Assay in the mouse for delayed-type hypersensitivity to murine leukemia virus

Area of Science:

• Immunology
• Virology
• Mouse Models

Background:

• Delayed-type hypersensitivity (DTH) is a critical immune response.
• Murine type-C viruses are oncogenic retroviruses.
• Assessing DTH in response to viral antigens is important for understanding immunity.

Purpose of the Study:

• To induce and characterize DTH responses in mice immunized with inactivated murine type-C viruses.
• To evaluate the specificity and reproducibility of the DTH assay for viral subtypes.
• To determine if DTH responses correlate with protection against live viral challenge.

Main Methods:

• Induction of DTH by footpad swelling in BALB/cCr mice immunized with formalin-inactivated, sucrose-banded murine type-C viruses.
• DTH response assessment with varying antigen concentrations and sensitization routes (subcutaneous, intramuscular, intraperitoneal).
• Statistical analysis of assay reproducibility and specificity using Tween 80-ether extracted antigens to differentiate viral subtypes.

Main Results:

• DTH response was inducible with as little as 11.25 mug of antigen.
• Subcutaneous sensitization yielded the greatest DTH response.
• The DTH assay demonstrated reproducibility and specificity, distinguishing between Rauscher and AKR murine leukemia virus strains.
• Mice exhibiting DTH responses were resistant to challenge with live murine leukemia viruses.

Conclusions:

• Formalin-inactivated murine type-C viruses can induce a specific DTH response in mice.
• The DTH assay is a reproducible and specific method for detecting immune responses to type-C virus subtypes.
• Induced DTH correlates with resistance to exogenous live murine leukemia virus infection, suggesting its potential role in protective immunity.