Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: EC:3.4.22.6 (chymopapain)
 407 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Selection of CD34+ hematopoietic progenitor cells from autografts may be performed in multiple myeloma (MM) to minimize contamination with tumor cells. This approach is based on the assumption that the malignant cells do not express the CD34 antigen. Therefore, we first compared the CD34+/CD10+ and CD34+/CD19+ subpopulations from bone marrow (BM) and peripheral blood (PB) of fourteen MM patients and five normal controls. No difference between the respective early B cell subsets of both groups could be observed. Using tricolor flow cytometry, the CD19 expression on CD34+/CD10+ cells in BM was found to increase continuously from CD19- to CD19dim. In contrast, circulating CD34+/CD10+ cells did not coexpress the CD19 antigen. This population may contain myeloid progenitor cells or bipotential progenitor cells of the myeloid and lymphoid lineage as suggested by data obtained with fetal liver cells. Further functional studies are required. Enrichment of CD34+ cells with immunomagnetic beads was performed from BM of three MM patients and four normal donors. The CD34+ cells were selected with the HPCA-1 antibody and detached from the beads with chymopapain. Compared with the starting cell preparation, a 3.97 +/- 0.48 log (mean +/- SE) reduction of plasma cells could be achieved after CD34 selection. On morphological examination, 84% +/- 4% of the cells in the CD34+ fraction (MM) were immature blasts. The plating efficiency for hematopoietic colony forming cells was 9.7% +/- 2.8% in the CD34 selected fraction of the MM group, reflecting a 51-fold increase as compared with the starting population.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:CD34 selection for purging in multiple myeloma and analysis of CD34+ B cell precursors. 751 57

A hollow-fibre immunoadsorption system has been developed for the purification of CD34+ cells from mononuclear cells. This cell separation technique is based on the use of uniform surface fluid shear stress to fractionate cells that attach to the inside surface of hollow fibres. Monoclonal antibody to the CD34 antigen was covalently coupled to the lumenal surface of cuprophan minidialysers (surface area 220 cm2). After the selective adsorption of CD34+ cells (28 min), a depleted fraction was collected at 5 dynes/cm2 followed by washes at 10 and 25 dynes/cm2. Antigen-positive cells were recovered after incubation with chymopapain. The device was tested by using peripheral blood mononuclear cells from seven patients who had received granulocyte colony-stimulating factor and chemotherapy. The average number of cells processed was 1.3 +/- 0.2 x 10(8) (+/- S.E.M.), and the preselection incidence of CD34+ cells ws 1.6 +/- 0.6% (range 0.21-4.13%; n = 7). The enrichment purity was 94.4 +/- 3.1%, and 61 +/- 9% of input CD34+ cells were recovered in the enriched fraction (n = 4). Enrichment resulted in a 3.3 +/- 0.1% log10 depletion of CD34- cells (n = 4). Hollow-fibre affinity cell separation has potential as a medium to large-scale cell enrichment technology.
 ...
PMID:Hollow-fibre affinity cell separation system for CD34+ cell enrichment. 886 18

A peptide sequence was identified by phage display technology that could be used as an alternative to chymopapain for the release of hematopoietic progenitor cells captured by anti-CD34 monoclonal antibodies. This was achieved by affinity selection screening (biopanning) of a random hexapeptide sequence phage display library. Four rounds of biopanning were performed to enrich for phage clones with specific affinity for anti-CD34 monoclonal antibody, 9C5. DNA sequence analyses of these phage clones revealed an enrichment of two predominant sequences, QQGWFP and TQGSFW. These two clones also shared a consensus sequence motif, QGxF, that exhibited 50% and 67% homology with a region spanning amino acids 14-19 of the mature CD34 antigen. Based on these data, synthetic peptides were generated and assessed for their ability to release 9C5 from CD34+ cells. Using a flow cytometric assay, it was found that the synthetic peptide, 9069N, effectively released 9C5 from the CD34-expressing cell line, KG1a, in a concentration-dependent manner (77% and 99% release of 9C5 at 0.14 and 0.70 mM peptide concentrations, respectively). In the Isolex 300i immunomagnetic selection system, this peptide was shown to be effective at releasing 9C5 sensitized CD34+ hematopoietic progenitors from sheep anti-mouse IgG Dynabeads. Thus, a synthetic peptide, which specifically and efficiently released immunomagnetically selected hematopoietic progenitor cells from paramagnetic beads, was identified. This reagent is a significant advance in the selection of hematopoietic progenitors in that it does not alter cell surface antigens. As such, further phenotypic characterization or immunoselection can be performed.
 ...
PMID:Identification of a peptide directed against the anti-CD34 antibody, 9C5, by phage display and its use in hematopoietic stem cell selection. 1034 Apr 10