Search PubMed⌕ Search

Biomedical subjects

J Wiels

Publications and source records attributed to J Wiels.

45 records · Page 3Linked to original sources

A monoclonal antibody with anti-Burkitt lymphoma specificity. I. Analysis of human haematopoietic and lymphoid cell lines.

38-13 is a hybridoma-produced monoclonal rat IgM which appears to define a Burkitt's lymphoma-associated antigen (BLA). In this paper, we described the reactivity of 38-13 with a panel of human haematopoietic and lymphoid cell lines. In indirect immunofluorescence (IF) assays, 15 of 26 Burkitt's lymphoma (BL) lines studied were clearly stained with 38-13 (from 13 to 100% positive cells) by microscope, with varying numbers of heavily labelled cells. In these positive cell lines, fluorescence-activated cell-sorter (FACS) analysis demonstrated that BLA was actually present on all the cells. Positive BL included Epstein-Barr virus (EBV) genome-carrying lines and EBV-negative ones; thus, BLA is not related to the presence of EBV. Most of the 15 BL cells that reacted with 38-13 contained a typical t(8;14) translocation, but had variant translocations such as t(2;8) and t(8;22). The cells were derived from BL patients of different geographical origins and clinical features. Four BL lines were poorly stained and seven were negative with 38-13 in IF assays. The 32 EBV-positive lymphoblastoid cell-lines (LCL) studied were negative. In three line pairs, consisting of a tumor line and an LCL from the same patient, only the BL line was demonstrated to react with 38-13. A series of non-BL cells, including haematopoietic, lymphoid and solid tumor lines, all failed to react with 38-13. Various attempts to modulate the expression of BLA on BL cells were unsuccessful. However, it cannot be ruled out that BLA is actually a transient B-cell differentiation marker.

Animals↗

Monoclonal antibody defining a Burkitt's lymphoma-associated antigen detects carbohydrate on neutral glycolipid.

Monoclonal antibody 38.13 detects an epitope presented on Burkitt's lymphoma cells that has not been detected on other lymphoid tissues or tumors. The biochemical nature of this Burkitt's lymphoma-associated antigen was investigated by staining inhibition assays. Indirect immunofluorescence and fluorescence-activated cell sorter analysis show that antibody 38.13 reacts with a protease-resistant structure present among the hydrophobic components extracted with chloroform-methanol from the Ramos Burkitt's cell line. These components were further separated by ion-exchange chromatography and activity resides in the unbound (neutral) fraction. The staining antibody is specifically absorbed when preincubated with D-galactose, and to a lesser extent with N-acetyl-galactosamine. Therefore, 38.13 appears to recognize a determinant of carbohydrate nature, which is carried on a neutral glycolipid.

Absorption↗

Monoclonal antibody against a Burkitt lymphoma-associated antigen.

A monoclonal antibody, referred to as 38.13, was obtained by fusing murine myeloma cells with Lewis rat splenocytes sensitized with Daudi cells (human Burkitt lymphoma containing Epstein--Barr virus genome but lacking HLA-A, -B, and -C and beta 2-microglobulin molecules at the cell surface). 38.13 antibody was demonstrated to be a rat IgM. By complement-dependent microcytotoxicity and indirect immunofluorescence assays, 38.13 antibody was shown to react specifically with cells derived from Burkitt tumors, including both Epstein--Barr virus genome-carrying and Epstein--Barr virus-negative Burkitt lymphoma. By contrast, Epstein--Barr virus-containing lymphoblastoid cell lines derived from normal B lymphocytes were not recognized by 38.13 antibody. Fresh malignant cells from patients affected with various lymphoproliferative disorders were negative, except 4/8 having abdominal Burkitt-like lymphomas. Normal lymphocytes from peripheral blood, spleen, lymph node, tonsil, and bone marrow and mitogen (phytohemagglutinin, pokeweed mitogen, and concanavalin A)-activated blasts were also negative. Thus, 38.13 antibody apparently recognized a Burkitt-associated antigen that is not related to Epstein--Barr virus. The pattern of reactivity of 38.13 antibody with various Burkitt lymphoma cells appeared quite heterogenous and some Burkitt cells were consistently negative. 38.13 antibody thus defines a subset of Burkitt lymphomas.

Animals↗

Natural killer cell activity in human bone marrow recipients: early reappearance of peripheral natural killer activity in graft-versus-host disease.

