Layer Of Squamous Cells Research Articles

Microscopic and biochemical analysis of the viability and permeability of guinea pig amnion and chorion leave in vitro.

Tissue viability and permeability of guinea pig amnion and chorion leave were analyzed microscopically and biochemically. The vital dyes T1111 and fluorescein diacetate were used to locate and determine the integrity of cell plasma membranes in early and late tissue in vitro using confocal laser scanning microscopy and scanning electron microscopy. Early amnion and chorion laeve were each found to contain a single epithelial cell layer, composed of membrane-intact cells. In contrast, plasma membrane lesions were present throughout the epithelium of late amnion. Late chorion laeve contained both regions of intact and damaged epithelial cells on its maternal side. There was also a layer of membrane-intact squamous cells on the fetal side of late chorion laeve. ATP measurements confirmed that early fetal membranes were viable after incubation in isotonic salt solutions at physiological pH. Late amnion was depleted of ATP stores while late chorion laeve retained its capacity for generating energy. These viability markers indicate that late guinea pig amnion is not a viable tissue in vitro, while late chorion laeve is a viable but probably degenerating tissue. Confocal X-Z scans were used to trace the movement of T1111 through the tissue as an indication of permeability to free solutes. Whereas dye will permeate across the main thickness of early amnion and chorion leave, it did not pass between cells, but was blocked, presumably by a line of tight junctions. Late amnion was characterized by the complete permeability to T1111. Late chorion leave contained regions where solute migration was blocked, but overall was a permeable tissue. These results provide an important context for the interpretation of molecular movement across fetal membranes.

Lectin bindings in non-neoplastic esophageal epithelium and esophageal carcinomas

Lectin binding was examined histochemically in 22 cases of primary esophageal carcinomas (10 well differentiated, 8 moderately differentiated and 3 poorly differentiated squamous cell carcinomas, and 1 undifferentiated carcinoma) and was compared with the adjacent non-neoplastic epithelium by means of a panel of 10 different lectins (RCA-I, WGA, Con A, LCA, SEA, UEA-I, HPA, PNA, DBA and GS-I) on formalin-fixed paraffin-embedded sections. In the non-neoplastic epithelium, RCA-I and WGA showed basal/parabasal binding, Con A, LCA, SEA, UEA-I, HPA and PNA revealed prickle cell binding, while DBA and GS-I only stained the surface cells of the squamous cell layer. In squamous cell carcinomas, no clear difference was evident regarding the grade of differentiation. However, basal/parabasal specific lectins were expressed in all the cases, the prickle cell-specific lectins were expressed less frequently, whereas lectins expressed at the surface cells of the squamous cell layer were only infrequently expressed. Therefore, basal/parabasal cell specific lectins were widely preserved in squamous cell carcinomas. One case of undifferentiated cancer tested was devoid of all the lectins.

Polymorphic light eruption-an immunopathological study of provoked lesions

Polymorphic light eruption (PLE) lesions were induced in 26 patients after an average of 60 J total body UVA irradiation. Using the criteria of the French literature, that make a distinction between PLE and benign summer light eruption (BSLE), the group of 26 patients with PLE was divided into 12 patients with BSLE and 14 patients with PLE, on the basis of historical criteria. Biopsies were taken and compared immunohistochemically with biopsies from 15 unirradiated normal control subjects, in order to find evidence in support of the hypothesis that PLE involves a delayed-type hypersensitivity reaction. The provoked lesions showed: ICAM-1 expression on the keratinocytes of the basal and suprabasal cell layers in 18 of 25 patients, i.e. 72%; HLA-DR expression on the keratinocytes of the basal, squamous and granular cell layer in 13 of 25 patients, i.e. 52%; and OKM5 expression on the keratinocytes of the granular cell layer in 13 of 26 patients, i.e. 50% of the cases. The control samples showed no such antigen expression on the keratinocytes, except for two cases where weak and very localized ICAM-1 positivity was observed; one of these also had a slight localized positivity for HLA-DR and OKM5. The results of the phototesting procedures and the immunohistochemical investigations were similar in both BSLE and PLE. This suggests that they are the same condition, and the term BSLE should therefore probably be discarded. The results of our investigations support the theory of an immunological basis for PLE.

