Free Access
Reprod. Nutr. Dev.
Volume 45, Number 4, July-August 2005
Page(s) 513 - 523
Reprod. Nutr. Dev. 45 (2005) 513-523
DOI: 10.1051/rnd:2005035

Mammary transmission of caprine arthritis encephalitis virus: a 3D model for in vitro study

Christian Le Jan, Claire Bellaton, Timothy Greenland and Jean-François Mornex

UMR 754, Rétrovirus et Pathologie Comparée, INRA/ENVL/UCBL/EPHE, Université Claude Bernard Lyon 1, IFR 128 Biosciences Lyon Gerland, 50 avenue Tony Garnier, 69366 Lyon Cedex 07, France

Abstract - Transmission of Caprine Arthritis Encephalitis virus (CAEV) from the mother to offspring is principally mediated by infected cells from colostrum and milk. The infection of the dam is often sub-clinical, and results in increased cellularity of milk, sometimes exacerbated by bacterial co-infections. Although monocytes are the major viral host cells, several other cell types, including epithelial mammary cells, fibroblasts and endothelial cells show low levels of in vivo infection. In vitro, however, all phenotypes of mammary gland cells are individually highly sensitive to CAEV infection. This suggests that local mechanisms act to control viral expression. Our goal is to analyse the mechanisms regulating local virus infection, including the physiological status of the mammary gland and bacterial co-infections. In this work, we present the development of a model for the in vitro reconstitution of mammary gland tissue using 3D cultures in Matrigel. Mononuclear cells from the blood are added to the 3D cultures in vitro. In these experimental conditions, the mammary cells spontaneously organize into mammospheres. Blood leucocytes migrate into the culture gel, and localize particularly at the periphery of the mammospheres. Mammospheres were susceptible to infection in vitro by CAEV, as shown by a cytopathic effect and expression of late CAEV antigen p30. This model will allow the in vitro study of virus expression, transfer of infection to mammary gland cells and interactions between the mammary gland cells, infected monocytes and immunocompetent cells. It will allow the study of mechanisms participating in the control of passage of pathogens into milk, according to the physiological and CAEV-infection status of the animal, microenvironment and the presence of bacterial co-infections.

Key words: mammary gland / goat / lentivirus expression / in vitro model

Corresponding author: Christian Le Jan

© INRA, EDP Sciences 2005