Showing papers on "Friend leukemia published in 1972"

Adjuvant Induced Resistance to Tumor Development in Mice

Abstract: SummaryMice pretreated with complete Freund's adjuvant had an enhanced resistance to autochthonous and transplanted tumors. Delayed time to death and/or increased survival was noted in CFA pretreated mice grafted intraperitoneally with Sarcoma 180, leukemia L1210, or Friend leukemia spleen cells. In addition, CFA pretreatment caused a statistically significant delay in spontaneous mammary tumor development in C3H/HeJ mice and spontaneous leukemia in AKR mice. We propose that host resistance to intracellular infectious agents and neoplasia is related in a fundamental way and the activated macrophage is a common effector arm for expression of this resistance. It is also suggested that a nonimmunologic growth control mechanism such as we have described offers a rapid acting homeostatic process for destruction of cells with abnormal growth properties in vivo.

Coating of Friend Leukemia Virus after Treatment with Specific Antiserum

Abstract: After Friend leukemia cells were treated with specific antiserum to Friend leukemia virus (FLV) both in vitro and in Millipore diffusion chambers in vivo in FLV-immunized mice, extracellular and budding viruses were coated with flocculent or filamentous material of variable thickness. Coats observed on viruses after 3 weeks in chamber cultures in FLV-immunized mice were denser and thicker than those seen after in vitro incubation with FLV antiserum. Almost all “enveloped A” as well as type C viruses were coated after FLV antiserum treatment in the two experimental systems. Virus budding sites were also occasionally coated, while the rest of the cell surface was not. As compared with untreated cultures, the number of budding viruses increased significantly in all cell samples grown in diffusion chambers, particularly in those taken from FLV-immunized mice. Ferritin or southern bean mosaic virus, used in conjunction with hybrid antibodies to detect virus-bound γ-globulin, labeled more than 90% of viruses treated with FLV antiserum in vitro , in contrast to 9% in controls treated with normal mouse sera; this strongly suggests the presence of FLV antibody within the coat.