Cell-free transmissible leukoses in Syrian hamsters, probably of viral aetiology

Abstract

IN an earlier communication we reported on multiple epithelial skin tumours in Syrian hamsters in which a Papova virus has been detected with great regularity, in large quantities, and in characteristic histological distribution, as evidenced by electron microscopic observation (Graffi et al., 1967). In experiments designed to transmit this disease by means of subcellular extracts from these tumours to other animals we surprisingly obtained in Syrian hamsters and, in certain circumstances, also in rats, leukoses and reticuloses. It is these that are the subject of the present report. MATERIALS AND METHODSSubcellular tumour extracts were prepared as follows: tissue from skin tumours of hamsters ( Fig. 1 and 2) was vigorously homogenized in a glass homogenizer in phosphate-buffered saline (PBS) solution and the homogenate was diluted 1: 5 to 1: 10 and centrifuged. One group of animals was treated with the supernatant of the homogenate obtained after centrifugation at 3000 r.p.m. for 20 minutes. In most experiments, however, the material injected was subjected to centrifugation at 4000 to 6000 r.p.m. twice or three times, followed by filtration through G4 glass filters twice. In some cases the filtrate was diluted 1: 1 with 0 * 25 M saccharose solution and centrifuged at 100,000 g for 40 to 60 minutes and the sediment was administered to the animals after suspension in PBS solution. By the same series of procedures, cell-free G4 filtrates were obtained from hamster leukoses induced by the injection of papilloma-derived material and from cell transplants of such leukoses. All manipulations were carried out in the cold (2°C.) as quickly as possible. The extracts were administered to (1) newborn Syrian hamsters of our own random-bred hamster colony that has a low spontaneous incidence of the type of skin tumour in question (maximum 5 per cent) and a low incidence of leukaemias mainly lymphomas (Horn and Siewert, 1968) arising in the mesenteric lymph nodes (about 3 per cent); (2) newborn Syrian hamsters of another hamster colony in which neither of the two types of tumour occur spontaneously; (3) newborn rats of a Wistar strain that has a spontaneous leukaemia incidence of about 0 5 per cent. The filtrate was in most cases injected subcutaneously, but occasionally intraperitoneally, in doses of 0 * 2 to 0 * 3 ml. per newborn hamster, or 0 -4 to 0 * 5 ml. per newborn rat.The electron microscopic investigation was performed with ultra-thin sections from tumours and from leukaemic infiltrates in liver, lymph nodes, spleen, kidney, etc. Material was fixed in glutaraldehyde and osmic acid and embedded in Epon. Uranyl and lead acetate were used to make contrast preparations.

A new member of the polyomavirus family: the hamster papovavirus. Complete nucleotide sequence and transformation properties.

“…The hamster papovavirus (HapV) has been isolated by Graffi et al from skin epitheliomas arising spontaneously in Syrian hamsters (Graffi et al, 1968). The tumors which are disseminated originate from the hair follicle epithelial cells.…”

Hamster-Tropic Sarcomagenic and Nonsarcomagenic Viruses Derived from Hamster Tumors Induced by the Gross Pseudotype of Moloney Sarcoma Virus

“…24 Immunologic and biologic studies to establish the relationship between the helper virus reported in this paper and the indigenous hamster C-type virus(es)23' 24 are in progress. The other possible, but unlikely, sources of the helper virus is that it is a mutant of the input Gross leukemia virus or that it existed as a contaminent in the original virus stocks.…”

Induction of Transmissible Lymphomas in Syrian Hamsters by Application of Dna From Viral Hamster Papovavirus-Induced Tumors and by Cell-Free Filtrates From Human Tumors

“…Observations of over 300 normal breeding animals up to a year of age revealed a zero incidence of spontaneous tumors. This special strain or colony, however, was found to be particularly susceptible to cell-free transmission of a lymphoma virus derived from lymphomas induced in hamsters following inoculations of a recently discovered papilloma-inducing papovavirus of the hamster.s1 3 Apparently the susceptibility to induced-lymphoma expression exhibited by the special colony of hamsters is present in only some of the hamsters because the highest incidence of induced lymphomas observed seldom exceeded 50%.…”