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. 2012 Dec;17(6):426-34.
doi: 10.1111/j.1523-5378.2012.00966.x. Epub 2012 Jun 29.

Antibodies anti-CagA cross-react with trophoblast cells: a risk factor for pre-eclampsia?

Francesco Franceschi  1 , Nicoletta Di Simone, Silvia D'Ippolito, Roberta Castellani, Fiorella Di Nicuolo, Giovanni Gasbarrini, Yoshio Yamaoka, Tullia Todros, Giovanni Scambia, Antonio Gasbarrini
Affiliations

Antibodies anti-CagA cross-react with trophoblast cells: a risk factor for pre-eclampsia?

Francesco Franceschi et al. Helicobacter. 2012 Dec.

Abstract

Background: Previous studies reported an epidemiological association between CagA-positive H. pylori strains and pre-eclampsia. As antibodies anti-CagA cross-react with endothelial cells and trophoblast cells show an endothelial phenotypic profile, we hypothesized that anti-CagA antibodies may recognize antigens of cytotrophoblast cells, thus impairing their function.

Materials and methods: Placenta samples were obtained from healthy women. Cytotrophoblast cells were cultured in a medium containing increasing concentration of polyclonal anti-CagA antibodies. Binding of anti-CagA antibodies to cytotrophoblast cells was evaluated by cell ELISA and immunofluorescence assay. Invasive potential of those cells was assessed by an invasion culture system and by measuring of MMP-2. Protein sequencing was performed on antigens precipitated by anti-CagA antibodies. Measurement of phosphorylated ERK expression and NF-kB DNA-binding activity in trophoblast cells incubated with anti-CagA or irrelevant antibodies was also performed.

Results: Anti-CagA antibodies recognized β-actin of cytotrophoblast cells, showing a dose-dependent binding. Incubation of cytotrophoblast cells with increasing doses of anti-CagA antibodies significantly reduced their invasiveness and determined a significant decrease in phosphorylated ERK expression and a reduced NF-kB translocation activity.

Conclusions: This study shows that anti-CagA antibodies recognize β-actin of cytotrophoblast cells, reducing their invasiveness ability, possibly giving a biological explanation for the epidemiological association.

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Conflict of interest statement

Competing interests: the authors have no competing interests.

Figures

Figure 1
Figure 1
Anti-CagA antibodies bind trophoblast cells in a dose-dependent manner (A). Indirect immunofluorescence assay performed on trophoblast cells using anti-CagA antibodies displayed a significant reactivity that was confined to the plasma cell membrane (B).
Figure 2
Figure 2
Matrigel invasion assay: polyclonal anti-CagA antibodies, but not normal mouse IgG impair trophoblast cell invasiveness in a dose-dependent manner.
Figure 3
Figure 3
Gelatin zymography assay: incubation of trophoblast cells with anti-CagA antibodies significantly reduced both pro-MMP-2 and active MMP-2.
Figure 4
Figure 4
Western blot analysis of total and phosphorylated ERK expression in cytotrophoblast cells treated with anti-CagA Ab (50 μg/mL). (A) A representative Western Blot analysis for total and phosphorylated ERK in cytotrophoblast cells. (B) Densitometric analysis. The level of total p-ERK protein after anti-CagA Ab treatment was estimated in comparison with the constant level of beta-actin and expressed as percentage of the control (untreated cells = 100%). A significant decrease in phosphorylated ERK-1 and -2, in presence of IgG anti-CagA Ab (50 μg/mL), but not in presence of irrelevant control antibody was observed. Total form expression was not modified in presence of anti-CagA Ab. Results are means ± SE of three independent experiments. Significance versus untreated cells (control): *p < .05.
Figure 5
Figure 5
Effects of anti-CagA on nuclear factor NF-kB DNA-binding activity in trophoblast cells. Polyclonal anti-CagA Ab (Anti-CagA, 50 μg/mL), but not irrelevant control antibody, reduced NF-kB translocation.
Figure 6
Figure 6
Immunoprecipitation performed on trophoblast, myometrial, ovarian and placental tissue lysates using anti-CagA antibodies revealed the presence of a cross-reactive band only for trophoblast cells.
Figure 7
Figure 7
Binding of anti-CagA (A) and anti-β-actin (B) antibodies on human trophoblast cells evaluated by indirect immunofluorescence. In the panel C trophoblast cells were exposed first to anti-β-actin and secondly to anti-CagA antibodies conjugated to FITC. Under such conditions a lower fluorescence was detected on trophoblast cells, suggesting that the antigen was masked by the anti-β-actin antibodies previously bound to cellular membranes.
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References

    1. Shenoy V, Kanasaki K, Kalluri R. Pre-eclampsia: connecting angiogenic and metabolic pathways. Trends Endocrinol Metab. 2010;21:529–36. - PubMed
    1. Steegers EA, von Dadelszen P, Duvekot JJ, et al. Pre-eclampsia. Lancet. 2010;376:631–44. - PubMed
    1. James JL, Whitley GS, Cartwright JE. Pre-eclampsia: fitting together the placental, immune and cardiovascular pieces. J Pathol. 2010;221:363–78. - PubMed
    1. Macey MG, Bevan S, Alam S, et al. Platelet activation and endogenous thrombin potential in pre-eclampsia. Thromb Res. 2010;125:e76–81. - PubMed
    1. Horton AL, Boggess KA, Moss KL, et al. Periodontal disease, oxidative stress, and risk for preeclampsia. J Periodontol. 2010;81:199–204. - PMC - PubMed