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PubMed2000

Organ-specific expression of the intestinal epithelium-related antigen A33, a cell surface target for antibody-based imaging and treatment in gastrointestinal cancer.

Murine monoclonal antibody A33 (mA33) was developed by the Memorial Sloan-Kettering Cancer Center and by the New York Branch of the Ludwig Institute for Cancer Research. It is an immunoglobulin (Ig)G2a antibody that detects a protease- and neuraminidase-resistant, periodate-sensitive epitope. Serological analysis of the antigen showed that it is expressed in a few colorectal cancer cell lines and a pancreatic cancer cell line, but is basically not reactive with other types of cell line. Normal fibroblasts and normal kidney cell lines reacted negatively to mA33. Immunohistochemical study of normal tissues identified the large and small intestinal mucosa as the principal site of A33 expression. Tests in tumor samples demonstrated that only tumors of the gastrointestinal tract are consistently A33 positive. A33 is found in 95% of primary and metastatic colorectal cancers, with uniform expression throughout the tumors in most cases. A33 is also detected in 63% of gastric cancers, with uniform expression in 45% of cases. Eighty-three percent of intestinal-type gastric cancers were positive for A33, and about 50% of the diffuse-type and mucinous cancers were mA33 positive. A33 was expressed in 50% of the pancreatic cancers but with marked heterogeneity. Other epithelial cancers, sarcomas, neuroectodermal tumors, and lymphoid neoplasms were generally A33 negative. A33 is the first example of a constitutively expressed, organ-specific epithelial membrane antigen permitting highly specific tumor targeting in patients with gastrointestinal cancer. Encouraged by the success of the biodistribution and imaging characteristic studies performed at Memorial Sloan-Kettering Cancer Center by the New York Branch of the Ludwig Institute in colorectal cancers, a new clinical study of humanized monoclonal antibody huA33 against A33 antigen-positive gastric cancers has been initiated in Japan.

Animals↗
PubMed2002

A novel class II-binding motif selects peptides that mediate organ-specific autoimmune disease in SWXJ, SJL/J, and SWR/J mice.

Idiopathic dilated cardiomyopathy (DCM) is responsible for approximately 25% of all cases of congestive heart failure. We have recently shown that immunization of autoimmune-susceptible SWXJ mice with whole cardiac myosin leads to T cell-mediated experimental autoimmune myocarditis (EAMC) and DCM. We have now identified two disease-inducing peptides from cardiac alpha-myosin heavy chain (CAMHC). Our approach involved the use of a novel MHC class II-binding motif contained in several peptides known to be immunogenic in SWXJ (H-2(q,s)) mice or in the parental SJL/J (H-2(s)) or SWR/J (H-2(q)) mouse strains. Two of four CAMHC peptides containing the -KXXS- peptide motif were found to be immunogenic. Immunization of SWXJ or parental SJL/J and SWR/J mice with CAMHC peptides palpha406-425 or palpha1631-1650 resulted in EAMC and DCM, characterized by inflammation, fibrosis, and decompensated right-sided ventricular dilatation. Despite mediating high incidences of severe disease, both peptides were found to be cryptic determinants, thereby providing further evidence for the importance and perhaps predominance of self crypticity in autoimmunity. Both peptides showed dual parental I-A(q) and I-A(s) restriction and mediated passive transfer of disease with activated CD4(+) T cells. An intact motif was necessary for antigenicity because loss of activity occurred in peptides containing nonconservative substitutions at the motif's terminal lysine and serine residues. Our studies provide a new model for EAMC and DCM in strains of mice widely used in autoimmune studies. Moreover, the -KXXS- motif may be particularly useful in implicating previously overlooked proteins as autoimmune targets and in facilitating the development of new organ-specific autoimmune mouse models for human diseases.

Amino Acid Motifs↗
PubMed1990

Depletion of CD8+ cells exacerbates organ-specific autoimmune diseases induced by CD4+ T cells in semiallogeneic hosts with MHC class II disparity.

