Showing papers by "D Y Mason published in 1993"

Detection of T and B cells in many animal species using cross-reactive anti-peptide antibodies.

Abstract: A wide range of lineage-specific Ag are detectable in the human lymphoid system using mAb, but only a few such markers are detectable in animal species. In this paper, we have investigated the interspecies reactivity of antibodies raised against intracytoplasmic peptide sequences from two T cell Ag (CD3 and CD5) and two B cell markers (the Ig-associated polypeptides encoded by the mb-1 and B29 genes). Immunocytochemical labeling of tissue sections showed that these antibodies cross-react widely between different species (including ungulates, rodents, and marsupials), staining B or T cell areas selectively in lymphoid tissue. The specificity of these antibodies for the animal homologues of the human T and B cell markers was confirmed for the rat by Western blotting analysis. The broad cross-reactivity of these antibodies appears to be due to the fact that they were raised against intracytoplasmic peptide sequences that are highly conserved between humans and rodents, i.e., 80% for mb-1, 85% for CD5, and 100% for CD3 and B29. This strategy should, in the future, widen the range of lineage-associated markers detectable in experimental animals.

Immunohistochemical detection of p53 and bcl‐2 proteins in non‐Hodgkin's lymphoma

Abstract: We have investigated the immunohistochemical expression of p53 protein in 96 cases of non-Hodgkin's lymphoma using a panel of five antibodies. Positive neoplastic cells were found in 30 (31.2%) cases, which could be divided into two groups according to their patterns of reactivity with the different antibodies; i.e. those positive with both polyclonal and monoclonal antibodies, and those which were stained only by monoclonal antibodies PAb1801 and/or PAb240. Positivity was nuclear in all but six cases in which cytoplasmic staining was found. In view of the hypothesis recently raised that p53 protein induces apoptosis we have compared our results with parallel staining for bcl-2 protein since bcl-2 is believed to be important, at least in lymphomas, in suppression of apoptosis. Staining for bcl-2 protein was performed on 83 cases and it was shown that p53-positive cases accounted for 10 out of 17 (59%) of the bcl-2-negative lymphomas but only for 15 out of the 66 (23%) bcl-2-positive cases, suggesting a possible relationship between the expression of these two proteins. Thus, our data show that p53 protein is abnormally expressed in a substantial proportion of non-Hodgkin's lymphomas and bears a significant inverse relationship to bcl-2 protein expression. However the molecular basis of this expression remains to be elucidated.

Immunohistological patterns of myeloid antigens: tissue distribution of CD13, CD14, CD16, CD31, CD36, CD65, CD66 and CD67

Abstract: A number of differentiation antigens on myeloid cells have been defined on the CD classification system by the four International Workshops on Human Leucocyte Differentiation Antigens. The distribution of eight of these antigens (CD13, CD14, CD16, CD31, CD36, CD65, CD66, CD67) have been studied in human tissues, with the aim of documenting their immunohistological patterns and their degree of myeloid restriction. CD13, the most widely distributed antigen, was found in skin, bile canaliculi, kidney and pancreas. CD14 was not restricted to monocytes and tissue macrophages, being also strongly expressed on dendritic reticulum cells. CD16 was expressed on granulocytes and tissue macrophages (alveolar and Kupffer cells) and in the red pulp of the spleen. CD31 and CD36 gave a characteristic staining of vascular endothelium, corresponding to their identification as the platelet glycoproteins gp IIa and gp IV. Antibodies against the most recently defined myeloid antigens (CD65, CD66 and CD67) appeared to be more specific for myeloid differentiation than previously described 'myeloid antigens'.

Transcription and protein expression of mb-1 and B29 genes in human hematopoietic malignancies and cell lines.

