The effect of anti-lymphocyte and anti-thymocyte serum on the pathogenesis of Rauscher leukaemia in inbred mouse strains.

Rauscher virus causes in inbred Balb/c mice a rapidly progressing hyperacute, in C57B1/10Sn mice an incipient, spontaneously healing leukaemia. In DBA/1 and DBA/2 mice the appearance of leukaemia is followed by a partial remissions then by an exacerbation of the disease. The infection in C57B1/10Sn, DBA/1 and DBA/2 mice results in a significant tumour-specific immune response. Inhibition of the immune response is followed by an increased progression of leukaemia in DBA/1 and DBA/2 mice only. It is assumed that in C57B1/10Sn mice the remission of incipient leukaemia is associated with a resistance determined in the target cells, whereas in DBA/1 and DBA/2 mice the remission is due to a tumour-specific immune response. As in animals treated with anti-lymphocyte and anti-thymocyte serum the course of the disease runs proportionally to the degree of the inhibition of the immune response, the tumour-specific antibodies play a decisive role in the elimination of the tumour cells. In Balb/c, DBA/1 and DBA/2 mouse strains failing to exhibit a spontaneous reversion of the tumour cells, the appearance of a significant tumour-specific immune response depends on the resistance against the helper component of the Rauscher virus complex.