Biomedical subjects

T M Chused

Publications and source records attributed to T M Chused.

At least 55 records · Page 3Linked to original sources

PubMed1985

Analysis of lymphocyte proteins from New Zealand black mice by two-dimensional gel electrophoresis.

Splenic lymphocyte proteins from New Zealand Black (NZB) mice, which spontaneously develop autoimmune disease, and several control strains were analyzed by two-dimensional polyacrylamide gel electrophoresis. A number of strain- and age-related differences were observed, among which was the persistently elevated synthesis of two peptides, 12.5 KD and 10.5 KD, by spleen cells from older NZB mice. Although synthesis of these peptides was moderately high in young NZB and control mice, it diminished with age in control mice. These proteins were found in the cytoplasm and were not expressed on the plasma membrane nor secreted into the medium. Production of these proteins was restricted to B and null cells; T cells did not synthesize these peptides. These proteins appear to be indicators of disease activity, because their increased synthesis was associated with lymphocyte subset alterations associated with the onset of overt autoimmune disease in NZB mice.

Aging↗

PubMed1985

Enlargement of Lyt-2-positive T cells is associated with functional impairment and autoimmune hemolytic anemia in New Zealand Black mice.

We investigated the relationship between the increased cell diameter of Lyt-2+ T cells and the development of autoimmune disease in aging NZB and NZB X NZW F1 hybrid (BW) mice. Individual animals were analyzed for Lyt-2+ T cell size (by narrow-angle forward light scatter), anti-erythrocyte autoantibodies, anemia, proteinuria, and splenomegaly. The peak light scatter of the Lyt-2+ T cells correlated with the level of anti-erythrocyte autoantibodies and severity of hemolytic anemia, but not with proteinuria or splenomegaly. The cell size of this T cell subset did not increase in old BW or in NZB mice homozygous for the xid gene (NZB.xid). The in vivo administration of bacterial lipopolysaccharide to young NZB mice did not stimulate the enlargement of Lyt-2+ T cells. Ly-2+ T cells from old NZB mice could be stimulated by concanavalin A (Con A) to express interleukin 2 (IL 2) receptors and to synthesize DNA in vitro. However, in vivo administration of Con A to old NZB mice did not induce the expression of IL 2 receptors on Lyt-2+ T cells. Further, in vivo T suppressor function was impaired in old NZB mice with enlarged Lyt-2+ T cells. Thus, the enlargement of Lyt-2+ T cells in old NZB mice appears related to impaired T cell function in vivo and is associated with the development of anti-erythrocyte autoantibodies and autoimmune hemolytic anemia.

Aging↗

PubMed1984

A proposal for a flow cytometric data file standard.

The increasing complexity of multiparameter data collection and analysis in flow cytometry and the development of relatively inexpensive arc-lamp-based flow cytometers, which increases the probability that laboratories or institutions may have more than one type of instrument, creates a need for shareable analysis programs and for the transport of flow cytometric data files within an installation or from one institution to another. To address this need, we propose a standard file format to be used for all flow cytometric data. The general principles of this proposal are: (1) The data file will contain a minimum of three segments, TEXT, DATA, and ANALYSIS; (2) The TEXT and ANALYSIS segments consist of KEYWORDS, which are the names of data fields, and their values; (3) All TEXT is encoded in ASCII; (4) KEYWORDS and their values may be of any length; (5) Certain KEYWORDS will be standard, i.e., having specified formats to be recognized by all programs. The structure of the DATA segment will be uniquely defined by the values of KEYWORDS in the TEXT area. It may be in any bit resolution, facilitating compatibility between machines with different word length and/or allowing bit compression of the data. The structured nature of the TEXT area should facilitate management of flow cytometric data using existing data base management systems. The proposed file format has been implemented on VAX, PDP-11, and HP9920 based flow cytometry data acquisition systems.

Computers↗

PubMed1984

Cyclophosphamide-induced changes in the MRL-lpr/lpr mouse: effects upon cellular composition, immune function, and disease.

