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)

Treatment of T cells with the cysteine protease bromelain has been widely used to enhance the binding of human T cells to human E (autologous E rosettes) and has been shown to remove surface T cell CD44 molecules. Ligand binding to CD44 has been shown to markedly augment T cell activation. To study the activation potential of bromelain-treated CD44 T cells, we have compared the proliferation of sham- and bromelain-treated normal human PBMC to mitogenic CD2 mAb. We found that bromelain not only removed T cell CD44, but also removed the CD45RA isoform of CD45 as well as E2/MIC2, CD6, CD7, CD8, and Leu 8/LAM1 molecules. T cell proliferation in response to CD2 mAb was increased 325% in bromelain-treated PBMC compared to sham-treated PBMC (p < 0.005). Reciprocal treatment experiments using purified T cells and monocytes demonstrated that the enhancement of T cell CD2 activation by bromelain occurred only when T cells were treated with bromelain and was accompanied by increased adhesion of T cells to monocytes. These data demonstrate that expression of portions of the extracellular domains of the CD44, CD45RA, E2/MIC2, CD6, CD7, CD8, and Leu 8/LAM1 surface molecules are not required for CD2 activation of human T cells. Rather, the removal of these surface molecules by bromelain is associated with enhanced T cell-monocyte aggregation and enhanced CD2-mediated T cell activation. Taken together with data that CD44, E2/MIC2, CD6, and CD7 mAb inhibit CD2/lymphocyte function-associated Ag-3-mediated cellular interactions and also augment CD2-mediated triggering of T cells, these data suggest that members of the bromelain-sensitive group of surface molecules may comprise a set of CD2-associated adhesion ligands that acts in concert to modulate human T cell activation.
 ...
PMID:Bromelain treatment of human T cells removes CD44, CD45RA, E2/MIC2, CD6, CD7, CD8, and Leu 8/LAM1 surface molecules and markedly enhances CD2-mediated T cell activation. 128 Nov 88

Rat monoclonal antibodies (mAb) against isolated pig Null T cells were derived using a novel two-colour cytofluorometric assay. One (MAC320) identified all blood CD2-sIg- 'Null' cells (present at up to approximately 6 x 10(6)/ml). Another type (MAC319 and MAC318) identified a subset comprising approximately 60% or approximately 30% of the Null cell population. This percentage appears genetically determined. This subset partially overlapped with a gamma delta T-cell receptor+ (TcR+) population which consisted of approximately 40% of Null T cells. The antibodies did not react with other leucocyte or lymphocyte populations. In non-reducing conditions, MAC320 precipitated two molecules at approximately 270,000-280,000 MW in SDS-PAGE; the larger of which was also precipitated by MAC319 (and MAC318, which binds to the same epitope). Under reducing conditions, MAC320 immunoprecipitated two or three polypeptide chains at approximately 130,000-160,000 MW; MAC319 precipitated only the largest of these polypeptides. The large MAC319+ MAC320+ molecule on one subset is removed by bromelain treatment; the smaller MAC319- MAC320+ molecule on the remaining Null cells is not bromelain sensitive. Several properties of this new antigen complex specific to pig Null T cells show that it is distinct from the ruminant T19 complex.
 ...
PMID:Subsets of null and gamma delta T-cell receptor+ T lymphocytes in the blood of young pigs identified by specific monoclonal antibodies. 135 15