Related Experiment Video
Updated: May 11, 2026
Use of In vivo Imaging to Monitor the Progression of Experimental Mouse Cytomegalovirus Infection in Neonates
Published on: July 6, 2013
MicroRNA-146a deficiency enhances host protection against murine cytomegalovirus
Pamela Wong1, Jeffrey W Leong1, Hyogon Sohn2
1Division of Oncology, Department of Medicine, Washington University School of Medicine, St. Louis, Missouri, USA.
Abstract:
Natural killer (NK) cells are innate lymphoid cells that protect a host from viral infections and malignancies. MicroRNA-146a (miR-146a) is an important regulator of immune function that is highly expressed in NK cells and is further upregulated during murine cytomegalovirus (MCMV) infection. Here we utilized mice with a global targeted deletion of miR-146a to understand its impact on the innate immune responses to MCMV infection. MiR-146a-/- mice were protected from lethal MCMV infection, which was intrinsic to the hematopoietic compartment based on bone marrow chimera experiments. NK cell depletion abrogated this protection, implicating NK cells as critical for the miR-146a-/- protection from MCMV. Surprisingly, NK cells from miR-146a-deficient mice were largely similar to control NK cells with respect to development, maturation, trafficking, and effector functions. However, miR-146a-/- mice had increased NK cell numbers and frequency of the most mature Stage IV (CD27-CD11b+) NK cells in the liver at baseline, enhanced STAT1 phosphorylation, and increased selective expansion of Ly49H+ NK cells and T cells during MCMV infection. This study demonstrates a critical role for miR-146a in the host response to MCMV, arising from mechanisms that include increased NK cell numbers and early T-cell expansion.
Insights
MicroRNA-146a deficiency protects mice from lethal murine cytomegalovirus infection, primarily through enhanced natural killer cell responses. This highlights miR-146a
Area of Science:
- Immunology
- Virology
- Molecular Biology
Background:
- Natural killer (NK) cells are crucial innate immune cells combating viral infections and cancer.
- MicroRNA-146a (miR-146a) is a key immune regulator, highly expressed in NK cells and upregulated during murine cytomegalovirus (MCMV) infection.
Purpose of the Study:
- To investigate the role of miR-146a in the innate immune response to MCMV infection using a global miR-146a-deficient mouse model.
Main Methods:
- Utilized miR-146a knockout (miR-146a-/-) mice and wild-type littermates.
- Conducted MCMV infection experiments.
- Employed bone marrow chimera experiments to assess hematopoietic-specific effects.
- Performed NK cell depletion studies.
- Analyzed NK cell development, maturation, trafficking, and effector functions.
- Quantified immune cell populations and STAT1 phosphorylation.
Main Results:
- miR-146a-/- mice exhibited significant protection against lethal MCMV infection.
- Protection was intrinsic to the hematopoietic system and dependent on NK cells.
- Despite similar baseline NK cell characteristics, miR-146a-/- mice showed increased hepatic NK cell numbers, particularly mature Stage IV cells.
- Enhanced STAT1 phosphorylation and selective expansion of Ly49H+ NK cells and T cells were observed during MCMV infection in miR-146a-/- mice.
Conclusions:
- miR-146a plays a critical role in regulating the host response to MCMV infection.
- The protective mechanisms involve increased NK cell populations and augmented early T-cell expansion.
- Targeting miR-146a pathways may offer therapeutic strategies against MCMV and potentially other viral infections.
Related Concept Videos
01:22MicroRNAs
02:43Mouse Models of Cancer Study
The development of transgenic, knockout, and knock-in mice has led to an exponential increase in their use as model organisms in research,...
01:22MicroRNAs