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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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CEACAM1 and 6 engagement stimulate CD105 expression. (A) Control-transfected (pcDNA) or CEACAM1 (CEA1)-expressing 293T or ME-180 cells were left uninfected or were infected for 8 h with OpaCEA N. gonorrhoeae (Ngo Opa−CEA). After RNA isolation, fragments of CD105 and β-actin mRNA were coamplified by RT-PCR (top), and the ratio of both signals from each sample was determined by densitometry (bottom). Bars represent the fold induction of infected compared with uninfected cells. A plasmid encoding full-length CD105 served as a positive control (pCD105). (B) Expression of CEACAM1 by the cells used in A, as analyzed by Western blotting of whole cell lysates (WCL) with mAb α-CEACAM. (C) Expression of CEACAM1 WT, CEACAM1 ΔCT, and CEACAM6 by the cells used in D and E (analyzed as in B). (D) Transfected 293T cells were infected for the indicated times (in hours) with Ngo OpaCEA or nonopaque gonococci (Ngo Opa−). CD105 mRNA levels were detected as in A. (E) Transfected 293T cells were infected for the indicated times with Ngo OpaCEA. CD105 mRNA levels were detected as in A.
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fig3: CEACAM1 and 6 engagement stimulate CD105 expression. (A) Control-transfected (pcDNA) or CEACAM1 (CEA1)-expressing 293T or ME-180 cells were left uninfected or were infected for 8 h with OpaCEA N. gonorrhoeae (Ngo Opa−CEA). After RNA isolation, fragments of CD105 and β-actin mRNA were coamplified by RT-PCR (top), and the ratio of both signals from each sample was determined by densitometry (bottom). Bars represent the fold induction of infected compared with uninfected cells. A plasmid encoding full-length CD105 served as a positive control (pCD105). (B) Expression of CEACAM1 by the cells used in A, as analyzed by Western blotting of whole cell lysates (WCL) with mAb α-CEACAM. (C) Expression of CEACAM1 WT, CEACAM1 ΔCT, and CEACAM6 by the cells used in D and E (analyzed as in B). (D) Transfected 293T cells were infected for the indicated times (in hours) with Ngo OpaCEA or nonopaque gonococci (Ngo Opa−). CD105 mRNA levels were detected as in A. (E) Transfected 293T cells were infected for the indicated times with Ngo OpaCEA. CD105 mRNA levels were detected as in A.

Mentions: To verify the results of the microarray screen, semiquantitative RT-PCR was performed on RNA samples that were isolated from control- (pcDNA) or CEACAM1-transfected 293T cells before or after infection. CD105 mRNA levels were found to specifically increase about four- to sixfold 8 h after infection of CEACAM1-expressing cells with CEACAM-binding gonococci (Fig. 3 A). As an internal control, an ∼350-bp fragment of β-actin was coamplified. In addition, the same set of primers was used on a plasmid template containing full-length CD105 cDNA as a positive control (Fig. 3 A). Western blotting of lysates from transfected 293T cells confirmed the expression of CEACAM1 (Fig. 3 B). When ME-180 cervix carcinoma cells that endogenously express CEACAM1 (Fig. 3 B) were infected with OpaCEA-expressing gonococci, a similar up-regulation of CD105 mRNA was observed (Fig. 3 A). The up-regulation of CD105 was also observed after the infection of CEACAM6-expressing cells with OpaCEA gonococci, which is consistent with the microarray analysis (Fig. 3 D). CEACAM6 is anchored to the plasma membrane via a glycosylphosphatidylinositol moiety, suggesting that a cytoplasmic domain is not required to initiate CD105 up-regulation. Indeed, deletion of the cytoplasmic domain of CEACAM1 did not alter its ability to induce an increase in CD105 mRNA in response to infection with OpaCEA N. gonorrhoeae (Fig. 3 E). Together, these data corroborated the findings of the microarray analysis. Furthermore, the results suggested that, as reported for CEACAM1- and 6-mediated bacterial internalization (Billker et al., 2002), CEACAM-initiated CD105 expression does not require the presence of a cytoplasmic domain.


