent the percentage of CEACAM1- or CD105-positive cells of a representative experiment repeated three times with similar results. (B) 293T cells were treated as in A using the indicated amounts of antisense or scrambled control oligonucleotides, respectively. After 8 h of infection with Ngo OpaCEA, cells were used in adhesion assays. Error bars represent means ± SD of eight samples. Statistical significance was determined by a two-tailed t test. Collagen-plated samples that differed significantly (P < 0.001) from the infected CEACAM1-expressing cells in the absence of oligonucleotides are marked by an asterisk.
Mentions: To investigate whether the observed up-regulation of CD105 could be required for bacteria-induced cell adhesion, 293T cells were cotransfected with CEACAM1 cDNA, and an antisense oligonucleotide was directed against CD105. The antisense oligonucleotide was complementary to sequences spanning the AUG start codon on the CD105 mRNA and has been shown to specifically suppress CD105 expression in human vascular endothelial cells (Li et al., 2000). In contrast to untreated cells or to cells receiving a scrambled control oligonucleotide, CEACAM1-expressing 293T cells that were treated with the CD105 antisense oligonucleotide did not exhibit CD105 up-regulation upon infection with CEACAM-binding gonococci (Fig. 5 A and Fig. S4, available at http://www.jcb.org/cgi/content/full/jcb.200412151/DC1). Importantly, the blockage of CD105 up-regulation by antisense oligonucleotide treatment also abolished increased cell adhesion in response to OpaCEA gonococci in a dose-dependent manner (Fig. 5 B). The cotransfection of 293T cells with the scrambled control oligonucleotide had no effect on bacteria-induced cell adhesion (Fig. 5 B). These results suggested that CD105 up-regulation is necessary to promote cell adhesion upon bacterial engagement of CEACAMs.

Bottom Line: Blockage of CD105 expression by antisense oligonucleotides abolished infection-induced cell adhesion.The CD105-mediated increase in cell adhesion was dependent on the presence and function of integrin beta1.CD105 expression did not elevate cellular integrin levels but caused a dramatic increase in the ECM-binding capacity of the cells, suggesting that CD105 affects integrin activity.

View Article: PubMed Central - PubMed

Affiliation: Zentrum für Infektionsforschung, Universität Würzburg, 97070 Würzburg, Germany.

ABSTRACT
Exfoliation, which is the detachment of infected epithelial cells, is an innate defense mechanism to prevent bacterial colonization. Indeed, infection with Neisseria gonorrhoeae induced epithelial detachment from an extracellular matrix (ECM) substrate in vitro. Surprisingly, variants of N. gonorrhoeae that bind to human carcinoembryonic antigen-related cell adhesion molecules (CEACAMs) failed to induce detachment and, instead, promoted enhanced host cell adhesion to the ECM. Microarray analysis revealed that CEACAM engagement by several human pathogens triggers expression of CD105. Blockage of CD105 expression by antisense oligonucleotides abolished infection-induced cell adhesion. The expression of full-length CD105 promoted cell adhesion to the ECM and was sufficient to prevent infection-induced detachment. The CD105-mediated increase in cell adhesion was dependent on the presence and function of integrin beta1. CD105 expression did not elevate cellular integrin levels but caused a dramatic increase in the ECM-binding capacity of the cells, suggesting that CD105 affects integrin activity. The exploitation of CEACAMs to trigger CD105 expression and to counteract infection-induced cell detachment represents an intriguing adaptation of pathogens that are specialized to colonize the human mucosa.

Show MeSH
Related in: MedlinePlus