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Reconstitution of T-cell function after CD6-depleted allogeneic bone marrow transplantation.

Patients who undergo allogeneic bone marrow transplantation (BMT) are clinically immunodeficient for a prolonged period after engraftment. In the present study, we examined immune function after BMT in a series of patients who had received HLA compatible sibling marrow grafts purged of T cells with anti-CD6 monoclonal antibody and complement. None of the patients in this analysis received immunomodulating agents and none had developed graft-versus-host disease (GVHD). Initially after BMT, natural killer (NK) cells are the predominant cell type, giving way to CD3+, CD5+ T cells after 4 to 8 weeks. Despite the return of normal numbers of T lymphocytes post-BMT phenotypic analysis reveals several long-term abnormalities, including an inverted T4:T8 ratio and a significant fraction of CD3+ T cells that do not co-express CD6. In mitogenic assays, stimulation by either nonspecific lectin (phytohemagglutinin; PHA) or antibodies to the CD2 surface structure (anti-T11(2) + anti-T11(3)) results in decreased levels of T-cell proliferation compared with controls for over 18 months post-BMT. In contrast, the ability of unstimulated peripheral blood mononuclear cells (PBMC) to respond to recombinant interleukin-2 (rIL-2) is relatively intact, most likely reflecting early functional reconstitution of the NK cell population. To further characterize the prolonged abnormalities in T-cell proliferation after PHA or CD2 stimulation, we examined more proximal events in T-cell activation such as induction of IL-2 receptor expression and stimulus-induced intracellular calcium flux. We found that the induction of IL-2 receptor (p55) after in vitro activation, although initially abnormal, recovers completely by 6 months post-BMT. We also found that, after CD2 stimulation, calcium flux in T cells was normal immediately after engraftment. In contrast, after stimulation with anti-CD3 antibodies, a large population of T cells do not develop intracellular calcium flux compared with controls. We conclude that despite the recovery of normal numbers of T lymphocytes early after engraftment of CD6-depleted marrow, these T cells exhibit several physiologic and functional abnormalities that persist for varying intervals post-BMT. At present, it is unclear which of these specific defects is most closely associated with increased susceptibility to infectious agents after BMT.

Adolescent↗

Immunohistochemical demonstration of growth factors, TGF-alpha, TGF-beta, IGF-I and neu oncogene product in benign and malignant human breast tissues.

The expression of growth factors, TGF-alpha, TGF-beta, IGF-I and neu oncogene product was studied immunohistochemically in the tissue of 120 benign and malignant human breasts. Growth factors were found only in benign or malignant mammary epithelial cells and not in stromal cells. Normal and benign lesions were found to be negative for reactivity with each antibody. Carcinoma in situ and invasive breast carcinomas demonstrated a significantly higher percentage of stained cells than that observed in benign lesions; forty (49%) of 82 invasive carcinomas were positive for TGF-alpha, 31 (38%) for TGF-beta, 31 (38%) for IGF-I and 34 (41%) for neu product. No overall correlations were found between expression of each growth factor and the clinical stage or degree of histologic differentiation of the carcinomas. A significant positive correlation was observed between ER status and IGF-I expression and between PgR status and TGF-beta expression. In the majority of the carcinomas, co-expression between TGF-alpha, TGF-beta and IGF-I was observed; the percentage of cases with parallel positive or negative expression of two growth factors was as follows; TGF-alpha - TGF-beta (70%), TGF-alpha - IGF-I (57%), TGF-beta - IGF-I (71%). The concomitant expression of TGF-alpha and neu oncogene product in cell surface was also observed. The relapse-free intervals of the patients were studied in association with expression of each growth factor. TGF-beta-positive tumors showed a significantly better prognosis than TGF-beta - negative tumors (within the first 2 years of observation). However, TGF-alpha, IGF-I and neu overexpression showed no effect on the prognosis of the patients.

Adult↗

Expression of human HLA-B27 transgene alters susceptibility to murine Theiler's virus-induced demyelination.

