Protection against bovine leukemia virus infection in two breeds of cattle.

Calves of two breeds--Brown Latvian and Black and White, were immunized against bovine leukemia virus with an immunogen produced from short-term cultured blood lymphocytes of BLV-positive Brown Latvian cows. The immunogen contained the viral proteins gp51 and p24 as well as some cellular proteins. As determined by bioassay in sheep, it did not contain infective bovine leukemia virus.

BLV-LB virus-specific sequences in cattle with spontaneous and experimentally induced leukemia.

Poly(A)-containing RNAs were extracted directly from the culture fluid of BLV-producing continuous and short-term lymphocyte cultures. The abovesaid poly(A)-RNAs were used as a template to synthesize complementary [3H]DNA (BLV cDNA). BLV cDNA possessed a high degree of homology to poly(A)-RNA isolated directly from the blood plasma of a leukemic animal.