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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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OpaCEA-expressing N. gonorrhoeae triggers enhanced epithelial cell adhesion. (A) Confluent layers of ME-180 cells were left uninfected or were infected for 14 h with piliated, nonopaque (Ngo P+), nonpiliated OpaHSPG-expressing (Ngo OpaHSPG), or nonpiliated OpaCEA-expressing N. gonorrhoeae MS11 (Ngo OpaCEA). Cultures were fixed in situ and were analyzed by scanning EM. Arrows highlight cell–cell contacts. (B) Confluent layers of ME-180 cells were infected for 14 h with the indicated bacterial strains. Cells were used in detachment assays, were fixed and stained, and the percentage of detached cells was determined. (C) Aliquots of detachment assays performed as in B were plated after 14 h of infection onto GC agar plates, and the resulting bacterial colonies were counted. (D) ME-180 cells were infected with the indicated gonococcal variants or were left uninfected. After 8 h, cells were used in adhesion assays. Adherent cells were fixed and stained with CV. Error bars represent means ± SD of five wells (B) and four determinations (C) or represent mean staining intensity ± SD of five wells (D).
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fig1: OpaCEA-expressing N. gonorrhoeae triggers enhanced epithelial cell adhesion. (A) Confluent layers of ME-180 cells were left uninfected or were infected for 14 h with piliated, nonopaque (Ngo P+), nonpiliated OpaHSPG-expressing (Ngo OpaHSPG), or nonpiliated OpaCEA-expressing N. gonorrhoeae MS11 (Ngo OpaCEA). Cultures were fixed in situ and were analyzed by scanning EM. Arrows highlight cell–cell contacts. (B) Confluent layers of ME-180 cells were infected for 14 h with the indicated bacterial strains. Cells were used in detachment assays, were fixed and stained, and the percentage of detached cells was determined. (C) Aliquots of detachment assays performed as in B were plated after 14 h of infection onto GC agar plates, and the resulting bacterial colonies were counted. (D) ME-180 cells were infected with the indicated gonococcal variants or were left uninfected. After 8 h, cells were used in adhesion assays. Adherent cells were fixed and stained with CV. Error bars represent means ± SD of five wells (B) and four determinations (C) or represent mean staining intensity ± SD of five wells (D).

Mentions: To analyze the interaction of N. gonorrhoeae with target tissues, we used the human cervix-derived epithelial cell line ME-180, which is an established model system that allows pilus- and Opa protein–mediated gonococcal adhesion (Rudel et al., 1992; Kupsch et al., 1993; Scheuerpflug et al., 1999). When confluent monolayers of ME-180 cells were infected for >8 h with piliated gonococci, the infected cells detached from the culture dish, whereas ME-180 cells that were infected with OpaCEA-expressing gonococci did not detach (unpublished data). To investigate this cellular response in more detail, scanning EM was performed on monolayers of ME-180 cells that were infected for 14 h. In contrast to uninfected cells, cells that were infected with piliated gonococci or nonpiliated OpaHSPG-expressing pathogens released cell–cell contacts and acquired a rounded morphology that was consistent with bacteria-induced cell detachment (Fig. 1 A). Strikingly, cells that were infected with CEACAM-binding gonococci remained attached throughout the 14 h of infection, although they showed reduced numbers of cell–cell contacts (Fig. 1 A, arrows). When the samples were inverted and centrifuged before fixation to remove loosely attached cells, ∼45–60% of ME-180 cells that were infected with OpaHSPG-expressing nonopaque, or piliated gonococci had detached (Fig. 1 B). Centrifugation also removed ∼15–20% of ME-180 cells from uninfected cultures; however, cells infected with OpaCEA-expressing gonococci almost completely stayed attached to collagen-coated culture dishes (Fig. 1 B). Importantly, all gonococcal variants exhibited the same growth properties in the cell culture medium (Fig. 1 C), suggesting that the lack of cell detachment after infection with OpaCEA-expressing bacteria was not a result of differences in total bacterial load. As infection with OpaCEA-expressing gonococci seemed to reduce the amount of cell–cell contacts (Fig. 1 A), we speculated that these bacteria stimulate increased cell matrix adhesion. Indeed, when ME-180 cells were used in an adhesion assay 8 h after infection, cells that were infected with OpaCEA gonococci showed dramatically enhanced cell adhesion to collagen compared with uninfected cells or with cells infected with nonopaque gonococci (Fig. 1 D).