Autoimmune diseases are known to be induced in some donor-recipient combinations of mice undergoing the graft-vs-host reaction (GVHR). In this paper, we report on the development of primary biliary cirrhosis (PBC)-like hepatic lesions and also on pancreatic insulitis in (B6 x bm12)F1 mice injected with B6 CD4+ T cells. At the sites of these lesions, cellular infiltration around ductal structure was observed. Immunohistochemical studies revealed that both CD4+ and CD8+ T cells were present in the lesions of the liver and pancreas. To clarify the role of the CD8+ T cells, which were probably of host origin, we used a mAb against the Lyt-2 molecule. Both the PBC-like hepatic lesions and pancreatic insulitis were exacerbated by eliminating CD8+ T cells from mice with MHC class II GVHR. Also, autoantibodies against the pyruvate dehydrogenase-E2 component, which has been recently found to contain an immunodominant site (autoepitope) for B cell reactivity in patients with PBC, were detected in the sera of these mice by ELISA and their presence was confirmed by immunoblotting procedures. Our findings suggest that similar mechanisms as in GVHR caused by MHC class II disparity are active in the development of PBC. It should also be noted that, in addition to the hepatic lesions, insulitis closely resembling that seen in the nonobese diabetic mouse was induced in our experimental system. The results suggest that our model provides a unique opportunity to study organ-specific autoimmune diseases. Because the effector in our experimental system was defined to be CD4+ T cells responding to Iabm12 Ag, our findings support the hypothesis that an excessive immune response directed against Ia Ag can produce autoimmune disease.

Animals↗
PubMedDate not supplied

Glutamate dehydrogenase from Medicago sativa L., purification and comparative kinetic studies of the organ-specific multiple forms.

NAD-specific glutamate dehydrogenase [L-glutamate: NAD+ oxidoreductase (deaminating) EC 1.4.1.2] from Medicago sativa constitutes organ-specific patterns of isoenzymes. The isoenzyme-patterns of seeds (GDH-I) and roots (GDH-II) were purified 1520-fold and 92-fold, respectively. All isoenzymes of both patterns remain stable throughout the purification procedures. Isoenzyme a7, the only isoenzyme common to both patterns was isolated from the GDH-I pattern. The three enzyme preparations were found to be identical in pH optima, substrate specificity and general kinetic properties. A comparative kinetic analysis revealed no pronounced differences between the various kinetic constants evaluated for the three enzyme preparations. Furthermore an identical order of substrate binding and product release could be established. Both initial rate measurements and product inhibition studies are consistent with an ordered ternary-binary kinetic mechanism. The results suggest that tissue-specific enzyme multiplicity of plant glutamate dehydrogenase is not related to differences in general or kinetic properties.

Glutamate Dehydrogenase↗
PubMed2005

Obesity and overweight in relation to organ-specific cancer mortality in London (UK): findings from the original Whitehall study.

OBJECTIVE: To examine the relation of obesity and overweight with organ-specific cancer mortality. METHODS: In the Whitehall prospective cohort study of London-based government employees, 18 403 middle-age men participated in a medical examination between 1967 and 1970. Subjects were followed up for cause-specific mortality for up to 35 y (median: interquartile range (25th-75th centile); 28.1 y: 18.6-33.8). RESULTS: There were over 3000 cancer deaths in this cohort. There was a raised risk of mortality from carcinoma of the rectum, bladder, colon, and liver, and for lymphoma in obese or overweight men following adjustment for range of covariates, which included socioeconomic position and physical activity. These relationships held after exclusion of deaths occurring in the first 20 y of follow-up. CONCLUSION: Avoidance of obesity and overweight in adult life may reduce the risk of developing some cancers.

Cohort Studies↗
PubMed1981

Presence of the organ-specific 'microsomal' autoantigen on the surface of human thyroid cells in culture: its involvement in complement-mediated cytotoxicity.