MRL-lpr/lpr mice develop massive lymphadenopathy with excessive proliferation of T cells and associated immune abnormalities. To examine whether to not the disease process is intrinsic and irreversible, an immunomodulatory drug, cyclophosphamide, was administered to 16-week-old, sick MRL-lpr/lpr mice. Analysis of lymph node cells by flow cytometry from injected and control MRL-lpr/lpr mice indicated that cyclophosphamide had a marked effect upon the lymphoid cellular composition. Whereas control lymph nodes had a very large number of abnormal dull Ly 1+ T cells and very few other cells, the cyclophosphamide-injected mice had normal T and B cells. The immune responses to a T-cell-dependent antigen, sheep red blood cells, and a T-cell mitogen, concanavalin A, were normalized in cyclophosphamide-injected mice as compared to controls. In addition, injected mice had prolonged survival, decreased arthritis, markedly reduced adenopathy and splenomegaly, improved renal histology, and significantly diminished autoantibody levels. This study suggests that the disease and associated immune abnormalities of MRL-lpr/lpr mice are reversible by selective elimination of the abnormal dull Ly 1+ T cells.

Animals↗

PubMed1984

Characterization of T lymphocyte and monocyte populations in HLA B8/DRw3 normal individuals and in patients with dermatitis herpetiformis.

Normal individuals who possess the HLA B8/DRw3 haplotype as well as patients with dermatitis herpetiformis have been found to have a number of immunologic abnormalities including decreased numbers of E rosette-positive, Fc IgG receptor-bearing lymphocytes (referred to as TG cells), and increased numbers of cells which spontaneously secrete immunoglobulin. HLA B8/DRw3-positive normal individuals also have an increased risk for the development of a number of immunologically mediated diseases. Since many of these findings are suggestive of B-cell hyperreactivity and since TG cells were initially thought to represent a portion of the T suppressor cell network, we have examined the peripheral blood mononuclear (PBM) cell populations of 14 normal HLA B8/DRw3-positive individuals, 14 patients with dermatitis herpetiformis (all of whom were HLA B8/DRw3-positive), and 9 non-HLA B8/DRw3 individuals using flow cytometry and monoclonal antibodies of the OK and Leu series directed against cell surface antigens. Normal HLA B8/DRw3 individuals were found to have a significantly lower percentage of PBM cells that expressed both OKT8 and Leu-2a when compared to normal non-HLA B8/DRw3 individuals (p less than .05 Student's t-test). When the ratio of T helper cells (OKT4 and Leu-3a) to T suppressor cells (OKT8 and Leu-2a) was calculated for each individual studied, normal HLA B8/DRw3 individuals were found to have a significantly elevated ratio (Leu-3a/Leu-2a = 2.41 +/- .16, mean +/- SEM) when compared to non-HLA selected individuals (Leu-3a/Leu-2a = 1.73 +/- .05) (p less than 0.025). In addition, normal HLA B8/DRw3 individuals had decreased numbers of TG cells when compared to normal non-HLA B8/DRw3 individuals (B8/DRw3 = 6.4 +/- .74%, non-B8/DRw3 = 13.2 +/- 1.0%, mean +/- SEM, p less than .01). In order to determine the cell surface marker characteristics of TG cells, purified TG cells from both normal HLA B8/DRw3 individuals and non-HLA B8/DRw3 individuals were studied using the Leu series monoclonal antibodies and OKM1. Good agreement was found in the percentages of cells expressing each cell surface marker between the two groups. In addition, the TG cells were found to be predominately T cells (78% Leu-1-positive), with both T helper cells (40% Leu-3a-positive) and T suppressor cells (30% Leu-2a-positive) present. These results suggest that the suppressor cell activity associated with the TG subset is not due to a depletion of the T helper cell subset, and that the decreased numbers of TG cells in HLA B8/DRw3 individuals is not due to a preferential loss of cells bearing Leu-1, Leu-2a, Leu-3a, or OKM1.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗

PubMed1984

Human neutrophils increase expression of C3bi as well as C3b receptors upon activation.

