Impairment of T lymphocyte functions in mice with motor end-plate disease.

The present paper reports complex immunological anomalies associated with motor end-plate disease (Med) in mice. Motor end-plate disease is a severe neuromuscular disorder which leads to death (around the 25th day of life) in the MedJ/MedJ mutant, while the heterozygote's quickly recover from mild manifestations. MedJ/MedJ and MedV + mice share some ofthe immunological aberrations: reduced PFC response to SRBC in 14-16 day old mice, with reduced suppressor cell function and precocious maturation of the cytotoxic response to allogeneic cells in 21-23 day old mice. The diminished PFC response is corrected in adult Med+ mice but persists in the small group of MedVMedJ which escape death and which were studied between the 6th and 16th week of life. In addition, the thymus and spleen of MedJ/MedJ mice are greatly reduced in size, a symptom which appears with the onset ofthe clinical disease. Also, a reduction in the NK activity in the small group of older, surviving mice was noted. T and B lymphocyte proportions and the proliferative responses to T cell mitogens were not impaired in 14-16 day old mice. The role of these abnormalities in the pathogenesis of the disease is not known. Since some of these anomalies are shared by Med'/ and MedV + , the latter of which present no or mild and transient neurological manifestations, there is no clear link between the immunological and neuromuscular disorders. [ABSTRACT FROM AUTHOR]