Disappearance of Langerhans cells and melanocytes after cryopreservation of skin

Cryopreserved skin allografts have been extensively reported to remain viable for longer periods after grafting, both in the laboratory and in the clinic, than skin stored by other methods. We investigated the immunocytochemical and electron microscopic properties of samples of cryopreserved human skin (-196 degrees C) for comparison with fresh samples. In an immunocytochemical study of fresh skin, reagents S-100 and CDIa indicated numerous mesenchymal origin cells in the squamous cell layer, basal layer and dermis; 2B7 identified these cells in the basal layer and PC-10 identified them in the basal and squamous cell layers. In cryopreserved skin, however, few cells reacted to these reagents. An electron microscopic study of the cryopreserved skin showed Langerhans cells (LC); however, these had suffered degeneration, with partial defects of the cell membrane and vacuolation in the cytoplasm. We speculate these effects are responsible for the virtually complete abolition of LC membrane and cytoplasm markers. In summary, we detected few mesenchymal origin cells, melanocytes, Langerhans cells, or S-phase cells, in cryopreserved skin by immunocytochemical methods. Langerhans cells existed but had degenerated. These results indicate that cryopreservation at -196 degrees C causes degeneration of Langerhans cells, and that is the reason for the prolonged viability of cryopreserved allograft.

Cell adhesion molecules in oesophageal epithelium.

The distribution of a range of integrins, E-cadherin, and carcino-embryonic antigen (CEA) like molecules in normal human oesophageal epithelium was investigated immunohistochemically on frozen sections of endoscopic biopsy specimens. The integrin subunits alpha 2, alpha 3, alpha 6, alpha v, beta 1, and beta 5 were expressed throughout the epithelium. There was strong expression of alpha 2, alpha 3, and beta 1 subunits in the basal cell layer and for all the subunits studied the intensity of the staining decreased as cells moved towards the lumen. The heterodimer alpha v beta 3 was expressed weakly in the basal aspect of the basal cell layer only. The CEA molecules were not present in the basal cells layer but there was weak expression in the prickle cell layer and strong positivity in the mature functional layer. E-cadherin was found throughout the epithelium but was weakly expressed at the basal aspect of the basal cells layer and showed strong positivity in the prickle cell and squamous cell layers. These results indicate that cell-cell (E-cadherin, CEA) and cell-matrix (integrins) adhesion molecules show a well defined spatial pattern of immunoreactivity in the oesophageal mucosa and may play a part in the maintenance of normal tissue architecture and physiological homeostasis.

Synthesis of Rabbit Corneal Epithelial Glycocalyx in vitro

A method to study the synthesis and cellular processing of epithelial apical membrane glycoproteins in the rabbit cornea was developed. Fluorescent derivatives of wheat germ agglutinin (WGA; α-N-acetylglucosamine and sialic acid hapten affinities), succinylated WGA (α-N-acetylglucosamine hapten affinity) and concavalin A (Con A; d-mannose and d-glucose hapten affinity) were reacted with the corneal surface and the extent of binding attained was measured by en face, microscope-aided fluorophotometry. Minimal binding of succinylated WGA and a large reduction in WGA binding following neuraminidase treatment demonstrated that the attachment of WGA to the corneal surface occurred via sialic acid residues, i.e. via structures associated with terminal glycosylation. Corneas were treated with digitonin to induce the exfoliation of the outer squamous-like cell layers. The time-dependent changes in lectin binding density at the apical surface of the newly exposed intrastratal cells were then determined. Binding densities for WGA and Con A at the time of exfoliation of the digitonin-devitalized squamous cell layers (< 2 hr post-devitalization) were similar to the densities measured at the surface of untreated corneas. Over the subsequent 18-20 hr, the WGA and Con A binding increased by 2·63 ± 0·24 and 3·0 ± 0·68 (± S.D., n = 4) fold, respectively. The effect of inhibitors of transcription (actinomycin D, α-amanitin), translation (cycloheximide), core glycosylation of polypeptides (tunicamycin), endoplasmic reticulum glucosidases (deoxinojirimycin) and Golgi mannosidase (swainsonine) indicated that the increases were underpinned by new glycoprotein synthesis driven by a stable, pre-existing mRNA pool. Retinoic acid (2 μM) inhibited the increase in WGA binding by 55 ± 6% (n = 4) but did not affect the Con A density increase suggesting that this agent either, modifies the terminal glycosylation pattern of apical membrane proteins and/or inhibits the synthesis of proteins bearing sialic acid. Actinomycin D or α-aminitin reverted the retinoic acid action, indicating that the retinoid effect is mediated by induced gene expression.

