[59] Assay of immunomodulation by type I interferon in Vivo

Publisher Summary This chapter presents various points found to be of practical importance while studying modulation by interferon of the delayed-type hypersensitivity reaction in the mouse. For experiment, mice should be of the same age and sex, unless the latter represents the very factors studied. The origin of the animals is of the utmost importance, and breeding one's own mice remains the best solution to this problem provided one has the proper breeding facilities and animal quarters. Mice commercially available do not always live up to standards, and significant variations have been observed in the extent and duration of delayed hypersensitivity reactions in mice belonging to the same inbred strain but of different commercial origins. The effects of interferon on delayed hypersensitivity are influenced by the genotype of the mouse, for example, more interferon is required to inhibit expression of delayed hypersensitivity to sheep red blood cells (SRBC) in C57BL/6 mice than in BALB/c mice. Therefore, it is preferable to use inbred mice of defined genotype, since such genetic effects can be masked when using random-bred strains. Suboptimal doses of antigen are usually required in order to bring out immune-enhancing effects of interferon. Interferon can be administered both intravenously and intraperitoneally.