Contact sensitivity in mice measured with thymidine labeled lymphocytes

Area of Science:

• Immunology
• Cellular Biology
• Pharmacology

Background:

• Delayed hypersensitivity is a critical immune response.
• Understanding antigen-specific cellular mechanisms is vital for immunology research.
• Developing reliable assays for immune response detection is essential.

Purpose of the Study:

• To investigate delayed hypersensitivity responses in mice using an ear assay.
• To differentiate immune responses based on sensitizing antigens.
• To evaluate the sensitivity of the assay in detecting antigen-specific cellular accumulation.

Main Methods:

• An ear assay was developed to measure delayed immune responses in mice.
• Animals were sensitized with specific antigens (dinitrochlorobenzene or sheep red blood cells).
• Radioactive labeling (3H thymidine) identified and quantified antigen-sensitive cells at reaction sites via scintillation counting.

Main Results:

• Consistent delayed responses were observed in dinitrochlorobenzene (DNCB)-sensitized mice.
• Mice sensitized to sheep red blood cells did not exhibit comparable delayed responses.
• Reactivity to DNCB was significantly reduced in tolerant or control-sensitized animals.
• Antigen-sensitized peritoneal exudate and spleen cells showed higher radioactive labeling than non-sensitized controls.

Conclusions:

• The ear assay effectively detects antigen-specific delayed hypersensitivity in mice.
• Immune responses are antigen-dependent, as demonstrated by differential reactivity to DNCB and sheep red blood cells.
• The assay provides a quantifiable measure of cellular accumulation indicative of immune sensitization.