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Biomedical subjects

H Zola

Publications and source records attributed to H Zola.

At least 109 records · Page 6Linked to original sources
PubMed1989

The p24 leucocyte membrane antigen: modulation associated with lymphocyte activation and differentiation.

Monoclonal antibodies of the CD9 cluster recognize a 24 kD protein (p24) found on platelets and endothelium, and expressed by lymphocytes at restricted stages of maturation and activation. In this study, we explore the possibility that p24 is involved in the response of lymphocytes to signals delivered by lymphokines. p24 is expressed only very weakly by resting B lymphocytes. We found no increase in expression when cells were activated with anti-immunoglobulin together with interleukin-4, or induced to proliferate by low-molecular weight B cell growth factor (LMW-BCGF). Culture of activated B cells with B cell differentiation factor was associated with an increased mean expression of p24. In cells from a patient with chronic lymphocytic leukaemia (CLL), culture with LMW-BCGF up-regulated p24 expression. Resting T cells (p24-negative) were induced to express p24 strongly when activated with antibody against CD3. CD9 antibody did not modulate B or T cell responses to activation stimuli. The results suggest that the p24 molecule is not involved in the primary interaction of cells with lymphokine, but rather may be involved in a secondary reaction, such as ion flux, which follows as a consequence of the action of lymphokines on cells.

Antigens, CD↗
PubMed1989

Effect of recombinant human tumour necrosis factor beta (TNF beta) on activation, proliferation and differentiation of human B lymphocytes.

Activation, proliferation and differentiation of B lymphocytes are processes controlled by T cells, and the control is mediated in part by the action of lymphokines derived from T cells. In this study we have examined the ability of tumour necrosis factor-beta (TNF beta), a T-cell product, to induce a state of activation in resting B cells, to induce proliferation of already activated B cells, and to stimulate differentiation. Recombinant tumour necrosis factor beta (rTNF beta) was used alone and in conjunction with known stimulators. As judged by several markers of activation (CD23, CDw40, LFA-1, 4F2, MHC class I and class II), rTNF beta did not contribute to the activation of resting B cells, either alone or in conjunction with anti-IgM and IL-4. However, the activation marker detected by the monoclonal antibody Leu 21 did show a greater degree of up-regulation by anti-IgM + IL-4 + rTNF beta when compared with anti-IgM + IL-4. rTNF beta induced proliferation of B cells, but only if activating stimuli were also present. Two other factors which induce proliferation of activated B cells, low molecular weight B-cell growth factor (LMW-BCGF) and IL-2, showed additive effects with rTNF beta. No evidence of changes in differentiation status of the B cells was seen.

B-Lymphocytes↗
PubMed1988

B lymphocyte/carcinoma antigen (BLCa): functional study in B cells.

BLCa is an antigen expressed on the surface of B lymphocytes and certain carcinomas. In this study we have demonstrated that BLCa is distinct from known B cell antigens classified by 'clusters of differentiation' (CD). In particular, the monoclonal antibody MA6, which identifies BLCa, can be distinguished from antibodies of the CDw40 group, which detect an antigen of similar molecular weight expressed also on B cells and certain carcinomas. The expression of BLCa on B cells was measured as tonsil B cells were activated (by anti-Ig and interleukin-4 (IL-4)), induced to proliferate (by low molecular weight B Cell Growth Factor (LMW-BCGF), and induced to differentiate (by B Cell Differentiation Factor, BCDF). Expression of BLCa increased in response to LMW-BCGF. The effect of inclusion of MA6 antibody in cultures with the B cell stimuli was also investigated. MA6 showed an anti-proliferative effect which was antibody-dose dependent, but did not otherwise inhibit or co-operate with anti-Ig. IL-4, LMW-BCGF or BCDF.

Antibodies, Monoclonal↗
PubMed1988

Further characterization of human myeloid antigens (gp160,95; gp150; gp67): investigation of epitopic heterogeneity and non-haemopoietic distribution using panels of monoclonal antibodies belonging to CD-11b, CD-13 and CD-33.

