Human T cell lymphoma leukemia virus (HTLV) is a human retrovirus (RNA tumor virus) that was originally isolated from a few patients with leukemias or lymphomas involving mature T lymphocytes. Here we report that the serum of Japanese patients with adult T cell leukemia, but not the serum of tested normal donors, contains high titers of antibodies to HTLV. These observations, together with data from Japan showing that adult T cell leukemia is endemic in southwest Japan, suggest that HTLV is involved in a subtype of human T cell malignancy, including Japanese adult T cell leukemia.

ABSTRACT. The interaction between simian virus 40(SV40)-induced endocytotic vacuoles and the nuclear membrane was investigated using cationized ferritin (CF) and concanavalin A (Con A) as cell membrane markers. These markers bound to the cell surfaces of CV-1 cells together with SV40 at 4°C. Following incubation of these modified cells at 37°C in serum-free medium, the cell membranes showed many invaginations. After incubation for 60 min at 37°C in the same medium, many various-sized vacuoles were present that contained membrane-bound CF, Con A and SV40. After 2 h of incubation at 37°C, Con A was present in some areas of the perinuclear cisterna along the nuclear membrane. The control experiment, however, showed no localization of Con A-binding on the nuclear membrane. These results provide evidence that SV40-induced endocytotic vacuoles migrate toward the nucleus and fuse with its membrane.

Cutaneous papillomas induced in domestic rabbits by inoculation of Shope papilloma virus (SPV) are known to regress spontaneously in approximately 30-50% of infected animals (1, 2). The regression takes place 5 to 12 weeks after the inoculation of SPV and those animals in which the tumors fail to regress during this period tend to carry the tumors almost indefinitely. Considerable evidence indicates that the phenomenon of spontaneous regression is probably due to specific immunological reactions against the tumor (1, 3, 4). Although data have been presented showing that some serum factor interferes with the inhibitory ability of immune lymph-node cells against the tumor (9, further investigations are needed to elucidate why this regression is observed in some animals and not in others.We used newborn domestic rabbits to investigate possible immunological mechanisms responsible for the regression of Shope papillomas. Rabbits are born immunologically immature and gradually acquire immunological competence. Newborn animals were inoculated with SPV within the first 24 neonatal hr and were then kept under observation for more than 6 months. Development and regression of Shope papillomas in these animals were recorded and immunological analyses were performed. The findings are discussed in comparison with those in adult rabbits.Materials and Methods. Rabbits. Adult rabbits of both sexes were purchased from local dealers and newborn animals were obtained by mating these purchased animals. The newborn, within the first 24 neonatal hr, were inoculated intradermally at two sites on the dorsal area with 0.05 ml of SPV suspension.SPV. Glycerinated Shope papillomas were obtained from the Earl Johnson Farm, Rago, Kansas, and stored at -20" until use. 64Virus suspension was prepared as described previously (3) and a 10% suspension was used throughout the experiment.In vitro neutralization test of SPV. A 10% SPV suspension was mixed with an equal volume of serum specimen and allowed to react at 37" for 30-60 min. The mixture was examined for papilloma-inducing capacity by inoculation onto the skin of an adult rabbit by the scarification method (3). The virus suspension treated with normal rabbit serum was similarly inoculated into the same rabbit. The results were assessed 3 weeks after the inoculation according to the degree of the papilloma produced. No papilloma production was recorded as positive, reduced papilloma production compared with the control was taken as weakly positive, and papilloma production similar to that of the control was recorded as negative.Delayed-type hypersensitivity test with SPV. SPV was partially purified by two cycles of differential centrifugation at 10,OOOg for 10 min and at 40,OOOg for 1 hr. Protein concentration of the virus suspension, purified as such, was estimated to be 142.5 pg/ ml by the Lowry et al. modification of the Folin-Ciocalteu method, using a calibration curve of bovine serum albumin. The suspension (0.05 ml) was injected intradermally into the rabbits and the results were assess...

The CD7 molecule is a differentiation antigen found on the surface of T lymphocytes and also on a very minor fraction of acute nonlymphocytic leukemia (ANLL). To study the genomic structure of the CD7 gene, two clones (SY4 and SY22) were isolated by screening a genomic library with a CD7 cDNA probe. Restriction mapping of these two phage clones showed that both overlapped each other, covering a total length of 23 kilobases (kb). Transfection of mouse L cells demonstrated that SY22 contains the gene expressing the CD7 antigen reactive with monoclonal CD7 antibody (Tp40), while SY4 does not. Subcloning of a 10.5 kb fragment from a 14.4 kb insert of SY22 contained the structural gene for the CD7 antigen. Detailed restriction mapping and partial sequence analysis revealed the CD7 gene to consist of four exons. By RNase protection assay, multiple initiation sites -122 base pairs (bp) to -38 bp from ATG translation initiation site were demonstrated. The promoter region had high G + C content and contained two SP1 binding sites (CCGCCC) and an AP2 binding site (CCCCAGGC), but lacked CAAT and TATA motifs.

No abstract