Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0153470 (Spleen)
 4,015 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Spleen cell populations depleted of both B and T lymphocytes produce interleukin 4 (IL-4) in response to stimulation with immunoglobulins bound to the surface of culture dishes. In the presence of interleukin 3 (IL-3), plate-bound (PB) IgE and PB-IgG1, IgG2a, and IgG2b are excellent stimulants, whereas PB-IgA and PB-IgM fail to stimulate IL-4 production. In the absence of IL-3, PB-IgE stimulates relatively modest production of IL-4, whereas PB-IgG2a generally does not. The response to PB-IgE is inhibited by soluble IgE; antibody to Fc gamma receptor II inhibits the response to PB-IgG2a. Thus, separate receptors mediate these stimulations, and Fc receptor cross-linkage is required for IL-4 production. Depletion of cells expressing asialo-GM1 does not diminish IL-4 production in response to PB immunoglobulins, indicating that natural killer cells are not essential for non-B, non-T cell production of IL-4. In addition to IL-4, non-B, non-T cells produce IL-3, but no detectable interleukin 2 or interferon gamma. Non-B, non-T cells may be an important source of lymphokines in a variety of immune responses and may serve to amplify the effects of T cells of the TH2 type.
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PMID:Cross-linking Fc receptors stimulate splenic non-B, non-T cells to secrete interleukin 4 and other lymphokines. 210 35

The ability of IL-4 to influence the developmental expression of the murine B cell IgE Fc receptor (Fc epsilon R) was examined. Spleen cells from neonatal mice of increasing age were incubated overnight with IL-4 and subsequently examined with multicolor flow cytometry. The results demonstrate that IL-4 can significantly increase the number of maturing B cells which express the Fc epsilon R. This effect was only seen however, on those neonatal B cells which already displayed surface IgD. Splenic B cells which were IgM+, IgD- failed to express the Fc epsilon R when treated with IL-4, even though they responded by increasing their level of class II Ag expression. Further experiments showed that the inability of IgD- immature B cells to express the Fc epsilon R could not be entirely explained by their assignment to the Ly-1 lineage. Taken together, these results indicate that IL-4 can accelerate the developmental expression of the B cell Fc epsilon R, but only on those B cells that are mature enough to express IgD.
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PMID:Expression of B cell surface receptors. II. IL-4 can accelerate the developmental expression of the murine B cell IgE Fc receptor. 253 Feb 79

A new class of synthetic biological response modifiers (BRMs) has been produced by combining a highly electrophilic reactant, 2-methyl-2, 5-dihydrofuran (a cyclic acetal of cis-3-acetyl acrolein), with L-ascorbic acid. The parent class of compounds can be referred to as methylfurylbutyrolactones (MFBL), previously termed Nafocare B. This parent molecule is amorphous, has a molecular weight of 252.7, and the chemical name [3,6] cyclohemiketal of 2-(5-methyl-2-furyl)-3-keto-L-butyrolactone. Two crystalline forms were produced by a reaction of the MFBL parent molecule with either succinic anhydride or succinimide, to create MFBL-SA (Nafocare B2) and MFBL-S (Nafocare B3) dimers, respectively. The structure of these compounds has been confirmed by modern methods of analytical chemistry, including x-ray crystallography. All three forms of the MFBLs showed negligible toxicity in single-dose acute LD-50s in mice. Also, the MFBLs did not demonstrate genotoxic activity at 800 mg/kg in the mouse micronucleus assay. The MFBLs are immunostimulatory in assays involving T- and B-lymphocytes, but not in immunoassays on macrophages derived from resident- or thioglycollate-elicited peritoneal exudate cells (PEC). Spleen cells from mice treated 4 days via the intraperitoneal, intravenous, or the oral routes responded significantly over controls to suboptimal stimulatory concentrations of polyclonal mitogens in the lymphocyte stimulation assay. The MFBLs were not mitogenic, since they did not increase DNA synthesis in resting spleen cells from MFBL-treated mice. Antibody production is also amplified by the MFBLs. Mice immunized with sheep erythrocytes, a T-cell-dependent antigen, and treated with MFBLs had a 200-800% increase in the numbers of antibody-producing splenic lymphocytes detected by the Jerne hemolytic plaque assay. Also, mice immunized with soluble bovine serum albumin (BSA), and treated with a MFBL, demonstrated at least a fourfold increase in IgG-specific antibodies to BSA, when compared with controls. To demonstrate effects of MFBLs on macrophages, we used the Fc receptor (FcR) surface marker and superoxide anion assays. Only at the highest in vitro dose of MFBL (16 micrograms/ml) was a significant increase in erythrocyte antibody rosette formation detected, using resident macrophages isolated from PEC. In the superoxide anion release assay neither resident- nor thioglycollate-elicited PECs, obtained from in vivo-treated mice or macrophages treated in vitro, showed increased production of superoxide anion.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:A new class of synthetic biological response modifiers: the methylfurylbutyrolactones (Nafocare B). 302 12

