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M D Cooper

Publications and source records attributed to M D Cooper.

At least 271 records · Page 15Linked to original sources
PubMed1984

Development of lymphocyte subpopulations identified by monoclonal antibodies in human fetuses.

We have used a panel of monoclonal antibodies to examine the development of lymphoid and myeloid subpopulations of cells in thymus, bone marrow, and liver of 16 fetuses from 12 to 16 weeks of gestational age. Pre-B and IgM+ B cells were present at a ratio of approximately 2:1 in all of the fetal bone marrow and liver samples; cells of both phenotypes were HLA-DR+ but did not express the mature B-cell antigen, HB-2. Cells expressing the myelomonocytic antigen, MMA or Leu-M1, were more frequent in bone marrow (40%) than in fetal liver (10%), and cells expressing the HNK-1 or Leu-7 antigen were rare (less than 1%) in all of the fetal tissues examined. Each of the T-cell antigens, T1, 4, 5, 6, and 8, was expressed by a majority of thymocytes irrespective of the age of the fetal donor. In contrast, cells with the T1, 4, 5, and 8 antigens were not seen in bone marrow and liver before the 13th week of gestation, and T6+ cells were never seen in these hemopoietic tissues. These results suggest that fetal liver and bone marrow precursors in humans do not express these T-cell antigens prior to thymic entry and the onset of thymocyte differentiation.

Antibodies, Monoclonal↗
PubMed1984

T-cell regulation of IgG subclass expression by mitogen-induced plasma cells: soluble factors versus the T cells.

The human IgG subclasses expressed by plasma cells generated from circulating B cells in response to soluble T-cell factors were examined by immunofluorescence using subclass-specific monoclonal antibodies. Soluble T-cell factors were induced by a mixed lymphocyte reaction, pokeweed mitogen (PWM), or phytohemagglutinin. The distribution of IgG subclasses expressed by plasma cells induced by these factors was IgG2 greater than 75%, IgG1 less than 25%, IgG3 less than 1%, and IgG4 less than 1%. On the other hand, IgG1 was dominant when B cells were cultured with T cells and PWM: IgG1 approximately 70%, IgG2 approximately 20%, IgG3 approximately 8%, and IgG4 approximately 1%. The addition of different amounts of the T-cell factors to B cells in culture did not alter the predominance of IgG2 plasma-cell differentiation. These results suggest that T cells and their soluble factors may preferentially enhance terminal differentiation of different IgG B-cell subpopulations. In contrast, the ratio of IgA1 to IgA2 plasma-cell responses was approximately 1.5 to 1 regardless of whether the B-cell precursors were induced by T-cell factors or by the T cells plus PWM.

Adult↗
PubMed1984

Attachment to and invasion of human fallopian tube mucosa by an IgA1 protease-deficient mutant of Neisseria gonorrhoeae and its wild-type parent.

In an investigation of the possible role of IgA1 protease in the initial encounter of Neisseria gonorrhoeae with human genital mucosa, the pathogenicity of an isogenic, piliated, wild-type gonococcal clone was compared with that of its IgA1 protease-deficient mutant in organ cultures of human fallopian tubes. The fallopian tube mucosa released IgA into the organ culture medium throughout the course of the infection; the rate of release was substantially higher in gonococcus-infected organ cultures. The wild-type gonococcus but not the IgA1 protease-deficient mutant elaborated IgA1 protease into the medium. The rate and extent of attachment, damage, and invasion of the fallopian tube mucosa by the IgA1 protease-deficient mutant were indistinguishable from those by the parental clone. These data are compatible with the hypothesis that, in the initial encounter with previously uninfected human genital mucosa, the production of IgA1 protease is not critical to the ability of the gonococcus to act as a mucosal pathogen.

Adhesiveness↗
PubMed1984

Discontinuous expression of a membrane antigen (HB-7) during B lymphocyte differentiation.

We have examined the expression of a cell surface antigen by B lineage cells in human fetuses, newborns and adults using a newly produced monoclonal antibody, HB-7. The HB-7 antigen was found to be a protease sensitive 45,000 MW molecule that appeared to be the same molecule recognized by the OKT-10 antibody. The HB-7 reactive molecule was expressed by all fetal pre-B and B cells, and 50% of newborn blood and adult bone marrow B cells. In contrast, only a small minority of B cells (2-12%) from blood, spleen and tonsil of adults were weakly HB-7+. The pokeweed mitogen-responsive B cell precursors of plasma cells were also HB-7-, but the HB-7 antigen was re-expressed during the plasma cell stage. We conclude that this antigen is unique among known B cell differentiation antigens in its intermittent pattern of expression during B cell development. The reactivity of the HB-7 antibody with immature, but not mature, B cells makes it well suited for studies of B cell ontogeny.