Molecular cloning of a novel human papillomavirus (Type 60) from a plantar cyst with characteristic pathological changes

In a plantar cyst composed of the wall of the squamous cell layer and the horny inner substance in the lower dermis, we found characteristic pathological changes, such as cytoplasmic eosinophilic inclusions and vacuolated structure, and, immunohistochemically, the papillomavirus capsid antigen. The human papillomavirus (HPV) DNA cloned from the cyst showed no homology with other known prototypes of HPV (HPV 1 through HPV 59) by Southern blot analysis under stringent conditions and was named as HPV 60. HPV 60 DNA was found in three other cases of plantar cyst with the identical pathological changes, but not in a plantar cyst without such changes. The results suggest that HPV 60 has unique biological properties to induce a plantar cyst as a distinct type of cutaneous HPV.

Reversibility of carcinogen-induced rat forestomach basal cell hyperplasia is due to squamous cell differentiation.

The mechanisms of reversibility of basal cell hyperplasia in the rat forestomach were investigated. Male F344 rats were given an initial single gastric intubation of N‐methyl‐N′‐nitro‐N‐nitoroso‐guanidine and then received 2% butylated hydroxyanisole in the diet from the third week to the 26th week. Rats were killed at weeks 26 and 46 after return to basal diet and their forestomachs were removed. Bromouracil deoxyriboside (BUdR) was administered as a single i.p. injection 1 h before death or by osmotic minipump (120 μg/h) continuously for 7 days before death. Additional animals were maintained for 2 or 4 weeks after removal of osmotic minipumps to allow assessment of the fate of proliferating populations. In each case BUdR‐labeled cells were demonstrated by immunohisto‐chemistry. At week 26, hyperplastic changes were more pronounced than at week 46. Squamous cells above basal cell hyperplasias were strongly labeled even 4 weeks after cessation of continuous BUdR administration, in clear contrast to those in normal‐appearing epithelium. Three‐dimensional reconstruction of persisting basal cell hyperplasias showed almost all basal cells limited to a thin sheet in direct contact with the squamous cell layer, occasional separate islands demonstrating differentiation to squamous cells and formation of epidermal cysts. The results thus showed that the mechanism of reversibility of basal cell hyperplasia involves differentiation of basal cells to squamous cells.

Localization of androgen receptor in male sex organ, accessory sex organs and external genital skin

Previously, we established an anti-androgen receptor (AR) monoclonal antibody. Using the antibody, we investigated immunohistological AR localization in human testes, epididymides, seminal vesicles and scrotal skins. The testes, epididymides and scrotal skins were obtained from a prostate cancer patient without pre-hormonal therapy undergoing bilateral orchiectomy. The seminal vesicles were obtained from a bladder cancer patient undergoing radical cystectomy. The tissues were immediately frozen in liquid nitrogen and kept at -80 degrees C until used. Cryostat-frozen sections were cut at 5 microns and stained by an indirect method. We obtained the following results. 1) In the testes, nuclei of Leydig cells were stained though Sertoli cells were not stained. AR localization in Leydig cells which produce testosterone suggests autocrine or intracrine mechanism in the testis. 2) In the epididymides, nuclei of epithelial cells of epididymal ducts were stained, while muscles and connective tissues were not stained. In the seminal vesicles, nuclei of glandular epithelial cells were stained. 3) In the scrotal skins, the cells of squamous cell layer have positive stainings. The cells in the upper portion of squamous cell layer were stained more intensely than the cells in the lower portion. The basal layer was not stained. The cells of the outer root sheath of hair follicles in the scrotal skins were also stained. 4) In androgen target organs, AR-positive cells and AR-negative cells were mixed in the epithelium of a glandular duct, which suggests heterogeneity of AR localization in the androgen target organs.