We have investigated the binding of over 30 different monoclonal antibodies (MAB) belonging to three distinct clusters of differentiation (CD-11b; CD-13; CD-33; as defined by the Third International Workshop on Leucocyte Differentiation Antigens (ILWS), 1986), and which are reactive with three distinct myeloid restricted surface antigens ('gp160,95'; 'gp150'; 'gp67'). By investigating reactivity with non-haemopoietic cells, we have confirmed that CD-11b and CD-33 MAB reactivity is largely restricted to haemopoietic cells, whilst CD-13 MAB showed additional binding to a wide range of non-haemopoietic cells. Epitopic heterogeneity was also investigated within each cluster of differentiation. Tested anti-CR3 (CD-11b) MAB varied in their ability to block the binding of complement coated sheep red blood cells and zymosan particles. A more detailed analysis of MAB binding heterogeneity was performed by competitive inhibition assays. It was demonstrated that MAB from both CD-11b and CD-13 bind to several distinct epitopes (at least six and five respectively) on their respective antigen molecules. In contrast, CD-33 MAB appear to bind to only a single site on 'gp67'. These data may allow for a clearer appreciation of the disparate functional effects obtained using different MAB reagents to individual myeloid antigens, as reported by a number of workers.

Antibodies, Monoclonal↗
PubMed1988

Monoclonal alkaline phosphatase-anti-alkaline phosphatase (APAAP) complex: production of antibody, optimization of activity, and use in immunostaining.

A mouse monoclonal antibody, FMC55 (an IgG1), to alkaline phosphatase was prepared and evaluated in immunostaining. Clones producing antibody to alkaline phosphatase were selected using a micro-ELISA which identified antibodies forming active soluble complexes (APAAP) with the enzyme. Conditions that influenced the formation of the complex were investigated by using a quantitative assay in which the complex was captured by a bridging anti-mouse antibody. The ratio of FMC55 to enzyme had a major influence on the activity of the complex. Although all complexes had some activity, those that contained excess antibody had reduced ability to bind to anti-mouse antibody because of competition with excess unlabeled antibody. The optimal complex was formed with 3 micrograms of FMC55 per unit of enzyme. This complex contained neither free enzyme nor free antibody. The molecular weight by gel permeation chromatography was 600,000, giving a composition of two enzyme and two antibody molecules or one enzyme and three antibody molecules. The size of the complex was not altered by adding excess antibody or excess enzyme. Immunoblotting showed that FMC55 bound only to the Mr 140,000 homodimeric form of alkaline phosphatase. The APAAP complex was used in combination with biotin-streptavidin-peroxidase reagent to detect two antigens labeled with two different mouse monoclonal antibodies in the same tissue preparation.

Alkaline Phosphatase↗
PubMed1988

Immunocytologic characterization using monoclonal antibodies of lung lavage cell phenotype in infants who have died from sudden infant death syndrome.

The phenotype of cells obtained from pulmonary lavage in infants who have died from sudden infant death syndrome were examined and compared with cells from control subjects. The only striking difference between the groups was a lack of reactivity of lavage cells with antibody of the CD14A cluster in the sudden infant death syndrome subjects, while antibodies of the CD14B cluster reacted strongly with cells from both the sudden infant death syndrome group and controls. Major histocompatibility complex class II antigens were expressed on approximately 95% of lavage cells, with DQ expressed more frequently than DR or DP. The majority of the lavage cells was macrophages, yet they reacted with CD3 (OKT3) and CD8 (OKT8) antibodies. No interleukin 2 was found in the lavage fluid.

Antibodies, Monoclonal↗
PubMed1988

B prolymphocytic leukemia cell lines: phenotype and response to B cell differentiation factor.

Three recently-derived cell lines of prolymphocytic leukemia origin were studied. The phenotype of the cells, analysed in terms of expression of immunoglobulin and other B cell maturation markers, indicates that the cells are mature B lymphocytes close to the plasma cell stage of differentiation. All three cell lines secrete IgM, and two of the three lines respond to B cell differentiation factor with an increased secretion of IgM.

Antigens, Differentiation, B-Lymphocyte↗
PubMed1987

Evaluation of CD5-positive B cells in blood and synovial fluid of patients with rheumatic diseases.

CD5 (OKT1, Leu-1) is an antigen originally associated only with T cells. This antigen has recently been detected on a population of B cells that have been implicated in autoimmune diseases, particularly in rheumatoid arthritis (RA). We determined the percentage of these cells in the peripheral blood (PB) and synovial fluid (SF) of patients with RA and other joint diseases (OJD) using flow cytometry and two-colour fluorescence. No significant difference was observed between the percentages of CD5-positive B cells in the PB of these two patient groups or healthy individuals. In comparison with PB, significantly higher percentages of these cells were observed in the SF of patients with RA, but not in SF of OJD patients. Higher percentages of B cells were also noted in RA SF. However, when B-cell percentages were accounted for, no significant difference was observed between the numbers of B cells expressing CD5 in SF. No correlation was observed between the percentages of CD5-positive B cells and the levels of rheumatoid factor (RF) or C-reactive protein (CRP). We conclude that CD5-positive B cells are an integral part of the B-cell pool of PB and that there is increased representation of B cells in SF. The increased percentages of B cells in RA SF, compared with OJD, may reflect the autoimmune phenomenon occurring in the rheumatoid joint.

