C-type virus-like particles specifically localized in Langerhans cells and related cells of skin and lymph nodes of patients with mycosis fungoides and Sezary's syndrome. A morphological and biochemical study.

Abstract

C-type virus-like particles were found in 7 skin biopsies and in 4 lymph nodes from 7 patients with mycosis fungoides (MF). In addition, such particles were also found in skin biopsies from 2 patients with Sezary’s syndrome (SS). The particles were invariably found in cells derived from the mononuclear phagocytic series i.e. Langerhans cells and “related cells”, but never in cerebriform mononuclear cells (CMC) nor in any other cell-type. No virus-like particles were found in control specimens consisting of skin biopsies from 8 patients with chronic benign skin lesions and peripheral lymph nodes from 4 patients with unrelated diseases. In one patient with MF particles possessing some characteristics of retraviruses could be released from skin lesions. They band at a density of about 1.16 g/cm3 in a sucrose gradient and exhibit reverse transcriptase activity (RNA-dependent DNA-polymerase activity). Electron microscopy of the skin lesions and of the 1.16 g/cm3 sucrose gradient fraction confirmed the presence of C-type virus-like particles. The presence of C-type virus-like particles only in Langerhans cells and in related cells: i.e. indeterminate cells in the skin and IDC in lymph nodecells with a specific preference for T cell regions-from patients with MF and SS might be related to the aetiology of these cutaneous T cell lymphomas.