Interleukin-4 induces expression of the CD45RA antigen on human thymocyte subpopulations.

Interleukin-4 (IL-4) is a multifunctional lymphokine which promotes the growth and/or maturation of multiple cell types. We have examined the ability of IL-4 to promote the phenotypic maturation of subsets of human thymocytes. When cultured in serum-free medium supplemented with recombinant IL-4, a subset of immature CD3-CD45RA- human thymocytes ceased to express the CD1 common thymocyte antigen and acquired phenotypic features characteristic of relatively mature thymocytes, such as high-density expression of the CD3 antigen and de novo expression of the CD45RA isoform of the common leukocyte antigen family.

Effect of corticosteroids on post-intubation tracheal stenosis.

A 57 year old patient presented with progressive tracheal stenosis two months after intubation. An intraluminal polypoid lesion was found at the site of the cuff of the endotracheal tube. It disappeared within five days of treatment with inhaled beclomethasone.

Phenotypic characterization of the post-thymic differentiation of human alloantigen-specific CD8+ cytotoxic T lymphocytes.

Cells comprising the CD8+ T cell population are heterogeneous with regard to their function, maturation, and/or expression of various membrane molecules such as the CD45R Ag. We have previously shown that the functionally distinct subsets of CD4+ lymphocytes identified by anti-CD45R mAb represent cells at different stages of an activation-dependent post-thymic differentiation pathway. In the present studies, we have analyzed the functional capabilities and the lineal relationship of the subsets of CD8+ cells defined by anti-CD45R mAb.

[The elderly and their health].

Health promotion aims to increase individuals' decision making toward their own health and help them control their quality of life through personal strategies. Seniors benefit from this process, says the author, who describes a collaborative health promotion and information program at the Ottawa-Carleton Regional Health Department--a program that involves seniors, professionals and volunteers. The needs of the seniors were identified, involvement of relevant organizations requested, then the program was tested with the help of pilot groups.

Abnormal differentiation of immunoregulatory T-lymphocyte subpopulations in the major histocompatibility complex (MHC) class II antigen deficiency syndrome.

The major histocompatibility complex (MHC) class II deficiency syndrome is a rare immunodeficiency disease associated with defective expression of class II MHC antigens. We have examined the consequences of this defect for the differentiation and functional capabilities of immunoregulatory T-cell subpopulations in an affected patient. Although the number of circulating T cells was normal, there was a striking reduction in the number of CD4+ T cells.

The functionally distinct subpopulations of human CD4+ helper/inducer T lymphocytes defined by anti-CD45R antibodies derive sequentially from a differentiation pathway that is regulated by activation-dependent post-thymic differentiation.

The CD4+ helper/inducer T cell population is comprised of functionally distinct subsets identifiable by the HB11 (anti-CD45R) mAb. We have previously shown that the cells that provide help for antibody production express the CD4+CD45R- phenotype. In contrast, CD4+ CD45R+ cells have minimal, if any, helper cell functions; rather, these cells function as inducers of Ts cell activity.

Characterization of a monocyte differentiation factor distinct from gamma-interferon, tumor necrosis factor, or G,M-colony-stimulating factor that regulates the growth and functional capabilities of the U937 monocytic cell line.

We have analyzed the characteristics and cellular sources of the T cell-derived lymphokines that affect the proliferation and the oxidative metabolic capabilities of the U937 monocytic cell line. Although gamma-interferon (gIFN) and tumor necrosis factor-alpha (TNFa) can, in high doses, inhibit the proliferation of U937 cells, the predominant antiproliferative factor produced by activated CD4+ and CD8+ T cells has a MW = 45-55 Kd, is resistant to heat treatment, and is distinct and independent from gIFN, TNFa, and GM-CSF. The inhibitory effect of this lymphokine on U937 cell growth requires an 18-24-hr induction period; thereafter, this growth arrest persists for up to 5 d, even in the absence of the factor.

Interferon-induced expression of class II major histocompatibility antigens in the major histocompatibility complex (MHC) class II deficiency syndrome.

Class II antigens encoded by genes of the major histocompatibility complex (MHC) are expressed by a variety of cell types and have a vital role in the cellular interactions required for an effective immune response. We have analyzed the regulation of HLA-DR, DP, and DQ class II antigen expression on cells of different lineage from an immunodeficient patient with the MHC class II deficiency syndrome. T and B lymphocytes, monocytes, and fibroblasts, which initially expressed no class II antigens, were treated with inductive stimuli that normally lead to enhanced expression of class II antigens.

