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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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Enhanced cell adhesion upon infection depends on host cell CEACAMs and de novo protein synthesis. (A) 293T cells were transfected with control vector (pcDNA) or CEACAM1; were infected or left uninfected for 8 h with piliated N. gonorrhoeae (Ngo P+), nonopaque N. gonorrhoeae (Ngo Opa−), OpaCEA N. gonorrhoeae (Ngo OpaCEA), or N. cinerea; and were used in an adhesion assay. (B) 293T cells were transfected with empty vector (pcDNA) or CEACAM6, were infected for 8 h with indicated bacteria, and were used in an adhesion assay. (C) 293T cells were transfected with control vector (pcDNA) or CEACAM1 and were infected for 14 h with indicated bacteria. Infected cultures were gently washed to remove loosely attached cells, and adherent cells were fixed and stained with CV. Pictures show representative fields of view. (D) 293T cells transfected as in C were infected for 8 h with Ngo OpaCEA in the presence of increasing amounts of cycloheximide (Chx) and were used in adhesion assays. (A, B, and D) Error bars represent means ± SD of five wells.
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fig2: Enhanced cell adhesion upon infection depends on host cell CEACAMs and de novo protein synthesis. (A) 293T cells were transfected with control vector (pcDNA) or CEACAM1; were infected or left uninfected for 8 h with piliated N. gonorrhoeae (Ngo P+), nonopaque N. gonorrhoeae (Ngo Opa−), OpaCEA N. gonorrhoeae (Ngo OpaCEA), or N. cinerea; and were used in an adhesion assay. (B) 293T cells were transfected with empty vector (pcDNA) or CEACAM6, were infected for 8 h with indicated bacteria, and were used in an adhesion assay. (C) 293T cells were transfected with control vector (pcDNA) or CEACAM1 and were infected for 14 h with indicated bacteria. Infected cultures were gently washed to remove loosely attached cells, and adherent cells were fixed and stained with CV. Pictures show representative fields of view. (D) 293T cells transfected as in C were infected for 8 h with Ngo OpaCEA in the presence of increasing amounts of cycloheximide (Chx) and were used in adhesion assays. (A, B, and D) Error bars represent means ± SD of five wells.

Mentions: To investigate whether OpaCEA-mediated stimulation of epithelial CEACAMs was responsible for increased cell adhesion, we infected the CEACAM-negative human 293T cell line with OpaCEA gonococci (Ergun et al., 2000; Schmitter et al., 2004). Adhesion of these cells was unaltered by bacterial infection (Fig. 2 A). However, when 293T cells were transfected with cDNA encoding either CEACAM1 or 6, infection with OpaCEA gonococci led to increased cell adhesion on a collagen matrix (Fig. 2, A and B). In contrast, neither isogenic nonopaque or piliated gonococci nor nonpathogenic Neisseria cinerea induced enhanced adhesion of CEACAM-expressing cells. Clearly, CEACAM1 or 6 expression in the absence of bacterial infection did not lead to alterations in cell adhesion (Fig. 2, A and B). Also, cell adhesion to an uncoated cell culture dish was not affected by any of the aforementioned conditions (Fig. 2, A and B). Increased cell adhesion in response to OpaCEA N. gonorrhoeae correlated with the ability of CEACAM1-expressing 293T cells to withstand detachment after prolonged infection, whereas infection of these cells with nonopaque gonococci resulted in cell detachment (Fig. 2 C). Interestingly, the increase in 293T cell adhesion in response to OpaCEA bacteria was abolished when host cell kinases were inhibited by staurosporine (Fig. S1, available at http://www.jcb.org/cgi/content/full/jcb.200412151/DC1) or when protein translation in the eukaryotic cell was blocked by cycloheximide (Fig. 2 D). These results suggested that CEACAM engagement by OpaCEA proteins of pathogenic N. gonorrhoeae stimulates signaling and gene expression events in the host cell that lead to altered cell adhesion and prevent detachment of infected cells.