Infection of certain strains of mice with Theiler's murine encephalomyelitis virus results in persistence of virus and an immune-mediated primary demyelination in the central nervous system that resembles multiple sclerosis. Because susceptibility/resistance to demyelination in B10 congeneic mice maps strongly to class I MHC genes (D region) we tested whether expression of a human class I MHC gene (HLA-B27) would alter susceptibility to Theiler's murine encephalomyelitis virus-induced demyelination. Transgenic HLA-B27 mice were found to co-express human and endogenous mouse class I MHC genes by flow microfluorimetry analysis of PBL. In the absence of the human transgene, H-2stf, or v mice but not H-2b mice had chronic demyelination and persistence of virus at 45 days after infection. No difference in degree of demyelination, meningeal inflammation, or virus persistence was seen between transgenic HLA-B27 and nontransgenic littermate mice of H-2f or H-2v haplotype. In contrast, H-2s (HLA-B27+) mice showed a dramatic decrease in extent of demyelination and number of virus-Ag+ cells in the spinal cord compared with H-2s (HLA-B27-) littermate mice. In addition, none of the eight H-2s mice homozygous for HLA-B27 gene had spinal cord lesions even though infectious virus was isolated chronically from their central nervous system. Expression of HLA-B27 transgene did not interfere with the resistance to demyelination normally observed in B10 (H-2b) mice. These experiments demonstrate that expression of a human class I MHC gene can modulate a virus-induced demyelinating disease process in the mouse.

Animals↗

The alpha 2(VIII) collagen gene. A novel member of the short chain collagen family located on the human chromosome 1.

Type VIII collagen is a major component of Descemet's membrane, the specialized basement membrane of corneal endothelial cells. Sequence analysis of a cDNA isolated from a library made with mRNA from rabbit corneal endothelial cells has indicated that type VIII molecules contain a polypeptide chain, alpha 1(VIII), consisting of a short triple-helical domain of 454 amino acid residues flanked by non-triple-helical domains of 117 and 173 amino acid residues at the amino and carboxyl ends, respectively (Yamaguchi, N., Benya, P. D., van der Rest, M., and Ninomiya, Y. (1989) J. Biol. Chem. 264, 16022-16029). The sequence of alpha 1(VIII) is strikingly similar to that of alpha 1(X) collagen, a product of hypertrophic chondrocytes. Also, characterization of the alpha 1(VIII) and alpha 1(X) collagen genes has shown that they are quite similar in their exon organization. It has been concluded, therefore, that they are homologous members of a distinct subclass of collagen genes (Yamaguchi, N., Mayne, R., and Ninomiya, Y. (1991) J. Biol. Chem. 266, 4508-4513). We have given this subclass the name short chain collagens because of the relatively small size of the triple-helical domain. In the present study, we report on the identification and characterization of a collagen gene encoding a polypeptide which is co-expressed with the alpha 1(VIII) chain in corneal endothelial cells. This collagen chain contains a triple-helical and a carboxyl non-triple-helical domain encoded by a single, large exon both in mice and humans. We conclude, therefore, that the genes encodes a novel member of the short chain collagen family, and we have given this chain the designation alpha 2(VIII) collagen. By in situ hybridization we demonstrate that the alpha 2(VIII) gene is located in the p32.3-p34.3 region of the short arm of chromosome 1.

Amino Acid Sequence↗

Phenotypic heterogeneity of intraepithelial T lymphocytes from mouse small intestine.

We have used two-colour flow cytometry to examine the heterogeneity of intraepithelial lymphocytes (IEL) from mouse small intestine. We have confirmed the predominance of CD3+ Thy 1- CD8+ IEL and show that a substantial but variable proportion of CD8+ IEL does not express the alpha beta T-cell receptor (TcR) for antigen. Simultaneous analysis of the co-expression of the alpha and beta chains of the CD8 heterodimer and of the alpha beta TcR revealed three populations of CD8+IEL. The first of these expressed both CD8 alpha and beta chains and had normal expression of V beta families and so represented conventional CD8+ alpha beta TcR+ T cells. The second population comprised alpha beta TcR- T cells (presumed gamma delta TcR+) which expressed only the alpha chain of the CD8 molecule. Finally, we identified a second, unique population of alpha beta TcR+ CD8+ IEL which were also CD8 beta-. Gamma delta + IEL predominated in mice aged less than 8 weeks, but there was a rapid increase in both populations of alpha beta TcR+ CD8+ IEL in older mice. CD8+ IEL were similar to peripheral CD8+ T cells in having high expression of the CD45RB molecule, but CD4+ IEL had generally lower expression of CD45RB than their peripheral counterparts, despite having normal expression of TcR. These findings emphasize the heterogeneity of IEL and underline the need to study phenotypically defined populations.

Aging↗

High level expression of functional full length and truncated glucocorticoid receptor in Chinese hamster ovary cells. Demonstration of ligand-induced down-regulation of expressed receptor mRNA and protein.

