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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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CEACAM engagement by human pathogens triggers up-regulation of CD105 mRNA and protein levels. (A) Control-transfected (pcDNA) or CEACAM1-expressing 293T cells were left uninfected or were infected with OpaCEA N. gonorrhoeae (Ngo OpaCEA) or piliated N. gonorrhoeae (Ngo P+) for the indicated times. After RNA isolation, fragments of CD105 and β-actin mRNA were coamplified by RT-PCR. A plasmid encoding full-length CD105 served as a positive control (pCD105). (B) 293T cells transfected as in A were left uninfected or were infected with Ngo OpaCEA, M. catarrhalis (Mcat), N. cinerea (Ncin), or H. influenzae (Hinf) for the indicated times. CD105 mRNA levels were analyzed as in A. (C) 293T cells transfected as in A were left uninfected or were infected as indicated for 14 h. Cells were detached, stained with monoclonal α-CD105 or control mouse IgG (control), and analyzed by flow cytometry. FSC-H, forward scatter; FL1-H, intensity of the signal detected in fluorescence channel 1.
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fig4: CEACAM engagement by human pathogens triggers up-regulation of CD105 mRNA and protein levels. (A) Control-transfected (pcDNA) or CEACAM1-expressing 293T cells were left uninfected or were infected with OpaCEA N. gonorrhoeae (Ngo OpaCEA) or piliated N. gonorrhoeae (Ngo P+) for the indicated times. After RNA isolation, fragments of CD105 and β-actin mRNA were coamplified by RT-PCR. A plasmid encoding full-length CD105 served as a positive control (pCD105). (B) 293T cells transfected as in A were left uninfected or were infected with Ngo OpaCEA, M. catarrhalis (Mcat), N. cinerea (Ncin), or H. influenzae (Hinf) for the indicated times. CD105 mRNA levels were analyzed as in A. (C) 293T cells transfected as in A were left uninfected or were infected as indicated for 14 h. Cells were detached, stained with monoclonal α-CD105 or control mouse IgG (control), and analyzed by flow cytometry. FSC-H, forward scatter; FL1-H, intensity of the signal detected in fluorescence channel 1.

Mentions: To verify that CD105 mRNA up-regulation in CEACAM-expressing cells was a specific result of CEACAM engagement by pathogens, cells were infected with different bacterial strains. Importantly, the increase of CD105 mRNA in CEACAM1-positive cells depended on the correct phenotype of the bacteria, as piliated but nonopaque gonococci did not induce CD105 expression (Fig. 4 A). In addition to N. gonorrhoeae and the closely related N. meningitidis that use Opa proteins to engage CEACAMs, several other human-specific bacterial pathogens have been described to firmly bind to CEACAMs (Virji et al., 2000). Examples include Haemophilus influenzae and Moraxella catarrhalis, which target human CEACAMs by distinct adhesins (Hill et al., 2001; Hill and Virji, 2003). Therefore, CEACAM1-expressing 293T cells were infected with H. influenzae, M. catarrhalis, or nonpathogenic N. cinerea for 3 or 8 h, and CD105 mRNA levels were detected by RT-PCR. Importantly, both CEACAM-binding pathogens led to a marked increase in CD105 mRNA within 3–8 h after infection, whereas non-CEACAM–binding N. cinerea did not influence CD105 mRNA levels (Fig. 4 B). Enhanced levels of CD105 mRNA were directly correlated to the presence of detectable amounts of CD105 on the surface of CEACAM-expressing cells after infection with OpaCEA gonococci (Fig. 4 C). Infection of CEACAM-deficient cells with OpaCEA gonococci or infection of CEACAM1-expressing cells with nonopaque bacteria or OpaHSPG-expressing gonococci did not result in elevated CD105 levels (Fig. 4 C and Fig. S3, available at http://www.jcb.org/cgi/content/full/jcb.200412151/DC1). Together, these data corroborated the findings of the microarray analysis and demonstrated that engagement of CEACAMs by several bacterial pathogens triggers characteristic gene expression events that lead to elevated levels of CD105 on human epithelial 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)