The presence of organ-specific cell surface-reactive antibodies in sera of patients with autoimmune thyroid diseases (ATD) has been detected by indirect immunofluorescence on viable blood group O normal thyroid cultures. The cell surface determinants involved in this reaction have been identified as the thyroid 'microsomal' antigen which is thus also represented on the outer surface of the plasma membrane. The reactivity persists when F(ab')2 fragments from positive sera are used. Non-thyroid cells present in the monolayers, as well as human adrenal or fibroblast cultures, do not show positive staining. Human thyroid cells progressively lose both cell surface and intracytoplasmic antigenic components during the first week of culture. The exposure and reactivity of this antigen on the cell surface do not depend upon unmasking effects of proteolytic enzymes used for dispersal of the cells. The 'microsomal' antigen on the cell surface is also involved in the complement-mediated cytotoxic effect of sera from ATD patients on freshly dispersed thyroid cells. Thyroglobulin antibodies failed to stain viable thyroid monolayers, even when these were previously incubated with purified human thyroglobulin, indicating that this protein or possible receptors for it cannot be detected on the cell surface under these conditions. Similarly, some thyrotoxicosis sera containing thyroid-stimulating but not microsomal antibodies, gave negative reactions on viable cultures.

Adult↗
PubMed2002

Organ-specific maturation of the major histocompatibility antigens in rats.

The essential role of major histocompatibility complex (MHC) class I and II in the process of rejection has been documented, and some studies suggest that fetal transplants could enjoy an organ-specific immunologic privilege. However, little is known as to when these antigens develop in fetal organs and which tissues mainly present them. This study investigated the dynamics of immunogenicity in the developing transplant organs of rats. The study focused on the classic transplant organs including lung, heart, liver, pancreas, intestine, and kidney. Fetal organs (14th and 20th day of gestation), organs at the 3rd, 7th, 10th, 14th and 28th days postpartum (pp), 2 and 3 months pp, and adult organs were taken and snap-frozen in liquid nitrogen. MHC expression was analyzed applying the APAAP technique on serial cryosections by two well-defined monoclonal antibodies (mAb) generated against rat MHC class I (Ox 18) and class II (Ox 6). Immunoreactivities were compared to those of different monoclonal markers against endothelial cells (HIS52, CD 31), histiocytes (ED 1, ED 2), dendritic cells (Ox-62), granulocytes (HIS48), B-cells (RLN-9D3), T-cells (Ox-52), CD 4 (Ox-35), CD 8 (Ox-8a), natural killer cells (10/78), and CD 45 (Ox-1, leukocyte common antigen). A non specific mAb (MR 12/53) served as a negative control. In all stages of organ maturation, MHC I expression was found predominantly on immunocompetent cells, endothelial cells, and certain parenchymal cells, whereas MHC II was almost entirely restricted to dendritic cells. In organ development, the onset of MHC I expression and the number of MHC II-positive cells varied in a time-dependent manner. However, between the 2nd and 3rd month pp the expression pattern was comparable to adult organs. The study indicates that each organ carries a variable immunologic burden, that matures heterogeneously. Consequently, the variable content of MHC I/II in organ maturation needs to be considered for any transplantation model.

Animals↗
PubMed1996

Organ specificity of antihypertensive therapy on ocular albumin vascular clearance and albuminuria in the hypertensive diabetic rat.

PURPOSE: The contributions of hypertension and diabetes to microvascular dysfunction in the kidney and eye were investigated. Two indices of microvascular dysfunction, urinary albumin excretion rate (AER) and albumin vascular clearance (AVC) in the eye, were studied in control and streptozocin diabetic Wistar Kyoto (WKY) and spontaneously hypertensive rats (SHR). METHODS: Studies were performed on four groups of untreated rats--nondiabetic and diabetic WKY and nondiabetic and diabetic SHR--and on three groups of diabetic SHR treated with a converting enzyme inhibitor (perindopril), a calcium-channel blocker (lacidipine), or triple therapy (hydrochlorothiazide, reserpine, and hydralazine). In all rats, AER and AVC were measured at 16 weeks. RESULTS: There was a progressive increase in both parameters in the order WKY, diabetic WKY, SHR, and diabetic SHR. When compared with nondiabetic WKY, diabetic SHR showed an approximately 30-fold increase in AER and an approximately threefold increase in AVC. Treatment of diabetic SHR with perindopril or triple therapy normalized AER compared to an equihypotensive dose of lacidipine, which had no effect. By contrast, the three antihypertensive regimens showed a different order of efficacy in preventing increases in ocular AVC. In diabetic SHR, the increase in retinal AVC was prevented largely by lacidipine, whereas the other two antihypertensive regimens showed lesser effects [AVC expressed as percentage nondiabetic WKY: untreated diabetic SHR 278% +/- 47%, lacidipine 93% +/- 10% (P < 0.001), triple therapy 132% +/- 37% (P < 0.05), and perindopril 167% +/- 9% (P < 0.05)]. Lacidipine also prevented the increase in AVC of the anterior and posterior uvea. By contrast, increases in AVC observed in the diabetic SHR were not prevented by perindopril in the posterior uvea or by triple therapy in the anterior uvea. Thus, hypertension and diabetes increased ocular AVC and AER, and effective antihypertensive therapy substantially prevented changes in both parameters. However, despite equivalent levels of blood pressure control for each regimen, discordant effects were noted on AVC and AER. Perindopril was associated with significantly lower AER than lacidipine, whereas lacidipine was more potent in preventing increases in ocular AVC. CONCLUSIONS: Results of this study suggest that different antihypertensive regimens in the diabetic rat may exert organ-specific effects on the retina and kidney despite equivalent effects on systemic blood pressure. These data also raise the possibility that retinal microvascular dysfunction in diabetes is ameliorated more readily by calcium-channel blockade than by converting-enzyme inhibition, whereas the reverse applies to renal microvascular dysfunction, as reflected by albuminuria.