Natural killer (NK) cell activity toward K562 target cells and antibody-dependent cell-mediated cytotoxicity (ADCC) toward L1210 cell sensitized with anti-L1210 antisera were sequentially tested in peripheral blood lymphocytes (PBLs) from 24 human bone marrow (BM) recipients. Although consistently decreased before the transplant, NK cell activity was restored in all of the patients tested that argues for a bone marrow origin of NK progenitors in humans. In patients without graft-versus-host disease (GVHD), peripheral NK cell activity remained low during the 1st month after the transplant, then rapidly increased and reached normal values usually between days 30 and 50. By contrast, peripheral ADCC appeared earlier restored (since day 13), suggesting that NK and ADCC are two distinct effector mechanisms. When restored, peripheral NK cell activity remained within normal range, except in seven cases with a drastic fall in NK cell values contemporary with a severe viral infection, mainly with cytomegalovirus (CMV). NK cells are thus suggested to play an important role in the control of viral infections in these deeply immunodepressed patients. In patients with acute GVHD, strikingly high NK values were observed early after the transplant, and during the 1st month a strong correlation did exist between high NK values and acute GVHD occurrence. These results suggest that cells involved in GVHD mechanism are able to exert NK cell activity at some stages of their maturation. The assessment of NK cell activity could be an attractive routine procedure for monitoring the prophylaxis of GVHD in human BM recipients.

Antibody-Dependent Cell Cytotoxicity↗

Functional study and detection of HLA-D products on fractionated human bone marrow cells.

Bone marrow cells from nine normal human volunteers obtained from the Iliac crest, were used in this work for antigen determination and functional studies. The bone marrow aspirated cells were sequentially separated: elimination of erythrocyte, granulocytes and monocytes achieved by Ficoll-Isopaque centrifugation followed by plastic adherence. Purified bone marrow cells were finally separated by size using velocity sedimentation. The slow sedimenting small cells were shown to be mainly T lymphocytes, probably of blood origin. The medium sized bone marrow cells were shown to contain myeloid precursors (CFu-c). Large immature cells were in cycle actively synthesizing DNA molecules. HLA-D and HLA-DR detections on the fractionated cells were performed using three techniques: fluorescence with specific anti HLA-DR allo and xeno antisera; primed lymphocyte typing (PLT) with anti HLA-DR monospecific in vitro primed lymphocytes and detection of the HLA-D stimulating product using the bone marrow fractionated cells as stimulators in a mixed leukocyte culture. Concordant results were obtained with the three techniques. Lymphocytes in the bone marrow express HLA-D products a peripheral lymphocytes. Bone marrow fractions depleted of lymphocytes and monocytes also contain approximately 20% of cells expressing HLA-D products The meaning of the expression of HLA-D products on immature precursors non-lymphoid cells is discussed.

Bone Marrow Cells↗

Association of the H-Y male antigen with beta2-microglobulin on human lymphoid and differentiated mouse teratocarcinoma cell lines.

The expression of the H-Y antigen has been tested on several human lymphoid lines and mouse teratocarcinoma cell lines during differentiation. The human male lymphoid cell line Raji is a very useful target for studies of the H-Y antigen by lymphocytotoxicity test with rat anti-H-Y sera. With a few exceptions, all cells carrying the Y chromosome were H-Y positive. One of the exceptions is the human Daudi cell line which, besides lacking H-Y antigen, also lacks beta2-microglobulin. We have studied a possible association between the H-Y antigen, beta2-microglobulin, and HLA antigen with redistribution experiments. The results strongly suggest that H-Y antigen is not associated with HLA antigens but with beta2-microglobulin.

Animals↗

Presence of SLA and Ia-like antigen on boar spermatozoa.

Several parameters for serological tests on boar spermatozoa were studied, and a reliable technique was developed and employed. Using SLA (the MHC system in pig) genotyped boars, and specific reagents, SLA and Ia-like antigens were demonstrated on the sperm using both the cytotoxic and the absorption test. No SLA activity was detected in the seminal fluid.

Animals↗

The expression and relation of HLA, beta2-microglobulin and receptor for marmoset red blood cells on man/mouse and man/Chinese hamster hybrid cells.

The expression of HLA, human and mouse beta2-microglobulin (beta2m), P red blood cell antigen and a receptor for marmoset red blood cells (MaRBC) were studied on 18 man/mouse and man/Chinese hamster hybrids. A positive correlation was found between the expression of HLA, P, and the receptor for MaRBC, which we interpret as a possible synteny between these different loci. We studied 3 hybrid clones where HLA antigens are still expressed despite the absence of human beta2m and where redistribution experiments demonstrate that HLA is associated with mouse beta2m. Synteny between HLA and the receptor for MaRBC can be a useful tool to select HLA-positive hybrid clones.

Animals↗

CD77.

Explore the source record for details and available documents.

Animals↗