CEACAM engagement by human pathogens triggers up-regulation of CD105 mRNA and protein levels. (A) Control-transfected (pcDNA) or CEACAM1-expressing 293T cells were left uninfected or were infected with OpaCEA N. gonorrhoeae (Ngo OpaCEA) or piliated N. gonorrhoeae (Ngo P+) for the indicated times. After RNA isolation, fragments of CD105 and β-actin mRNA were coamplified by RT-PCR. A plasmid encoding full-length CD105 served as a positive control (pCD105). (B) 293T cells transfected as in A were left uninfected or were infected with Ngo OpaCEA, M. catarrhalis (Mcat), N. cinerea (Ncin), or H. influenzae (Hinf) for the indicated times. CD105 mRNA levels were analyzed as in A. (C) 293T cells transfected as in A were left uninfected or were infected as indicated for 14 h. Cells were detached, stained with monoclonal α-CD105 or control mouse IgG (control), and analyzed by flow cytometry. FSC-H, forward scatter; FL1-H, intensity of the signal detected in fluorescence channel 1.
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2171332&req=5

fig4: CEACAM engagement by human pathogens triggers up-regulation of CD105 mRNA and protein levels. (A) Control-transfected (pcDNA) or CEACAM1-expressing 293T cells were left uninfected or were infected with OpaCEA N. gonorrhoeae (Ngo OpaCEA) or piliated N. gonorrhoeae (Ngo P+) for the indicated times. After RNA isolation, fragments of CD105 and β-actin mRNA were coamplified by RT-PCR. A plasmid encoding full-length CD105 served as a positive control (pCD105). (B) 293T cells transfected as in A were left uninfected or were infected with Ngo OpaCEA, M. catarrhalis (Mcat), N. cinerea (Ncin), or H. influenzae (Hinf) for the indicated times. CD105 mRNA levels were analyzed as in A. (C) 293T cells transfected as in A were left uninfected or were infected as indicated for 14 h. Cells were detached, stained with monoclonal α-CD105 or control mouse IgG (control), and analyzed by flow cytometry. FSC-H, forward scatter; FL1-H, intensity of the signal detected in fluorescence channel 1.
Mentions: To verify that CD105 mRNA up-regulation in CEACAM-expressing cells was a specific result of CEACAM engagement by pathogens, cells were infected with different bacterial strains. Importantly, the increase of CD105 mRNA in CEACAM1-positive cells depended on the correct phenotype of the bacteria, as piliated but nonopaque gonococci did not induce CD105 expression (Fig. 4 A). In addition to N. gonorrhoeae and the closely related N. meningitidis that use Opa proteins to engage CEACAMs, several other human-specific bacterial pathogens have been described to firmly bind to CEACAMs (Virji et al., 2000). Examples include Haemophilus influenzae and Moraxella catarrhalis, which target human CEACAMs by distinct adhesins (Hill et al., 2001; Hill and Virji, 2003). Therefore, CEACAM1-expressing 293T cells were infected with H. influenzae, M. catarrhalis, or nonpathogenic N. cinerea for 3 or 8 h, and CD105 mRNA levels were detected by RT-PCR. Importantly, both CEACAM-binding pathogens led to a marked increase in CD105 mRNA within 3–8 h after infection, whereas non-CEACAM–binding N. cinerea did not influence CD105 mRNA levels (Fig. 4 B). Enhanced levels of CD105 mRNA were directly correlated to the presence of detectable amounts of CD105 on the surface of CEACAM-expressing cells after infection with OpaCEA gonococci (Fig. 4 C). Infection of CEACAM-deficient cells with OpaCEA gonococci or infection of CEACAM1-expressing cells with nonopaque bacteria or OpaHSPG-expressing gonococci did not result in elevated CD105 levels (Fig. 4 C and Fig. S3, available at http://www.jcb.org/cgi/content/full/jcb.200412151/DC1). Together, these data corroborated the findings of the microarray analysis and demonstrated that engagement of CEACAMs by several bacterial pathogens triggers characteristic gene expression events that lead to elevated levels of CD105 on human epithelial 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