Proliferation and differentiation of mouse uterine epithelial cells in primary serum-free culture: Estradiol-17β suppresses uterine epithelial proliferation cultured on a basement membrane-like substratum

The effects of different substrata and estradiol-17 beta (E2) on proliferation and differentiation of mouse uterine epithelial cells was examined in a serum-free primary culture system. When cultured on rat-tail collagen gels, the epithelial cells rapidly increased in number to form a simple squamous cell layer that exhibited a relatively undifferentiated state (a few short microvilli, no secretory granules, and poorly developed endoplasmic reticulum). Addition of E2 into the culture medium did not affect the proliferation of epithelial cells on collagen gel. Uterine epithelial cells grown on a reconstituted basement membrane-like substratum (Matrigel) formed a simple columnar/cuboidal cell layer exhibiting fully developed characteristics (many long microvilli, many secretory granules, and fully developed endoplasmic reticulum). Examination of epithelial proliferation by counting substratum-attached cell number revealed only a slow increase in cell growth on Matrigel, and E2 did not significantly affect it. However, measurement of proliferating cells by labeling cells with 5-bromo-2'-deoxyuridine revealed that cells on Matrigel were replicating and that E2 (10(-7) to 10(-11) M) actually significantly suppressed epithelial proliferation. However, there was not an effect of E2 on total cell number, indicating that the cells in control medium replicate faster and detach more readily from the substratum than those in E2-supplemented medium on Matrigel. Thus, it is probable that E2 significantly reduces the rate of cell detachment from the substratum, which may mimic the in vivo condition where significant decrease in apoptosis or cell death is induced by E2.

Antiperinuclear factor, a marker autoantibody for rheumatoid arthritis: colocalisation of the perinuclear factor and profilaggrin.

The antiperinuclear factor, an autoantibody specific for rheumatoid arthritis, was found in 51/63 (81%) patients with rheumatoid arthritis by indirect immunofluorescence on human buccal mucosa cells. The sensitivity of the antiperinuclear factor test was increased by pretreating the buccal mucosa cells with 0.5% Triton-X100. The specificity of the test for rheumatoid arthritis as compared with control serum samples was maintained. The localisation of the perinuclear factor in the keratohyalin granules of the buccal mucosa cells was verified by immunoelectron microscopy. The perinuclear factor was found to be an insoluble protein whose antigenicity was sensitive to various fixation procedures. In serum samples from patients with rheumatoid arthritis there was a positive correlation between the presence of antiperinuclear factor and the presence of the so called antikeratin antibodies as detected by immunofluorescence on unfixed rat oesophagus cryostat sections. No relation was found between the presence of the perinuclear factor and either the rheumatoid factor, Epstein-Barr virus components, or any cytokeratin. By double immunofluorescence an exact colocalisation of the perinuclear factor and profilaggrin was found. Although the precise biochemical identity of the perinuclear factor remains unclear, our results suggest that it is a protein only present in the fully differentiated squamous epithelial cell layer.

Destruction of tumour parenchyma in basal cell carcinoma by tumour-associated neutral proteases: a histochemical study

Proteolytic activity was demonstrated histochemically in frozen sections of basal cell carcinomas (BCCs). After incubation of tissue sections in 0.1 M phosphate buffer with 0.25 M NaCl the tumour epithelium was almost completely destroyed. The basal and squamous cell layers of the epidermis disintegrated to varying degrees, particularly where they were directly in contact with tumour epithelium. Serine and metalloprotease inhibitors diminished this tissue destruction. Iodoacetate enhanced tumour destruction, urea and potassium thiocyanate even more so. The high proteolytic activity of BCC demonstrated in this study may be an important factor in the proliferative, invasive and destructive behaviour of this tumour.