Adult↗
PubMed1987

Expression of the non-T ALL-associated p24 antigen on leukaemic blasts from patients with ANLL.

Leukaemic cells from the peripheral blood of 90 patients with acute leukaemia (54 non-lymphocytic (ANLL) 36 lymphocytic (ALL)) have been examined for the presence of the platelet/ALL-associated p24 membrane antigen by indirect immunofluorescence and flow cytometry using monoclonal antibody FMC8. Cells from 28 of the ANLL patients and 24 of the ALL patients expressed the antigen. In many specimens, both ANLL and ALL, blast cell populations were heterogeneous with respect to FMC8 binding. In ANLL, FMC8-positive cells were observed in specimens from a range of morphological subtypes. Proteolytic stripping/resynthesis experiments demonstrated that the antigen was synthesized by ANLL cells, not passively acquired. Immunoprecipitation and electrophoretic analysis of the antigen from NP40 lysates of 125I surface labelled cells from a patient with acute monoblastic leukaemia confirmed that the epitope identified by FMC8 was present on a peptide of the same molecular weight (p24) as that observed on ALL cells.

Acute Disease↗
PubMed1987

Antigen expression during early human granulocyte development studied with immuno-electron microscopy.

Expression of the hapten fucosyl-N-acetyllactosamine was correlated with ultrastructural development in human granulocyte precursors using the monoclonal antibody FMC 10 with immunogold techniques. The antigen was detectable from the myeloblast/early neutrophilic promyelocyte stage onwards and was associated with striking development of the rough endoplasmic reticular system. In addition, low levels of labelling were seen on monocytes, eosinophils and some basophil precursors. Contraction and alignment of the cisternae of the rough endoplasmic reticulum during the promyelocyte stage of neutrophilic differentiation gave the appearance of a plasma cell. However, on closer examination it was apparent that true plasma cells did not react with this antibody.

Antibodies, Monoclonal↗
PubMed1987

Transplantation of monoclonal antibody-purged autologous bone marrow for treatment of poor risk common acute lymphoblastic leukemia.

Two murine monoclonal antibodies, FMC-8 and WM-21, reactive with the human leucocyte differentiation antigens CD-9 (p-24) and CD-10 (CALLA), respectively, have been used for purging leukemic cells from remission bone marrow. Nine patients with the common variant of acute lymphoblastic leukemia (c-ALL) in second or subsequent remission underwent bone marrow harvesting. Bone marrow mononuclear cells underwent lytic incubation in vitro with antibodies FMC-8 and WM-21, and rabbit serum as a source of complement, and were then cryopreserved. A mean of 0.90 +/- 0.50 x 10(8) nucleated cells per kilogram of recipient body weight remained after treatment, with 0.38 +/- 0.24 x 10(8) nucleated cells and 8.3 +/- 10.3 x 10(4) CFUGM per kg being recovered on thawing. Seven patients subsequently received marrow-ablative treatment with high dose cyclophosphamide (120 mg/kg) and fractionated total body irradiation (12 Gy), followed by infusion of antibody-purged autologous bone marrow. Three deaths due to sepsis occurred within the first 35 days, compounded in one patient by poor marrow engraftment. All other patients engrafted promptly, and four remain in continuous complete remission at 2, 6, 9, and 28 months after transplantation. The procedure carries a substantial risk of early toxicity, but offers a significant chance of prolonged unmaintained remission to selected patients with poor prognosis acute lymphoblastic leukemia.

Adolescent↗
PubMed1987

The expression of mature myeloid cell differentiation markers in acute leukemia.

Cells from 82 patients with leukemia in acute phase (40 ANLL, 1 AUL, 36 ALL, 5 CGL in blast crisis) were studied for the expression of mature cell markers of the major nonlymphocytic cell lineages (monocytes, granulocytes, erythrocytes and platelets) using monoclonal antibodies. In addition, cells were examined for the presence of HLA-A, B, C antigens, Ia antigens and common ALL antigen, as well as Fc receptors capable of binding murine immunoglobulins. Approximately one-third of ANLL specimens lacked any of the mature-cell differentiation markers studied. These were always in the relatively undifferentiated morphological subgroups (M1 and M2). Some of the specimens in these groups also expressed little or no HLA-A, B, C and/or Ia antigen. Of the lineage-specific MAb, FMC32 and FMC34, which bind to monocytes, and monocytes plus granulocytes respectively, gave the most interesting results. Together with the anti-CALLA antibody J5, they contributed to the differential diagnosis of ANLL and ALL. In addition they detected phenotypic heterogeneity within the FAB types of ANLL, particularly the M1 and M2 groups. Binding of murine IgG2a and IgG3 antibodies, apparently via Fc receptors, was commonly observed with ANLL cells. This is a potentially serious source of "false positives" in studies using murine MAb with human leukemic cells.