We used monoclonal antibodies and flow cytometry to study the expression of the receptors for the complement fragments C3bi (CR3) and C3b (CR1) on human polymorphonuclear neutrophil leukocytes (PMN). Expression of both receptors was minimal on cells stained in anticoagulated whole blood incubated at 0 degree or 37 degrees C. PMN isolated with Percoll density gradients and held at 0 degree C also had only minimal expression of both receptors. With the isolated cells, however, a spontaneous increase in expression of both receptors occurred upon warming to 37 degrees C. This did not represent complete expression of either receptor since additional increments in surface expression could be induced upon stimulation with N-formyl-methionyl-leucyl-phenylalanine or Raji cell supernatant. The increases in complement receptor (CR) expression appeared to be specific since there were no changes in expression of the Fc gamma receptor or beta-2-microglobulin under any of these conditions. The increased CR expression seems to involve translocation from an intracellular pool since it is complete within minutes and is not blocked by puromycin or cycloheximide. These results demonstrate that both CR3 and CR1 expression increase rapidly upon activation of PMN and that isolated cells can be used to study this phenomenon, which may be a critical part of neutrophil function in vivo.

Antibodies, Monoclonal↗

PubMed1984

Studies of lymphoproliferation in MRL-lpr/lpr mice.

MRL-lpr/lpr mice develop massive lymphoproliferation and an associated autoimmune process that includes anti-DNA formation, vasculitis, and glomerulonephritis. We have investigated the lymphoproliferation of MRL-lpr/lpr mice and have found that multiple factors are operative. Although neonatal thymectomy markedly retards the syndrome, chronic injection of poly rI.rC could substitute for the thymus. The resulting cells had the phenotype characteristic of the abnormal MRL-lpr/lpr T cells, Thy-1+, dull Ly-1+, Lyt-2-, 6B2+, Ig-. Splenectomy at 2 wk of age markedly retarded the development of this syndrome; however, splenectomy at birth did not. Some protection was afforded by splenectomy at 5 wk. Thus, there appears to be a critical period in the life of an MRL-lpr/lpr mouse when the spleen contributes importantly to the lymphoproliferation. A most remarkable observation was that an MRL-lpr/lpr spleen graft under the kidney capsule could induce lymphadenopathy characteristic of lpr/lpr mice in MRL +/+ recipients. Cells within the graft had to be able to proliferate for the adenopathy to occur because irradiation of the spleen with 800 R just before grafting abrogated the lymphadenopathy-inducing potential. No adenopathy was induced by +/+ spleen grafts placed into +/+ mice. Although MRL-lpr/lpr males develop disease slightly more slowly than female littermates, the differences are small. Manipulations that retard disease, such as splenectomy at 2 wk or neonatal thymectomy, magnified the sex differences. Male MRL-lpr/lpr mice that were thymectomized and splenectomized and given polyclonal immune activators failed to develop either anti-DNA or lymphadenopathy, whereas their female littermates expressed both abnormalities. We conclude from these studies that multiple factors serve to modulate the magnitude of the lymphoproliferation and autoimmune syndrome of MRL-lpr/lpr mice.

Animals↗

PubMed1984

Sex and H-2 haplotype control the resistance of CBA-BALB hybrids to the induction of T cell lymphoma by Moloney leukemia virus.

CBA/N and CBA/CaHN have a significantly longer latent period than other inbred mouse strains between infection with Moloney murine leukemia virus and the appearance of T cell lymphoma. The genetic characteristics of this resistance have been analyzed in the F1 hybrids of CBA/N and CBA/CaHN with BALB H-2 congenic strains. Sexual phenotype and H-2 haplotype significantly influenced survival in the F1 hybrids of CBA/CaHN with BALB. In the F1 with BALB/cJ and BALB/cAnN (both H-2d), the males survived significantly longer than the females; but in the F1 with BALB.K (H-2k) and BALB.B (H-2b), the survival of males and females was the same. Survival was not prolonged by the recessive X-linked immunodeficiency gene xid or other genes on the CBA/N X-chromosome, because the (CBA/N X BALB/c)F1 male and the reciprocal (BALB/c X CBA/N)F1 male, which does not carry the CBA X-chromosome, were equally resistant. H-2 haplotype did not influence survival among the BALB H-2 congenics, and sex had little effect on the resistance of the CBA and BALB parents. These results demonstrate that a sex-dependent gene linked to H-2 significantly influences the expression of CBA genes for lymphoma resistance in the F1 hybrid with BALB.