Full length human glucocorticoid receptor and truncated receptor derivatives lacking the major amino-terminal trans-activating domain were expressed in stably transfected Chinese hamster ovary (CHO) cells. The receptors were co-expressed together with human metallothionein IIa, and the expression levels were amplified in the presence of increasing concentrations of metal. In amplified cells, both synthesized receptor forms showed the expected molecular weights, as assayed by affinity labeling and immunoblotting. They were expressed at concentrations of about 350,000-520,000 molecules/cell which corresponds to a 10-fold increase in receptor levels as compared to rat liver cells. The hormone (agonist or antagonist) binding properties of the expressed proteins were very similar to those characteristic of authentic glucocorticoid receptors in tissues or cultured cells. Moreover, the expressed proteins specifically recognized a glucocorticoid-response element sequence motif in in vitro protein-DNA binding experiments. The activation of a glucocorticoid-responsive reporter gene by the expressed full length receptor was dramatic (about 75-fold) and strictly ligand-dependent. In contrast, the expressed amino-terminal deletion mutant exhibited considerably weaker functional activity but showed normal hormone-binding properties. Upon exposure to dexamethasone in vivo, the expressed receptor mRNAs and proteins were down-regulated about 2- to 6-fold, indicating that regulatory signals important for autoregulation may be contained within structures corresponding to the ligand and DNA-binding domains. Transcription from the expression vector was not negatively regulated from the hormone, strongly arguing that receptor down-regulation was due to a post-transcriptional mechanism. In conclusion, this expression system should be a useful tool for further structural and functional studies of the receptor, including the biochemistry of its activation from a cryptic to a functional species, and its ligand-dependent autoregulation.

Affinity Labels↗

Antigen variation in a human glioblastoma: from the primary tumor to the second recurrence, permanent cell line and xenotransplantation tumors.

Antigen expression in a human glioblastoma was investigated by immunochemical methods in the primary tumor, the first and second recurrence, a permanent cell line derived from the first recurrence and in its xenotransplantation tumors. In the primary tumor, GFAP, vimentin, S100, Leu-7 and glioma-associated antigens (GAA) as defined by the monoclonal antibodies (mAbs) MUC 2-39, MUC 8-22 and MUC 2-63 were markedly expressed. In the recurrences, gradual loss of GFAP and Leu-7 could be observed, whereas S100, vimentin and GAA gave similar results to those in the primary tumor. In contrast, fibronectin and collagen IV, which were restricted to the vessel walls in the primary tumor, were represented in sarcomatous areas of the recurrences. In some of these areas, co-expression of glial cell markers was observed. In short-term cell cultures, expression of glia- and glioma-associated antigens as well as fibronectin and collagen IV was comparable to that of the recurrent tumor tissue. In long-term passages, immunoreactivity of GFAP, Leu-7 and S100 decreased, whereas GAA, vimentin and fibronectin increased. Collagen IV positive cells were not visible beyond passage 15. Transplantation tumors were only partly positive for glial cell markers, but revealed strong immunoreactivity for GAA, fibronectin and collagen IV. With these observations we confirm that the phenotypic variability of glioma cells makes it difficult to identify the origin of cells in human glioblastomas from their antigenicity.

Animals↗

[Molecular characterization of cutaneous neuroendocrine (Merkel cell) carcinoma. Review of the literature and presentation of a caseload].

Molecular characterization of neuroendocrine (Merkel cell) carcinoma of the skin. Review of the literature and report of three cases. Although neuroendocrine carcinoma of the skin (NECS) is comparatively a rare clinical-histological entity, numerous morphological and ultrastructural studies have been carried out since the tumor was identificated by Toker (1972). Recently immunocytochemistry has allowed a better molecular characterization (immunophenotype) of this tumor and a more exact diagnosis. The main problem for the pathologist is the differential diagnosis between NECS and skin neoplasms--both primitive and metastatic--which require a more aggressive treatment. Often the classical morphological criteria do not distinguish NECS from non-Hodgkin's lymphoma, amelanotic melanomas, cutaneous metastases of lung small cell carcinoma or of neuroblastoma. The co-expression of cytokeratins and neurofilaments constantly found in NECS, is surely the best differential criterion from non-neuroendocrine carcinomas. Furthermore, the typical paranuclear location of both the intermediate filaments in NECS is a distinctive peculiarity as opposed to lung microcytoma, where cytokeratins and neurofilaments, when present, show widespread perinuclear positivity. Chromogranin A is found only in a small percentage of tumor cells, whilst synthesis of calcitonin, somatostatin, gastrin, ACTH, is very rare. Finally, the lack of common leukocyte antigen (CLA), S-100 protein and vimentin in NECS rules out the diagnoses of lymphoma, melanoma and sarcoma respectively.