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)

CEACAM1 and 6 engagement stimulate CD105 expression. (A) Control-transfected (pcDNA) or CEACAM1 (CEA1)-expressing 293T or ME-180 cells were left uninfected or were infected for 8 h with OpaCEA N. gonorrhoeae (Ngo Opa−CEA). After RNA isolation, fragments of CD105 and β-actin mRNA were coamplified by RT-PCR (top), and the ratio of both signals from each sample was determined by densitometry (bottom). Bars represent the fold induction of infected compared with uninfected cells. A plasmid encoding full-length CD105 served as a positive control (pCD105). (B) Expression of CEACAM1 by the cells used in A, as analyzed by Western blotting of whole cell lysates (WCL) with mAb α-CEACAM. (C) Expression of CEACAM1 WT, CEACAM1 ΔCT, and CEACAM6 by the cells used in D and E (analyzed as in B). (D) Transfected 293T cells were infected for the indicated times (in hours) with Ngo OpaCEA or nonopaque gonococci (Ngo Opa−). CD105 mRNA levels were detected as in A. (E) Transfected 293T cells were infected for the indicated times with Ngo OpaCEA. CD105 mRNA levels were detected as in A.
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fig3: CEACAM1 and 6 engagement stimulate CD105 expression. (A) Control-transfected (pcDNA) or CEACAM1 (CEA1)-expressing 293T or ME-180 cells were left uninfected or were infected for 8 h with OpaCEA N. gonorrhoeae (Ngo Opa−CEA). After RNA isolation, fragments of CD105 and β-actin mRNA were coamplified by RT-PCR (top), and the ratio of both signals from each sample was determined by densitometry (bottom). Bars represent the fold induction of infected compared with uninfected cells. A plasmid encoding full-length CD105 served as a positive control (pCD105). (B) Expression of CEACAM1 by the cells used in A, as analyzed by Western blotting of whole cell lysates (WCL) with mAb α-CEACAM. (C) Expression of CEACAM1 WT, CEACAM1 ΔCT, and CEACAM6 by the cells used in D and E (analyzed as in B). (D) Transfected 293T cells were infected for the indicated times (in hours) with Ngo OpaCEA or nonopaque gonococci (Ngo Opa−). CD105 mRNA levels were detected as in A. (E) Transfected 293T cells were infected for the indicated times with Ngo OpaCEA. CD105 mRNA levels were detected as in A.
Mentions: To verify the results of the microarray screen, semiquantitative RT-PCR was performed on RNA samples that were isolated from control- (pcDNA) or CEACAM1-transfected 293T cells before or after infection. CD105 mRNA levels were found to specifically increase about four- to sixfold 8 h after infection of CEACAM1-expressing cells with CEACAM-binding gonococci (Fig. 3 A). As an internal control, an ∼350-bp fragment of β-actin was coamplified. In addition, the same set of primers was used on a plasmid template containing full-length CD105 cDNA as a positive control (Fig. 3 A). Western blotting of lysates from transfected 293T cells confirmed the expression of CEACAM1 (Fig. 3 B). When ME-180 cervix carcinoma cells that endogenously express CEACAM1 (Fig. 3 B) were infected with OpaCEA-expressing gonococci, a similar up-regulation of CD105 mRNA was observed (Fig. 3 A). The up-regulation of CD105 was also observed after the infection of CEACAM6-expressing cells with OpaCEA gonococci, which is consistent with the microarray analysis (Fig. 3 D). CEACAM6 is anchored to the plasma membrane via a glycosylphosphatidylinositol moiety, suggesting that a cytoplasmic domain is not required to initiate CD105 up-regulation. Indeed, deletion of the cytoplasmic domain of CEACAM1 did not alter its ability to induce an increase in CD105 mRNA in response to infection with OpaCEA N. gonorrhoeae (Fig. 3 E). Together, these data corroborated the findings of the microarray analysis. Furthermore, the results suggested that, as reported for CEACAM1- and 6-mediated bacterial internalization (Billker et al., 2002), CEACAM-initiated CD105 expression does not require the presence of a cytoplasmic domain.

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