Ultrastructure of the atrioventricular valve and ventricular endo- and myocardium of the tigerfish, Hydrocynus forskahlii.

AbstractGeneral ultrastructural properties of the atrioventricular valve and the endo‐ and myocardium of the tigerfish Hydrocynus forskahlii add further information to our knowledge of fish heart morphology. Small pieces of tissue from the heart of H. forskhalii were immersion‐fixed in 3% glutaraldehyde in Sörensen's phosphate buffer. Samples were postfixed in 1% osmium tetroxide and processed for transmission electron microscopy using standard techniques. The atrioventricular valve consists of dense collagen and fibroblasts lying between two layers of squamous endothelial cells. The ventricular endothelium consists of squamous cells with large nuclei protruding into the lumen of the ventricle. These cells lie on a basal lamina which overlies loose collagen in the subendothelial space. The ventricular myocardium is built up of distinctive nucleated fibres. Mitochondria, ribosomes, and glycogen are abundant in the sarcoplasm. Less conspicuous intercalated discs with no typical, steplike pattern are found between the myocardial cells. The Z lines as well as the I and A bands are clearly visible. The M lines are prominent, but the most important feature is the N line which is found on either side of the Z line in the lateral parts of the I band. The current research clearly underlines the fact that cardiac ultrastructure presents considerable diversity in different fish species.

Ultrastructure of the epidermis and digestive tract inSebastes embryos, with special reference to the uptake of exogenous nutrients

Ultrastructural features of the epidermis and rectum were studied inSebastes schlegeli andS. melanops during the late stages of embryonic development, to confirm uptake of maternal substances. Ruthenium red (RR) and horseradish peroxidase (HRP) were used at fixation and in live embryos, respectively. Epidermal tissue of embryos after developmental stage 24 comprised two squamous cell layers. The outer, thinner cells and their intercellular spaces were easily infiltrated with RR, but the inner cells had no RR deposition. The HRP was not incorporated into the epidermis except in a few outer cells, which had well-developed microvillous projections of cytoplasm. Sacciform cells, chloride cells, and mucous cells distributed in the inner layer but protruding to the epidermal surface had no intracellular RR and HRP depositions. The rectal cells of embryos at about developmental stage 28 had many globular inclusions containing electron-dense substances. The rectal cells were found to take up and digest HRP actively. It is suggested that the embryonic epidermis is structurally loose and takes up low weight molecules, while rectal cells, after the opening of the mouth, actively ingest exogenous, high weight molecules.

Amelanotic Malignant Melanoma of the Esophagus: Case Report and Review of the Literature

A case of amelanotic malignant melanoma of the esophagus in a 76-year-old woman is reported. A whitish polypoid tumor, measuring 3 x 2 x 2.7 cm, surrounded by black pigmented mucosa, was detected in the middle intrathoracic esophagus. The tumor showed a lobulated surface lined by squamous cell layer, and had epithelioid and polyhedral cells forming alveolar clusters. Melanin pigments or stainability for the dihydroxyphenylalanine (DOPA) reaction were only observed in a few tumor cells. Junctional changes and mucosal melanosis, however, were found freely in the mucosa around the tumor. Many tumor cells showed a strongly positive immunohistochemical reaction for neuron specific enolase (NSE) and S100 protein. The patient died of widespread metastases six months after surgery. Further, a review of 106 reported cases of primary esophageal malignant melanoma, including 29 autopsies, was made; the melanomas were found to include 10 of amelanotic type, eight of which had been misdiagnosed at biopsy. Junctional changes could be found in the mucosa over or around the tumor, in four cases, and mucosal melanosis in one. Lymph node metastasis was the most frequently observed development at autopsy regardless of whether the tumor was amelanotic or melanotic. For correct diagnoses of melanomas of the amelanotic type, peripheral mucosal findings, such as junctional changes or melanosis, should be helpful; and, in order to obtain a good prognosis, a careful resection of the regional lymph nodes could prove valuable.

