Tubuloreticular structures in human and veterinary medicine

Tubuioreticular structures (TRS) belongs to the Ghadiaily's Microtubular group nosography (Ghadiaily, 1997).They are cytoplasmic inclusions which appears as discrete collections of undulating or reticulated microtubules mostiylying within the rough endoplasmic reticulum, the perinuclear envelope or, less fiequently, withm the cytoplasmicmabix (Ghiadialiy, 1997; Luu et ai, 1989). TRS have been reported most fiequently in lymphocyìes, monocytes orendothelial ceiis, and occasionaily in other cell type of mesodermal and ectodermal origin bericyte, fibroblast andmuscle cells) of both humans and animals, in association with Wal infections, autoimmune diseases, neoplasms andother diseases. (Ghadially, 1997; Cheville, 1994). The most common type of TRS is that composed of moderatelypackedmicrotubules (20-30 nm in dmneter) giving rise to the well-known picture of dense interwoven microtubularreticular inclusions. The second type is a compact "crystaliine" form. Additional examples include the TRS composedof simght undulating microtubuies (Schaff et al., 1973) A transition between the undulating, the loose array and atightly packed arrangernents is common, and a relationship between ihe packing density of the tubuloreticularinclusions and the variations in its appearance have been suggested by Bhinger et al. (1972).In human medicine "microtubuloreticular structures" have been fiequently seen in vascular endothelial cellsbut also in blood mononuclear ce& and histiocyìes in patients with Necrotmng lymphadenitis, AcquiredImrnunodeficiency Syndrme (associated with the presence of cylindrical co&onting cisterne), severa1 hyper- andauto-immune diseases (such as Systemic lupus erytematosus), in patients with viral hepatitis, in lymphoid andplasmacytic tumors (Sidhu et al., 1985; Henderson et al., 1986; Ghadially, 1997; Papadimtriou et al., 1992; Varma etal., 2000).In veterinq literattue such inclusions appears to be more comrnon in the geometric (crystalline) form (SchafTet al., 1973), and lie in the cytoplasmic ma& (as chimpanzee hepatitis-type mclusion). They have been seen indifferent cell types, sometimes (as in human pathology) muddled with virus-like particles. TRS are observed in horseswith equine wal Wus (Estes and Cheville, 1970), equine sarcoid tumour ceils (Madewell and Munn, 1989), pigs withporcine polioencephalitis virus (Koestner et ai, 1966) or experimentally infected with Aiiican swine fever vim (Nuneset ai, 1983; Mozos et al, 2003), mink with Aleutian disease (Tsai et al., 1969), dogs with canine infectious hepatiiis anddistemper (Bestetti et al., 1978; Givan and Jezequel, 1969; Blinzinger et al., 1972), Globoid cell leukodystrophy (Yunis,1976) or with pancreatic acinic cell carcinomas (Banner et al., 1978), rhesus monkeys with leukemia (Feldman et al.,l986), spontaneous myxosarcoma in a cotton-td rabbit (SchaE et al., 1973).Cytochemical studies indicate that they consists of phospholipidds and acidic glycoproteins (Boor et ai, 1979),and that ihey did not contain nucleic acids. Clinica1 and experimenta1 studies indicate that the occurrence ofmicrotubuloreticular stmctures in human endohelial cells is directly related to ihe endogenous elevation of alpha- andbeta-interferon but not to gamma-interferon (Hamrnar et al., 1992). The predominantly type of interferon that have beenfound in the s e m of patients with diseases related with TRS (sa SLE) appears to be a subspecies of alpha- interferonthat is partially inactivated at pH 2 (acid labile). Severa1 human lymphoblastoid celi lines are able to spontaneouslyproduce type I (Alpha and Beta) intederon without viral or chemical induction. The cultured ce& liberate suchinterferon only during logarithmic growth phase (Pickering et al., 1980). A new interferon-alpha induced protein @36)tha[...]