Protection against Mycobacterium ulcerans lesion development by exposure to aquatic insect saliva. - Université Pierre et Marie Curie Accéder directement au contenu
Article Dans Une Revue PLoS Medicine Année : 2007

Protection against Mycobacterium ulcerans lesion development by exposure to aquatic insect saliva.

Priscille Brodin

Résumé

BACKGROUND: Buruli ulcer is a severe human skin disease caused by Mycobacterium ulcerans. This disease is primarily diagnosed in West Africa with increasing incidence. Antimycobacterial drug therapy is relatively effective during the preulcerative stage of the disease, but surgical excision of lesions with skin grafting is often the ultimate treatment. The mode of transmission of this Mycobacterium species remains a matter of debate, and relevant interventions to prevent this disease lack (i) the proper understanding of the M. ulcerans life history traits in its natural aquatic ecosystem and (ii) immune signatures that could be correlates of protection. We previously set up a laboratory ecosystem with predatory aquatic insects of the family Naucoridae and laboratory mice and showed that (i) M. ulcerans-carrying aquatic insects can transmit the mycobacterium through bites and (ii) that their salivary glands are the only tissues hosting replicative M. ulcerans. Further investigation in natural settings revealed that 5%-10% of these aquatic insects captured in endemic areas have M. ulcerans-loaded salivary glands. In search of novel epidemiological features we noticed that individuals working close to aquatic environments inhabited by insect predators were less prone to developing Buruli ulcers than their relatives. Thus we set out to investigate whether those individuals might display any immune signatures of exposure to M. ulcerans-free insect predator bites, and whether those could correlate with protection. METHODS AND FINDINGS: We took a two-pronged approach in this study, first investigating whether the insect bites are protective in a mouse model, and subsequently looking for possibly protective immune signatures in humans. We found that, in contrast to control BALB/c mice, BALB/c mice exposed to Naucoris aquatic insect bites or sensitized to Naucoris salivary gland homogenates (SGHs) displayed no lesion at the site of inoculation of M. ulcerans coated with Naucoris SGH components. Then using human serum samples collected in a Buruli ulcer-endemic area (in the Republic of Benin, West Africa), we assayed sera collected from either ulcer-free individuals or patients with Buruli ulcers for the titre of IgGs that bind to insect predator SGH, focusing on those molecules otherwise shown to be retained by M. ulcerans colonies. IgG titres were lower in the Buruli ulcer patient group than in the ulcer-free group. CONCLUSIONS: These data will help structure future investigations in Buruli ulcer-endemic areas, providing a rationale for research into human immune signatures of exposure to predatory aquatic insects, with special attention to those insect saliva molecules that bind to M. ulcerans.
Fichier principal
Vignette du fichier
journal.pmed.0040064.pdf (280.94 Ko) Télécharger le fichier
Origine : Fichiers éditeurs autorisés sur une archive ouverte
Loading...

Dates et versions

inserm-00700851 , version 1 (24-05-2012)

Identifiants

Citer

Laurent Marsollier, Estelle Deniaux, Priscille Brodin, Agnès Marot, Christelle Mbondji Wondje, et al.. Protection against Mycobacterium ulcerans lesion development by exposure to aquatic insect saliva.. PLoS Medicine, 2007, 4 (2), pp.e64. ⟨10.1371/journal.pmed.0040064⟩. ⟨inserm-00700851⟩
283 Consultations
270 Téléchargements

Altmetric

Partager

Gmail Facebook X LinkedIn More