Ultrastructure of oocyte migration through the mouse ovarian surface epithelium during neonatal development

Previous studies using light microscopy have described the presence of oocytes within the ovarian surface epithelium (OSE) of the neonate ovary and their subsequent release into the periovarian space. The ultrastructural examination and quantitative estimate of oocyte migration through the OSE is described in this study. The surface of the mouse ovary is covered by a simple squamous to simple cuboidal epithelium resting on a distinct basal lamina. Healthy, non-atretic primordial follicles located in the periphery of the ovarian cortex interact with the OSE. Oocytes within the primordial follicles are large (50-70 microns), spherical cells surrounded by a single layer of squamous granulosa cells. Migratory oocytes initially display a ruffled border and extend pseudopodia-like cellular extensions towards the OSE. These processes subsequently compromise the basal lamina of the OSE and extend between the epithelial cells. Granulosa cells retract as junctional complexes between them and the oocyte are no longer observed. The oocyte migrates between the OSE cells and passes into the periovarian space without the loss of either OSE or granulosa cells. The rate of oocyte migration reaches a peak during the first week of neonatal development and then gradually diminishes until by day 28 of development no oocyte migration was observed.

Microcystic adnexal carcinoma: a light microscopic, immunohistochemical and ultrastructural study

We report a case of microcystic adnexal carcinoma (MAC) occurring on the upper lip of an 82-year-old woman. Microscopically the tumor showed both pilar and sweat gland differentiation, involved the entire dermis and subcutaneous tissue, and invaded perineural spaces. Immunoperoxidase studies revealed carcinoembryonic antigen to be present in the ductal lining cells and in the amorphous content in the lumen, confirming sweat gland differentiation. The S-100 protein was positive in dendritic cells within the solid cell nests, but negative in cells lining cystic spaces. Ultrastructural study confirmed that the neoplasm was composed of two components, with pilar and eccrine differentiation. The former showed concentric layers of squamous epithelial cells with well-developed desmosomes and cytofilaments. The latter had ductal and alveolar structures; the ultrastructural features included: i) numerous villous folds of plasma membrane to interdigitate each other by focal desmosomes, ii) aggregates of cytofilaments, and iii) basally located myoepithelial cells which were separated from the surrounding stroma by rather thick basement membrane. In addition, distinct amyloid deposition was also observed on ultrastructural examination. To our knowledge, amyloid deposition has not been previously reported in MAC.

