Related Experiment Videos
Absence of splenic latency in murine gammaherpesvirus 68-infected B cell-deficient mice
E J Usherwood1, J P Stewart, K Robertson
1Department of Veterinary Pathology, University of Edinburgh, Summerhall, UK.
Abstract:
Murine gammaherpesvirus 68 (MHV-68) is a natural pathogen of mice which causes an acute lung infection and establishes a latent infection in B lymphocytes. In this paper we describe the infection in transgenic B cell-deficient (muMT) mice, to determine whether a latent infection can be established in a mouse lacking circulating B lymphocytes. Little difference was observed in the acute lung infection, although there was a slight delay in virus clearance in the muMT mice. This indicates that antiviral antibody is of little importance in the resolution of the lung infection. Neither free nor latent virus could be detected in the spleen in the muMT mice. In addition, these mice did not develop MHV-68-induced splenomegaly. These data suggest that within the lymphoid compartment B lymphocytes are the sole reservoir for MHV-68 infection in vivo, confirming earlier work which identified B cells as the site of latent infection based on cell fractionation studies. In addition, our study shows that CD4-driven lymphocyte expansion leading to splenomegaly is dependent on the presence of MHV-68-infected B cells in the spleen. Although no free virus was detected (using conventional biological assays) in the lung after the resolution of the acute infection, MHV-68 genome was detected in the lungs of both control and muMT mice by PCR analysis. This suggests that cells in the lung may act as a reservoir of latent virus which is independent of the B lymphocyte infection.
Insights
Murine gammaherpesvirus 68 (MHV-68) primarily infects B lymphocytes for latent infection. However, the lungs may harbor latent MHV-68 independently of B cells, suggesting a dual reservoir.
Area of Science:
- Virology
- Immunology
- Infectious Diseases
Background:
- Murine gammaherpesvirus 68 (MHV-68) causes acute lung infection and latent infection in B lymphocytes.
- B lymphocytes are considered the primary reservoir for latent MHV-68 infection.
Purpose of the Study:
- To investigate MHV-68 infection in B cell-deficient (muMT) mice to determine the role of B cells in latent infection.
- To assess the importance of antiviral antibodies in resolving lung infection.
- To identify potential alternative reservoirs for latent MHV-68.
Main Methods:
- Infection of transgenic B cell-deficient (muMT) mice and control mice with MHV-68.
- Assessment of acute lung infection, virus clearance, and detection of free/latent virus in the spleen.
- Analysis of MHV-68-induced splenomegaly and CD4-driven lymphocyte expansion.
- PCR detection of MHV-68 genome in lung tissue post-acute infection.
Main Results:
- muMT mice showed similar acute lung infection but delayed virus clearance compared to controls.
- No free or latent virus was detected in the spleen of muMT mice, and they did not develop splenomegaly.
- MHV-68 genome was detected in the lungs of both control and muMT mice by PCR, indicating a non-B cell lung reservoir.
Conclusions:
- B lymphocytes are the sole lymphoid reservoir for MHV-68 in vivo.
- CD4-driven splenomegaly is dependent on the presence of infected B cells in the spleen.
- The lung can serve as an independent reservoir for latent MHV-68, separate from B lymphocyte infection.