Antibodies, Monoclonal↗
PubMed1984

Analysis of structural properties and cellular distribution of avian Ia antigen by using monoclonal antibody to monomorphic determinants.

In this report, we describe the analysis of Ia-like antigens in the chicken by using a monoclonal antibody (CIa-1) reactive with monomorphic determinants of the Ia-like (B-L) antigens. This antibody reacts with determinants on B cells in all avian species tested, but does not detect antigens on lymphocytes of representative mammals, reptiles, and amphibians. In addition to B cells, this antibody defines a subpopulation of the monocyte-macrophage series and reacts with mitogen-activated T cells. Immunochemical analysis indicates that the CIa-1 reactive antigen is a 65,000-dalton glycoprotein consisting of an alpha-chain of 32,000 daltons noncovalently bound to a beta-chain of 27,000 daltons. Under nonreducing conditions, the beta-chain migrates with slightly faster mobility. Two-dimensional gel analysis indicates that the beta-chain is the more heterogeneous of the two chains. Thus, the antigen detected by CIa-1 antibody is similar in cell distribution and structure to the murine Ia antigens and human DR antigens. During in ovo development, Ia+Ig- cells were not found in the yolk sac but were detected in the spleen, mesonephros, and bursa of 9-day embryos. Two populations of Ia+Ig- cells were identified in the bursa: 40 to 60% of the bursacytes, mostly larger cells, exhibited brighter immunofluorescence reactivity than the smaller bursacytes.

Animals↗
PubMed1984

Expression of C3d receptors during human B cell differentiation: immunofluorescence analysis with the HB-5 monoclonal antibody.

We have examined human B lymphocytes at different stages of differentiation for the expression of surface receptors for the C3d fragment of complement. C3d receptors (C3dR) were identified by indirect immunofluorescence using the HB-5 monoclonal antibody, which recognizes a 145,000 m.w. C3dR molecule on B lymphocytes. Pre-B and immature B cells from fetal bone marrow and liver did not express C3dR, whereas a small subpopulation (25%) of B cells in fetal spleen were C3dR+. Approximately 50% of the B cells in adult bone marrow were C3dR+, whereas the more mature B cells in the blood of newborns and adults and in peripheral lymphoid tissue of adults uniformly expressed the C3dR. Activated B cells responsive to T cell-derived differentiation factors were C3dR+, whereas plasma cells rarely expressed C3dR. T cells, NK cells, erythrocytes, and myelomonocytic cells did not express detectable surface C3dR. These results suggest that in hematopoietic and lymphoid tissues, the expression of C3dR is a specific feature of relatively mature lymphoid cells of B lineage.

Adult↗
PubMed1984

An immunofluorescence analysis of the ontogeny of myeloid, T, and B lineage cells in mouse hemopoietic tissues.

The population dynamics of granulopoietic cells, B-lineage cells, and T lymphocytes were analyzed by immunofluorescence in mouse hemopoietic tissues as a function of age. Mac-1+ myeloid cells were present on day 11 of gestation in the liver, where they peaked shortly after birth and declined subsequently. Waves of myeloid population growth began in spleen and bone marrow by days 15 and 19, respectively. Mac-1+ cells increased in number to relatively low plateau levels in spleen by the 3rd wk after birth, whereas in the bone marrow higher plateau levels were reached around 3 mo of age. The 14.8 monoclonal antibody was utilized as one marker of B-lineage precursor cells. 14.8+ cells were detected in the liver on day 11 of gestation, reached peak numbers during the first week after birth and decreased thereafter. On day 15 and 19, 14.8+ cells were found in spleen and bone marrow, respectively, and progressively increased in numbers to reach plateau levels in both sites by 3 mo of age. Mu+ pre-B cells appeared in significant numbers in the 13-day fetal liver, reached a peak shortly after birth, and disappeared from the liver by the end of the second postnatal week. Pre-B cells were found in the spleen and bone marrow on days 15 and 19, respectively. In the spleen pre-B cells reached peak values at birth and disappeared 2 wk later. In spite of the sequential appearance of mu+ pre-B cells in fetal liver, spleen, and bone marrow, their sIgM+ B cell progeny appeared in all these hemopoietic tissues on day 17 of gestation. In the liver, sIgM+ B cells reached their peak at birth and declined thereafter. In the spleen and bone marrow, B cells increased to plateau levels between 1 and 4 mo of age. Thy-1.2+ T cells were relatively late acquisitions in all three hemopoietic tissues. Finally, the expression of the 14.8 antigen by mu+ cells was examined as a function of gestational age. While pre-B cells from day-13 fetuses had no detectable 14.8 antigen, the antigen was weakly expressed on the vast majority of the mu+ pre-B cells by day 17 of gestation. Newborn liver cells expressing 14.8 antigen were found to include a small proportion of cells with peroxidase+ granules. Thus, demonstration of rearrangement and expression of immunoglobulin genes may be required for precise identification of cells of B lineage early in ontogeny.

