bluuebunny/crossref_metadata_2025 huggingface dataset:
Modulation of the heterogeneous membrane potential response of neutrophils to N-formyl-methionyl-leucyl-phenylalanine (FMLP) by leukotriene B4: evidence for cell recruitment.
Authors: Fletcher M P
Published: December 2022

Individual human neutrophils (PMN) isolated by Hypaque-Ficoll gradient sedimentation, dextran sedimentation, or buffy coat preparation were assessed for the effects of leukotriene B4 (5S,12R dihydroxy 6,14-cis-8, 10 trans eicosatetraenoic acid (LTB4)-pretreatment on N-formylmethionyl-leucyl-phenylalanine (FMLP)-mediated membrane potential or oxidative responses by using flow cytometry and a lipophilic probe of membrane potential (di-pentyl-oxacarbocyanine, di-O-C(5)3), or the nitroblue tetrazolium dye (NBT) reduction test, respectively. Although exposure to LTB4 (10(-7) M) had no effect on the membrane potential of resting PMN and little effect on oxidant production, pretreating PMN with LTB4 followed by FMLP (10(-6) M) demonstrated a significant enhancement in the proportion of depolarizing PMN over that seen with FMLP alone (p = 0.0014, N = 9). This recruitment of previously unresponsive cells by LTB4 was dose and time dependent, with the maximal relative increase in the proportion of depolarizing cells occurring at LTB4 concentrations of 10(-8) to 10(-7) M and within 1 min of LTB4 addition. The recruitment effect persisted despite vigorous washing of the cells. LTB4 also increased the proportion of NBT-positive PMN in response to FMLP. Although LTB4 alone did not depolarize PMN it did induce a light scatter shift indicative of cell activation. 3H-FMLP binding studied at 0 degree C comparing buffer and LTB4-treated PMN indicated no significant change in the number or affinity of FMLP binding. The data provide evidence for the recruitment of a greater proportion of cells into a FMLP-responsive state as a mechanism for the enhanced functional response of PMN pretreated with LTB4, as well as for a dissociation of the membrane potential and light scattering responses of cells to this pro-inflammatory LT. The mechanism of recruitment remains unclear, but it most likely involves the modulation of a post-FMLP binding step.
Monoclonal antibodies against avian reticuloendotheliosis virus: identification of strain-specific and strain-common epitopes.
Authors: Cui Z Z , Lee L F , Silva R F , Witter R L
Published: December 2022

We report the generation and partial characterization of a panel of 11 monoclonal antibodies (MCA) made against the nondefective strain T reticuloendotheliosis virus (REV). In an enzyme-linked immunosorbent assay (ELISA), nine MCA cross-reacted with both homologous strain T and heterologous strain chick syncytial virus (CS), whereas two MCA were strain specific and reacted with strain T but not with CS. Competitive antibody inhibitory ELISA tests demonstrated that the nine MCA recognized at least two distinct type-common epitopes. By using MCA-mediated immunoprecipitation and polyacrylamide gel electrophoresis analysis, we identified a 62,000 dalton glycoprotein that may contain both type-common epitopes and a 21,000 dalton glycoprotein that contains one of these epitopes. The competitive antibody inhibitory ELISA tests confirmed that the remaining two MCA recognize a strain T-specific epitope. We identified a 54,000 to 72,000 dalton glycoprotein that contains the type-specific epitope. All of the MCA reacted in an ELISA assay with cell-free virus preparations, suggesting that the polypeptides we identified are virion envelope glycoproteins. To identify the nonglycosylated precursor proteins, we treated infected cells with tunicamycin. We found a 48,000 polypeptide that was the nonglycosylated precursor to the 54,000 to 72,000 glycoprotein, and 48,000 and 20,000 dalton proteins that were the nonglycosylated precursors to the 62,000 and 21,000 dalton glycoproteins, respectively. These MCA may be of value in the field. They were able to distinguish in preliminary tests in ELISA between strains T and CS, which were otherwise undistinguishable in assays that made use of conventional polyvalent serum.
Both species of chlamydia and two biovars of Chlamydia trachomatis stimulate mouse B lymphocytes.
Authors: Levitt D , Danen R , Bard J
Published: December 2022

