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J R Wunderlich

Publications and source records attributed to J R Wunderlich.

At least 37 records · Page 2Linked to original sources
PubMed1988

Targeting of cytotoxic cells against tumors with heterocrosslinked, bispecific antibodies.

Cytotoxic cells express specific receptors on their surfaces by which they distinguish altered or foreign cells from normal autologous cells. Recently, a method has been developed by which the natural recognition system of cytotoxic cells can be artificially manipulated, giving rise to cytotoxic cells of any desired specificity, including specificity against tumor and virally infected cells. The method for retargeting cytotoxic cells employs heterocrosslinked antibodies, in which one antibody is directed against the cytotoxic cell receptor (CCR) involved in lysis, while the second antibody is directed against a target cell structure, for example a tumor or viral antigen. By linking the CCR directly to the target cell, the heterocrosslinked antibodies promote the formation of effector: target conjugates and signal the cytotoxic cell to deliver a lethal hit. T cells can be targeted by heteroconjugates containing antibodies against components of the T cell receptor complex, e.g., Ti or CD3, while several types of antibody-dependent cellular cytotoxicity (ADCC) effector cells, including K/NK cells, macrophages, and neutrophils, are targeted using heteroconjugates containing antibodies against Fc gamma receptors. In peripheral blood from normal donors at least six types of targetable activities have been identified in vitro. In Winn type tumor neutralization assays in nude mice, targeted T and K cells can prevent the establishment of subcutaneous tumor at low effector: tumor ratios. Moreover, targeted human peripheral blood T cells cause the eradication of established intraperitoneal human ovarian carcinoma in nude mouse models. Targeted cytotoxic cells therefore hold great promise as a novel form of cancer immunotherapy in humans.

Animals↗
PubMed1987

Human T cells targeted with anti-T3 cross-linked to antitumor antibody prevent tumor growth in nude mice.

Human peripheral blood T cells were tested for the ability to prevent tumor growth in nude mice when targeted with anti-T3 cross-linked to antitumor antibodies. LS174T human colon adenocarcinoma cells were mixed with human PBL coated either with anti-T3 (Fab) cross-linked to 315F6 (Fab) (an antitumor monoclonal antibody) or with no antibody, and were injected subcutaneously into nude mice. Tumor growth was totally inhibited at effector to target (E:T) ratios of 7.0:1 and 2.1:1, and was partially inhibited at 0.7:1 with antibody-coated PBL, but was not inhibited by uncoated PBL. T cell-mediated protection against tumor growth occurred when an antitumor was physically cross-linked to anti-T3. Neither a mixture of unlinked anti-T3 and antitumor antibodies nor anti-human MHC class I cross-linked to antitumor antibody prevented tumor growth. Whereas in vitro cytotoxicity was mediated exclusively by T8+ cells and was augmented by brief exposure of effector cells to IL 2, tumor neutralization in vivo was mediated by both T4+ and T8+ cells and was not significantly stimulated by prior exposure of the cells to IL 2. We conclude that human T cells, when targeted with appropriate antibody heteroaggregates, can specifically inhibit tumor growth at low E:T ratios, and that cells mediating tumor neutralization in vivo may differ from those mediating cytotoxicity in vitro.

Adenocarcinoma↗
PubMed1986

Changes in mouse MHC expression during the cell cycle of Con A-treated spleen cells.

This study was directed at correlating the expression of class I MHC determinants with different segments of the cell cycle by using dual laser flow microfluorometry to measure levels of both DNA and cell surface H-2Kd or H-2Dd determinants for single cells. Con A-treated mouse spleen cells were identified as being in the G2/M or G0/G1 phases of the cell cycle on the basis of propidium iodide or Hoechst 33342 dye bound to DNA. Monoclonal anti-H-2 antibodies, indirectly fluoresceinated with goat anti-mouse IgG, were used to detect MHC determinants. The average level of both Kd and Dd determinants expressed by G2/M cells was about 1.6-fold higher than that expressed by G0/G1 cells. These observations indicate that the average-size G0/G1 and G2/M cells have the same apparent surface density of Kd and Dd determinants, insofar as we estimate that these cells differ in surface area by a factor of about 1.5. We also analyzed the expression of Kd and Dd determinants by measuring how they changed as a function of the intensity of forward light scatter from cells. For both G2/M and G0/G1 cells, changes in light scatter intensity were associated with parallel changes in levels of Dd and Kd determinants, indicating a common mechanism(s) that controls their cell surface expression.

