Prostatic acid phosphatase expression in human tissues

Prostate cancer is the most common cancer and the second leading cause of cancer deaths among males in most Western countries. Autologous cellular immunotherapy for the treatment of cancer seeks to induce tumor-specific immunity in the patient and is consequently dependent on a suitable target antigen and effective presentation of that antigen to the patient's immune system. Prostatic acid phosphatase (PAP) has been tested as a target antigen due to its high and apparently specific expression in the prostate. We used a variety of approaches to analyze PAP expression, including immunohistochemistry, in situ hybridization, and quantitative polymerase chain reaction. We complemented these laboratory-based techniques with an in silico analysis of reported PAP expression in human cDNA libraries. Our studies confirmed that, while PAP expression is not restricted to prostate tissues, its expression in other human tissues is approximately 1-2 orders of magnitude less than that observed in the prostate. The relative specificity of PAP expression in the prostate supports its use as a target of autologous cellular immunotherapy. The approach described here, involving the use of multiple correlates of tissue-specific expression, is warranted as a prerequisite in selecting any suitable target for immunotherapy.     

Zymograms of the human red cell acid phosphatase obtained with different substrates

A lead-sulfide method has been developed to produce zymograms of human red cell acid phosphatase. Two somewhat different zymograms were detected; the one was obtained with phenyl phosphate or [3-naphthyl phosphate and the other with p-nitrophenyl phosphate or phenolphthalein diphosphate as the substrate. On this basis it was suggested that these substrates could be classified into two groups: aromatic compounds with no substituent in addition to the ester group; and compounds with a substituent attached to the carbon at the para position relative to the ester group. The idea that the position of a substituent may be of importance for the catalytic activity of the red cell acid phosphatase was supported by the observation that o- and m-nitrophenyl phosphate were only slowly hydrolyzed in contrast to p-nitrophenyl phosphate.     

A comparison of some properties of human red cell acid phosphatase in different phenotypes

1. The red cell acid phosphatase types A, BA, B, CA and CB have been compared with respect to a number of different properties. 2. Types CA and CB have been found to be relatively much more thermostable than types B, BA and A. In the latter group, type B appears to show slightly greater thermostability than type A and type BA appears to be intermediate in this respect. 3. No significant differences between the types were found in denaturation by guanidine or urea. 4. Phosphotransferase activity determined with PNPP as substrate and methanol as acceptor, and expressed as percentage of hydrolytic activity in the absence of the alcohol, appeared to be much the same in the different types. A similar result was obtained when glycerol, propanol and ethanol were used as acceptors. The greatest phosphotransferase activities (more than three times the hydrolytic activities) were observed with glycerol and methanol in concentrations of 20–26%. 5. No marked differences between the types in the pattern of substrate specificity were detected. 6. Considerable retardation of red cell acid phosphatase in gel atration using Biogel P-60 was observed. The elution peak emerged from the column subsequent to myoglobin and cyto-chrome c markers. This suggests that the enzyme may have a relatively low molecular weight. Similar results were obtained with each type.     

Adenosine deaminase activity in thymus and other human tissues.

Adenosine deaminase activity (ADA) has been estimated in human tissues. Levels in the thymus during childhood were very much higher than in any of the other 6 tissues studied. Intermediate activities were obtained from spleen and lymph nodes and also skin. Cerebral cortex, liver and kidney had relatively low levels. ADA activity in lymphocytes from peripheral blood was significantly increased after antigenic stimulation by TAB immunization. The available evidence appears to be consistent with T-lymphocyte growth and development in the thymus being dependant on ADA.     

Expression of the membrane protein tyrosine phosphatase CD148 in human tissues

CD148, a receptor-like protein tyrosine phosphatase also known as HPTP-eta/DEP-1, is involved in signal transduction in leucocytes and is thought to contribute to mechanisms of cellular differentiation. We have investigated the in situ expression of CD148 in various fresh-frozen tissues by immunohistology and analyzed its expression on subpopulations of activated peripheral blood leucocytes by flow cytometry. In lymphoid organs, CD148 was found to be widely expressed on B and T cells, granulocytes, macrophages, certain dendritic cells as well as mature thymocytes. The cellular level of CD148 was increased after in vitro activation of peripheral blood leucocytes. Comparative analysis of tissue samples from normal gut and from patients with active Crohn's disease showed that leucocytes expressing CD148 are significantly upregulated in inflamed tissues and that a subset of these cells co-express the activation marker CD25. In non-lymphoid tissues, CD148 was found to be present on many epithelial cell types with glandular and/or endocrine differentiation as well as on fibrocytes, melanocytes and Schwann cells. CD148 expression was maintained also in malignant counterparts of such tissues. However, a marked loss of CD148 immunoreactivity was apparent in some of the investigated high-grade carcinomas. In summary, our results confirm a role of CD148 as a leucocyte activation marker. Among non-hematopoietic cells, CD148 is expressed by characteristic types of epithelial and non-epithelial cells. Downregulation of CD148 might promote dedifferentiation and autonomous growth of such cells in malignant tumors.     