We have investigated the ability of both species of chlamydiae (C. trachomatis and C. psittaci), two major biovars of C. trachomatis (lymphogranuloma venereum and trachoma), and the two developmental forms of chlamydia (reticulate and elementary bodies) to stimulate murine spleen lymphocytes. All of these forms of the bacteria induce potent proliferation and differentiation to plaque-forming cells by B lymphocytes in vitro. Chlamydiae induce a broad antibody response, suggesting that stimulation is polyclonal in nature. Although all chlamydiae possess a lipopolysaccharide (LPS) genus-specific molecule similar to LPS found on Re mutant enterobacteria, polyclonal B cell stimulation is likely caused by molecules other than LPS, since i) polymyxin B failed to inhibit chlamydia-induced immunostimulation and ii) C3H/HeJ mice (LPS nonresponders) produced normal numbers of PFC after culture with chlamydia (but not LPS). Thus, a cross-species moiety that is not LPS is responsible for polyclonal stimulation by chlamydia. Because these bacteria can exist in latent forms in an animal, and all forms are immunostimulatory, the question of whether these bacteria can alter immune responses if released during other infections or immunizations has been raised.
Requirement for recognition of class II molecules and processed tumor antigen for optimal generation of syngeneic tumor-specific class I-restricted CTL.
Authors: Kern D E , Klarnet J P , Jensen M C , Greenberg P D
Published: December 2022

The roles of Class II-restricted L3T4+ T cells and of accessory cells (AC) during the in vitro generation of Class I-restricted Lyt-2+ cytotoxic T cells (CTL) specific for a Class II-negative syngeneic tumor cell line, FBL, was examined. Treatment of responder FBL-immune spleen cells with alpha L3T4 plus complement before culture, as well as the direct addition of alpha L3T4 to cultures, diminished the generation of FBL-specific CTL. The contribution of L3T4+ cells could be completely replaced by the addition of exogenous cytokines. The data demonstrate that the optimal generation of FBL-specific Lyt-2+ CTL requires the presence of L3T4+ cells, presumably to provide necessary lymphokines. FBL-specific CTL could not be generated from purified FBL-immune T cells in the absence of AC. Syngeneic Ia+ macrophages (M phi), added at the initiation of culture, restored the response of purified T cells. Pretreatment of M phi with ammonium chloride or chloroquine, or the addition of monoclonal alpha I-Ab antibody at the initiation of culture, inhibited the ability of M phi to reconstitute the CTL response. Finally, the addition of exogenous helper factors could replace M phi and reconstitute the FBL-specific response of AC-depleted immune T cells. These results suggest that during the generation of Lyt-2+ CTL to a syngeneic tumor expressing only Class I MHC antigens, Ia+ AC are required to biochemically process antigen released from the tumor cells and present this modified antigen to Class II-restricted T helper cells.
Concomitant immunization by the fully antigenic counterparts prevents modulated tumor cells from escaping cellular immune elimination.
Authors: De Boer R J , Michelson S , Hogeweg P
Published: December 2022

In a mathematical model of the cellular antitumor immune response, we studied the possible role of antigenic modulation as a tumor escape mechanism. Modulated tumor cells arise from normal (fully antigenic) tumor cells when the latter interact with antibodies. Modulated tumor cells demodulate when antibody concentrations are sufficiently low. Through modulation, tumor cells become less sensitive to cytotoxic macrophages (cell lysis) and contribute less to the stimulation of the immune system. These experimental data are incorporated in a model which we have analyzed previously. The model incorporates interactions between macrophages and T lymphocytes, which lead to cellular antitumor immune reactions (i.e., to cytotoxic macrophages). Parameters were derived from the immune resistance of DBA/2 mice to the SL2 tumor. Although all parameters were chosen deliberately to favor the modulation process (i.e., modulation proceeds fast, demodulation slowly, and the killing rate is reduced 50-fold), modulation is found to be a poor tumor escape mechanism. Heterogeneous populations of modulated and normal tumor cells are easily rejected. Homogeneous populations of modulated cells do escape, however. We conclude that the impact of modulation as an escape mechanism remains small because modulated tumor cells do not appear until the immune system has been stimulated (immunized) by the fully antigenic tumor cells. Thus, the elimination of modulated tumor cells generally occurs merely as a side effect of the immune response which is directed primarily against the fully antigenic tumor cells. Parameter sensitivity analysis shows that this conclusion holds true only for cellular immunity. Conversely, the parameter analysis suggests that antigenic modulation plays a deleterious role in cytotoxic antibody responses (e.g., monoclonal antibody therapy).
H2-restricted recognition of cloned HLA class I gene products expressed in mouse cells.
Authors: Maryanski J L , Accolla R S , Jordan B
Published: December 2022

