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N L Warner

Publications and source records attributed to N L Warner.

At least 55 records · Page 3Linked to original sources
PubMed1981

Expression of Lyt-1 antigen on certain murine B cell lymphomas.

Although the Lyt-1 antigen has previously been considered a T cell-specific marker, recent evidence suggests that a population of Thy-1-, Lyt-1+ cells exists in normal lymphoid tissues. In this study, we have observed that the WEHI-55, WEHI-259, and CH5 B cell lymphomas express high levels of the Lyt-1 antigen, as detected by monoclonal antibodies using the fluorescence activated cell sorter. Three other B cell lymphomas of the 11 examined also gave weak but detectable reactions with the anti Lyt-1 monoclonal antibody. Except for the expression of the Lyt-1 antigen, these lymphomas are typical of cells in the B cell lineage with respect to surface phenotype. The Lyt-1 glycoprotein immunoprecipitated from metabolically labeled WEHI-55 cells is similar in structure to the Lyt-1 glycoprotein on thymocytes. These findings are similar to recent reports that B-type human lymphocytic leukemia cells express the putative human homologue of Lyt-1, the Leu-1 antigen.

Animals↗
PubMed1981

Flow cytometry analysis of T cells and continuous T-cell lines from autoimmune MRL/l mice.

The study of spontaneous autoimmunity in mouse models affords an opportunity to determine the cellular basis of the immune dysregulation observed in this disease. Recently, a new mouse strain, MRL/Mp-Ipr/Ipr (MRL/l) has been developed which carries an autosomal recessive gene (lpr) that results in massive lymph node enlargement concomitant with the development of several autoantibodies. The interest in this strain lies in the possibility that the defect in T-cell regulation of the immune response is manifested at a different level from that in the NZB mouse. It has been reported that the proliferating population of lymphoid cells in the nodes of these mice are T cells, but that many of them are devoid of Lyt surface antigens. We have accordingly initiated several lines of research with these mice, including quantitative flow cytometry characterization of Lyt antigen expression of cells in the lymph nodes of the mice. In an approach to isolate and study the properties of these cells, we have also established continuous cell lines from the lymph node cells of MRL/l mice, using techniques similar to those used to establish continuous lines of antigen-activated cytotoxic T cells and helper T-cell populations.

Animals↗
PubMed1981

Flow cytometry and cytoadherence studies of sera from children with juvenile rheumatoid arthritis and normal controls.

Recently, antibodies reactive with T cell subpopulations have been reported to exist in children with active juvenile arthritis (JRA). In an attempt to verify and extend these observations, we have studied children with JRA for the presence of anti-T cell antibodies by flow cytometry and cytoadherence rosette techniques. T cells were isolated from peripheral blood mononuclear cells (PBL) by two methods: 1) Differential sedimentation of PBL rosetted with neuraminidase-treated sheep erythrocytes, and 2) removal of immunoglobulin positive PBL by rosetting with rabbit anti-human F(ab')2 coated bovine erythrocytes and differential sedimentation. Utilizing these methods to detect lymphoreactivity of JRA sera to either population of T cell isolates, we observed the binding of ultracentrifuged normal human sera (NHS) to be comparable to JRA sera (active and quiescent). NHS reacted with 15-25% of T cells. Further studies demonstrate that monomeric IgG was chiefly responsible for lymphoreactivity. The results of these studies are discussed in the context of previous observations.

Adolescent↗
PubMed1981

Paraformaldehyde fixation of hematopoietic cells for quantitative flow cytometry (FACS) analysis.

The objective of this study was to find a simple method to preserve cells for subsequent flow cytometry (FACS) analysis. We determined that fixation in 1% paraformaldehyde-0.85% saline solution did not significantly alter the Coulter volume, light scatter of fluorescence properties of the cells. This method was suitable for all cell types analyzed, including mouse, human and rat lymphoid cells, erythrocytes and transformed cell lines. Furthermore, fixed cells, previously stained with fluorescein conjugated antibodies, could be stored at 4 degrees C in the dark for at least a week prior to FACS analysis. This method should prove useful to those who work with in vivo derived specimens or have limited access to flow cytometry facilities.

Animals↗
PubMed1981

Monoclonal anti-erythrocyte auto-antibodies from unimmunized NZB mice.

