Tubuloreticular structures (TRS) which are found in the endoplasmic reticulum and measure 20-30 mm in diameter represent a distinct morphologic entity in which three basic forms are recognized, a membrano tubular form exemplified in arbovirus infections, a tubuloreticular form observed in human neoplastic cells and connective tissue diseases, and a geometrically organized form found in several animal tumors. The biologic nature of the TRS has not been resolved. It has been proposed that they could represent an incomplete form of virus, specifically the nucleocapsids of a paramyxovirus. TRS found in cultured human lymphoid cells (Raji cells originated from a Burkitt's lymphoma) induced by treatment with 5 bromo 2' deoxyuridine, a drug known to activate tumor viruses, were compared with the cytochemical reactions of paramyxovirus nucleocapsids. The glycolmethacrylate embedded TRS resisted digestion by ribonuclease and deoxyribonuclease, and stained intensely with the Rambourg's phosphotungstic acid method for glycoprotein, and after fixation with potassium permanganate. The paramyxovirus nucleocapsids were digested by ribonuclease and did not stain with phosphotungstic acid at pH 1 and KMnO4 fixation. Cytochemistry does not support the contention that the TRS in themselves are a form of virus, although the experiments with 5 bromo 2' deoxyuridine leave this possibility open. The findings suggest that they represent a specialized form of membrane amplification, a cell product which accumulates in response to virus infection.
|Number of pages||15|
|Publication status||Published - Jan 1 1974|
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