Role of the Major Histocompatibility Complex in Resistance to Marek’s Disease: Restriction of the Growth of JMV-MD Tumor Cells in Genetically Resistant Birds

Summary

B ²¹ is associated with resistance to Marek’s disease (MD). Forty populations of chickens from all over the world were examined for the presence of the B ²¹ allele. B ²¹ was found in twelve of these populations and it’s presence was confirmed by GVH testing in all ten populations which were tested. The populations in which B ²¹ was detected represent the extreme production types of the species and include the progenitor of the species, the Red Jungle Fowl. Our studies suggest that B ²¹ may have strong survival value for the species. An allogeneic transplantable lymphoma of MD, the JMV tumor cell line, grows more slowly in MD resistant chicks than in MD susceptible (B ²/ B ²) chicks. This is the first direct evidence that genetic resistance to MD may involve an active (immunological?) restriction of tumor cell growth. JMV cells were further characterized as a transplant of B₁ carrying lymphoblastoid cells, an allele which may be associated with susceptibility to MD.