Lymphocyte sensitization in sheep inoculated with extracts of spontaneously occurring malignant lymphomas.

A macrophage migration inhibition test showed that the blood lymphocytes of 15 of 27 sheep inoculated in utero or at birth with disrupted cells from ovine malignant lymphomas responded in culture to antigens derived from three other lymphomas. A close association was seen between animals whose lymphocytes were antigen-sensitive and those which developed lymphocytosis. This association and the specificity of reaction between the various tumour antigens employed in the tests is interpreted as further evidence toward a viral aetiology in ovine malignant lymphoma.