Related Experiment Video
Updated: Aug 16, 2026
Influenza A Virus Studies in a Mouse Model of Infection
Published on: September 7, 2017
Comparative sensitivity of infectivity assay and mouse antibody production (MAP) test for detection of mouse thymic
1Rockefeller University, Laboratory Animal Research Center, New York, NY 10021.
Abstract:
Mouse thymic virus (murid herpesvirus-3; MTLV) is a naturally occurring T lymphotropic herpesvirus of mice. We compared the sensitivity of infectivity assay, which tests for induction of thymic necrosis in newborn mice, and an enzyme immunoassay (ELISA)-based modified mouse antibody production (MAP) test. Infection in adult mice was verified by infectivity assay of salivary glands. Approximately ten times as much virus was required to infect adult mice as newborns. No adults became infected at the lowest dose (just below 1 ID50 by thymic necrosis in newborn mice); a dose tenfold higher resulted in both infection and seroconversion in three out of five mice. At higher doses tested (up to 8000 ID50), all mice became infected and seroconverted. Infected mice shed virus and remained seropositive for at least six months. False positives were observed in ELISA; these could be eliminated by adding control (uninfected) thymic homogenate (1/10 volume of a 10% homogenate) to the sample diluent. These data suggest that the MAP assay can be a reliable and sensitive indicator of infection in adult mice undergoing primary infection. Although slightly less sensitive than infectivity assay for detecting MTLV, the MAP test is likely to detect most samples containing virus. It is recommended that several mice be used for each sample and that all positive serum samples be retested with control thymic homogenate for increased reliability.
Insights
Mouse thymic virus (MTLV) infection requires higher doses in adult mice than newborns. The modified mouse antibody production (MAP) test, with controls, reliably detects MTLV infection in adult mice.
Area of Science:
- Virology
- Immunology
Background:
- Mouse thymic virus (MTLV) is a T lymphotropic herpesvirus naturally infecting mice.
- Assessing MTLV infection sensitivity in different age groups is crucial for accurate diagnosis.
Purpose of the Study:
- To compare the sensitivity of infectivity assays and ELISA-based modified mouse antibody production (MAP) tests for detecting MTLV infection in mice.
- To determine the viral dose required for MTLV infection and seroconversion in adult mice.
Main Methods:
- Infectivity assays were used to determine the 50% infectious dose (ID50) in newborn mice and to verify infection in adult mice salivary glands.
- Enzyme immunoassay (ELISA)-based modified mouse antibody production (MAP) tests were performed on adult mouse sera.
- ELISA results were re-evaluated after adding control thymic homogenate to mitigate false positives.
Main Results:
- Adult mice required approximately ten times the viral dose of newborn mice for infection.
- MTLV infection and seroconversion were observed in adult mice at doses tenfold higher than the newborn ID50.
- False positive ELISA results were reduced by incorporating control thymic homogenate.
Conclusions:
- The MAP assay is a reliable and sensitive method for detecting primary MTLV infection in adult mice.
- While slightly less sensitive than infectivity assays, the MAP test effectively detects most MTLV-containing samples.
- Recommendations include using multiple mice per sample and retesting positive sera with control homogenate for enhanced MAP assay reliability.
