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J E Gessner

Publications and source records attributed to J E Gessner.

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Fc gamma-receptor III (CD 16) is involved in NK-B cell interaction.

CD16, the low affinity receptor for monomeric IgG (Fc gamma RIIIA), is a well characterized activation molecule on NK cells. In this study we investigated the role of CD16 in NK cell-mediated regulation of immunoglobulin production. Cocultures of the CD16+ human NK clone CNK6 and highly purified SAC/IL-2-activated B lymphocytes with various CD16 antibodies showed significantly diminished NK-enhanced immunoglobulin production in a dose-dependent manner, indicating that CD16 is relevant in NK-B cell interaction. Similarly, recombinant soluble CD16 incubated with B cells before cultures, suppressed the NK cell-stimulated B cell antibody response. Enhanced immunoglobulin production was also inhibited by Fc-specific F(ab')2 anti-body fragments. Coculture of NK cells with B lymphocytes resulted in induction of mRNA for IFN-gamma and TNF-alpha. The accumulation of mRNA for these cytokines was prevented by addition of CD16 and Fc-specific antibodies. It is proposed that interaction of CD16 on NK cells with B cell bound immunoglobulin leads to induction of cytokines in NK cells which stimulate immunoglobulin production by B cells.

Antibodies, Monoclonal↗

Impaired IgG-dependent anaphylaxis and Arthus reaction in Fc gamma RIII (CD16) deficient mice.

The family of receptors for IgG (Fc gamma R) plays an essential role in antibody-mediated effector functions of the immune system. However, the specific contribution of each of the Fc gamma R classes to in vivo immune reactions is still unclear. Here, we demonstrate that mice deficient for the ligand-binding alpha chain of Fc gamma RIII lack NK cell-mediated antibody-dependent cytotoxicity and phagocytosis of IgG1-coated particles by macrophages. Strikingly, these mice lack IgG-mediated mast cell degranulation, are resistant to IgG-dependent passive cutaneous anaphylaxis, and exhibit an impaired Arthus reaction. These results indicate a prominent role for Fc gamma RIII in inflammatory and anaphylactic responses, making this receptor a potential target in immunotherapy.

Animals↗

The human low affinity immunoglobulin G Fc receptor III-A and III-B genes. Molecular characterization of the promoter regions.

The human Fc receptor with low affinity for IgG (Fc gamma RIII, CD16) is encoded by two nearly identical genes, Fc gamma RIII-A and Fc gamma RIII-B, resulting in tissue-specific expression of alternative membrane-anchored isoforms. The transmembrane CD16 receptor forms a heteromeric structure with the Fc epsilon RI (gamma) and/or CD3 (zeta) subunits on the surface of activated monocytes/macrophages, NK cells, and a subset of T cells. The expression of the glycosylphosphatidylinositol-anchored CD16 isoform encoded by the Fc gamma RIII-B gene is restricted to polymorphonuclear leukocytes and can be induced by Me2SO differentiation of HL60 cells. We have isolated and sequenced genomic clones of the human Fc gamma RIII-A and Fc gamma RIII-B genes, located their transcription initiation sites, identified a different organization of their 5' regions, and demonstrated four distinct classes of Fc gamma RIII-A transcripts (a1-a4) compared with a single class of Fc gamma RIII-Bb1 transcripts. Both CD16 promoters (positions -198 to -10) lack the classical "TATA" positioning consensus sequence but confer transcriptional activity when coupled to the human lysozyme enhancer. Both promoters also display different tissue-specific transcriptional activities reflecting the expected gene expression of Fc gamma RIII-A and Fc gamma RIII-B in NK cells versus polymorphonuclear leukocytes. Within the -198/-10 fragments, the sequences of the two CD16 genes have been identified to differ in 10 positions. It is suggested that these nucleotide differences might contribute to cell type-specific transcription of Fc gamma RIII genes.

Amino Acid Sequence↗

Differentially regulated expression of human IgG Fc receptor class III genes.

The expression of the human Fc receptor with low affinity for IgG (Fc gamma RIII, CD16) encoded by the Fc gamma RIII-A or Fc gamma RIII-B genes is restricted to natural killer (NK), a subset of T cells and macrophages or neutrophils (PMN). The genetic heterogeneity of Fc gamma RIII generates alternative membrane-anchored proteins with distinct signaling capacities when cross-linked by immune complexes. Of great importance is the characterization of the regulatory gene elements directing the expression of a particular Fc gamma RIII isoform to a given specific cell type. Molecular characterization of the Fc gamma RIII-A and Fc gamma RIII-B genes has revealed that the promoter regions display distinct tissue-specific transcriptional activities. In addition, the differential Fc gamma RIII-A/B gene activation can be regulated by enhancer elements located in the more upstream and intron regions. Transcription initiation in NK cells occurs also outside the normal promoter region by a second independent Fc gamma RIII-A promoter. Analysis of the additional Fc gamma RIIIa2-4 transcripts suggests the expression of novel, as yet unknown Fc gamma RIII receptor isoforms on NK cells.

