In Entamoeba histolytica, a BspA family protein is required for chemotaxis toward tumour necrosis factor

Anne Silvestre; Aurélie Plaze; Patricia Berthon; Roman Thibeaux; Nancy Guillen; Elisabeth Labruyère

doi:10.15698/mic2015.07.214

In Entamoeba histolytica, a BspA family protein is required for chemotaxis toward tumour necrosis factor

Microb Cell. 2015 Jul 6;2(7):235-246. doi: 10.15698/mic2015.07.214.

Authors

Anne Silvestre¹, Aurélie Plaze², Patricia Berthon³, Roman Thibeaux², Nancy Guillen², Elisabeth Labruyère²

Affiliations

¹ Institut Pasteur, Unité Biologie Cellulaire du Parasitisme, F-75015 Paris, France. ; INSERM U786, F-75015 Paris, France. ; INRA, UMR1282 Infectiologie et Santé Publique, F-37380 Nouzilly, France. ; Université de Tours, UMR1282 Infectiologie et Santé Publique, F-37000 Tours, France.
² Institut Pasteur, Unité Biologie Cellulaire du Parasitisme, F-75015 Paris, France. ; INSERM U786, F-75015 Paris, France.
³ INRA, UMR1282 Infectiologie et Santé Publique, F-37380 Nouzilly, France. ; Université de Tours, UMR1282 Infectiologie et Santé Publique, F-37000 Tours, France.

Abstract

Background: Entamoeba histolytica cell migration is essential for the development of human amoebiasis (an infectious disease characterized by tissue invasion and destruction). The tissue inflammation associated with tumour necrosis factor (TNF) secretion by host cells is a well-documented feature of amoebiasis. Tumour necrosis factor is a chemoattractant for E. histolytica, and the parasite may have a TNF receptor at its cell surface.

Methods: confocal microscopy, RNA Sequencing, bioinformatics, RNA antisense techniques and histological analysis of human colon explants were used to characterize the interplay between TNF and E. histolytica.

Results: an antibody against human TNF receptor 1 (TNFR1) stained the E. histolytica trophozoite surface and (on immunoblots) binds to a 150-kDa protein. Proteome screening with the TNFR1 sequence revealed a BspA family protein in E. histolytica that carries a TNFR signature domain and six leucine-rich repeats (named here as "cell surface protein", CSP, in view of its cellular location). Cell surface protein shares structural homologies with Toll-Like receptors, colocalizes with TNF and is internalized in TNF-containing vesicles. Reduction of cellular CSP levels abolished chemotaxis toward TNF and blocked parasite invasion of human colon.

Conclusions: there is a clear link between TNF chemotaxis, CSP and pathogenesis.

Keywords: BspA protein; Entamoeba histolytica; chemotaxi; tumour necrosis factor.

Grants and funding

The authors greatly appreciate the support and enthusiasm of Dr Dominique Buzoni-Gatel as part of this collaboration between the INRA and the Institut Pasteur. We thank Guillaume Vogt for very helpful discussions in the early stages of this work, and Chung Chau-Hon for the RNASeq data. For all their support and advice, we thank Emmanuelle Perret and Pascal Roux (Plateforme Imagerie Dynamique, PFID, Imagopole IP), Laurence Fiette and Patrick Avé (Unité d’histologie humaine et modèles animaux IP), and Michèle Bernier and Marie Morcelet (Service d’Anatomopathologie, Hôpithal Foch, Suresnes, France). The authors gratefully acknowledge the Institut Pasteur's Pôle Intégré de Recherche Clinique for helping us to comply with guidelines on research on human tissues and with the French Bioethics Act. Funding. The work was funded by the National French Research Agency (ANR; grant MIE-08, Intestinalamibe), the French Parasitology consortium Labex ParaFrap (grant ANR-11-LABX0024), the Institut Pasteur (grant PTR 391) and the INRA Infectiologie et Santé Publique ISP Cluster (grant 32000266)