Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.32 (bromelain)
 1,025 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The mechanism of polyclonal B cell activation in autoimmune diseases was investigated by using an autoreactive B cell clone established by somatic hybridization with B cells derived from NZB X NZW (B/W) F1 mice. Briefly, splenic B cells from B/W F1 mice were fused with M12.4.1, a mutant of a B cell line, in the presence of polyethylene glycol and DMSO. NW47.7, a subclone of a resulting hybridoma, expresses B cell surface antigens on the cell membrane, namely IAd, IgM, B220, the receptors for the C3 fragment of complement (C3R), and the Fc portion of IgG (Fc gamma R). It also possesses a receptor molecule for mouse red blood cells treated with bromelain (Br-MRBC) on its surface, by rosette-forming assay with Br-MRBC. In contrast, parental M12.4.1 does not express IAd and IgM on the cell membrane, and does not bind to Br-MRBC under the same conditions. Thus, it is likely that NW47.7 may be an autoreactive B cell clone specific for Br-MRBC. Interestingly, NW47.7 was induced to generate a significant number of IgM-secreting cells when treated with Br-MRBC and rIL-5. Furthermore, mAb against IAd molecules, but not IAk and KdDd, markedly inhibited the differentiative effect of polyclonal activators such as LPS and rIL-5. Also, when MHC identical irradiated B cells were added to the culture of NW47.7 as a stimulator, the induction of IgM-producing cells was greatly augmented, but this augmenting effect was lost by interfering with direct contact of NW47.7 cells with stimulator B cells using a semipermeable membrane, as well as by the addition of mAb against IAd molecules. In addition, irradiated NW47.7, but not M12.4.1, by itself could enhance the secretion of IgM by NW47.7 as a stimulator, but this enhancing effect markedly decreased in the presence of anti-IAd mAb. The present results suggest that surface IA molecules on B cells are involved during the differentiative response to polyclonal activators, and may directly provide a differentiative signal for maturation of B cells into IgM-secreting cells.
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PMID:Functional role of self IA molecules in polyclonal B cell activation using an autoreactive B cell clone derived from (NZB X NZW) F1 mice. 173 10

Splenic lymphocytes from BALB/c mice immunized with "cores" of influenza virus, obtained after bromelain cleavage of the surface glycoprotein, were fused with the P3-NS1/1-Ag-1 mouse cell line to yield hybridoma cultures. Among 20 stable cloned hybrid cells secreting monoclonal antibodies, one was specific for the nucleoprotein (NP), 11 were specific for the membrane (M) protein and eight were specific for the hemagglutinin (HA). These "cores" used as immunogen contained only the internal proteins of the influenza virus, namely the three polymerases, the NP and the M protein and no HA when examined by standard procedures of SDS-PAGE, electron microscopy and hemagglutination activity. It thus appeared that a small amount of contaminating antigens can sensitize a sufficient number of mouse B cells to be selected as hybrid partners. These antibodies were provisionally assigned as anti-carbohydrate attached to the HA.
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PMID:Hybridoma antibodies produced against bromelain derived cores of influenza virus. 240 34

Splenic B cells of BALB/c mice were fused with 2.52M, a mutant of a B cell line, in the presence of polyethylene glycol and dimethyl sulfoxide. AT73.14 a subclone of a resulting hybridoma, expresses B cell surface antigens on the cell membrane, namely IAd, IgM, B220, and receptors for C3 fragment of complement (C3R), the Fc portion of IgG (Fc gamma R), and interleukin 2 (IL-2R). It also possesses a receptor molecule for mouse red blood cells treated with bromelain (Br-MRBC) on its surface, by rosette-forming assay with Br-MRBC. In contrast, parental 2.52M does not express IAd on the cell membrane and does not bind to Br-MRBC on the same conditions. Thus, it is likely that AT73.14 may be an autoreactive B cell clone specific for Br-MRBC. Interestingly, AT73.14 could generate a significant number of IgM-secreting cells when treated with Br-MRBC; this was followed by a marked decrease in the expression of B cell surface markers on the cell membrane. In addition, this differentiative response of the cells greatly augmented in the presence of B151-TRF, a B cell differentiation factor, although B151-TRF alone showed only a marginal effect on the generation of IgM-secreting cells. The result suggests that this kind of an autoreactive B cell clone may provide a good model for the study on the mechanism of autoimmune responses.
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PMID:Establishment of a bromelain-treated isologous red blood cell reactive B cell clone by somatic hybridization. 278 47

Spleen and peritoneal cells from unimmunized BALB/c mice were cultured in the presence of LPS for 24 hr and fused to produce hybridomas secreting antibodies against bromelain-treated mouse erythrocytes (BrMRBC). Three clones from spleen cells and eight clones from peritoneal cells were isolated and characterized further. All the monoclonal antibodies had IgMK isotype. Their reactivities against untreated and bromelain-treated erythrocytes from various species were assessed by hemolysis and indirect radioimmunoassay; all the clones had similar antigen specificities. On the isoelectric focussing patterns of light chains, they were separated into two groups, two and nine clones, and all the light chains in each group showed identical patterns. The two groups shared no common idiotope detectable by anti-idiotype antibodies prepared by immunization of rabbits with the monoclonal antibodies, but all the antibodies in each group shared common idiotopes. In each group, one antibody had a unique idiotope different from any other antibody, but eight antibodies in a group shared another identical idiotope. These findings suggest the restricted heterogeneity of anti-BrMRBC antibodies in the mouse.
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PMID:Mouse monoclonal antibodies against bromelain-treated mouse erythrocytes: reactivity with erythrocytes of various species of animals and idiotypes. 310 56