Base Sequence↗

[Activation-dependent expression of Fc gamma-receptors on glomerular mesangial cells].

Resting, non-cycling mesangial cells (MCs) can be induced by IFN gamma to express the Fc gamma-RIIIa and Fc epsilon RI-gamma subunits of the CD16TM receptor complex. After cell surface expression of CD16TM by IFN gamma induction the binding of immune complexes to MCs induces IL-6 secretion. A Fc epsilon RI-gamma gene knockout has recently been described. It is now possible to study the function of Fc gamma RIIIa and other gamma chain associated Fc receptors in the initiation and progression of chronic glomerular inflammation in the context of the intact immune system in vivo.

Animals↗

Intrinsic human glomerular mesangial cells can express receptors for IgG complexes (hFc gamma RIII-A) and the associated Fc epsilon RI gamma-chain.

Immune complexes localize to the glomerular mesangium in many forms of human glomerulonephritis. In this investigation, we determined whether primary cultured human glomerular mesangial cells (HMC) express mRNA and functional protein of FcR for IgG. Performing reverse transcription-PCR with subsequent control Southern blots, we showed that in contrast to human monocytes or granulocytes, mRNA for Fc gamma RI and Fc gamma RII is not detectable in either growth-arrested (48 h serum free) or unstimulated proliferating (medium with 10% FCS) HMC. However, IFN-gamma in combination with LPSE.coli (LPS), but not LPS alone elicited a significant transcription of hFc gamma RIII mRNA in resting HMC, whereas cytokines, such as IL-1 beta or TGF-beta, failed to induce any of the three Fc gamma Rs in resting HMC. Proliferating HMC showed a basal transcription of Fc gamma RIII mRNA, which was enhanced by IFN-gamma in combination with LPS. Slot-blot analysis indicated that only the Fc gamma RIII-A gene encoding the transmembrane isoform of Fc gamma RIII was expressed by HMC. For the first time, transcripts for the gamma-chain of Fc epsilon RI were found in HMC. Fc gamma RIII protein expression was detected after LPS/IFN-gamma stimulation both by specific staining of paraformaldehyde-fixed HMC and immunoprecipitation of Fc gamma RIII protein from HMC membranes. Fc gamma RIII-A receptors are functionally active, as HMC IL-6 mRNA synthesis was stimulated by heat-aggregated IgG or F(ab')2 fragments of CLBGran1 mAb only after induction of Fc gamma RIII-A. These in vitro data suggest that HMC that are basically negative for Fc gamma RIII can be stimulated to express low affinity Fc gamma Rs, and thus may participate actively in human glomerulonephritis involving immune complexes.

Amino Acid Sequence↗

Defect of a complement receptor 3 epitope in a patient with systemic lupus erythematosus.

Complement receptor 3 (CR3) is expressed on cells of the reticuloendothelial system and involved in the clearance of immune complexes. In this article a patient with a deficiency of the C3bi binding site of this receptor is described. Clinically this patient exhibited predominantly cutaneous manifestations of a systemic lupus erythematosus with an immune vasculitis and panniculitis. The deficiency of the CR3 epitope was demonstrated using flow cytometry. The functional relevance of this defect was demonstrated in a rosetting assay with C3bi-loaded erythrocytes. C3bi binding was found to be significantly decreased. Furthermore, there was an impairment of phagocytosis of opsonized Escherichia coli. The CR3 defect is not due to an autoantibody but is assumed to have a genetic basis. These data suggest that the defect of the CR3 may be involved in the pathogenesis of the immune vasculitis in this patient.

Adult↗

Fc gamma RIII activation is different in CD16+ cytotoxic T lymphocytes and natural killer cells.

The transmembrane protein CD16 (Fc gamma RIII) is detected on activated macrophages, natural killer (NK) cells and a small subset of T lymphocytes. From CD3-CD56+ CD16+bright NK cells and CD3+ CD56+ CD16+dim non-major histocompatibility complex (MHC)-restricted cytotoxic T lymphocyte (CTL) clones were generated reflecting the stable, but different, CD16 expression of the respective peripheral blood subpopulations. To compare the role of CD16 on NK cells and non-MHC-restricted CTL, Fc gamma RIII activation and its mechanisms were investigated using monoclonal antibodies (mAb). Cross-linking of CD16 induced Ca2+ influx in CD16+bright NK clones. In contrast, there was no Ca2+ mobilization after CD16 activation in CD16+dim CTL, which revealed a good response to cross-linking of CD3 antigen. Pretreatment with CD16 mAb alone or cross-linked CD16 mAb did not block the CD3 response of CD16+dim CTL. Again, CD16 cross-linking induced more interferon-gamma transcription in NK cell clones than in non-MHC-restricted CTL clones. Also a higher tumor necrosis factor-alpha production of NK clones after CD16 cross-linking compared to CD16+dim CTL could be observed. These data suggest that after CD16 activation CD16+dim CTL and CD16+bright NK cells use different second messengers. In addition, signal transduction via CD3 and CD16 appears to function independently in CD16+dim non-MHC-restricted CTL.