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)

Enhanced cell adhesion upon infection depends on host cell CEACAMs and de novo protein synthesis. (A) 293T cells were transfected with control vector (pcDNA) or CEACAM1; were infected or left uninfected for 8 h with piliated N. gonorrhoeae (Ngo P+), nonopaque N. gonorrhoeae (Ngo Opa−), OpaCEA N. gonorrhoeae (Ngo OpaCEA), or N. cinerea; and were used in an adhesion assay. (B) 293T cells were transfected with empty vector (pcDNA) or CEACAM6, were infected for 8 h with indicated bacteria, and were used in an adhesion assay. (C) 293T cells were transfected with control vector (pcDNA) or CEACAM1 and were infected for 14 h with indicated bacteria. Infected cultures were gently washed to remove loosely attached cells, and adherent cells were fixed and stained with CV. Pictures show representative fields of view. (D) 293T cells transfected as in C were infected for 8 h with Ngo OpaCEA in the presence of increasing amounts of cycloheximide (Chx) and were used in adhesion assays. (A, B, and D) Error bars represent means ± SD of five wells.
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fig2: Enhanced cell adhesion upon infection depends on host cell CEACAMs and de novo protein synthesis. (A) 293T cells were transfected with control vector (pcDNA) or CEACAM1; were infected or left uninfected for 8 h with piliated N. gonorrhoeae (Ngo P+), nonopaque N. gonorrhoeae (Ngo Opa−), OpaCEA N. gonorrhoeae (Ngo OpaCEA), or N. cinerea; and were used in an adhesion assay. (B) 293T cells were transfected with empty vector (pcDNA) or CEACAM6, were infected for 8 h with indicated bacteria, and were used in an adhesion assay. (C) 293T cells were transfected with control vector (pcDNA) or CEACAM1 and were infected for 14 h with indicated bacteria. Infected cultures were gently washed to remove loosely attached cells, and adherent cells were fixed and stained with CV. Pictures show representative fields of view. (D) 293T cells transfected as in C were infected for 8 h with Ngo OpaCEA in the presence of increasing amounts of cycloheximide (Chx) and were used in adhesion assays. (A, B, and D) Error bars represent means ± SD of five wells.
Mentions: To investigate whether OpaCEA-mediated stimulation of epithelial CEACAMs was responsible for increased cell adhesion, we infected the CEACAM-negative human 293T cell line with OpaCEA gonococci (Ergun et al., 2000; Schmitter et al., 2004). Adhesion of these cells was unaltered by bacterial infection (Fig. 2 A). However, when 293T cells were transfected with cDNA encoding either CEACAM1 or 6, infection with OpaCEA gonococci led to increased cell adhesion on a collagen matrix (Fig. 2, A and B). In contrast, neither isogenic nonopaque or piliated gonococci nor nonpathogenic Neisseria cinerea induced enhanced adhesion of CEACAM-expressing cells. Clearly, CEACAM1 or 6 expression in the absence of bacterial infection did not lead to alterations in cell adhesion (Fig. 2, A and B). Also, cell adhesion to an uncoated cell culture dish was not affected by any of the aforementioned conditions (Fig. 2, A and B). Increased cell adhesion in response to OpaCEA N. gonorrhoeae correlated with the ability of CEACAM1-expressing 293T cells to withstand detachment after prolonged infection, whereas infection of these cells with nonopaque gonococci resulted in cell detachment (Fig. 2 C). Interestingly, the increase in 293T cell adhesion in response to OpaCEA bacteria was abolished when host cell kinases were inhibited by staurosporine (Fig. S1, available at http://www.jcb.org/cgi/content/full/jcb.200412151/DC1) or when protein translation in the eukaryotic cell was blocked by cycloheximide (Fig. 2 D). These results suggested that CEACAM engagement by OpaCEA proteins of pathogenic N. gonorrhoeae stimulates signaling and gene expression events in the host cell that lead to altered cell adhesion and prevent detachment of infected cells.

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