Aged↗

Properties of FV and Fab fragments of the antibody McPC603 expressed in E. coli.

The FV and Fab fragments of the phosphorylcholine binding antibody McPC603 were functionally expressed in E. coli. This was achieved by the co-expression and co-secretion of both chains to the periplasm, where correct processing, folding and assembly occurred. Interestingly, the fraction of correctly folded Fab fragment is smaller than that of the Fv fragment in E. coli. The intrinsic hapten binding affinity was shown to be identical for the recombinant FV or Fab fragment, the whole antibody and the Fab fragment obtained by proteolysis from the mouse antibody. Fluorescence and crosslinking analyses showed that the FV fragment dissociates at high dilution, but that it is stabilized by hapten binding. The recombinant FV fragment was shown to have catalytic activity to hydrolyze choline-p-nitrophenyl carbonate and constitutes therefore a promising model system with which the structural requirements of catalytic antibodies can be studied by altering the protein itself.

Animals↗

Regulation of erythroid-specific gene expression.

The aim of our group's work has been to elucidate how the alpha- and beta-globin genes come to be co-expressed together with a set of characteristic non-globin genes during erythroid cell differentiation. Our most significant progress concerns the identification and analysis of a species-conserved transcription factor, EF1, that appears to play a general role in the regulation of erythroid-specific gene transcription. We have shown that the 4 kb of 5' flanking region of the mouse alpha-globin gene contains two erythroid-specific cis-control elements, both of which involve EF1 binding sites. We have also identified functionally active EF1 binding sites in the mouse beta-globin promoter, as well as in the erythroid-specific promoter of the gene encoding the haem biosynthetic enzyme, porphobilinogen deaminase (PBG-D). The function of the PBG-D promoter depends in part on the cooperation between an EF1 binding site and an adjacent CACCC motif, this being abolished if their spacing is increased beyond 40 nt. We have also investigated the mechanisms involved in the up-regulation in erythroid cells of two non-globin genes we have cloned, encoding the RBC-specific lipoxygenase (LOX) and glutathione peroxidase (GSHPX). As judged by the presence of tissue-specific DNAse I hypersensitive sites, the tissue-specific regulation of the GSHPX gene seems to be due to regulatory regions 3' to the gene. The level of GSHPX is also regulated by selenium and this occurs at two levels: during mRNA formation, and during translation of the mRNA due to the regulation of selenocysteine incorporation specified by a unusual use of the UGA codon.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Adhesion of human T-lymphoid cells to fibronectin is mediated by two different fibronectin domains.

Lymphocyte adhesion to components of extracellular matrices (i.e. fibronectin) is important for their proper localization in tissues and inflammatory sites. We have studied the attachment of the human cell line HUT-78 (mature T lymphocytes) to fibronectin and to several tryptic fragments of fibronectin. HUT-78 cells effectively adhered to surfaces coated with two Hep II domain-containing fragments of 38,000 and 58,000 MW derived from the A and B chains of fibronectin, respectively. Cells also bound to an 80,000 MW fragment containing the RGDS sequence of fibronectin. Cell adhesion to the 38,000 MW fragment was completely inhibited (100%) by cell preincubation with the soluble 38,000 MW fragment; it was partially inhibited (30-37%) by preincubation with the 58,000 MW fragment or with a synthetic peptide CS-1, comprising the first 25 amino acid residues of the alternatively spliced connecting segment (IIICS), which is present in the A chain of fibronectin and in the 38,000 MW fragment. Cell preincubation with RGDS-containing synthetic peptides or with the 80,000 MW fragment, did not affect attachment to 38,000 MW-coated surfaces. Moreover, preincubation of HUT-78 cells with 38,000 MW fragment had no effect on cell adhesion to 80,000 MW-coated wells, while preincubation with 80,000 MW fragment completely inhibited cell attachment to these surfaces. These results strongly suggest the involvement of two different cell surface receptors which recognize the Hep II/IIICS site and the RGDS site independently. Preincubation with either 38,000 or 80,000 MW fragments prevented cell attachment to fibronectin, indicating that adhesion to the intact molecule requires interaction with both regions. Therefore T-lymphocyte adherence to fibronectin-containing matrices may be regulated by the co-expression of both receptors at the cell surface.