Albuminuria↗
PubMed1983

B-cell function and islet cell and other organ-specific autoantibodies in relatives to insulin-dependent diabetic patients.

The pancreatic B-cell function (glucose tolerance, C-peptide release) and organ-specific autoantibodies, including islet cell cytoplasmic and cell surface (mouse), were studied in 45 first-degree relatives of patients with insulin-dependent diabetes mellitus diagnosed before the age of 30 years. Compared to 107 healthy persons without any family history of either insulin-dependent or non-insulin-dependent diabetes mellitus, the prevalence of autoantibodies was increased among the relatives. The prevalence of islet cell antibodies did not differ between relatives and controls and none of the individuals had complement-fixing islet cell antibodies. There was no difference in glucose tolerance or C-peptide release between relatives and controls, whether they had autoantibodies or not. At a three-year follow-up, none of the individuals had developed insulin-dependent diabetes.

Adult↗
PubMed2000

[Tubular localization and drug recognition of kidney-specific organic anion transporters, OAT-K1 and OAT-K2].

The renal proximal tubular cells play a principal role in limiting or preventing toxicity by actively secreting organic anions from the circulation into the urine. We isolated a cDNA coding a novel rat kidney specific organic anion transporter, OAT-K1, mediating transport of methotrexate (MTX). Moreover, we have isolated a new cDNA coding a rat OAT-K2, showing the 91% amino acid identity with OAT-K1. In this study, the mRNA distribution along the nephron segments and the transport characteristics of OAT-K1 and OAT-K2 have been analyzed. By the use of a reverse transcription-coupled PCR, OAT-K1 and OAT-K2 mRNAs were detected predominantly in the proximal straight tubules. When expressed in Xenopus oocytes, OAT-K1 mediated the uptake of MTX and folate, but not of taurocholate (TCA) and prostaglandin E2 (PGE2), although OAT-K2 stimulated the uptake of MTX, folate, TCA and PGE2. In stable transfectants (MDCK OAT-K1 and MDCK-OAT-K2), each transporter was localized functionally to the apical membrane and showed transport activity similar to those in the oocytes. The efflux of preloaded MTX was enhanced in both MDCK-OAT-K1 and MDCK-OAT-K2 cells. These results suggest that both OAT-K1 and OAT-K2 are apical membrane bidirectional organic anion transporters, and participate in epithelial transport of lipophilic organic anions in the kidney.

Animals↗
PubMed1997

Reservations and preferences among procurement professionals concerning the donation of specific organs and tissues.

Previous research has established that organ procurement professionals who talk with families about donation have strong personal preferences concerning the donation of specific organs and tissues. This study examines possible reasons for such preferences and compares them with those of hospital personnel who talk with families about donation. The findings suggest that preferences among procurement personnel closely resemble those of hospital personnel, but procurement professionals' reasons reflect a slightly higher rate of self-interest. Aversions among procurement personnel differ from those of hospital personnel. Procurement personnel have fewer aversions to donating eyes and skin and more aversions to bone, and their aversions are more likely to reflect professional experience with particular donations. The findings suggest the need for changes both in the way donation options are offered to families and the way hospital and procurement personnel are educated.