Animals↗
PubMed1985

In vitro and in vivo antitumor activity of lymphokine-induced cytotoxic cells.

The present study demonstrates that LICC possess both in vitro and in vivo antitumor activity. The LICC were generated by culturing normal spleen cells with syngeneic peritoneal cells and indomethacin, or with a conditioned medium containing IL 2 with or without a putative new lymphokine, the CCDF. The LICC thus generated selectively killed the lymphoid or solid tumor targets of different H-2 haplotypes and of different etiological origins. The precursors of LICC were probably NK-like cells. The effectors were neither classical NK nor classical cytotoxic T lymphocytes. The LICC were very effective in preventing growth of both lymphoid and solid tumors in vivo, and Thy I+ cells were essential for the anti-tumor effect. The ability to generate LICC was preserved in the tumor-bearing hosts until the terminal stage of tumor growth, when the generation of suppressor T-cells interfered with LICC induction. LICC seem to play an important role in defense against non-immunogenic tumors.

Animals↗
PubMed1984

Filipin as a flow microfluorometry probe for cellular cholesterol.

The polyene antibiotic filipin, which forms specific complexes with 3 beta-hydroxysterols, displays spectral properties compatible with its use in flow microfluorometry (FMF). The purpose of this study was to test the suitability of filipin as an FMF probe for unesterified cellular cholesterol. The following experimental conditions appeared optimal for cells with an average unesterified cholesterol content of less than 3 nmol per 10(6) cells: 2 X 10(6) fixed cells (1-4% p-formaldehyde, 30 min, 21 degrees C) stained for 2-4 h with 100 micrograms/ml filipin and excited at 350.7/356.7 nm. Fluorescence emission (Em) was measured above 510 nm. Less suitable conditions involved excitation at 488 nm or using cells which had not been fixed. Fixation preserved the live-dead cell discrimination provided by forward light scatter measurements, so that dead cells could be excluded from the FMF analysis of cellular cholesterol. Under the above conditions FMF analysis of a variety of murine cell types showed that in all cases the fluorescence intensity of filipin-stained cells was clearly increased above autofluorescence levels of the unstained control cells. The increase in fluorescence signal in different filipin stained cell types correlated (P less than or equal to .001) with the cellular content of unesterified cholesterol determined by an independent enzymatic assay. The sensitivity of the FMF assay was in the femtomole (10(-15) ) range. Mixing experiments with cells of different cholesterol levels showed that the technique distinguishes cell populations with distinctive levels of unesterified cholesterol. We therefore concluded that filipin is a useful FMF probe for determining relative levels of unesterified cholesterol in cells.

Animals↗
PubMed1983

Supplement-induced cytotoxic cells (SICC) generated from mouse thymus or spleen cells cultured in the presence of interleukin 2 and/or polyinosinic acid.

Mouse thymocytes and spleen cells from unprimed C57BL/6 donors generate broadly reactive cytotoxic cells during 5 days of culture in vitro with polyinosinic acid (5') (poly(I] and/or supernatant from PMA-treated EL4 leukemia cells which contains interleukin 2 (IL-2) activity. We refer here to such cytotoxic cells as "supplement-induced cytotoxic cells" or SICC. Thymocytes are dependent on the supernatant factor(s), whereas spleen cells are usually stimulated by poly(I) alone. Polyinosinic acid acts synergistically with supernatant factor(s) to stimulate generation of SICC by both thymocytes (SICC-T) and spleen cells (SICC-S) when the IL-2 activity of the supernatant is inadequate alone. SICC can be generated by both splenocytes and thymocytes in medium supplemented with fetal calf serum or syngeneic plasma. SICC are active in 4 hr 51Cr-release tests against syngeneic, allogeneic, and xenogeneic tumors but not against lipopolysaccharide-induced lymphoblasts. Embryonic fibroblasts, too, are sensitive to SICC generated by thymocytes. In complement-dependent depletion tests, cytotoxic activity is partially sensitive (SICC-T) or fully sensitive (SICC-S) to anti-Thy-1 and -H-2 but not to anti-Lyt-1, -Lyt-2, or -asialo GM1.