Spleen cells obtained from C57BL/6 (B6) mice with an experimental autoimmune hepatitis were transferred to normal C57BL/6 recipient mice. Most prominent liver damages occurred in the recipient mice injected with sensitized nylon wool column-adherent spleen cells from the donor mice. Production of such liver damage was blocked by treatment of the sensitized adherent spleen cells with anti-Thy 1,2 monoclonal antibody and complement before injection. Based on these in vivo results, a microcytotoxicity assay was performed using isolated C57BL/6 hepatocytes as target cells and sensitized spleen cells obtained from hepatitis donor mice as effector cells. The fraction of sensitized nylon wool-adherent spleen cells demonstrated a high cytotoxic activity against isolated syngeneic hepatocytes, although the other fractions and spleen cells of control animals showed no such effect. The cytotoxic activity of sensitized-adherent spleen cells against target hepatocytes was significantly reduced after treatment with anti-Thy 1,2 antibody and complement, but it increased after depletion of B cells and Fc receptor-bearing T-cells. Although these sensitized nylon wool-adherent spleen cells showed high cytotoxic activities against syngeneic hepatocytes, their cytotoxicity against allogeneic hepatocytes was lower. They exerted no cytotoxic activity against syngeneic renal glomerular cells and EL-4 thymoma cells. These results suggest that sensitized T-cells in the nylon wool column-adherent fraction play the role of cytotoxic killer cells against target liver cells in vitro.
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PMID:Cell-mediated cytotoxicity of sensitized spleen cells against target liver cells--in vivo and in vitro study with a mouse model of experimental autoimmune hepatitis. 402 89

Spleen effector cells for IgG- and IgM-induced antibody-dependent cellular cytotoxicity (ADCC) were characterized with respect to density and cell surface markers by using sheep erythrocytes (SRBC) coated with hybridoma-derived monoclonal anti-SRBC IgG or anti-SRBC IgM antibodies as targets. While basically the same effector cells are cytolytic for IgG and IgM antibody-coated SRBC, they differ with respect to their relative killing capacity for IgG- versus IgM-coated target cells. On the basis of physical and biochemical properties three populations with cytolytic capacity could be separated: (I) A light fraction of large cells had high cytolytic potential for both IgG- and IgM-coated SRBC. The cells were negative for the Fc receptor for IgG (Fc gamma-R-) and the C3-receptor (C3-R-), they carried the receptor for Helix pomatia A agglutinin (HP-A+), and reactivity was strongly reduced after treatment with anti-Thy-1 and complement (C). (II) High activity was also observed with a medium-dense fraction, preferably lysing IgG antibody-coated cells. The cells were Fc gamma-R+, partly C3-R+, mostly HP-A-, and only a minor portion of the cells were Thy-1+. (III) A dense fraction, displaying on a per cell basis low cytolytic potential, was more active in IgM than IgG ADCC. The cells were Fc gamma-R+, HP-A+ and Thy-1+. All three effector cell populations were non-adherent, non-phagocytic, and surface immunoglobulin-negative (s-Ig-).
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PMID:Characterization of effector cells mediating IgG and IgM antibody-dependent cellular cytotoxicity. 660 20

Spleen cells from 8-week-old, nonimmunized donor chickens can transfer resistance to a supralethal dose of the JMV leukemia line of Marek's disease (MD) to newly hatched, highly susceptible, histocompatible recipients. The population of cells transferring resistance has previously been shown to be non-T, non-B, and nonmacrophage in nature. We present data here showing that heavily x-irradiated spleen cells were unable to protect recipients from leukemia challenge. Both complement receptor-bearing and -lacking cells could confer resistance to newly hatched recipients. Fc receptor-bearing cells conferred significant protection to recipients, whereas spleen cells depleted of Fc receptor-bearing cells were unable to protect chickens from death after JMV challenge. This indicates that the population of spleen cells, which is moderately radiosensitive and which possesses Fc receptors, is responsible for the transfer of natural resistance to the malignancy in vivo.
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PMID:Transfer of natural resistance to Marek's disease (JMV) with nonimmune spleen cells. II. Further characterization of protecting cell population. 739 77

A novel conserved member of the leukocyte Fc receptor (FcR) family was identified in human and mouse. The presumably secreted protein, designated FCRL (FcR-like) is comprised of four domains. The three N-terminal domains are related to the extracellular region of FcgammaRI, with the second (35-37% residue identity) and the third (46-52%) domains showing highest similarity. The C-terminal domain is a unique sequence enriched with proline residues. In humans, alternative transcripts for six FCRL isoforms were revealed. Spleen and tonsils were found to be the major sources of FCRL mRNA in human tissues. Western blotting of tonsil cell lysate using FCRL-specific antibodies recognized a 44-kDa protein produced as a monomer containing free sulfhydryl groups. The monomer, however, was able to form disulfide-linked homo-oligomer upon oxidation. In COS-7 cells transiently transfected with two human FCRL isoforms, both resided intracellularly. Immunohistochemical staining of tonsil sections demonstrated the FCRL expression in germinal centers, suggesting that the protein may be implicated in germinal center-specific stages of B cell development. The phylogenetic analysis of the FCRL relationships with the leukocyte FcR supports a view that the three-domain structure was primordial in the evolution of the family.
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PMID:FCRL, a novel member of the leukocyte Fc receptor family possesses unique structural features. 1175 7