Attitude of Health Personnel↗
PubMed1996

A hematopoietic organ-specific 49-kD nuclear antigen: predominance in immature normal and tumor granulocytes and detection in hematopoietic precursor cells.

A 49-kD protein was specifically detected in hematopoietic organs by Western blotting with a novel mouse monoclonal antibody (B92) raised against stromal cells. The protein was found in the immunizing cells using a sensitive method. However, its detection in the bone marrow by the B92 antibody seemed to stem from the abundance of p49 in immature cells of the myeloid lineage. Study of the bone marrow following in vivo irradiation or 5-fluorouracil (5-FU) treatment, in vitro culture with differentiation-inducing factors and long-term culture, and cell sorting all pointed in the same direction: the protein was found in early myeloid cells and in hematopoietic precursor cells. These results were in accordance with the specific presence of p49 in primary radiation-induced myeloid leukemia and its absence in spontaneous B lymphoma. Immunofluorescent staining using B92 antibody detected a nuclear antigen forming a dotted pattern in early myeloid cells and day 12 colony-forming units-spleen (CFU-S). Nuclear localization of p49 was further demonstrated by subcellular fractionation followed by Western blotting. We thus identified a nuclear protein that within the hematopoietic population is detected in hematopoietic precursor cells, predominates in early myeloid cells, and is reduced following differentiation. These properties imply that p49 might be involved in the regulation of hematopoietic cell growth or differentiation.

Acute Disease↗
PubMedDate not supplied

Characterization of a gadolinium-labeled cholesterol derivative as an organ-specific contrast agent for adrenal MR imaging.

The purpose of the study was to determine if derivatization of cholesterol with a paramagnetic label could result in an organ-specific contrast agent for magnetic resonance imaging of the adrenal glands. Gadolinium-DO3A-labeled cholesterol was synthesized and the relaxivities in water and blood plasma determined at 0.47 T and 40 degrees C. Organ distribution was measured at 2 (n = 2) and 24 (n = 2) hours after intravenous injection of a 50 mumol/kg dose of Gd-DO3A-cholesterol in rats weighing 220-240 g. T1-weighted spin-echo images were acquired at 2 T before and after injection of 50 mumol/kg Gd-DO3A-cholesterol (n = 2) and Gd-DTPA (diethylenetriaminepentaacetic acid)-albumin (n = 2). More than 99% of the Gd-DO3A-cholesterol was found to be protein bound in bovine serum. High T1 and T2 relaxivities were found in water and plasma. High tissue concentrations of Gd-DO3A-cholesterol were found only in adrenal glands and liver. At 24 hours, adrenal gadolinium concentrations were about 10 times higher than in blood. At 2 hours after injection of Gd-DO3A-cholesterol, enhancement was 162% in adrenal glands and 146% in liver. With Gd-DTPA-albumin, enhancement values were 57% and 56%, respectively.

Adrenal Glands↗
PubMed2004

Organ-specific expression of the lacZ gene controlled by the opsin promoter after intravenous gene administration in adult mice.

BACKGROUND: The tissue-specific expression of an exogenous gene, under the influence of a tissue-specific promoter, has been examined in the past with pro-nuclear injections of the transgene and the development of transgenic mouse models. 'Adult transgenics' is possible with the acute expression of an exogenous gene that is administered to adult animals, providing the transgene can be effectively delivered to distant sites following an intravenous administration. METHODS: The organ specificity of exogenous gene expression in adult mice was examined with a bacterial beta-galactosidase (LacZ) expression plasmid under the influence of the bovine rhodopsin gene promoter. The 8-kb plasmid DNA was delivered to organs following an intravenous administration with the pegylated immunoliposome (PIL) non-viral gene transfer technology. The PIL carrying the gene was targeted to organs with the rat 8D3 monoclonal antibody (MAb) to the mouse transferrin receptor (TfR). RESULTS: The rhodopsin/beta-galactosidase gene was expressed widely in both the eye and the brain of adult mice, but was not expressed in peripheral tissues, including liver, spleen, lung, or heart. Ocular expression included the retinal-pigmented epithelium, the iris, and ciliary body, and brain expression was observed in neuronal structures throughout the cerebrum and cerebellum. CONCLUSIONS: The expression of trans-genes in adult animals is possible with the PIL non-viral gene transfer method. The opsin promoter enables tissue-specific gene expression in the eye, as well as the brain of adult mice, whereas gene expression in peripheral tissues, such as liver or spleen, is not observed.