Long-term syngeneic mouse cytolytic T lymphocyte (CTL) clones were obtained from DBA/2 (H2d) mice immunized with P815 (H2d) cells transfected with cloned human class I histocompatibility genes, HLA-CW3 or HLA-A24. Three distinct patterns of specificity were defined on P815 HLA transfectant target cells. One clone lysed HLA-CW3 but not -A24 transfectants, and a second lysed HLA-A24 but not -CW3 transfectant target cells. The third clone lysed P815 targets transfected with either HLA gene. None of the CTL clones lysed L cells (H2k) transfected with the same HLA genes or human targets that expressed these HLA specificities. Several lines of evidence indicated that recognition of HLA transfectants by these CTL clones was H2 restricted. First, lysis of P815 HLA transfectants could be inhibited by anti-H2Kd monoclonal antibody. In addition, the anti-P815-HLA CTL clones could lyse a (human X mouse) hybrid target that expressed both HLA class I and H2Kd antigens, but not a clonal derivative that no longer expressed H2Kd. The most direct evidence for H2-restricted recognition of P815-HLA transfectants by the syngeneic CTL clones was obtained by double transfection of mouse L cells (H2k) with both HLA and H2 class I genes. L cells transfected with HLA and H2Kd genes were susceptible to lysis by the same CTL clones that lysed the corresponding P815-HLA transfectant targets. Thus under certain conditions, CTL recognition of xenogeneic class I histocompatibility gene products can be restricted by other class I gene products.
Alloreactive bovine T lymphocyte clones: an analysis of function, phenotype, and specificity.
Authors: Teale A J , Baldwin C L , Ellis J A , Newson J , Goddeeris B M , Morrison W I
Published: December 2022

A bovine alloreactive cell population was subjected to complement-dependent lysis with monoclonal antibody (mAb) IL-A11. The original population and the population depleted of cells bearing the determinant recognized by mAb IL-A11 were cloned. Parent cultures and 21 clones were examined for cytolytic function and for expression of determinants recognized by mAb IL-A11 and two additional mAb, IL-A12 and IL-A17. Clones could be classified according to maximal achievable levels of cytolysis by using Theileria parva-infected bovine lymphoblastoid target cells. In this way, three groups were identified--one capable of high level cytolysis, one of intermediate levels, and one group comprising apparently noncytolytic clones. The clones in the first group reacted with mAb IL-A17; those in the second and third groups, with mAb IL-A11 and IL-A12. It was shown that cytotoxicity effected by IL-A17+ clones could be inhibited by this mAb and also by a mAb directed to MHC class I determinants on target cells. Conversely, cytotoxicity effected by IL-A11+/IL-A12+ clones could be inhibited by mAb IL-A11 and by a mAb directed to MHC class II determinants on target cells. The levels of expression of class I and class II determinants on target cells correlated with the levels of killing by clones of the IL-A17+ phenotype and clones of the IL-A11+/IL-A12+ phenotype, respectively. The results indicate that cytotoxic bovine T lymphocyte clones specific for class I MHC antigens and both cytotoxic and noncytotoxic clones specific for class II MHC antigens can be obtained. Further, their specificity for class I or class II antigens can be determined by phenotyping with mAb.
Autoimmunity after induction of neonatal tolerance to alloantigens: role of B cell chimerism and F1 donor B cell activation.
Authors: Luzuy S , Merino J , Engers H , Izui S , Lambert P H
Published: December 2022

