Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Lymphoid cells”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 109 records · Page 6Linked to original sources

Comparison of in vitro and in vivo cell cycle parameters of lymphoid cells in pig spleens.

Parameters of the cell cycle of lymphoid cells were estimated by analyzing percent labeled mitoses curves after a 3H-thymidine flash. Either anaesthetized pigs were labeled and multiple biopsies taken from the spleen in vivo or isolated perfused pig spleens were labeled in vitro. The data from in vivo and in vitro experiments were very similar. The mean values for cell cycle parameters were: 20.2 to 20.5 hours for the generation time, about 0.5 to 1 hour for G2, about 1.2 to 1.3 hours for M; about 17 to 16.4 hours for S and about 1.5 to 1.7 hours for G1. The mean grain count halving time of labeled mitoses was in accordance with the measured generation time. The isolated perfused spleen seems to give results equal to in vivo data and could, therefore, be employed as a model for studying cell cycle parameters not only in animal but also in human lymphoid tissue.

Animals↗

Colocalization of the viral interleukin-6 with latent nuclear antigen-1 of human herpesvirus-8 in endothelial spindle cells of Kaposi's sarcoma and lymphoid cells of multicentric Castleman's disease.

Human herpesvirus-8 (HHV-8) also called Kaposi's sarcoma-associated herpesvirus infects spindle cells in Kaposi's sarcoma (KS) and lymphoid cells in multicentric Castleman's disease (MCD). In KS cells, HHV-8 is mainly latent with the expression of latent nuclear antigen-1 (LNA-1), whereas in MCD both lytic and latent antigens are produced by lymphoid cells. We show by immunohistochemical labeling that in KS viral interleukin-6 (vIL-6) is expressed in rare spindle cells, whereas in MCD, vIL-6 is detectable in lymphoid cells around lymphoid follicles but also within the follicular dendritic reticulum cell network. The staining of apoptotic bodies with anti IL-6 antibody suggests the achievement of a complete lytic cycle in a subset of lymphoid cells. Interestingly, in MCD, some areas contained vascular spindle cells latently infected by HHV-8 on the basis of LNA-1 expression. This finding might imply that in MCD, both vascular and lymphoid cells proliferate in response to the viral infection. Double immunostaining with anti LNA-1 and anti vIL-6 in MCD and KS identifies 2 subsets of HHV-8 infected (vascular and lymphoid) cells, some with exclusive expression of LNA-1 and some with coexpression of vIL-6 and LNA-1. This suggests that in vivo the regulation of the expression vIL-6 and LNA-1 protein varies with the cell type. In addition, the detection of infected endothelial cells in MCD may indicate that these cells belong to the reservoir for HHV-8.

Apoptosis↗

The Hurler syndrome: a study of cultured lymphoid cell lines.

Lymphoid suspension lines have been established from three patients with the Hurler syndrome and four normals. The Hurler lines can be distinguished from normals by (a) staining characteristics, (b) increase in total cellular mucopolysaccharide content, and (c) increase in dermatan sulfate. Hyaluronic acid is absent in cultured lymphoid cells from normal persons and patients with the Hurler syndrome. The availability of biochemically marked suspension cultures should prove useful for enzymatic studies as well as for further elucidation of this clinical syndrome.

Carbohydrate Metabolism, Inborn Errors↗

Adenosine-5'-triphosphate-(ATP) mediated stimulation and suppression of DNA synthesis in lymphoid cells. I. Characterization of ATP responsive cells in mouse lymphoid organs.

The effects of various nucleotides and nucleosides on DNA synthesis of mouse lymphocyte populations were studied. Significant stimulation of DNA synthesis was observed in the cells from bone marrow or the thymus in the presence of ATP. In contrast, the DNA synthesis of the cells from spleen, lymph nodes, and peripheral blood was markedly inhibited by ATP. Guanosine 5'-triphosphate had nonspecific stimulatory effects on the DNA synthesis of various lymphoid cells, whereas cytidine triphosphate had no effect. When thymocytes or bone marrow cells were separated by 1 x g velocity sedimentation, a distinct cell population was identified as being responsible for the ATP-mediated stimulation of DNA synthesis. Further characterization of ATP-responsive cells revealed that the highest concentration of terminal deoxynucleotidyl transferase, a marker enzyme for precursor T cells, was present in these cells. ATP-mediated stimulation of DNA synthesis may, therefore, serve as a specific marker restricted to a certain population of differentiating T cells.

Adenine↗

Functional depletion of T- and B-memory cells and other lymphoid cell subpopulations-during trypanosomiasis.