Animals↗

PubMed1984

Ly-2+ T cell enlargement and null cell proliferation occur at the onset of splenomegaly and autoantibody production in New Zealand Black mice.

Splenic T and B lymphocyte and null cell populations were analyzed in NZB mice as autoimmune disease developed during the first year of life. In the B lymphocytes, a progressive shift occurred from the surface IgD bright subset to the surface IgM bright subset. There was a slight increase in the ratio of Ly-2- to Ly-2+ T cells. Splenomegaly was not detected until after 40 wk of age and was primarily due to an increase in the number of null cells. This change was accompanied by an increase in the size, as determined by narrow-angle forward light scatter, of the Ly-2+ but not the Ly-2- T cells, an elevation of IgG-containing plasma cells, and the appearance of anti-erythrocyte autoantibody. The splenic B cell subset distribution and the enlargement of the Ly-2+ T cells were reflected in the peripheral blood, whereas the T cell subset ratio was not. The B cell subset alteration did not correlate with any of the other changes observed. Statistical associations were found between the ratios of T cell subsets, the enlargement of the Ly-2+ T cells, and the increased number of null cells, suggesting a linkage among those late changes that immediately precede the development of overt autoimmune disease.

Aging↗

PubMed1984

Differential binding of chemoattractant peptide to subpopulations of human neutrophils.

Binding of the fluoresceinated chemoattractant N-formylmethionylleucylphenylalanyllysine to neutrophils was measured simultaneously with cell membrane potential by flow cytometry to determine how chemoattractant was bound by different populations of responding neutrophils. Cells exhibiting an apparent depolarization of membrane potential bound more chemoattractant than cells which did not respond or which exhibited a small hyperpolarization. Approximately 45% of the peptide bound to depolarized cells was displaced by unlabeled peptide, whereas only 3% was displaced from the nonresponding cells. By utilizing the well-known observation that extracellular fluorescein fluorescence is quenched by acid pH, it was determined that approximately one-half of the nondisplaceable peptide of both cell types was internalized, but a significant amount remained tightly bound to the extracellular membrane surface and accessible to lowering of the extracellular pH to 5.5. Treatment of cells with cytochalasin B to convert nonresponding cells to depolarizing cells also resulted in expression of displaceable binding by these cells, suggesting a close correlation between displaceable peptide binding and depolarization. Differential binding of chemoattractant among neutrophils and its modulation may account for observations of functional heterogeneity of neutrophils.

Cytochalasin B↗

PubMed1983

Production and characterization of monoclonal antibodies to guinea pig lymphoid differentiation antigens.

We have prepared 2 mouse monoclonal antibodies which react with differentiation antigens on guinea pig lymphoid cells. Monoclone 5AB2 recognizes an antigen expressed on both T and B lymphocytes and absent on macrophages. It has proven useful in the preparation of populations of antigen presenting cells which are free of T and B lymphocytes. The second monoclonal, 8BE6, is specific for peripheral T cells and 10% of thymocytes. It reacts with a 68,000 dalton molecule which is also expressed on the guinea pig B cell leukemia, EN-L2C. 8BE6 has proven to be lytic for peripheral T cells in the presence of rabbit complement and has been used to deplete T cells from heterogenous cell populations.

Animals↗

PubMed1983

Isolation of human basophils by flow microfluorometry.

