PubMed Health⌕ Search

PubMed · 9597574

Sequential CD34+ and CD4+ cell selection from leukapheresis components.

Abstract

We tested the feasibility of sequential selection of CD34+ and CD4+ cell-enriched fractions from aliquots of five autologous leukapheresis components. CD34+ cells were selected from a median 8.0 x 10(8) mononuclear cells using the CellPro CEPRATE LC cell separation system. All cells in the CD34-depleted fraction (median 4.8 x 10(8), range 0.6-10.0 x 10(8) were then incubated with the appropriate antibodies for CD4+ cell selection and passed through a second LC column. Median target cell purities of the CD34+ cell-enriched fraction and CD4+ cell-enriched fraction were 90.5% and 86.0%, respectively. This study demonstrates that high purity CD34+ and CD4+ cell-enriched fractions can be isolated sequentially from leukapheresis components. In addition, CD8+ lymphocytes, implicated in graft-versus-host disease, were depleted in the course of both positive selection procedures. This approach could decrease the number of donor procedures by providing separate CD34(+)-enriched and CD4(+)-enriched populations for allogeneic peripheral blood progenitor cell transplantation and subsequent donor lymphocyte infusion from the same leukapheresis component.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

I J Webb, M Beach, J F Daley, D M Schott, K C Anderson. 1998. Sequential CD34+ and CD4+ cell selection from leukapheresis components.. https://doi.org/10.1089/scd.1.1998.7.169

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Human dendritic cells express neuronal Eph receptor tyrosine kinases: role of EphA2 in regulating adhesion to fibronectin.

Eph receptor tyrosine kinases and their ligands, the ephrins, have been primarily described in the nervous system for their roles in axon guidance, development, and cell intermingling. Here we address whether Eph receptors may also regulate dendritic cell (DC) trafficking. Reverse transcription-polymerase chain reaction (RT-PCR) analysis showed that DCs derived from CD34+ progenitors, but not from monocytes, expressed several receptors, in particular EphA2, EphA4, EphA7, EphB1, and EphB3 mRNA. EphB3 was specifically expressed by Langerhans cells, and EphA2 and EphA7 were expressed by both Langerhans- and interstitial-type DCs. EphA and EphB protein expression on DCs generated in vitro was confirmed by staining with ephrin-A3-Fc and ephrin-B3-Fc fusion proteins that bind to different Eph members, in particular EphA2 and EphB3. Immunostaining with anti-EphA2 antibodies demonstrated the expression of EphA2 by immature DCs and by skin Langerhans cells isolated ex vivo. Interestingly, ephrin expression was detected in epidermal keratinocytes and also in DCs. Adhesion of CD34+-derived DCs to fibronectin, but not to poly-l-lysine, was increased in the presence of ephrin-A3-Fc, a ligand of EphA2, through a beta1 integrin activation pathway. As such, EphA2/ephrin-A3 interactions may play a role in the localization and network of Langerhans cells in the epithelium and in the regulation of their trafficking.

Antigens, CD34↗

Male DNA in female donor apheresis and CD34-enriched products.

Increased risk of graft-versus-host disease (GVHD) has been described in recipients of hematopoietic stem cell transplantations when the donor is a parous woman. Cells from prior pregnancies are now known to persist in women and could contribute to GVHD. We asked whether male DNA (presumed fetal microchimerism) is present in apheresis products of female donors. A total of 50 samples were studied by using real-time quantitative polymerase chain reaction (PCR) for the Y chromosome-specific sequence DYS14. Among 29 growth factor-mobilized peripheral blood mononuclear cell (G-PBMC) products, 34% were positive for male DNA. Quantitative results, expressed as DNA genome equivalent of male cells per million host cells (gEq/mil), ranged from 0 to 35 gEq/mil. Among 21 CD34-enriched cell fractions, 48% were positive with a range of 0 to 357 gEq/mil. In summary, male DNA was frequently detected in G-PBMC and CD34-enriched products from female donors. Whether fetal microchimerism contributes to GVHD merits further investigation.

Antigens, CD34↗

Proteasome inhibitors induce growth inhibition and apoptosis in myeloma cell lines and in human bone marrow myeloma cells irrespective of chromosome 13 deletion.

PURPOSE: In this study, we investigated the effects of cell-permeable proteasome inhibitors MG-132, MG-262, PSI, and lactacystin on multiple myeloma cell lines OPM-2, U266, RPMI 8226-S, freshly isolated plasma cells with or without deletion of chromosome 13 from patients with multiple myeloma and plasma cell leukemia, and CD34+ human hematopoietic stem cells. The effects of proteasome inhibitors on cell cycle progression, cell growth, and apoptosis were determined. METHODS: MTT-assay was used to examine the cytotoxicity, and annexin-V staining to quantify apoptosis. Cell cycle analyses were performed using 7-ADD and Ki-67 staining by flow cytometry. RESULTS: PSI was the most potent proteasome inhibitor among those tested with a half maximal cytotoxicity (IC(50)) of 5.7 nM, followed by MG-262, MG-132, and lactacystin. Growth inhibition occurred irrespective of chromosome 13 status. Cell cycle arrest occurred in a dose- and time-dependent manner. Low, subapoptotic dosages led to a partial loss of Ki-67 antigen, whereas apoptotic dosages led to reduced Ki-67 levels. Apoptosis was partially dependent on activation of caspase-3, since Ac-DEVD-cho, a caspase-3 inhibitor, could reduce apoptosis significantly. The cytotoxicity of the four proteasome inhibitors tested was significantly lower in human hematopoietic stem cells than in myeloma cells. CONCLUSIONS: Our results show that proteasome inhibitors induce time- and dose-dependent cell cycle alterations, growth inhibition, and apoptosis in human myeloma cells irrespective of chromosome 13 deletion.

Antigens, CD34↗