Immunological unresponsiveness of genetically thymusless (nude) mice

Mice homozygous for the nude mutation completely lack a thymus. Their response to antigenic stimulus is very poor. They do produce a small amount of hemolysing antibody in response to sheep red blood cells but significant hemagglutinating antibody, or antibody against bacteriophage T4 could not be demonstrated and they did not reject allogeneic skin grafts.