A panel of monoclonal antibodies to rat plectin: distinction by epitope mapping and immunoreactivity with different tissues and cell lines.

A panel of twelve monoclonal antibodies (mAbs) to plectin was analyzed to localize molecular epitopes and assess their utility for various immunotechniques. Based on staining patterns obtained by immunoblotting of proteolytic plectin fragments five groups of mAbs with spatially closely linked epitopes were distinguished. In combination with previous results obtained with recombinant mutant proteins, the epitopes of all mAbs could be shown to reside within three separated domains of plectin's rod domain.

Aspiration cytology, immunocytochemistry and electron microscopy of a malignant peripheral neuroectodermal tumor. A case report.

The findings of fine needle aspiration (FNA) cytology, immunocytochemical staining and electron microscopy (EM) in a case of malignant peripheral neuroectodermal tumor (PNET) presenting as a soft tissue mass in the lateral abdominal wall are reported. The immediate evaluation of the aspirate revealed cells of a small round cell malignant tumor. To provide a specific preoperative diagnosis, additional cytologic material was aspirated for immunocytochemical and ultrastructural investigations.

Expression of microtubule-associated proteins, MAP-1 and MAP-2, in human neuroblastomas and differential diagnosis of immature neuroblasts.

The expression of microtubule-associated proteins, MAP-1 and MAP-2, was studied in human neuroblastomas at various developmental stages using the immuno-alkaline-phosphatase technique and immunofluorescence microscopy. Of 15 cases examined, including grade I, grade II, and grade III neuroblastomas (M. Hughes, H.

Identification of plectin in different human cell types and immunolocalization at epithelial basal cell surface membranes.

The occurrence of plectin in various human tissues and cell lines was investigated using immunofluorescence microscopy and antibody gel overlay/immunoblotting techniques. Plectin was identified in all tissues and cell lines tested, namely placenta, kidney, cornea, foreskin and eyelid skin, skin fibroblasts, monocytes, keratinocytes and HeLa cells. In frozen sections of cornea and skin, plectin was found to be enriched at epithelial basal cell surface membranes.

Widespread occurrence of polypeptides related to neurotubule-associated proteins (MAP-1 and MAP-2) in non-neuronal cells and tissues.

The occurrence and cellular localization of polypeptides related to hog brain microtubule-associated proteins 1 and 2 (MAP-1 and MAP-2) in non-neuronal cell lines of various species and types, and in several tissues from rat was studied. When insoluble cell fractions were prepared by incubation of isotonic cell extracts with 20 microM taxol, polypeptides co-migrating with MAP-1 and MAP-2 upon gel electrophoresis were observed in virtually all cases examined. Immunoblotting of preparations from 3T6, CHO, HeLa and N2A cells, as well as pituitary, heart, testis and liver revealed immuno-reactivity with antibodies to neuronal MAP-1 for polypeptides co-migrating with MAP-1 in all cases, except for HeLa cells and liver.

Occurrence and immunolocalization of plectin in tissues.

Various tissues from rat were examined for the occurrence and cellular localization of plectin, a 300,000-dalton polypeptide component present in intermediate filament-enriched cytoskeletons prepared from cultured cells by treatment with nonionic detergent and high salt solution. The extraction of liver, heart, skeletal muscle, tongue, and urinary bladder with 1% Triton/0.6 M KCl yielded insoluble cell residues that contained polypeptides of Mr 300,000 in variable amounts.

Proteins of intermediate filaments. An immunohistochemical and biochemical approach to the classification of soft tissue tumors.

The intermediate filament cytoskeleton of various types of human soft tissue tumors was analyzed by immunofluorescence microscopy with the use of specific antibodies against cytokeratins, vimentin, and desmin, as well as by one- and two-dimensional gel electrophoresis of high-salt buffer- and detergent-resistant cytoskeletal preparations. All leiomyomas as well as a leiomyosarcoma contained desmin. Leiomyomas of both gastrointestinal and uterine derivation and the retroperitoneal leiomyosarcoma showed strong reaction for desmin in the smooth muscle cells, but the latter two exhibited also vimentin staining.

Differential distribution of microtubule-associated proteins MAP-1 and MAP-2 in neurons of rat brain and association of MAP-1 with microtubules of neuroblastoma cells (clone N2A).

To study the individual location of the microtubule proteins MAP-1 and MAP-2 in neuronal tissues and cells, antisera to electrophoretically purified MAP-1 and MAP-2 components were raised in rabbits. When frozen sections through rat brain were examined by immunofluorescence microscopy the antibodies to MAP-1 strongly stained a variety of nerve cells including dendrites and myelinated axons in the cerebrum and cerebellum. Antibodies to MAP-2 showed similar staining patterns, except that myelinated axons were unstained.

Immunocytochemical identification of epithelium-derived human tumors with antibodies to desmosomal plaque proteins.

Epithelial cells contain desmosomes, special intercellular junctions providing sites of membrane attachment for intermediate-sized filaments of the cytokeratin type (tonofilaments). Such sites of anchorage of tonofilaments appear as dense plaques on the cytoplasmic side of the desmosomal membrane. We have isolated desmosome-enriched fractions from bovine snout epidermis and tongue mucosa and have characterized the major protein associated with the desmosomal plaque.

Immunological and biochemical characterization of the keratin-related component of Mallory bodies: a pathological pattern of hepatocytic cytokeratins.

Mallory bodies induced by long-term griseofulvin feeding in mouse liver were isolated and analyzed by one- and two-dimensional gel electrophoresis and reaction of the separated polypeptides with cytokeratin antibodies using the blotting technique. Comparison with normal intermediate filament cytoskeletons from mouse hepatocytes revealed that Mallory bodies contain two polypeptides: Component II (Mr: 55,000; apparent isoelectric point values: 6.45, 6.

Antibodies to intermediate filament proteins as molecular markers in clinical tumor pathology. Differentiation of carcinomas by their reaction with different cytokeratin antibodies.

Antibodies to human and bovine epidermal prekeratin and antibodies to mouse liver cytokeratin component D (Mr 49 000) have been applied in indirect immunofluorescence microscopy on sections of human tumors of mammary gland and liver. In non-neoplastic mammary gland all epithelial cells were stained with these antibodies. In pre-invasive and invasive ductal and lobular carcinomas a cell population was observed which was not significantly stained with antibodies to epidermal prekeratin but did strongly react with antibodies to liver cytokeratin D.