Animals↗
PubMed2003

Non-organ-specific autoantibodies in children with chronic hepatitis C: clinical significance and impact on interferon treatment.

We evaluated the prevalence and clinical significance of non-organ-specific autoantibodies (NOSAs) in 47 hepatitis C virus (HCV)-positive children with abnormal alanine transaminase levels and analyzed the association between NOSAs and virus level, genotype, human leukocyte antigen status, and interferon (IFN) response. Forty-two hepatitis B virus (HBV)-positive children and 25 age- and sex-matched healthy children served as control subjects. NOSAs were found in 34% of the HCV-positive children, 12% of the HBV-positive controls, and none of the healthy control subjects. Liver-kidney microsomal antibody type 1 (LKM1) was detected in 11% of the HCV-positive children but in none of the controls. The HCV load was significantly higher in NOSA-negative than in NOSA-positive children. HCV genotype distribution and human leukocyte antigen alleles were similar, irrespective of NOSA status. Long-term response to IFN therapy was achieved by 18% of the NOSA-positive and 55% of the NOSA-negative subjects. Two LKM1-positive children developed acute, self-limited hepatocellular necrosis while receiving IFN therapy. NOSAs are frequently present in children with hepatitis C, who are less likely to benefit from IFN therapy.

Antiviral Agents↗
PubMed1978

[Multi-organ specific autoimmunity in idiopathic adrenal insufficiency: autosensitization to steroid hormone-producing cells and antigens of the anterior pituitary gland (author's transl)].

Multi-organ specific autosensitization to endocrine active cells, with particular reference to steroid hormone-producing (STH) tissues and cells of the anterior pituitary, has been studied in 23 patients with idiopathic Addison's disease (IAD). Adrenal antibodies were found in 57% of the patients and antibodies reacting with StH-cells (thecal and interstitial cells of the ovarial stroma, placental syncytiotrophoblast and Leydig's interstitial cells) were detected in 22% of cases. A specific staining reaction with antigens of the anterior pituitary was obtained in 2 patients. Dense lymphocytic infiltrates were found in the anterior pituitary, adrenal and thyroid gland in one of the pituitary antibody-positive patients. In addition, dense IgG deposits were observed in some areas of adrenal tissue, which points to in vivo fixation of adrenal antibodies. On the basis of the clinical and immunological heterogeneity observed in patients with adrenal insufficiency a more precise differentiation of Addison's disease is suggested.

Adrenal Insufficiency↗
PubMed2001

A comprehensive expression analysis of all members of a gene family encoding cell-wall enzymes allowed us to predict cis-regulatory regions involved in cell-wall construction in specific organs of Arabidopsis.

The Arabidopsis thaliana genome sequencing project has revealed that multigene families, such as those generated by genome duplications, are more abundant among plant genomes than among animal genomes. To gain insight into the evolutionary implications of the multigene families in higher plants, we examined the XTH gene family, a group of genes encoding xyloglucan endotransglucosylase/hydrolase, which are responsible for cell-wall construction in plants. Expression analysis of all members (33 genes) of this family, using quantitative real-time RT-PCR, revealed that most members exhibit distinct expression profiles in terms of tissue specificity and responses to hormonal signals, with some members exhibiting similar expression patterns. By comparing the flanking sequences of individual genes, we identified four sets of large-segment duplications and two sets of solitary gene duplications. In each set of gene duplicates, long nucleotide sequences, ranging from one to two hundred base pairs, are conserved. Furthermore, gene duplicates exhibit similar organ-specific expression profiles. These facts allowed us to predict putative cis-regulatory regions, particularly those responsible for cell-wall construction, and hence for morphogenesis, that are specific for certain organs or tissues in plants.

Arabidopsis↗