Cell Adhesion↗

Comparative studies on FcR (FcRII, FcRIII, and FcR alpha) functions of murine B cells.

Distribution of FcR II, FcRIII, and FcR alpha on murine splenic B cells was examined by using FITC-labeled heat-aggregated IgG of each subclass and IgA. Almost 60 to 80% of B cells expressed both FcRII and FcRIII. However, FcR alpha was expressed on only a small proportion (6%) of B cells that co-expressed FcRII. By inhibition assays with the use of cold IgG of each subclass and IgA in addition to anti-FcRII mAb (2.4G2), it was found that IgG1, IgG2a, and IgG2b utilized the same receptor (FcRII), whereas IgG3 and IgA bound only to their unique receptors, FcRIII and FcR alpha, respectively. Immune complexes IC prepared by IgG1, IgG2a, IgG2b, and IgA anti-TNP mAb with TNP-coupled SRBC inhibited the polyclonal Ig secretion and proliferative responses of B cells stimulated with either IL-4 or LPS. The inhibition of B cell activation was associated with the blockade of the membrane depolarization. Moreover, IC prepared by these antibodies caused production of suppressive B cell factor (SBF) as is the case with rabbit IgG antibody to SRBC, and SBF thus prepared regulated antibody responses in an isotype-nonspecific manner. In contrast, no inhibition for these responses or production of SBF was attained by the IC of IgG3 antibody. We concluded that FcRII and FcR alpha mediates a suppressive signal for B cells by acting on the initial step of activation, whereas FcRIII lacks this activity.

Animals↗

Nonadrenergic [3H]idazoxan binding sites are physically distinct from alpha 2-adrenergic receptors.

We have recently demonstrated that the alpha 2-adrenergic radioligand [3H]idazoxan also labels additional sites that do not recognize catecholamines but bind with high affinity several chemically distinct drugs previously assumed to be highly selective for alpha 2-adrenergic receptors [Mol. Pharmacol. 35:324-330 (1989)]. We now have used three approaches to distinguish the nonadrenergic [3H]idazoxan sites from alpha 2-adrenergic receptors. (a) No nonadrenergic [3H]idazoxan binding sites were found in COS-7 cells transfected with the genes for the two known alpha 2-adrenergic receptor subtypes. (b) The ratio of alpha 2-adrenergic and nonadrenergic [3H]idazoxan sites in human platelet membranes varied considerably between various donors. (c) Highly purified platelet plasma membranes were enriched for alpha 2-adrenergic receptors but did not contain any nonadrenergic [3H]idazoxan binding sites. We conclude that the nonadrenergic [3H]idazoxan binding sites are not co-expressed with alpha 2-adrenergic receptors and at least in human platelets may be located in an intracellular compartment.

Animals↗

Down-regulation of KOLT-2 antigen (CD28) by interleukin 2; role of IL-2R (p70).

Using KOLT-2 monoclonal antibody (mAb) recognizing a 44,000 molecular weight (MW) T-cell activation antigen (CD28), we observed the co-expression of KOLT-2 (CD28) antigen and Tac (CD25) antigen, associated with a 55,000 MW chain of the interleukin-2 receptor (IL-2R) complex. IL-2R (p55), on several T-cell lines transformed by human T-lymphotropic virus-I (HTLV-I), as well as several subclones of the natural killer (NK)-like cell line YT. When YT cells (YTC3T, YT5.1) and IL-2-dependent HTLV-I+ T-cell line cells (ED, ATL35C) expressing both IL-2R (p55) and IL-2R (p70) chains were cultured with recombinant IL-2 (rIL-2), KOLT-2 antigen was down-regulated in 24 hr. However, KOLT-2 antigen on HPB-ALL (Kurume) cells expressing neither of the IL-2R chains was unaffected by IL-2. IL-2 also failed to down-regulate KOLT-2 antigen on MT-1 cells bearing IL-2R (p55)/Tac without IL-2R (p70). To clarify the role of IL-2R (p70) in the IL-2-induced down-regulation of KOLT-2 antigen, we analysed the effect of IL-2 on a Tac- subclone of YT (YT2C2) that expresses IL-2R (p70). As was the case with Tac+ YT cells, KOLT-2 antigen was down-regulated by IL-2, and this down-regulation was inhibited by anti-IL-2R (p70) mAb but not by anti-Tac mAb. These results show that the signalling through the IL-2/IL-2R system down-regulates KOLT-2 (CD28) antigen by way of the interaction between IL-2 and IL-2R (p70), irrespective of IL-2R (p55)/Tac. Possible involvement of the IL-2/IL-2R system in the CD28-mediated mitogenic mechanism is discussed.