BALB/c mice rendered tolerant by the neonatal injection of semiallogeneic (C57BL/6 X BALB/c)F1 spleen cells develop features of autoimmune disease. The possible mechanisms involved in autoantibody production, particularly anti-DNA antibodies, were investigated. In the first 5 wk, there was polyclonal B cell activation, as indicated by marked hypergammaglobulinemia, with a predominance of IgG1 and an increased production of antihapten antibodies. IgG1 anti-SSDNA and anti-DSDNA antibodies were detected with similar kinetics, but at higher titers than the anti-hapten antibodies. Also, there was a correlation between the effective induction of tolerance, as evaluated by the measurement of alloantigen-specific cytolytic T lymphocyte precursors, the persistence of B cell chimerism, and the production of anti-DNA antibodies. Anti-DNA antibodies were observed only in mice exhibiting a persistence of immunoglobulins bearing the donor's allotype. To determine the origin of anti-DNA antibodies, experiments were conducted whereby newborn BALB/c (Igh-1a) mice were injected with F1 cells from mice resulting from a crossing between Igh congenic BALB/c mice bearing the IgCHb allotype and conventional C57BL/6 mice (Igh-1b). All anti-DNA and anti-hapten antibodies exhibited the Igb allotype and thus were produced by the F1 donor B cells. The initial phase of tolerance induction was apparently associated with an allogeneic helper effect, because DNP-KLH-primed F1 donor cells transferred to newborn BALB/c could be stimulated after challenge with DNP-BGG. The triggering of persisting auto-reactive F1 donor B cells may reflect an activation by "incompletely" tolerant semiallogeneic T cells.
The effect of 1,25-dihydroxyvitamin D3 on in vitro immunoglobulin production in human B cells.
Authors: Iho S , Takahashi T , Kura F , Sugiyama H , Hoshino T
Published: December 2022

1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) dose-dependently suppressed immunoglobulin (Ig) production of human B cells, as evaluated by IgG-plaque-forming cells (IgG-PFC) in the culture of pokeweed mitogen (PWM)-activated B cells. Similar suppressive effect of 1,25(OH)2D3 on Ig production of B cells was observed in the Staphylococcus aureus Cowan I(SAC)-induced Ig-producing system. The mean percentage of inhibitions at a concentration of 10(-9) M were 60.0 +/- 8.2% (mean +/- SE, n = 6) and 65.1 +/- 4.7% (n = 10) in PWM- and SAC-stimulated cultures, respectively. The suppression was strongly exhibited only when 1,25(OH)2D3 was added at the start of the 6-day culture, accompanied by a decrease in DNA synthesis of B cells in both culture systems. On the other hand, the addition of 1,25(OH)2D3 on day 4, when DNA synthesis reached at plateau and IgG-PFC began to be detectable, had no noticeable affect on either the number of PFC or DNA synthesis of B cells. Furthermore, 1,25(OH)2D3 suppressed Ig production even when B cells were exposed to the agent for 4 hr after the activation with PWM or SAC, but not before the activation. These results indicate that 1,25(OH)2D3 inhibits B cell proliferation before differentiation to Ig-secreting cells, consequently reducing Ig production; and that its action appears to be mediated by the cytosol receptors expressed on activated B cells. Thus, the agent may serve as an immunoregulating hormone in vivo, as well as in vitro.
Leukocyte migration inhibitory factor (LIF) to sperm from autoimmune men in infertile couples.
Authors: Mathur S , Pathak S , Kandel A , Ziegler J , Rust P F , Wiliamson H O
Published: December 2022

Leukocyte migration inhibitory factor (LIF) is produced by lymphocytes with receptors specific to sensitizing antigens. This principle was used to detect possible antigenic differences between sperm of autoimmune and nonautoimmune men. Sixteen fertile and 91 infertile couples were screened for cytotoxic and hemagglutinating antibodies to sperm from their husbands and controls. Their lymphocytes were tested for the production of LIF to sperm extracts and seminal plasma from the husbands and controls by a direct leukocyte migration inhibition assay. Twenty-nine of 35 men producing LIF to sperm and/or seminal plasma were positive for sperm antibodies (p = 0.0004, vs sperm antibody-negative controls). Twenty-three of 29 wives with LIF production had sperm-autoimmune husbands (p = 0.04). Leukocyte migration was significantly inhibited in sperm-autoimmune men by autologous sperm extracts and seminal plasma in contrast to control sperm extracts and seminal plasma (p = 0.0006 and 0.001, respectively). The wives of autoimmune men had significantly higher LIF responses to their husbands' sperm extracts than to other antigens (p = 0.02). Men with cytotoxic antibodies in their seminal plasma produced LIF to autologous sperm (p = 0.001). It is suggested that certain sperm and seminal plasma antigens of autoimmune men may lead to specific humoral and cell-mediated immune responses in both partners.
Accessory cell competence of ovine oligodendrocytes in mitogenic activation of human peripheral T cells.
Authors: Cashman N R , Noronha A
Published: December 2022