Bare lymphocyte syndrome. Consequences of absent class II major histocompatibility antigen expression for B lymphocyte differentiation and function.

The bare lymphocyte syndrome is a rare combined immunodeficiency disorder associated with the absence of class I and/or class II major histocompatibility (MHC) antigens. Although it has been inferred that the immune deficiency is a consequence of disordered MHC-restricted interactions among otherwise normal cells, the biological capabilities and differentiation of B lymphocytes deficient in class II MHC antigens have not been rigorously analyzed. We have examined the phenotypic and functional attributes of B cells with absent class II MHC antigens.

Distribution of ecto-5'-nucleotidase on subsets of human T and B lymphocytes as detected by indirect immunofluorescence using goat antibodies.

Human T and B lymphocyte subsets were characterized for ecto-5'-nucleotidase (ecto-5'-NT) expression by two-color immunofluorescence by using polyclonal goat antibodies to 5'-NT and murine monoclonal antibodies to T and B cell subsets. Anti-5'-NT antibodies were prepared by immunizing a goat with purified human placental 5'-NT. Lymphocyte surface 5'-NT was detected with F(ab')2 fragments of immune goat IgG followed by biotinylated F(ab')2 rabbit anti-goat IgG and fluorescein isothiocyanate-avidin.

Cholera toxin and pertussis toxin regulate the Fc receptor-mediated phagocytic response of human neutrophils in a manner analogous to regulation by monoclonal antibody 1C2.

Data presented in this paper indicate that polymorphonuclear leukocyte (PMN) Fc receptor-mediated phagocytosis can be markedly augmented and that this augmentation is under regulatory control. Stimulation of PMN with either a low m.w.

Stimulation of human neutrophil Fc receptor-mediated phagocytosis by a low molecular weight cytokine.

Human neutrophil Fc receptor-mediated phagocytosis can be markedly enhanced by a low m.w. (less than 10,000) heat-labile cytokine(s) derived from specifically stimulated human mononuclear cells and from a human T cell line, MO(t).

Differential expression of ecto-5' nucleotidase activity by functionally and phenotypically distinct subpopulations of human Leu-2+/T8+ lymphocytes.

Subsets of Leu-2+/T8+ cytotoxic/suppressor T lymphocytes were isolated by using various methods of purification and were investigated for expression of ecto-5' nucleotidase (5'NT) enzyme activity by radiochemical, cytochemical, and ultrastructural techniques. By using both the radiochemical and the cytochemical methods. T4-OKM1- cells displayed higher 5'NT activity in comparison with the entire T4- subpopulation.

Antibodies reactive with class II antigens encoded for by the major histocompatibility complex inhibit human B cell activation.

Although class II antigens encoded by genes in the major histocompatibility complex (MHC) are important as recognition structures for immunoregulatory cell interactions, the precise functional role of these molecules in the biological responses of B lymphocytes is unknown. In the studies described here, we have examined the effects of six monoclonal antibodies reactive with human class II MHC antigens on B cell activation and proliferation. Peripheral blood IgM+ B cells purified by fluorescence-activated cell sorter (FACS) techniques were stimulated with anti-mu antibodies, protein A-bearing Staphylococcus aureus (SAC), or in T cell-dependent activation cultures.

The role of receptors for complement in the induction of polyclonal B-cell proliferation and differentiation.

A panel of monoclonal antibodies and ligands that bind to the CR1 or CR2 complement receptors of B cells has been used to investigate the role of these membrane molecules in regulating B-cell proliferation and differentiation. When CR2 was modulated from the surface of B cells by treatment with the HB-5 antibody and a secondary goat anti-mouse immunoglobulin antibody, Epstein-Barr virus-induced polyclonal B-cell proliferation and immunoglobulin production were inhibited by 83 and 90%, respectively. In contrast, modulation of other cell surface molecules, HB-2, B1, and the C3b receptor (CR1), or pretreatment of B cells with C3d,g (a CR2 ligand) or HB-5 antibody, alone minimally inhibited these responses.

Characterization of the human syncytiotrophoblast plasma membrane associated components.

A purification procedure of synctiotrophoblast plasma membrane (STPM) has previously been described. We now report a further characterization of their associated components. By immunochemical analysis two groups of proteins were found.