CLINICAL AND PATHOLOGICAL STUDY OF ORAL LEUKOPLAKIA

Clinical and pathological observation has been carried out in 68 cases of oral leukoplakia examined in our department and results are as follows.1) The patients consisted of 42 males and 26 females, and a high prevalence was observed in males in their forties.2) Foci most frequently occured on the gingiva, then on the tongue, lips and buccal mucous membrane, and were found least frequently on the oral floor.On the gingiva, a great many white-spotted types and plateau types occurred but on the tongue erosive types were seen most frequently.On the lips and buccal mucous membrance, many white-spotted types were observed but on the oral floor only one white-spotted type and one erosive type were seen. Five cases were accompanied by cancer and four cases became malignant, all of these being derived from the erosive type.3) In relation to smoking, the incidence was 70% in males and 44% in females and was higher than the average percentage of adult smokers in our country. Score of Brinkman index (B.I.) was 562 on average and this was higher then B.I. 400 which is a standard value of the high-risk group for lung cancer, therefore smoking is considered to be the cause of this disease.4) Investigation of the relationship between metal restorations and dentures using patch testing revealed in 53% of a positive reaction cases. Many positive reactions were observed toward metals most commonly used in dental materials, and this suggested a great possibility of local stimululation by metal allergy. Cases associated with a local stimulus deriving from unfitted dentures, dental caries and metal allergies amounted to 56%.5) In the results of glucose tolerance testing, a significant difference was not shown in comparison with healthy persons in the same age bracket. Levels of serum immunoglobulins IgA, IgG, IgM, and vitamin A, vitamin B2 and cholesterol in blood were within normal values.The above results indicate that systemic factors were not influencing factors as much as were local factors.6) In histological studies, as to the first pattern (that without a differential pattern in epithelial cells, with a thin epithelial layer a great difference was not observed in comparison with other groups. However, as to the second pattern (that without a differential pattern in the epithelial cells, with a thickened epithelial layer) the epithelial layer was thickened and intercellular edema in the squamous cell layer and prolongation and acumination of the rete ridge were shown. As to the third pattern (one accompanied by a differential pattern in the epithelial cells) the tissues observed were similar to those in the second pattern, but cells with enlarged nuclei and increased chromatin content in the basement layer, and on increased mitosis rate were observed.In electron microscopic examination, in the basement cell layer, Langerhans cells (L.C.) were often observed.7) In the chemical examination of immunohistologic patterns clinically found, the degree of infiltration of sub-epithelial tissue, and S-100 protein-positive cells in the epithelium were analysed.Results showed that the number of S-100 protein-positive cells in the epithelia were increasing significantly in plateaupatterns, accompanied by erosion and cancer patterns.Pathologically, the relationship between degree of infiltration of sub-epithelial tissue and S-100 protein-positive cells was clearly observed to be correlative.The increase in L.C. in the case of plateaupattern and erosivepattern leukoplakia and in cases where lesions developed into cancer is considered to suggest functional acceleration of antigen recognition mechanism in the foci, together with the acceleration of cellular infiltration to sub-epithelial tissue in these patterns.

Diversity in immunoreactivity of tumor-derived cytokeratin monoclonal antibodies.

The cytokeratins 8, 18, and 19, expressed in many normal and malignant epithelial cells, were purified from human gastrointestinal tumors and used as immunogen for hybridoma generation. The reactivity pattern of five of the generated ten monoclonal antibodies (MAb) was characterized biochemically and immunohistochemically. All of the generated MAb were reactive with the central rod portion of the cytokeratins, as determined after partial enzymatic degradation, and displayed characteristic reactivity patterns. MAb TS 4 exhibits pan-epithelial immunohistochemical reactivity staining of all epithelial structures, including all layers of epidermis and non-keratinizing squamous epithelium and myoepithelial cells. The determinant involved is present on several different cytokeratins, i.e., nos. 1, 5, 7, 8, and 15, as determined by immunoblotting experiments from different tissues and cell lines. MAb TS 1, TS 3, and TS 7 reveal pluri-epithelial reactivity pattern immunohistochemically, similar to TS 4, but they are unreactive with whole epidermis and with superficial cell layers of non-keratinizing squamous cells. MAb TS 1 was found to be highly specific and reactive only with cytokeratin 8. Furthermore, the TS 1 MAb alone can precipitate the antigen, indicating reactivity with repetitive epitopes on cytokeratin 8. MAb TS 3 and 7 bind to cytokeratins 7 and 8. Finally, MAb TS 8 was found to be immunohistologically the most restricted, in general lacking reactivity to hepatocytes, pancreatic and salivary gland acinar cells, proximal renal tubules, and luminal cells of the epididymis. TS 8 was mainly reactive with cytokeratin 19 and showed weak binding to cytokeratin 8 and 14.

Distribution of neu (c-erbB-2) Protein in Human Skin

The neu (c-erbB-2) gene encodes a transmembrane protein with tyrosine kinase activity that appears to be a growth factor receptor. Antibody was generated by immunization of rabbits with a synthetic polypeptide that was based on an internal sequence at the carboxy terminus of the molecule. This antibody was used to survey the expression of neu in human skin by immunohistochemistry. Significant protein was found in the squamous cell layer of the surface epidermis, in squamous cell carcinomas, in the external root sheath of hair follicles, and in eccrine gland secretory cells; it was poorly expressed in the basal cell layer and in a basal cell carcinomas. Increased neu expression appears to be associated with the differentiation of keratinocytes.