Human mononuclear cells labeled with fluorescein-conjugated anti-IgE antibody were subjected to flow microfluorometric analysis. Basophils were enriched to 97-99% purity with a 2-step cell sorting procedure. Trypan blue exclusion of sorted cells exceeded 90% and the net yield of the procedure was 15%.

Basophils↗

PubMed1983

Differentiation antigens identify subpopulations of rabbit T and B lymphocytes. Definition by flow cytometry.

A panel of six monoclonal antibodies produced against cell surface glycoproteins of a rabbit T lymphocyte line was used with flow cytometry to define rabbit lymphocyte subpopulations. Four thymocyte populations were characterized by size and expression of cell surface antigens and appear to represent stages in thymocyte differentiation. Rabbit spleen contained five subpopulations: two of T lineage, two of B, and a null cell subset. Bimodal distribution of staining of thymocytes and peripheral T cells was observed using an antibody (9AE10) directed against a Thy-1 analogue in the rabbit, suggesting two separate T cell lineages. One of the monoclonal reagents, L11/135, reacted strongly with peripheral rabbit T cells as shown by two-color immunofluorescence. In functional studies, only the L11/135-bearing cells responded to the T cell mitogens concanavalin A and phytohemagglutinin and to allogeneic splenocytes. The thymocyte subpopulations and the peripheral T and B cell subsets differ from those described in mouse and man.

Animals↗

PubMed1983

Primary Sjogren's syndrome and autoimmune hemolytic anemia in sisters. A family study.

Familial primary Sjogren's syndrome is infrequently reported despite a strong association with a genetically determined factor, HLA-DR3. Although autoimmune hemolytic anemia occurring with secondary Sjogren's syndrome has been well-documented, its association with primary Sjogren's syndrome has not previously been well-recognized. Thus, the unique occurrence of primary Sjogren's syndrome and autoimmune hemolytic anemia in two sisters prompted investigation of other family members for autoimmune diseases and serologic phenomena and their relationships to HLA genotypes. Serologic analysis (antinuclear antibodies, anti-single-stranded DNA, biologic false-positive result for syphilis, and rheumatoid factor) and HLA-A, B, C, and DR typing were performed in 19 relatives in the kindred. Although HLA-DR3 occurred in those affected with Sjogren's syndrome and thyroid disease, there was no consistent segregation of HLA haplotype with serologic abnormalities in other relatives. These data suggest that there are other, non-HLA-linked, factors contributing to the autoimmune diseases in this family.

Aged↗

PubMed1983

Diversity of immunological phenotypes of lymphoblastic lymphoma.

Eleven cases of lymphoblastic malignancy, presenting as lymphoma, were investigated for immunological and differentiation markers prior to the onset of therapy. Biopsy specimens exhibited the typical morphological features of lymphoblastic lymphoma (convoluted T-cell lymphoma). Intranuclear terminal deoxynucleotidyl transferase was detected in the neoplastic cells from each case by indirect antibody staining of cytocentrifuge preparations. Eight cases were T-cell type as evidenced by unsensitized sheep erythrocyte rosette formation and staining with the monoclonal antibody OKT11. Three T-cell cases were OKT4 positive, two were OKT8 positive, and none were positive with both OKT4 and OKT8. Three cases failed to react with any monoclonal antibodies specific for T-cells and did not form unsensitized sheep erythrocyte rosettes or stain for surface immunoglobulin. However, these three cases were Ia positive and J5 (common acute lymphoblastic leukemia antigen) positive. Cells from two of these erythrocyte rosette-negative, Ia-positive, common acute lymphoblastic leukemia-positive cases contained intracytoplasmic mu heavy chains and were therefore of pre-B-cell phenotype. These cases were histologically indistinguishable from the T-cell cases. However, clinically, they were distinguished by the absence of mediastinal masses and by a clinical presentation as isolated lytic lesions of bone in two of the three. OKT9 and OKT10 stained neoplastic cells from T-cell, as well as pre-B-lymphoblastic, lymphoma. Although morphologically homogeneous, lymphoblastic lymphomas are comprised of an immunologically diverse group of neoplasms which include cells of "common" and "mature" thymocyte, non-T, non-B, and pre-B phenotypes and are closely related to the cells of acute lymphoblastic leukemia. In addition, intratumor heterogeneity was observed in most instances and may reflect growth or differentiation differences between subpopulations of individual neoplastic clones.