Evaluation of lymphocyte differentiation in primary and secondary immunodeficiency diseases.

The differentiation status of T and B cells was evaluated in patients with common variable immunodeficiency (CVI), selective IgA deficiency (IgA), X-linked agammaglobulinemia (XLA), and the acquired immune deficiency syndrome (AIDS) with the use of conventional lymphocyte markers and four new monoclonal antibodies that identify lymphocyte subpopulations. These antibodies are HB 4, which identifies a subpopulation of resting B cells; HB 5, which identifies the C3d/EBV receptor on mature B cells; HB 7, which identifies immature B lymphocytes; and HB 10, which reacts with virgin but not activated or memory T cells. T and B cells from the IgA patients typically had normal phenotypic profiles, whereas diverse patterns of lymphocyte maturation were observed in CVI.

Quantitative and functional analysis of a human lymphocyte subset with the T-helper (Leu 3/T 4+) phenotype and natural killer (NK)-cell characteristics in patients with malignancy.

Approximately 20% of normal blood lymphocytes expressing the T-helper (Leu 3/T 4+) surface phenotype display natural killer (NK)-like features such as cytoplasmic granules and the ability to bind NK-cell targets. In this study, we have assessed the frequency, phenotypic features, and functional capabilities of such cells in a variety of lymphoid malignancies or solid tumors. In each patient group, the percentage of granular lymphocytes within the Leu 3/T 4+ T-helper subset was significantly increased.

Analysis of the monocyte Fc receptors and antibody-mediated cellular interactions required for the induction of T cell proliferation by anti-T3 antibodies.

The induction of human T cell proliferation by antibodies that cross-link T3 antigens is dependent on functional interactions of anti-T3 antibodies with monocyte Fc receptors. In this report, we used a panel of anti-T3 antibodies of differing heavy chain isotype and a variety of other monoclonal antibodies to analyze several features of the antibody-mediated interactions between T cells and monocytes that are required for mitogenesis. Whereas three IgG2a anti-T3 antibodies were mitogenic for cells from all individuals, IgM and IgG2b anti-T3 antibodies did not induce T cell proliferation in any donor and could block the proliferative responses induced by other mitogenic anti-T3 antibodies.

Human lymphocyte differentiation antigens HB-10 and HB-11. II. Differential production of B cell growth and differentiation factors by distinct helper T cell subpopulations.

Two monoclonal antibodies (HB-10 and HB-11), which react with human T, B, and NK cells, identify approximately 50% of the Leu-3+ T helper (TH) cells in adult blood. In the present studies, the functional capabilities of the HB-11+ and HB-11-TH cell subpopulations were examined after purification by fluorescence-activated cell sorting. Both subpopulations proliferated in response to PHA, Con A, PWM, and OKT-3 antibodies.

Human lymphocyte differentiation antigens HB-10 and HB-11. I. Ontogeny of antigen expression.

T, B, and NK cells appear to represent separate lymphocyte lineages, but indirect evidence suggests that they may be related via a common lymphoid precursor cell. We have produced two monoclonal antibodies, HB-10 (IgM) and HB-11 (IgG1), by fusing spleen cells from mice immunized with the human B cell line SB, and have shown that both antibodies react with lymphocyte-specific cell surface antigens present on T, B, and NK cells, but not on other types of blood cells. The antibodies were reactive with most cell lines and malignancies of B cell origin and with some of T and NK cell lineage.

Development and distribution of a human B cell subpopulation identified by the HB-4 monoclonal antibody.

Monoclonal antibodies have been successfully used to identify B cell differentiation antigens, few of which mark discrete B cell subpopulations. We have produced a monoclonal antibody, HB-4, against a cell surface antigen on the human B cell line, BJAB, which has an unusual distribution on normal lymphoid cells. HB-4, an IgM antibody, was found to react with an antigen that is expressed by a subpopulation of B cells, approximately 50% of natural killer cells, and not by other types of cells in bone marrow, blood, and lymphoid tissues.

Morphologic and phenotypic features of the subpopulation of Leu-2+ cells that suppresses B cell differentiation.

The Leu-2 antigen is expressed on a subpopulation of human T cells that perform suppressor and cytotoxic functions. In addition, this antigen is also present on a portion of cells with morphologic characteristics of granular lymphocytes. Although both Leu-2+ cells and granular lymphocytes have been shown to suppress B cell differentiation, the interrelationship of these two suppressor populations has not previously been fully characterized.

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.