Antibodies, Monoclonal↗

Multiparameter analyses of normal and malignant human plasma cells: CD38++, CD56+, CD54+, cIg+ is the common phenotype of myeloma cells.

Plasma cells obtained from bone marrow samples of 45 patients with MM, eight patients with MGUS, eight patients with Waldenström's macroglobulinaemia (WM), one patient with immunocytoma, and 12 controls were characterized by immunophenotyping, estimation of DNA content, and labeling index, as well as by morphological analysis. Plasma cells from 37/45 myeloma and 5/8 MGUS patients expressed CD38 and CD56 (N-CAM) on their surface but were negative for other NK cell-associated antigens such as CD16 (Fc gamma RIII) or CD2. All tumor cells of less-differentiated cell type (WM, immunocytoma) and normal polyclonal plasma cells were negative for CD56. CD56-specific mRNA was demonstrated in myeloma cells by northern blot analysis. Another adhesion molecule, ICAM-1 (CD54), was found on plasma cells from all patients and controls examined. Coexpression of CD19 (1/45), CD20 (9/45), or CD33 (3/45) was rare and CD10 with CD14 was expressed by a small tumor cell subpopulation of only one myeloma patient. The individual pattern of surface marker expression was not associated with a special-type myeloma protein isotype, stage or status of disease, LI or histological classification; however, a correlation between CD56 expression or histological classification and DNA content of the tumor cells was found.

ADP-ribosyl Cyclase↗

Analysis of CD16+dim and CD16+bright lymphocytes--comparison of peripheral and clonal non-MHC-restricted T cells and NK cells.

The Fc gamma RIII receptor (CD16) has been described on natural killer cells and a small subset of T lymphocytes. CD16+bright lymphocytes represent the typical population of peripheral blood CD3- NK cells. In these studies in addition to CD16+bright NK cells Fc gamma RIII expressing cytotoxic T lymphocytes in peripheral blood from one healthy individual are characterized as CD16+dim non-MHC-restricted CTLs either expressing the alpha/beta (80%) or the gamma/delta T cell receptor (20%). Both CD16+ subsets are clearly distinct in their functional capacity performing NK and ADCC activity. Freshly isolated CD16+dim T cells exert higher ADCC, CD16+bright NK cells higher NK activity. They are also differentially activated by interleukin-2 since CD16+bright NK cells reveal a bright expression of the p75 IL-2 receptor beta-chain in contrast to the very low p75 expression on CD16+dim T cells. This activation leads to a gradual increase of ADCC by NK cells. Finally the CD16 expression pattern with low and bright intensity represents a stable phenotype expressed by clones generated from these different subpopulations. On a clonal level CD16+dim non-MHC-restricted T cells can be distinguished from CD16+bright NK cells by their lower capacity in NK killing, but they are equally potent in ADCC. Finally these CD3+CD16+dim clones provide the basis for studies of Fc gamma RIII and TcR interaction.

Antibody-Dependent Cell Cytotoxicity↗

Rehabilitation in the extended care facility.

Rehabilitation can be readily carried out in an extended care facility. A technique is presented for accomplishing this objective by organizing existing personnel within the facility into a rehabilitation team which is goal-oriented. The Barthel Index serves as an objective measurement of the patient's progress. By use of this approach, significant numbers of patients with stroke, orthopedic disorders and other neuromusculoskeletal impairments can be returned to their previous living situations in a relatively short period, and at minimal cost.

Activities of Daily Living↗

"Bell's" palsy.

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Facial Paralysis↗

On the role of complement and Fc gamma-receptors in the Arthus reaction.

The contribution of either the complement system or the activation of Fc receptors for IgG (FcyRs) to the inflammatory response in immune complex (IC) disease is puzzling. A series of studies has been performed in mice with engineered deficiencies of either FcgammaRs, the complement components C3, C4 or the C5a receptor. In addition, different C5-deficient mice strains have been evaluated. Mice with gene targeted disruption of the gamma-subunit, which mediates surface expression and signal transduction of the high affinity Fc receptor type I for IgG (FcgammaRI), the low affinity receptor Fc receptor type III for IgG (FcgammaRIII) and the high affinity receptor type I for IgE (IgepsilonRI), showed an impaired inflammatory response in the reverse passive Arthus reaction in skin, peritoneum and lung. These data suggest, that the activation of FgammaRs is the initial event triggering the inflammatory cascade in IC disease. On the other hand, C5aR deficient mice are either protected from tissue injury induced by ICs, as in the lung, or the degree of the inflammatory response is markedly attenuated, as in peritoneum and skin. A detailed analysis of data obtained with the different knock-out strains revealed that both the activation of the complement system as well as the activation of different effector cells via FcgammaRs contribute to the inflammatory sequelae leading to tissue destruction in IC disease. The relative contributions of FcgammaRI or FcgammaRIII and the main effector cells through which these receptors mediate their effector functions are tissue dependent. The activation of the C5a receptor pathway appears to be the prominent contribution of the complement system.

Animals↗