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)

OpaCEA-expressing N. gonorrhoeae triggers enhanced epithelial cell adhesion. (A) Confluent layers of ME-180 cells were left uninfected or were infected for 14 h with piliated, nonopaque (Ngo P+), nonpiliated OpaHSPG-expressing (Ngo OpaHSPG), or nonpiliated OpaCEA-expressing N. gonorrhoeae MS11 (Ngo OpaCEA). Cultures were fixed in situ and were analyzed by scanning EM. Arrows highlight cell–cell contacts. (B) Confluent layers of ME-180 cells were infected for 14 h with the indicated bacterial strains. Cells were used in detachment assays, were fixed and stained, and the percentage of detached cells was determined. (C) Aliquots of detachment assays performed as in B were plated after 14 h of infection onto GC agar plates, and the resulting bacterial colonies were counted. (D) ME-180 cells were infected with the indicated gonococcal variants or were left uninfected. After 8 h, cells were used in adhesion assays. Adherent cells were fixed and stained with CV. Error bars represent means ± SD of five wells (B) and four determinations (C) or represent mean staining intensity ± SD of five wells (D).
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Related In: Results  -  Collection

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getmorefigures.php?uid=PMC2171332&req=5

fig1: OpaCEA-expressing N. gonorrhoeae triggers enhanced epithelial cell adhesion. (A) Confluent layers of ME-180 cells were left uninfected or were infected for 14 h with piliated, nonopaque (Ngo P+), nonpiliated OpaHSPG-expressing (Ngo OpaHSPG), or nonpiliated OpaCEA-expressing N. gonorrhoeae MS11 (Ngo OpaCEA). Cultures were fixed in situ and were analyzed by scanning EM. Arrows highlight cell–cell contacts. (B) Confluent layers of ME-180 cells were infected for 14 h with the indicated bacterial strains. Cells were used in detachment assays, were fixed and stained, and the percentage of detached cells was determined. (C) Aliquots of detachment assays performed as in B were plated after 14 h of infection onto GC agar plates, and the resulting bacterial colonies were counted. (D) ME-180 cells were infected with the indicated gonococcal variants or were left uninfected. After 8 h, cells were used in adhesion assays. Adherent cells were fixed and stained with CV. Error bars represent means ± SD of five wells (B) and four determinations (C) or represent mean staining intensity ± SD of five wells (D).
Mentions: To analyze the interaction of N. gonorrhoeae with target tissues, we used the human cervix-derived epithelial cell line ME-180, which is an established model system that allows pilus- and Opa protein–mediated gonococcal adhesion (Rudel et al., 1992; Kupsch et al., 1993; Scheuerpflug et al., 1999). When confluent monolayers of ME-180 cells were infected for >8 h with piliated gonococci, the infected cells detached from the culture dish, whereas ME-180 cells that were infected with OpaCEA-expressing gonococci did not detach (unpublished data). To investigate this cellular response in more detail, scanning EM was performed on monolayers of ME-180 cells that were infected for 14 h. In contrast to uninfected cells, cells that were infected with piliated gonococci or nonpiliated OpaHSPG-expressing pathogens released cell–cell contacts and acquired a rounded morphology that was consistent with bacteria-induced cell detachment (Fig. 1 A). Strikingly, cells that were infected with CEACAM-binding gonococci remained attached throughout the 14 h of infection, although they showed reduced numbers of cell–cell contacts (Fig. 1 A, arrows). When the samples were inverted and centrifuged before fixation to remove loosely attached cells, ∼45–60% of ME-180 cells that were infected with OpaHSPG-expressing nonopaque, or piliated gonococci had detached (Fig. 1 B). Centrifugation also removed ∼15–20% of ME-180 cells from uninfected cultures; however, cells infected with OpaCEA-expressing gonococci almost completely stayed attached to collagen-coated culture dishes (Fig. 1 B). Importantly, all gonococcal variants exhibited the same growth properties in the cell culture medium (Fig. 1 C), suggesting that the lack of cell detachment after infection with OpaCEA-expressing bacteria was not a result of differences in total bacterial load. As infection with OpaCEA-expressing gonococci seemed to reduce the amount of cell–cell contacts (Fig. 1 A), we speculated that these bacteria stimulate increased cell matrix adhesion. Indeed, when ME-180 cells were used in an adhesion assay 8 h after infection, cells that were infected with OpaCEA gonococci showed dramatically enhanced cell adhesion to collagen compared with uninfected cells or with cells infected with nonopaque gonococci (Fig. 1 D).

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