In order to study the heterogeneity of the anti-erythrocyte auto-antibody response in NZB mice, we have developed hybridomas producing monoclonal auto-antibodies with anti-erythrocyte activity. These monoclonals were prepared by fusion of NZB splenocytes with the P3 X 63.Ag8 myeloma and were screened for activity by indirect immunofluorescence using flow cytometry. We have produced a variety of monoclonal anti-red cell auto-antibodies that have differing antigenic reactivities and immunoglobulin isotypes. Eleven monoclonal antibodies extensively studied thus far react with intact mouse erythrocytes, whereas only two of the eleven also cross react with sheep erythrocytes and bromelain treated mouse erythrocytes. These results suggest that the fusion pattern may represent the range of anti-red cell auto-antibodies found in the intact NZB mouse, with the exception of monoclonal auto-antibodies against cryptic red cell auto-antigens, which were not demonstrated in this initial fusion study.

Animals↗
PubMed1981

Fate of phase I and phase II Coxiella burnetii in several macrophage-like tumor cell lines.

Several macrophage-like tumor cell lines of murine origin were exposed to phase I and phase II Coxiella burnetii, and the subsequent fate of the parasites was determined by electron and bright-field microscopy. Phase I C. burnetii proliferated within and established a persistent infection of P388D1, J774, and PU-5-IR cell lines but not of WEHI-3 and WEHI-274 cell lines. Phase II C. burnetii, however, entered into and persistently infected all five cell lines. The parasites proliferated within vacuoles. Macrophage cell lines persistently infected with phase I and phase II C. burnetii were maintained for over 200 and 100 days, respectively. Within P388D1 cells, the phase I C. burnetii converted, in part, to phase II; phase II organisms remained in the phase II state. The differential fate of the two rickettsial phases after exposure to the WEHI-3 and WEHI-274 cells may be attributable to surface differences such as lipopolysaccharide content.

Animals↗
PubMed1981

Continuous cytotoxic T cell lines reactive against murine plasmacytoma tumor-associated antigens.

Continuous cytotoxic T cell lines against murine tumor-associated antigens (TAA) were generated from normal BALB/c and (C57BL/6 X BALB/c)F1 spleen lymphocytes by sensitizing these cells in vitro to the BALB/c plasmacytoma (PCT) MPC-11. These cytotoxic T cell lines (CTLL) were maintained for periods of over 1 yr in T cell growth factor from cultures of mitogen-stimulated rat spleen cells. The lines were highly cytotoxic against the immunizing tumor, as well as against a select number of other tumor cell lines, and the patterns of reactivity of 3 of these lines against the various tumor cell targets indicated that these lines each recognized different PCT TAA. The antigens recognized included an MHC-restricted PCT antigen, an antigen shared by PCT and T lymphomas, and an MPC-11 unique PCT antigen. phenotypic characterization of the CTLL populations for cell surface marker expression indicated that they were largely homogeneous with respect to their differentiation state, and expressed Thy-1.2, Lyt-2, Lyt-3.2, and T30 antigens on their cell surface. In addition, 1 of the lines demonstrated variable low-level expression of Lyt-1. Thus, the populations were characteristics of mature T cells, and did not express cell surface markers characteristic of other lymphocyte subpopulations.

Animals↗
PubMed1981

Cell cycle related heterogeneity of Ia antigen expression on a murine B lymphoma cell line:analysis by flow cytometry.

In this investigation we have used quantitative flow cytometry to study the expression of I region antigens on an established B lymphoma cell line, WEHI-231. Although a majority of the WEHI-231 cells do not react with antisera against the Ia.7 (I-E/C) or Ia.8 (IaA) antigens, a distinct subpopulation of cells, comprising 20 to 30% of the total population, reacts strongly with these alloantisera. Several mechanisms were proposed to explain this intratumor Ia antigen heterogeneity: 1) the effect of volume (surface area) heterogeneity on antigen expression; 2) the existence of a stable variant of Ia+ cells in the cell line; 3) cell cycle regulation of Ia antigen expression. The first possibility was excluded on the basis of FCM analysis, which failed to detect any relationship between cell volume and fluorescence intensity of anti-Ia stained cells. Additionally, the rapid reappearance of Ia antigen heterogeneity within Ia- and Ia+ lines, sorted by the fluorescence-activated cell sorter, argued against the presence of a stable variant population of Ia+ cells. Rather, our data suggest that cell cycle related events are responsible for the Ia antigen heterogeneity. The Ia.7+ sorted cells were shown to be significantly enriched in the G0/G1 phase of the growth cycle. In contrast, it was the Ia.8- cells that were enriched in this phase of the cell cycle. These results suggest that the I-A and I-E/C region gene products are independently regulated in this cell line and imply that similar controls may possibly influence Ia antigen expression on normal B lymphocytes.