T. brucei infection in mice causes generalized immunosuppression with multiple changes in the cells of the lymphoid tissue. Loss of B cell responsiveness to antigens and mitogens, and the induction of suppressive T-cells and macrophages, have been previously reported (Hudson, Byner, Freeman & Terry, 1976; Corsini, Clayton, Askonas & Ogilvie, 1977; Jayawardena & Waksman, 1977). In this study, purified B- or T-cell populations from infected mice have been tested functionally in vitro or in vivo by transfer into syngeneic irradiated hosts to separate the cells from trypanosomes or their products. B-memory cells for thymus dependent (DNP-KLH) and thymus independent (DNP-Ficoll) antigens are depleted or lose their potential to respond to the antigen during T. brucei infection. Similarly, purified T-helper cells, and T-cells reactive to allogeneic target cells in mixed lymphocyte reactions are functionally defective. By 16 days of infection all these responses are less than 10% of the normal level. The loss of B-cell function follows the peak parasitaemia and is accompanied by increases in the serum levels of both IgM and IgG. Enhanced Ig production and decline in B-cell potential also occur in T-deprived mice and in CBA/N mice which lack a subset of T-independent B-cells. Cells affecting delayed hypersensitivity reactions retain their activity throughout trypanosome infection and so far provide the only exception to the general decline in immune potential.

Animals↗

Receptors for IgM on murine lymphoid cells.

Murine lymphoid cells from the thymus, lymph node and spleen were shown by indirect immunofluorescence, to bear membrane receptors for purified IgM of human origin. The bond between IgM and the cells took place through the Fc re gion, as demonstrated with isolated fragments of the normal IgM molecule. Two distinct myeloma IgM lacked this biological activity. The cytophilic origin of part of the immunoglobulin usually described on T-cell membranes is discussed.

Animals↗

A rapid and efficient procedure for the removal of nonviable cells from suspension culture of lymphoid cell lines.

The selective removal of nonviable cells from suspension cultures of lymphoid cell lines by buoyant density centrifugation at 400 x g on a Ficoll-Hypaque (FH) cushion is described. Viable cells collect at the medium-FH interface whereas nonviable cells pellet. This method has proven useful in separating viable from nonviable cells with human lymphoblastoid cell lines, rabbit lymphoid cell lines and mouse myeloma and hybridoma cell lines.

Animals↗

V alpha 14+ NK T cells: a novel lymphoid cell lineage with regulatory function.

A novel lymphoid lineage, NK T cells, was recently found. The NK T cells are the major population in the periphery comprising 5% of splenic T cells and 40% of bone marrow T cells. They express a unique TCR composed of invariant V alpha 14J alpha 281 and V beta 8.2 together with NK receptor (NKRPI). Surprisingly, the invariant V alpha 14+ TCR is exclusively expressed on NK T cells but not on conventional T cells. As the selective decrease in V alpha 14+ NK T cell population in the periphery is tightly correlated with autoimmune disease development, V alpha 14+ NK T cells control development of autoimmune diseases. We also found that V alpha 14 TCR gene rearrangement and transcripts were detected at an early embryogenesis (d9.5) before the thymus formation. Therefore NK T cells are in the distinct category from conventional T cells. The target of NK T cells is found to be CD1 (class 1b, monomorphic class I MHC-like molecule) present on bone marrow-derived cells and is killed by Fas-FasL interaction or perforin-mediated mechanisms. These results indicate that NK T cells consist of an immunoregulatory system different from defense system in terms of homogeneous repertoire, extrathymic development in early stage of gestation, and their regulatory functional role.

Animals↗

Synergistic cytotoxic effect of quercetin and heat treatment in a lymphoid cell line (OZ) with low HSP70 expression.

Heat shock protein 70 (HSP70) protects cells from various injurious stimuli and is important in cell growth and differentiation. However, its expression in leukemia cells has not been analyzed systematically. We, therefore, investigated the expression of HSP70 in various types of leukemia cells and hematopoietic cell lines. Immunoblot analysis revealed that HSP72/73 were expressed at low levels in the acute lymphocytic leukemia cells and lymphoid cell lines examined. However, heat (43 C for 2 h) preferentially augmented HSP72/73 expression in lymphoid cells. This induction was partially blocked by the treatment with quercetin (10 microM for 24 h). Finally, heat shock following quercetin treatment synergistically induced apoptosis in a lymphoid cell line (OZ). These observations suggest the possibility of selective purging of lymphocytic leukemia cells by combination with quercetin and heat.

Apoptosis↗

In vitro growth of murine T cells. V. The isolation and growth of lymphoid cells infiltrating syngeneic solid tumors.

A method has been developed for isolating and growing lymphoid cells infiltrating murine solid tumors. When tumor cell suspensions are placed in T cell growth factor (TCGF) lymphoid cells and not tumor cells proliferate. By 7 to 9 days lymphoid cells free of tumor can be harvested and grown continuously in TCGF. The growth of these cells is dependent on the presence of TCGF but not on the presence of concanavalin-A. Tumor cell suspensions that have been freed of T lymphoid cells by treatment with anti-Thy-1.2 serum and complement or by fractionation on Ficoll gradients exhibit no cell out-growth in TCGF. The lymphoid cells growing in TCGF exhibit significant cytotoxicity for syngeneic tumor cells and normal fibroblasts grown in culture but do no lyse normal lymphoid cells.

