HSV-1 could accelerate the occurrence of L6565 mouse leukemia induced by L6565 MLV

Objective Numerous studies have shown that herpes simplex virus type 1 and 2 (HSV 1 and HSV 2) are able to activate an endogenous type C virus of mouse. However, the influences of HSV 1 or HSV 2 on the disease induced by type C virus (such as retrovirus) are not clear. This experimental study was designed to understand the influence of HSV 1 on the L6565 mouse leukemia induced by L6565 MLV. Methods Ninety two suckling mice were randomly divided into 3 groups, i.e., group 1 inoculated with L6565 MLV alone (36 mice) group 2 inoculated with L6565 MLV plus HSV 1 group (35 mice), and group 3, control group without any inoculation (21 mice). After inoculations, two mice from each group were sacrificed every week. The peripheral blood, thymus, lymph node, spleen and liver were removed from each mouse. The tissue pathological changes were observed and the L6565 MLV RNA was detected by using RT PCR. Results In group 1, L6565 MLV RNA was detected firstly in mouse thymus and spleen at the second week after inoculation, and the viral RNA was detected in many murine organs at the 8th week post inoculation. The early phase of leukemia was induced in some mice 10 12 weeks post L6565 MLV inoculation, the incidence was 42%. In group 2, L6565 MLV RNA was detected in murine thymus at the first week after inoculation. Then, the viral RNA was detected in murine spleens and peripheral blood at the 2nd week post inoculation, and the viral RNA was detected in many murine organs at the 6th week post inoculation. The early phase of leukemia was induced in mice 7～8 weeks post L6565 MLV plus HSV 1 inoculation, the incidence was 74%. Conclusion HSV 1 could accelerate the L6565 mouse leukemia induced by L6565 MLV.