Abstract: The transmembrane forms of all immunoglobulin (Ig) classes are associated with two glycoproteins, mb-1 and B29, that are crucial for signal transduction following antigen binding to the Ig molecule. We have investigated the transcription and protein expression of mb-1 and B29 genes during B-cell development. Sixty human continuous cell lines (35 B-lineage, 11 T-lineage, 11 myeloid-lineage and three non-hematopoietic) and 75 hematopoietic malignancies (55 B-lineage, 12 T-lineage and eight myeloid-lineage), were tested for RNA expression by Northern blotting experiments with the mb-1 pRA3 cDNA probe, and a newly isolated B29 cDNA probe. Protein expression was analyzed by immunofluorescence microscopy of cytocentrifuge preparations, which were labeled with the anti-mb-1 HM57 monoclonal antibody (mAb) and an anti-B29 polyclonal antiserum, directed against intracellular epitopes of these polypeptides. Except for two early precursor B-cell lines, mb-1 and B29 transcripts and proteins were detected in all B-cell lines and B-cell malignancies, i.e. from immature to more mature B cells, irrespective of their Ig class expression. Transcription of mb-1 genes seems to be down-regulated at the plasma cell stage, because no mb-1 transcripts and mb-1 proteins could be detected in the four plasma cell lines and two plasma cell leukemias tested. B29 transcripts were detectable in these cell samples, but low levels of B29 proteins were only detected in one plasma cell line. The HM57 mAb gave strong labeling on fresh cytocentrifuge preparations of all B-cell samples, and this mb-1 protein expression appeared to be B-cell specific. We therefore conclude that the HM57 mAb is well suited for the detection of the mb-1 molecule as a pan-B-cell marker for the diagnosis of immature and mature B-cell malignancies. The expression pattern of the mb-1 protein is comparable to that of the CD19 and CD22 antigens, but has the advantage of being B-lineage specific. Although B29 protein expression was restricted to B-lineage cells, the anti-B29 antiserum is less suitable for diagnosis of B-cell malignancies, because of the variable and generally weak signals on cytocentrifuge preparations.

ICAM-3 expression on endothelium in lymphoid malignancy.

Abstract: Intercellular adhesion molecule-3 (ICAM-3), the third receptor for lymphocyte function-associated antigen molecule-1 and a new member of the immunoglobulin superfamily has been recently characterized using specific monoclonal antibodies. In the present study, we show immunocytochemically that ICAM-3 is present on T and B cells in the mantle zones and on a subpopulation of follicular center cells in reactive lymph nodes and only occasionally in endothelium. In 52 cases of Hodgkin's disease, ICAM-3, although present on the majority of the reactive lymphoid cells, was absent from the Reed-Sternberg cells and their variants. However, in 28 cases (54%), there was prominent endothelial staining in small vessels. Similar findings were noted in 16 out of 49 cases (33%) of non-Hodgkin's lymphomas. This finding suggests that analogous to ICAM-1 and ICAM-2, ICAM-3 expression can be induced on endothelial cells in lymphoid neoplasms, probably by an as yet unidentified cytokine-mediated mechanism.

Antibody By114 is selective for the 90 kD PI-linked component of the CD66 antigen: a new reagent for the study of paroxysmal nocturnal haemoglobinuria.

Abstract: This paper describes a monoclonal antibody which reacts with transfected cells carrying a gene (NCA-50/90) which has been shown to encode the human CD66 antigen. However, antibody By114 recognizes only a single 90 kD polypeptide from human neutrophils, whereas the antibodies which originally defined the CD66 antigen also recognize a larger 180-200 kD protein. We conclude that antibody By114 is selective for the smaller of the two CD66 gene products, which is a surface membrane phosphatidyl-inositol (PI)-linked molecule. The reactivity of antibody By114 on peripheral blood cells (positive on neutrophils, weak or negative on eosinophils, and negative on basophils, monocytes and lymphocytes) and myeloid precursor cells was identical to those of a reference CD66 antibody, as was the staining of leukaemic cells. However, the reactions of the two antibodies differed on kidney, liver and pancreas, and in cases of myeloma, Waldenstrom's macroglobulinaemia and lymphoma, indicating that By114 represents a new CD66 sub-specificity. Granulocytes from a case of paroxysmal nocturnal haemoglobinuria (PNH) were negative with antibody By114, indicating that it may be of value in detecting the defect in PI-linked surface molecules characteristic of this condition. Antibody By114 also stained formalin fixed paraffin embedded tissues and may therefore be of use in routine diagnostic histopathology.

ZB51: a monoclonal antibody reactive with human plasma cells

Abstract: Summary. Several monoclonal antibodies have been raised in the past which react with human plasma cells but they have all shown additional reactions with other cell types. In this paper we describe a new monoclonal antibody, ZB51, which recognizes an intracellular antigen in normal plasma cells in cryostat tissue sections and cell smears, and which also reacts with neoplastic cells in most cases of myeloma and with plasma cell lines. The antibody shows minimal reactivity with a few eosinophils and myelocytes in bone marrow and stains a myeloid cell line. Whilst normal epithelium is not labelled, antibody ZB51 stains two carcinoma cell lines. Although it was not possible to characterize the target antigen in terms of molecular weight, the reactivity of antibody ZB51 with normal and neoplastic plasma cells makes it a useful new immunocytochemical reagent.