Adolescent↗

PubMed1983

Evidence for thymic regulation of autoimmunity in BXSB mice: acceleration of disease by neonatal thymectomy.

BXSB mice spontaneously develop an autoimmune syndrome characterized by autoantibody production, immune complex renal disease, and lymphadenopathy containing B cells. The male BSXB mouse has a rapid onset of disease that is determined by defective stem cells. Although the B cell hyperactivity has been traced to the stem cell, previous studies did not evaluate the T cells of BXSB mice with regard to a role in modifying their natural history. The present study was carried out in an attempt to determine whether or not thymic regulation played a role in modulating the stem-B cell abnormalities in BXSB mice. It was found that neonatal thymectomy led to a marked increase in autoantibody production (anti-RBC, anti-DNA), a dramatic increase in lymphadenopathy, and worsening of renal disease. Flow cytometric analysis of the lymph node cells from intact and thymectomized mice demonstrated a loss of Lyt-2+ cells from the thymectomized mice and an increased proportion of Ly-1+, Thy-1.2- cells. These results indicate that although the B cell hyperactivity of BXSB mice is determined by a marrow stem cell defect, thymic regulation normally serves to dampen that B cell hyperactivity; neonatal thymectomy reduces the thymic regulation of autoimmunity in the BXSB males and leads to excessive B cell numbers and function.

Animals↗

PubMed1983

Studies of congenic MRL-Ipr/Ipr.xid mice.

Highly inbred MRL-Ipr/Ipr.xid congenic mice were bred and compared with their + littermates. The xid-bearing congenics developed lymphadenopathy consisting of dull Ly-1+ T cells and impairment of cellular proliferation and IL 2 production in response to the T cell mitogen Con A. Thus, the lpr gene was fully expressed. The xid gene, however, was also expressed as indicated by the failure to respond to immunization with TNP-Ficoll and flow cytometric analysis of splenic B cells. The xid gene was associated with a marked reduction in IgM anti-ssDNA and anti-nDNA of both classes, and serum Ig-bound gp 70. Kidney disease was markedly retarded as was death from the autoimmune process. These studies suggest that the T cell lymphoproliferation and dysfunction characteristic of MRL-Ipr/Ipr mice is not sufficient to induce accelerated autoimmunity; xid is able to markedly slow the process. The xid gene interferes with the development of a B cell subset necessary for maximum autoantibody production, anti-gp 70 production, and the resultant immune complex renal and cardiac disease. The present finding of protection against accelerated autoimmunity in MRL-Ipr/Ipr mice by xid, coupled with previous demonstrations of protection against autoimmunity in other autoimmune mouse strains, suggests that a common approach to the therapy of systemic lupus may be possible.

Animals↗

PubMed1983

The effect of the X-linked immune deficiency gene (xid) upon the Y chromosome-related disease of BXSB mice.

BXSB mice develop a lupus-like disease characterized by B cell hyperplasia, hypergammaglobulinemia, autoantibodies, nephritis and coronary artery disease. To determine the subset of B cells responsible for disease in these mice, we bred a congenic BXSB.xid strain (greater than 99.2% inbred) with the xid gene that deletes a subset of splenic B cells. Because BXSB disease is associated with the Y chromosome, BXSB males and the autoimmune cross (NZB X BXSB)F1 males were studied. BXSB.xid males had profoundly reduced lymphoid hyperplasia, hypergammaglobulinemia, autoantibodies, renal disease, cardiac disease, and markedly prolonged survival. (NZB.xid/+ X BXSB)F1 males also demonstrated a marked protection associated with the xid gene. These studies suggest that the autoimmune disease of BXSB males is dependent upon the B cell subset deleted by xid.

Animals↗