Existence of a reverse transcriptase-p30 complex in AKR mice with a high incidence of spontaneous lymphocytic leukaemia.

The virus proteins, reverse transcriptase (RT) and p30, were found to increase with time in the subcellular fractions of lymphocytic tissue from either the thymus or spleen of AKR mice with spontaneous lymphocytic leukaemia. Significant levels of RT activity were first detected in the microsomal fractions of the two tissues at 15 and 20 weeks old, respectively. Although low amounts of p30 could be found in both tissues within the first week of life, the overall increase in the amount of p30 within each tissue followed much the same course as that shown by RT. In addition, a protein complex consisting of p30 and RT was first found in thymus and spleen lymphocytes of 15 and 20 week-old animals, respectively. The complex increased in amount in both organs as the animals aged, reaching a maximum level in 30 week-old mice. Repeated attempts to detect other virus proteins such as gp70 in association with the complex by immunological means were unsuccessful. The complex could not be found in lymphocytic tissue taken from younger animals or in 'non-target' organs, such as liver or kidney, of animals with leukaemia. In animals treated with antiviral IgG, which delayed the development of spontaneous leukaemia, the complex did not appear until much later in life (45 weeks) and then in considerably smaller amounts.