Linkage data on red cell acid phosphatase from family studies

An analysis of the linkage relationships of red cell acid phosphatase (ACP1) with 36 other loci is presented. Close linkage is excluded for many loci. The hint of loose linkage with MNSs is not statistically significant, nor is it apparently consistent with the assignment of ACP1 and and MNSs to different arms of chromosome 2.     

Further studies on the molecular size of red cell acid phosphatase

Estimates of the molecular weight of red cell acid phosphatase have been made by gel filtration under denaturing conditions, i.e. in 6 M guanidine hydrochloride. The results suggest a figure of 14,800 which is almost twice as high as previous estimates obtained by gel filtration in the native form.     

Beyond the red cell: pegylation of other blood cells and tissues.

Immunological recognition of allogeneic tissue is of critical concern in transfusion and transplantation medicine. While the major emphasis of our work on the immunocamouflage of cells has been focused on the erythrocyte, we have extended this research beyond the red blood cell (RBC) to other tissues. Our studies from blood transfusion (i.e., a specialized form of cellular transplantation) suggest that covalent modification of cells and tissues with methoxypoly(ethylene glycol) mPEG can significantly diminish immunologic recognition of other allogeneic tissues and, furthermore, may enhance the induction of tolerance. The mechanisms underlying the mPEG-mediated immunocamouflage of alloantigens is the global camouflaging of antigenic sites, membrane surface charge and the attenuation of receptor-ligand and cell-cell interactions. As a consequence of the immunocamouflage imparted by the grafted mPEG, weak costimulation of alloreactive T cells is observed which subsequently induces apoptosis of these reactive cells. As a result of this clonal deletion, a pro-tolerance state is induced. The potency of immunocamouflage is readily observed in in vivo murine models of transfusion-associated graft versus host disease. Furthermore, initial studies on the in vivo transplantation of pegylated rat and murine pancreatic islets have demonstrated that mPEG-derivatization does not impair the finely tuned signaling necessary for glucose homeostasis. Finally, in contrast to the pharmacological inhibition of the immune response by agents such as cyclosporine, mPEG-mediated immunocamouflage directly attenuates the inherent antigenicity and immunogenicity of the donor tissue itself while leaving the recipient a fully competent immune system.     

Histochemical studies of alkaline and acid phosphatase activity in the uterus and placenta of pregnant white rats

Summary In investigating the activity of the alkaline and acid phosphatases in the uterine and placental tissues on the 6th, 10th, 15th, 17th and 18th day of pregnancy certain regular cytochemical features are revealed.Phosphatases are localized mainly in the nucleoli, nucleus and then in the cellular cytoplasm. Large amounts of alkaline and acid phosphatases are found in the leukocytes of the maternal blood and in the embryoblasts. Alka-line phosphatase appears in the uterus at the onset of pregnancy and gradually increases until its termination. Acid phosphatase appears only on the 10th day and greatly increases until the end of the pregnancy.The largest amounts of phosphatase are revealed in the trophoblastic syncytium which covers the fetal blood vessels and lies next to the lacunae filled with matemal blood.Presented by Active Member Acad. Med. Sci. USSR Prof. S. E. Severin     

Expression of galanin in human placenta

The neuropeptide galanin was originally implicated in the regulation of feeding behaviour. Today, galanin is implicated in several physiological functions including reproduction and feeding. Many hypothalamic neurohormones of the hypothalamo--pituitary axis (HPA) are also expressed in the placenta where the specialized topological compartments of the HPA are missing and where paracrine and autocrine regulatory mechanisms consequently prevail. Since galanin influences gonadotrophin-releasing hormone secretion in the HPA, we argued that a similar regulatory role for galanin might exist in human placenta. Since the presence of galanin in human placenta had not been previously reported, we analysed galanin expression in the human placenta by immunohistochemistry and quantitative polymerase chain reaction (PCR) throughout gestation. We found that the peptide hormone localizes to the syncytio- and cytotrophoblast layers; its RNA could be detected. By quantitative PCR we observed that throughout gestation, there is a loss of galanin mRNA which parallels the fall in signal intensity from immunohistochemical detection of the galanin oligopeptide. Furthermore, we detected secretion of galanin from isolated trophoblastic cells. We conclude that galanin may be an important and novel regulator of placental function.