Antibodies, Monoclonal↗
PubMed1987

Markers of differentiated B cell leukaemia: CD22 antibodies and FMC7 react with different molecules.

FMC7, a monoclonal antibody used extensively to characterize B cell leukaemias of differentiated phenotype (prolymphocytic, hairy cell, and similar leukaemias) was compared directly with antibodies of the CD22 cluster, which also react with B cells at a late stage in differentiation. Detailed comparison shows that the reaction spectrum, though similar, is not identical. Differences were particularly prominent in chronic lymphocytic leukaemia (CLL) and non-Hodgkin's lymphoma (NHL). Binding studies show that the antibodies react with different antigenic determinants, and immunochemical studies show that they react with different molecules. The FMC7 antigen, not previously characterized, was shown to be a protein of apparent molecular weight 105,000, by immunoblotting after electrophoresis of membrane extracts.

Antibodies, Monoclonal↗
PubMed1987

Evaluation of a monoclonal IgM antibody for purging of bone marrow for autologous transplantation.

A monoclonal antibody of the IgM class, reacting with the CD9 (p24) antigen is described. The antibody (FMC27) is cytotoxic against cells of the common type of acute lymphoblastic leukaemia (c-ALL), giving killing at higher dilutions than an IgG antibody (FMC8) against the same antigen. FMC27 and FMC8 recognise different epitopes, and FMC27 may thus be used in a cocktail together with FMC8 and an antibody against the c-ALL antigen, WM21. Furthermore, the IgM antibody can be coated directly onto magnetic microparticles for magnetic purging, unlike the IgG antibody which must be used in a two-layer procedure.

Antibodies, Monoclonal↗
PubMed1987

Peripheral blood leucocyte subpopulations in patients splenectomized for trauma.

Monoclonal antibodies were used to type leucocyte subpopulations in peripheral blood mononuclear leucocytes (MNL) from patients who had had spleens removed following trauma. The proportion of OKT3+ (T) cell and OKT4+ ('T helper/inducer') cell was significantly decreased in splenectomized subjects. While a decrease was also observed for the OKT8+ ('T suppressor/cytotoxic') cells, this was not significant. The ratio of OKT4+/OKT8+ cells was significantly decreased in the splenectomized group. Interestingly, the absolute numbers of OKT3+, OKT4+ and OKT8+ cells were increased. The % of B lymphocytes (identified as Ig+ and FMC1+ cells) was significantly increased in patients. The proportion of MHC Class II+ cells (FMC4+) was also increased although not significantly. A marked increase in % of monocytes (FMC33+) was observed in patients. The changes in proportion of regulatory T cells and monocytes may in part explain the depressed mitogen responses of MNL from splenectomized subjects.

Adult↗
PubMed1986

The purification of mouse monoclonal antibodies from ascitic fluid.

A method is described for the purification of monoclonal antibody from mouse ascitic fluid. The fluid is clarified and the lipid removed using silicon dioxide powder, before the immunoglobulin is precipitated using polyethylene glycol. The method provides IgM antibody in high yield and good purity. In the case of IgG antibodies the purity is 30-40% after PEG precipitation and the yield is high. The enriched IgG is adequate for many purposes and is suitable for further purification on an ion exchange column.

Animals↗
PubMed1986

A human retinoblastoma cell line expressing the common acute lymphoblastic leukemia antigen and displaying an unusual chromosome abnormality.

A new continuous cell line derived from an untreated human retinoblastoma has been established. This cell line, FMC-RB1 is strongly positive for common acute lymphoblastic leukemia antigen and shows a number of ring chromosomes and two marker chromosomes considered to be derivations of chromosome #17; the nonrandom chromosomal changes associated with retinoblastoma, particularly the loss of a chromosome #13 or the deletion of 13q14 was not observed. The establishment of the cell line initially required the presence of bone marrow stromal cells. Morphologically, this cell line grew as a suspension of small round cells in grape-like clusters with periodic "shedding" of single cells. FMC-RB1 could be cloned in soft agar, even in the absence of bone marrow stromal cells as "feeders", making it suitable for a variety of biological studies.

Antigens, Neoplasm↗