globotriaosylceramide and Lymphoma--B-Cell

Post-transplant lymphoproliferative disease (PTLD) is an invasive, EBV expressing B lymphoma and a major cause of morbidity and mortality following organ transplantation. Presently there is limited therapy available; rather the patient often loses the allograft or succumbs to the malignancy. CD77 (or globotriaosyl ceramide -Gb(3)) is a germinal center B cell marker [Gregory et al. Int J Cancer 1998;42:213-20; Gregory et al., J Immunol 1987;139:313-8; Mangeney et al. Eur J Immunol 1991;21:1131-40], expressed on most EBV infected B cells and is the receptor for the E. coli derived verotoxin (VT) [Lingwood CA. Advances in Lipid Research 1993;25:189-212]. We present the basis of a possible novel approach to PTLD therapy utilizing the specific targeting of VT to the infiltrating lymphoma cells. Biopsies of adenoid, kidney or liver tissue of four PTLD patients were stained with verotoxin to determine expression of CD77. VT is a potent inducer of necrosis/apoptosis of receptor positive cells. In each PTLD case, the infiltrating EBV positive B lymphoma cells were strongly and selectively stained with VT, identifying CD77 as a new marker for these cells. For such individuals, VT might provide the basis of an approach to control their malignancy.

Topics: Adolescent; Biopsy; Child; Epstein-Barr Virus Infections; Female; Humans; Infant; Lymphoma, B-Cell; Male; Organ Transplantation; Postoperative Complications; Shiga Toxins; Transfection; Trihexosylceramides

The ribosome-inactivating protein, Shiga-like toxin-1 (SLT-1), targets cells that express the glycolipid globotriaosylceramide (CD77) on their surface. CD77 and/or SLT-1 binding was detected by flow cytometry and immunocytochemistry on lymphoma and breast cancer cells recovered from biopsies of primary human cancers as well as on B cells or plasma cells present in blood/bone marrow samples of multiple myeloma patients. Breast cancer cell lines also expressed receptors for the toxin and were sensitive to SLT-1. Treatment of primary B lymphoma, B-cell chronic lymphocytic leukemia, and myeloma B or plasma cells with SLT-1-depleted malignant B cells by 3- to 28-fold, as measured by flow cytometry. Depletion of myeloma plasma cells was confirmed using a cellular limiting dilution assay followed by reverse transcriptase-polymerase chain reaction analysis of clonotypic IgH transcripts, which showed a greater than 3 log reduction in clonotypic myeloma cells after SLT-1 treatment. Receptors for the toxin were not detected on human CD34(+) hematopoietic progenitor cells (HPC). HPC were pretreated with a concentration of SLT-1 known to purge primary malignant B cells and cultured for 6 days. The number of HPC was comparable in toxin-treated and untreated cultures. HPC were functionally intact as well. Colony-forming units (CFU) were present at an identical frequency in untreated and SLT-1 pretreated cultures, confirming that CFU escape SLT-1 toxicity. The results suggest the ex vivo use of SLT-1 in purging SLT-1 receptor-expressing malignant cells from autologous stem cell grafts of breast cancer, lymphoma, and myeloma patients.

Topics: Antibodies, Monoclonal; B-Lymphocytes; Bacterial Toxins; Biomarkers; Biomarkers, Tumor; Blood Cells; Bone Marrow Cells; Bone Marrow Purging; Breast Neoplasms; Carcinoma; Cell Separation; Cells, Cultured; Colony-Forming Units Assay; Female; Flow Cytometry; Genes, Immunoglobulin; Glycolipids; Hematopoietic Stem Cell Transplantation; Hematopoietic Stem Cells; Humans; Immunoglobulin Heavy Chains; Lymphoma, B-Cell; Lymphoma, Follicular; Male; Multiple Myeloma; Neoplasm Proteins; Neoplastic Stem Cells; Organ Specificity; Plasma Cells; Receptors, Cell Surface; Reverse Transcriptase Polymerase Chain Reaction; Shiga Toxin 1; Transplantation, Autologous; Trihexosylceramides; Tumor Cells, Cultured; Tumor Stem Cell Assay