Age Factors↗
PubMed1983

Changes in cell-surface expression of MHC and Thy-1.2 determinants following treatment with lipid modulating agents.

Treatment of normal mouse spleen cells with lipid fluidity modulators changes the expression of cell-surface H-2 determinants. BALB/c spleen cells treated for 1 to 2 hr with cholesteryl hemisuccinate (CHS) displayed reduced levels of all tested H-2 determinants (H-2L, H-2K, and H-2D) as evaluated by flow microfluorometry and increased membrane lipid packing density as determined by 1,6-diphenyl-1,3,5-hexatriene (DPH) fluorescence polarization. In contrast, decreasing membrane lipid packing density by phosphatidylcholine treatment decreased DPH fluorescence polarization and increased the expression of MHC determinants. The effects were selective in that expression of Thy-1.2 determinants was decreased by the latter treatment and not increased by CHS. The results are discussed in terms of passive modulation of antigenic expression.

Animals↗
PubMed1980

Susceptibility of adherent versus suspension target cells derived from adherent tissue culture lines to cell-mediated cytotoxicity in rapid 51Cr-release assays.

Preparation of target cells from tissue culture lines which grow adherent to tissue culture vessels is often desirable for tests of cell-mediated cytotoxicity (CMC). In the present study we used cells derived from adherent tissue culture lines to compare the merits of suspension vs. adherent target cells in short-term 51Cr-release assays. Cytotoxic activity of murine spleen cells sensitized in vitro against allogeneic spleen cells or syngeneic sarcoma cells was tested with fibroblast or sarcoma target cells. In parallel tests, aliquots of tissue culture lines were detached and used as either suspension or adherent target cells in CMC assays, matching the concentrations of suspension and adherent target cells. In both allogeneic and syngeneic combinations adherent target cells released less 51Cr spontaneously and were more susceptible to CMC than their suspension counterparts.

Animals↗
PubMed1980

Chemical enhancement of tumor immunogenicity.

C57BL/6 spleen cells immunized in vitro against syngeneic methylcholanthrene-induced sarcoma cells(MC-1 cells) modified with various chemical reagents show cytotoxic activity against unmodified MC-1 cells in a short-term 51Cr release assay, whereas unmodified MC-1 cells are nonimmunogenic. The effector cells cross-react widely with many other fibroblastic and epithelioid tumors, even those that are not H-2 matched, as well as with some nonneoplastic cells. Priming mice in vivo with a hapten leads to enhanced anti-tumor cytotoxicity developed by spleen cells from these mice immunized in vitro against tumor cells modified with the same hapten. Cytotoxic activity is largely, but not completely, removed by treatment with anti-theta serum and C. The existence of suppressor cells that can inhibit an anti-tumor response is demonstrasted in in vitro immunizations of mixtures of spleen cells from normal mice and mice primed with mitomyhcin-treated tumor cells, the latter suppressing the former.

Animals↗
PubMed1980

The cellular nature of concanavalin A-stimulated antibody-dependent cell-mediated cytotoxicity.

Enhanced antibody-dependent cytotoxic cell (ADCC) activity, generated in vitro by concanavalin A (Con A) stimulation of human peripheral blood lymphocytes, was analyzed to identify the nature of the killer (K) cell. Stimulated and unstimulated 2-day cultured cells were separated into sheep erythrocyte rosetting (E+) and non-rosetting (E-) subpopulations, and ADCC activity was determined by using the slopes of linear dose-response plots as a measure of K cell activity. Quantitative comparisons were made by examining activity on a per cell basis ("specific" activity) and total K cell activity recovered per subpopulation. This analysis revealed that although the E- cells were enriched for specific ADCC activity, the E+ subpopulation contained the major proportion of the total recovered activity and nearly all of the Con A-induced increase in K cell activity.