Animals↗
PubMed1984

Electron microscope studies of attachment to human fallopian tube mucosa by a gonococcal IgA1 protease deficient mutant and wild type parent.

Organ cultures of human fallopian tube were used to assess the potential role of gonococcal IgA1 protease in infection of mucosal tissue. A genetically cloned IgA1 protease deficient mutant and its wild type parent were used to infect fallopian tube organ cultures. The comparative rate and extent of attachment, invasion and damage to the organ cultures by the gonococcal mutant and its parent type were assessed by scanning and transmission electron microscopy and determined to be indistinguishable from one another. These results indicate that the lack of IgA1 protease does not compromise the gonococcus in its ability to infect previously uninfected human fallopian tube mucosa.

Fallopian Tubes↗
PubMed1984

Pre-B cell leukemia associated with chromosome translocation 1;19.

Chromosome banding studies on 60 children with acute lymphocytic leukemia (ALL), including "null," pre-B, B, and T cell phenotypes, were performed. In 4 of 17 patients with pre-B cell ALL, we noted a previously undescribed chromosome translocation, t(1;19)(q23;q13). This translocation was not found in patients with "null" cell, B cell, or T cell ALL. Since each patient with the 1;19 translocation experienced early treatment failure, t(1;19)(q23;q13) may mark a subgroup of patients with pre-B cell ALL who have an especially poor prognosis.

Adolescent↗
PubMed1983

Ultrastructural studies of human lymphoid cells. mu and J chain expression as a function of B cell differentiation.

J chain expression was examined as a function of the stage in differentiation along the B cell axis in humans. Intracellular distribution of J and mu chains in leukemic HLA-DR+ null and pre-B cells, and in normal B cells stimulated with pokeweed mitogen (PWM) was determined by immunoelectron microscopy and radioimmunoassay (RIA). J chain was detected in leukemic null and pre-B cells on free and membrane-bound ribosomes in the cytoplasm, or on perinuclear cisternae. Mu chain was found on free ribosomes and ribosomal clusters in leukemic pre-B cells but was absent in the leukemic null cells. In pre-B cell lines, mu chain was seen within rough endoplasmic reticulum (RER) and the Golgi apparatus whereas J chain was not detected in these organelles. However, both mu and J chain were detected in RER and the Golgi apparatus of immature and mature plasma cells induced by PWM stimulation of normal peripheral blood lymphocytes. Low levels of J chain were also detected by RIA in lysates of leukemic null and pre-B cells. Most of the intracellular J chain became detectable after reduction and alkylation of cell lysates, and free J chain was not found in the culture supernatants. The amount of intracellular and secreted immunoglobulin-bound J chain increased dramatically after PWM stimulation of peripheral blood lymphocytes. The majority of J chain-positive cells seen over an 8 d culture interval were lymphocytes and lymphoblasts, while mu chain was found primarily in plasma cells. These results suggest that J chain expression precedes mu chain synthesis during B cell differentiation and that a combination of the two chains for secretion is not initiated until the onset of plasma cells maturation.

B-Lymphocytes↗
PubMed1983

T cell hybrids that express a VH idiotope-related determinant on a glycoprotein distinct from H-2, Thy-1, and Lyt-1 molecules.

Two mouse monoclonal antibodies to chicken immunoglobulin VH-associated idiotypes (Id), CId-1 and CId-2, were used as probes for Id determinants on mouse T cells. CId-1, which recognized chicken antibodies to N-acetyl glucosamine (NAGA), and approximately 0.4% of chicken T lymphocytes also reacted with approximately 0.2% of BALB/c splenic Thy-1.2+ cells. When enriched CId-1+ splenic T cells from NAGA-immune BALB/c mice were fused with the AKR thymoma BW 5147 cell line, 2 of 72 resulting hybrids, termed CId-1A and CId-1B, were reactive by indirect immunofluorescence with the CId-1 antibody. CId-1 determinants were expressed both in the cytoplasm and on the cell surface. Immunofluorescence studies revealed that both CId-1+ T cell hybrids were phenotypically identical: CId-2-/Ig-/Lyt-1+2-/Thy-1.2+/II-2d+/I-Ad-/I-Ak-/I-Jd+/I-Jk+. Incubation of CId-1B hybrid cells with concanavalin A or lentil lectin resulted in capping of the CId-1 determinant, whereas incubation with pokeweed mitogen, lipopolysaccharide, phytohemagglutinin, and wheat germ agglutinin had no effect on the cell surface distribution of the CId-1 molecule. Trypsin or pronase treatment resulted in the loss of detectable CId-1 determinant on the cell surface. Treatment of CId-1B cells with tunicamycin also reduced the immunofluorescence intensity of the surface CId-1 determinant, but had no effect on its cytoplasmic expression. CId-1 antibody-induced capping of the CId-1 marker did not affect the surface distribution of Lyt-1, Thy-1.2, H-2d, I-Jd, or I-Jk molecules. Conversely, capping of I-Jd and I-Jk determinants did not alter the surface distribution of CId-1. These results suggest that the CId-1 determinant is on a glycoprotein that is not physically linked to the Lyt-1, Thy-1.2, H-2d, I-Jd, and I-Jk molecules. The clonal restriction of CId-1 expression by T cells suggests that the CId-1+ molecule could be a T cell antigen receptor.