Animals↗
PubMed1981

Quantitative immunofluorescent analysis of surface phenotypes of murine B cell lymphomas and plasmacytomas with monoclonal antibodies.

In this study, a large series of murine B lymphomas and plasmacytomas were examined by quantitative flow cytometry analysis using a panel of monoclonal antibodies against murine differentiation antigens. These cell lines appear to represent subpopulations of lymphoid cells arrested at distinct stages of differentiation. In general, the pattern of reactions of these monoclonal antibodies with the B cell neoplasms was comparable to the reactions seen with normal cells in the same lineage. The Thy-1.2, Lyt-2, and T-30 differentiation antigens were not detected on any B lymphoma or plasmacytoma. However, certain surface Ig-positive B lymphomas do express the Lyt-1 antigen. With respect to other differentiation markers examined, including E2, F1, ThB, Lgp-100 (Ly 9.1), G2, and T-200 (Ly 5), the reaction of the B cell tumors reflected the expression of these markers on comparable normal cells. This investigation also emphasized the marked intratumor and intertumor heterogeneity that is observed when cloned cell lines are analyzed quantitatively for a large number of surface markers. Thus, this approach may be particularly useful in defining heterogeneity in maturation states within cloned tumor cell lines.

Animals↗
PubMed1980

Cyclic AMP modulation of Fc receptor expression on a pre-B cell lymphoma.

Cyclic AMP-elevating agents have been shown to increase the expression of Fc receptors on the Abelson virus-induced pre-B cell tumor ABE-8. Such agents included isoproterenol, PGE1, 3-isobutyl-1-methyl xanthine, and 8 BrcAMP. The positive inductive effect produced by these agents was inhibited by 8 BrcGMP and PGF2 alpha, which putatively elevate cyclic GMP levels. Other agents also shown to induce Fc receptor expression were LPS and certain batches of fetal calf sera. In contrast to the inductive effect produced by cyclic AMP elevating agents, 8 BrcGMP and PGF2 alpha were unable to reverse the increased Fc receptor expression produced by LPS and fetal calf sera. Thus, these latter agents may act via a qualitatively different mechanism in producing a change in phenotypic expression. The results of this study are discussed in terms of the use of tumor cells as a model system for studying the pharmacologic control of lymphocyte differentiation.

Animals↗
PubMed1980

Differential natural killer cell reactivity against T cell lymphomas by cells from normal or stimulated mice.

One of the major problems confronting the study of NK cell populations concerns their potential recognition patterns and specificity. In this study three T cell lymphomas that differ markedly in their susceptibility to NK-mediated lysis from normal mice are shown to bear quantitatively but not qualitatively different degrees of NK target structures. The ability of these tumors to be lysed by NK cells can be drastically changed by augmentation of NK activity by LCM virus, but in a manner that differs relatively for the different targets. Comparison of the growth of these tumors in vivo strongly suggests an in vivo action for NK cells.

Animals↗
PubMed1980

Tumor immunity to murine plasma cell tumors. V. Genetic control of the in vitro cytotoxic T-cell response to plasma cell tumor-associated antigens of NZB mice.

Cytotoxic T-lymphocytes (Tc) were induced in vitro to plasmacytoma tumor-associated antigens (TAA) by coculture of irradiated cells of plasma cell tumors (PCT) from NZB mice and viable nonimmune or PCT-immune spleen cells from NZB. (NZB X C57BL)F1, (NZB X B10.D2)F1, and (NZB X B10,BR)F1 mice. When nonimmune spleen cells were used, major histocompatibility complex (MHC)-linked genetic control of te primary in vitro induction of Tc to NZB PCT was demostrated for a shared TAA expressed on NZB and BALB/c PCT. Evidence was also obtained for a non-MHC-linked genetic control of the primary in vitro induction of Tc to a second TAA that ws expressed on both PCT and T-lymphomas. When the spleen cells were obtained from mice preimmunized to an NZB PCT, a secondary in vitro Tc response was observed, and a PCT-specific and strain-specific TAA or NZB mice was identified. In addition, results with the F1 hybrids also indicated an MHC-linked genetic control of the in vitro Tc response to this strain-specific TAA.

Animals↗