Susceptibility of mouse mammary glands to murine gammaherpesvirus 72 (MHV-72) infection: evidence of MHV-72 transmission via breast milk.
Murine gammaherpesvirus 72 (MHV-72) is a virus of wild rodents and serves as a convenient small animal model to understand the pathogenesis of Epstein-Barr virus (EBV) and human herpesvirus 8 (HHV8) infection. In laboratory mice MHV-72 causes an acute infection of lung epithelial cells and establishes the latency in B lymphocytes. In this study, we investigated athymic nude and immunocompetent mice for distribution of virus in organs after infection with MHV-72. Ten days following subcutaneous dorsal injection of nude mice, virus replicated in lungs, lymphoid organs, salivary glands and also in mammary glands. The virus titre decreased by day 21 post-infection in former tissues, but increased in mammary glands. Presence of virus DNA sequences was detected in the lymphoid and non-lymphoid tissues until the death of the animals (about 1 month post-infection). Infection of immunocompetent mice with MHV-72 induced replication of virus up to 42 days post-infection in mammary glands reaching the highest level of infectious virus at day 8 post-infection. These data show that there is latent infection in mice never detected before. Moreover, virus DNA was detected using nested PCR (by amplification of a portion of gp150 gene sequence) in the mammary glands and the milk of mouse mothers infected with MHV-72 2 days before delivery. We demonstrated the presence of virus DNA also in the milk removed from the stomach of non-infected newborn mice, which were nourished by infected mothers (wet-nurses) for 1 or 2 days. The failure to detect the virus DNA in newborn mice lungs confirmed that they did not become infected from wet-nurses by the intranasal route. This suggests that MHV may be naturally transmitted to newborn mice via breast milk.
Raslova
H
H
Institute of Virology, Slovak Academy of Sciences, Dubravska cesta 9, 842 45 Bratislava, Slovak Republic.
Berebbi
M
M
Rajcani
J
J
Sarasin
A
A
Matis
J
J
Kudelova
M
M
D000818:Animals; D000833:Animals, Suckling; D001940:Breast / Q000821:virology*; D004279:DNA, Viral / Q000032:analysis; D004195:Disease Models, Animal; D005260:Female; D018142:Gammaherpesvirinae / Q000302:isolation & purification* / Q000502:physiology; D006566:Herpesviridae Infections / Q000635:transmission* / Q000821:virology; D007121:Immunocompetence; D018445:Infectious Disease Transmission, Vertical; D008168:Lung / Q000821:virology; D008198:Lymph Nodes / Q000821:virology; D051379:Mice; D008807:Mice, Inbred BALB C; D008819:Mice, Nude; D008892:Milk / Q000821:virology*; D016133:Polymerase Chain Reaction; D011247:Pregnancy; D012469:Salivary Glands / Q000821:virology; D013997:Time Factors; D017735:Virus Latency
D004279:DNA, Viral