Animals↗

Suppression of sialyl Lewis X expression and E-selectin-mediated cell adhesion in cultured human lymphoid cells by transfection of antisense cDNA of an alpha1-->3 fucosyltransferase (Fuc-T VII).

The antisense cDNA approach was used to identify the endogenous fucosyltransferase species responsible for synthesis of the sialyl Lewis X (NeuAcalpha2-->3 Galbeta1-->4[Fucalpha1-->3]GlcNAcbeta1-->R) determinant in human lymphoid cells. The cultured human adult T-cell leukemia cell line, ED40515-N, expressed the message of alpha1-->3 fucosyltransferase (Fuc-T) IV and VII, with a low level of the Fuc-T III and VI message, and manifested the sialyl Lewis X as well as Lewis X (Galbeta1-->4 [Fucalpha1-->3]GlcNAcbeta1-->R) determinant at the cell surface. Transfection of this cell line with the pRc/CMV vector containing an antisense human Fuc-T VII construct (pRc/CMV/5'FT7AS) resulted in a significant decrease of endogenous Fuc-T VII message and a marked reduction in the cell surface expression of sialyl Lewis X determinant as well as a reduction in the enzymatic activity of alpha1-->3 fucosyltransferase against sialylated type 2 chain substrate. This was accompanied by diminution of cell adhesive activity toward E-selectin on interleukin-1beta-treated endothelial cells. These results indicated that the synthesis of the sialyl Lewis X determinants that were functionally active as E-selectin ligands was mainly mediated by Fuc-T VII in these lymphoid cells. On the other hand, the message of Fuc-T IV showed no significant change in the transfectant clones, and the surface expression of the Lewis X antigen as well as the enzymatic activity of alpha1-->3 fucosyltransferase against non-sialylated type 2 chain substrate was well preserved. The clear contrast between the diminished expression of sialyl Lewis X and the conserved manifestation of Lewis X in the transfectant clones suggested that the synthesis of sialyl Lewis X and that of Lewis X are independently regulated by different fucosyltransferases in human lymphoid cells. Fuc-T VII must be involved in the synthesis of sialyl Lewis X, while the synthesis of Lewis X is mediated by an enzyme other than Fuc-T VII, most probably Fuc-T IV.

Adult↗

Specific suppression of graft-versus-host responsiveness by incubation of donor lymphoid cells with a solubilized membrane fraction of host lymphoid cells.

BALB/c spleen cells were incubated with a solubilized membrane fraction (SMF) prepared from spleen and thymus cells of (BALB/c x C3H/He)F1 or (BALB/c x A/J)F1 hybrid mice. Cells incubated with (BALB/c x C3H/He)F1 SMF produced less graft-versus-host (GVH) splenomegaly in (BALB/c x C3H/He)F1 hosts than did untreated BALB/c cells. The reduction of GVH splenomegaly was specific, inasmuch as the GVH activity of (BALB/c x C3H/He)F1 SMF-treated and untreated cells was similar in (BALB/c x C57BL)F1 hosts, and BALB/c cells treated with (BALB/c x A/J)F1 SMF showed no alteration of GVH activity in either (BALB/c x C3H/He)F1 hosts or (BALB/c x C57BL) F1 hosts. The time course of splenomegaly did not differ for SMF-treated and untreated cells. Donor cells that were labeled with tritiated adenosine and treated with (BALB/c x C3H/He) F1 SMF produced a reduction in the amount of label appearing in (BALB/c x C3H/He)F1 host spleens but not in (BALB/c x C57BL)F1 host spleens. Mechanisms which could account for the ability of SMF to cause specific reductions in both GVH activity and host spleen labeling are discussed.

Animals↗

Appearance of Epstein-Barr virus-determined nuclear antigen in human epithelial cells following fusion with lymphoid cells.

When human epithelial FL cells were fused with lymphoid cells harboring Epstein-Barr virus (EBV) genome, EBV-determined nuclear antigen (EBNA) immunofluorescence became evident in high frequency in FL nuclei of heterokaryons several days after fusion. The implications of the findings are discussed in relation to the presence of EBV genome in nasopharyngeal carcinoma cells.

Amnion↗

In situ lymphoid cells of mouse mammary tumors. I. Development and evaluation of a method for the separation of lymphoid cells from mouse mammary tumors.

A method of separating lymphoid cells from solid mouse mammary tumors was developed and evaluated. In this method the tumors are digested with 0.01% collagenase, 0.01% DNAase, and 0.025% trypsin in Dulbecco's PBS into suspensions of cells with a viability of 90%. The suspensions are fractionated on a continuous gradient of Ficoll in tissue culture medium. In model experiments this gradient was found to separate, cleanly, admixed cells of an established mammary tumor cell line and dissociated thymus glands. Recovery rates were 50% for the tumor cells and 80% for the thymocytes. The preparation of the cell suspensions and the gradient separation procedure are not harmful to the cells as indicated by trypan blue exclusion and the ability to grow in cell culture.

Animals↗