Animals↗
PubMed1983

Enumeration of human lymphocyte subpopulations by immunofluorescence: a comparative study using automated flow microfluorometry and fluorescence microscopy.

These studies reveal that the enumeration of peripheral blood mononuclear cells by fluorescence microscopy and automated flow microfluorometry show a high degree of correlation whether the cells came from normals, individuals with common variable immunodeficiency, chronic lymphocytic leukemia of B cell origin or chronic lymphocytic leukemia of T cell origin. There was excellent agreement between these two methods when counting positive cells stained by the pan-T monoclonal antibodies OKT3 and Leu-1, the helper T reagents OKT4 and Leu-3a, and the suppressor T antibodies OKT8 and Leu-2a. The values obtained for B cells using a pan-B (HB-2) cell antibody analyzed by fluorescence microscopy and automated flow microfluorometry gave a correlation coefficient of 0.86. The percentage of cells identified by antibodies with reactivities toward peripheral blood monocytes (MMA or Leu-M1), the HLA-DR determinant, and HNK-1 (Leu-7) positive cells gave correlation coefficients of 0.90, 0.90, and 0.80 respectively when compared by the 2 methods mentioned above. These data suggest that comparable values for lymphocyte subpopulations in human blood samples can be obtained using the most convenient and available technology.

Antibodies, Monoclonal↗
PubMed1983

Immunoglobulin heavy-chain switching in pre-B leukaemias.

Immunoglobulin gene expression is initiated in pre-B cells by rearrangements of heavy-chain variable genes V, D and J, for transcription together with the constant region gene C mu (refs 1-7). The subsequent joining of light-chain V-J genes in the kappa or lambda families leads to formation of complete IgM molecules, which are then expressed on the surface of B cells. Heavy-chain isotype switching has been thought to occur later and to involve CH gene rearrangement via deletion of DNA between a switch site 5' to C mu and a switch site 5' to the downstream C gamma, C epsilon or C alpha gene expressed by a mature plasma cell. On the other hand, isotype switching has been seen in human pre-B-cell leukaemias and in a murine pre-B-cell line before light-chain gene rearrangements and without C mu gene deletion. To explore further the isotype switching in pre-B cells, we used monoclonal antibodies in immunofluorescence assays to allow unambiguous assignment of the heavy-chain isotypes expressed by individual leukaemic cells in 11 pre-B-cell leukaemias. Switching in these leukaemic clones invariably led to expression of gamma 1 heavy-chain and kappa light-chain determinants, occasionally together with gamma 4 and alpha. These results indicate a nonrandom order for heavy-chain isotype switching and for light-chain isotype expression, and also suggest that a mechanism exists for coordinating the two events.

Antibodies, Monoclonal↗
PubMed1983

Response time variations in an online search system.

The response time characteristics of the National Library of Medicine's (NLM) ELHILL bibliographic search system are examined in this article. Transactions for a five-week period are analyzed and average response times are calculated for typical search commands, by time of day, and by file being searched. Overall, the response time of the system was found to be 2.1 seconds, a very low value. Based on statistical tests of significance applied to the data, it was concluded that response time differences can be explained in terms of the number of users on the system and not the command issued by the user nor the file the user searched.

Analysis of Variance↗
PubMed1983

Effect of anti-gamma 3 antibodies on immunoglobulin isotype expression in lipopolysaccharide-stimulated cultures of mouse spleen cells.

To test the hypothesis that gamma 3 is the pivotal isotype for sequential heavy chain switching from mu to each of the gamma isotypes, we have compared the effects of anti-gamma 3 and anti-mu antibodies on the expression of immunoglobulin isotypes in lipopolysaccharide (LPS)-stimulated cultures of mouse spleen cells. IgM-, IgG1-, IgG2b- and IgG2a-containing plasma cells were enumerated by immunofluorescence and secreted immunoglobulins were measured by radioimmunoassay. Although anti-gamma 3 and anti-mu were equally effective in inhibiting the LPS-induced differentiation of IgG3 plasma cells, anti-gamma 3 had no effect on the differentiation of IgM, IgG1, IgG2b, or IgG2a plasma cells. These results support a direct mechanism of heavy chain immunoglobulin switching.

Animals↗