Antibody-Dependent Cell Cytotoxicity↗
PubMed1979

Cell-mediated cytotoxic responses of spleen cells from mice bearing primary, chemically induced tumors.

Sarcomas were induced in C57BL/6 mice by using 3-methylcholanthrene. Spleen cells taken from these mice bearing primary, chemically induced tumors and from matched control mice were assessed for the capacity to generate cell-mediated cytotoxic cell activity after in vitro sensitization. Spleen cells from tumor-bearing mice generated strong cell-mediated cytotoxic responses against alloantigens and antigens on syngeneic cells.

Animals↗
PubMed1976

Temporary inhibition of antibody-dependent, cell-mediated cytotoxicity by pretreatment of human attacking cells with ammonium chloride.

Treatment of lymphoid cell preparations with ammonium chloride buffers to remove contaminating erythroid cells markedly reduced the ability of these cells to function as attacking cells in antibody dependent cell mediated cytotoxicity tests (ADCC). The lymphoid cells, however, retained their ability to adhere to antibody-coated target cells. Recovery of function 20 hr after exposure to ammonium chloride suggests a metabolic rather than receptor effect of these salts on the ADCC function of lymphocytes.

Ammonium Chloride↗
PubMed1976

T cell memory for the cytotoxic response to hapten-modified target cells.

This study describes the development of memory and cytotoxic murine T cells against syngeneic haptne N equals[N-(3-nitro-4-hydroxy-5-iodophenyl-acetyl)-Beta-alanylglycylglycyl] associated antigen. Memory activity in this system had the following characteristics. a) In vitro challenged cells primed in vivo resulted in an augmented cytotoxic response compared to cells primed in vitro. b) The augmented cytotoxic response in vitro was antigen-specific for both target cells in the lytic reaction and stimulator cells in the secondary response. c) Memory activity was long lasting (at least 2 months). d) Memory cells were not cytotoxic. e) Memory activity as well as the cytotoxic cells generated in a secondary response in vitro were T cell dependent, These findings are consistent with the results of others who have investigated T cell dependent memory in other cell-mediated reactions.

Animals↗
PubMed1975

Augmented antibody-dependent cell-mediated cytotoxicity following sensitization or nonspecific stimulation of human effector cells.

Human peripheral blood leukocytes were stimulated in vitro with mitogens (poke-weed mitogen, concanavalin A, and phytohemagglutinin) or allogeneic cells. Each form of stimulation augmented the cytotoxic effector cell activity of lymphoid cells in a 4-hr test for antibody-dependent cell-mediated cytotoxicity. This augmented activity did not involve release of detectable nonspecific toxins, nor did it require the presence of mitogen during the cytotoxicity test. Stimulated attacking cells appeared more cytotoxic either because of a more potent cytotoxic mechanism per individual cytotoxic cell or because of an increased percentage of cytotoxic cells.

Antibodies↗
PubMed1975

Anti-HL-A7 lymphocyte-dependent antibody.

Target cell specificity of a human cytotoxic lymphocyte-dependent antiserum correlated with the presence of HL-A7 on target cells. Target cells from 10 of 11 HL-A7-positive donors were damaged in vitro by this antiserum together with lymphocytes from normal donors. Target cells from six donors lacking HL-A7 were not damaged. Cytotoxic activity was removed by adsorption of the antiserum with lymphocytes from any one of four HL-A7-positive donors. Adsorption with lymphocytes from any one of three HL-A7-negative donors failed to eliminate cytotoxic activity.

Adsorption↗
PubMed1975

Identification of macrophage-like characteristics in a cultured murine tumor line.

A mouse tumor line P388D1 passaged in tissue culture for many years has been characterized morphologically and functionally as a macrophage like cell. P388D1 cells phagocytize latex particles and firmly adhere to glass and plastics. In addition they have been shown to carry cellbound receptors for immunoglobulin (Fc) and complement (C3). They fail to stain with fluorescent anti-mouse Ig or heterologous anti-mouse. Functionally, these cells exhibited high effector activity in an antibody-dependent, cell-mediated cytotoxic system. The accessibility of well characterized and pure macrophage-like cell lines, such as P388D1, will facilitate studies where cell purity is essential.

Animals↗