Antigens, Differentiation, T-Lymphocyte↗

Transphosphorylation as a possible mechanism for insulin and epidermal growth factor receptor activation.

Fully functional chimeric receptors, consisting of major epidermal growth factor and insulin receptor domains, were co-expressed with kinase-negative epidermal growth factor and insulin receptor mutants in human kidney fibroblasts. Under these conditions, homologous extracellular and cytoplasmic domains mediated association of receptors and their precursors. The significance of receptor-receptor interaction was confirmed by transphosphorylation of kinase-negative receptors by ligand-activated chimeric receptors, which was observed between receptors sharing the same cytoplasmic domain as well as between receptors bearing only the same extracellular domain and containing heterologous kinases. Furthermore, the impaired ligand internalization capacity of a kinase-deficient insulin receptor was partially restored by transphosphorylation. Our experiments suggest interreceptor transphosphorylation and transactivation as a possible mechanism for signal amplification.

Cell Line↗

Lectin histochemical studies on renal tumors.

Histochemical characteristics on lectin binding of 16 cases of nephroblastoma and of 57 cases of renal cell carcinoma were studied on those of six embryonal and fetal kidneys in 4 to 24 gestational weeks and in six normal adult kidneys using four biotinylated lectins (PNA, LTA, SBA and UEA-1), which show segment specific binding for normal nephron. In normal nephrogenesis, Gal beta 1-3 GalNAc (PNA receptor) appeared at first in developing tubuli of the metanephros at 10 gestational weeks, and remained positive in proximal tubuli of 13 gestational weeks, where the Lewis X antigen (LTA receptor) emerged. In adult kidneys, Gal beta 1-3 GalNAc distributed along distal tubuli and collecting ducts and not in proximal tubuli. Type 2 H antigen (UEA-1 receptor) was confined to collecting ducts. In nephroblastomas, positive reaction to these lectins were almost exclusively confined to tubular structures. Gal beta 1-3 GalNAc was constantly positive there. Intensely positive stain of Lewis X antigen was observed in three cases of histologically well differentiated type. Lewis X antigen positive tubuli co-expressed Gal beta 1-3 GalNAc. There were six type 2 H antigen positive cases showing differentiation toward ureteric bud or collecting ducts. In view of the cell surface glycosylation, regular differentiation of fetal renal tubuli was also retained in nephroblastomas according to their degree of histological differentiation. In renal cell carcinoma, Gal beta 1-3 GalNAc was positive in 49% (28/57) and Lewis X antigen was positive in 54% (31/57). Type 2 H antigen was completely negative. In contrast to the nephroblastoma, there was no correlation between histological features and lectin binding patterns in renal cell carcinoma.

Adult↗

Specificity of interactions of receptors and effectors with GTP-binding proteins in native membranes.

Individual G-proteins are highly similar in primary sequence. It is thus pertinent to ask what degree of specificity of interaction each of these display with the various receptors and effector systems. Many of the identified G-proteins are co-expressed in a single tissue or cell. As the extreme C-terminus of the alpha-subunit of each G-protein appears to be a key domain for the interactions of receptors and G-proteins, we have generated a series of G-protein-selective anti-peptide antisera against this region and then have used these antisera to attempt to interfere with receptor-G-protein coupling. With this approach, we have demonstrated that delta-opioid receptor-mediated inhibition of adenylate cyclase in neuroblastoma x glioma (NG108-15) cell membranes is transduced specifically by Gi2 and in the same cell that alpha 2-adrenergic inhibition of Ca2+ currents is transduced by G0.

Animals↗

[Pathogenetic and clinical significance of the adhesion molecule expression on T cells of the lung in sarcoid alveolitis].

A double immunofluorescence analysis of CD4+ cell population from bronchoalveolar lavage (BAL) fluid samples of patients with active pulmonary sarcoidosis was carried out. The results showed that, unlike BAL and peripheral blood CD4+ cells of healthy subjects, almost all BAL CD4+ cells of the patients highly express, besides CDw29 antigen, LFA-1 and ICAM-1 adhesion molecules. The co-expression of these molecules on BAL CD4+ cells during high intensity sarcoid alveolitis could represent a marker of immunological memory. The relevant pathogenetic and clinical implications of this observation are discussed.

Adhesiveness↗