The multiple sclerosis (MS) plaque is characterized by mononuclear inflammatory cell infiltration, demyelination, loss of oligodendrocytes (OGC), and proliferation of astrocytes. Although antigen-specific, Ia-dependent cellular immune mechanisms have been sought in plaque pathogenesis, Ia-independent T cell activation has not been actively investigated. We examined a potential role of OGC in accessory cell-dependent T cell mitogenesis with the anti-T3 monoclonal antibody OKT3. OGC isolated from ovine white matter on sucrose density gradients were uniformly negative for esterase activity, unlike ovine monocytes. Purified human T cells did not exhibit significant proliferation in 3-day cultures with OKT3, autologous peripheral blood adherent cells (PBAC), or ovine OGC. When T cells were cultured with either PABC or OGC in the presence of OKT3, brisk mitogenesis was observed. Thus, OGC have the capacity to function as accessory cells in the mitogen-induced proliferation of T cells.
The relationship of CD16 (Leu-11) and Leu-19 (NKH-1) antigen expression on human peripheral blood NK cells and cytotoxic T lymphocytes.
Authors: Lanier L L , Le A M , Civin C I , Loken M R , Phillips J H
Published: December 2022

We examined the antigenic and functional characteristics of human peripheral blood lymphocytes that differentially express the CD16 (Leu-11) and Leu-19 (NKH-1) antigens. Leu-19 is a approximately 220,000 daltons protein expressed on approximately 15% of freshly isolated peripheral blood lymphocytes. Within the Leu-19+ subset, three distinct populations were identified: CD3-,CD16+,Leu-19+ cells; CD3+,CD16-,Leu-19+ cells; and CD3-,CD16-,Leu-19bright+ cells. Both the CD3+,CD16-,Leu-19+ and CD3-,CD16+,Leu-19+ populations mediated non-major histocompatibility complex (MHC)-restricted cytotoxicity against the NK-sensitive tumor cell K562 and were large granular lymphocytes. CD3-,CD16+,Leu-19+ NK cells were the most abundant (comprising approximately 10% of peripheral blood lymphocytes) and the most efficient cytotoxic effectors. The finding that CD3+,Leu 19+ lymphocytes mediated cytotoxicity against K562 unequivocally demonstrates that a unique subset of non-MHC-restricted cytotoxic CD3+ T lymphocytes are present in the peripheral blood of unprimed, normal individuals. However, CD3+,CD16-,Leu-19+ cells comprised less than 5% of peripheral blood lymphocytes, and the cytotoxic activity of this subset was significantly less than CD3-,CD16+,Leu-19+ NK cells. Most CD3+,Leu-19+ T cells co-expressed the CD2, CD8, and CD5 differentiation antigens. The antigenic and functional phenotype of peripheral blood CD3+,Leu-19+ cytotoxic T lymphocytes corresponds to the interleukin 2-dependent CD3+ cell lines that mediate non-MHC-restricted cytotoxicity against NK-sensitive tumor cell targets. A small population of Leu-19bright+ lymphocytes lacking both CD3 and CD16 was also observed. This population (comprising less than 2% of peripheral blood lymphocytes) contained both large agranular lymphocytes and large granular lymphocytes. CD3-,CD16-,Leu-19bright+ lymphocytes also mediate non-MHC-restricted cytotoxicity. The relationship of these CD3-CD16-,Leu-19bright+ lymphocytes to CD3+ T cells or CD16+ NK cells is unknown.
Expression of interleukin 2, interferon-gamma, and the IL 2 receptor by human peripheral blood lymphocytes.
Authors: Grabstein K , Dower S , Gillis S , Urdal D , Larsen A
Published: December 2022

Human peripheral blood T lymphocytes were treated with recombinant interleukin 2, mitogens, and dexamethasone. The resulting accumulation of mRNA for interleukin 2 (IL 2), the interleukin 2 receptor (IL 2R), and interferon-gamma (IFN-gamma) was measured. IL 2 was found to regulate the levels of each of these mRNA. The expression of mRNA for IL 2, IL 2R, and IFN-gamma correlated very well with the levels of protein observed. In populations of peripheral blood T lymphocytes, the production of IL 2 and IFN-gamma were not necessarily coordinately expressed. The sequential expression of these mRNA was investigated in order to determine whether they might be independent of the action of IL 2. IFN-gamma and IL 2 mRNA showed biphasic accumulations. IL 2 mRNA accumulated very rapidly, within 60 min after mitogen stimulation and before any detectable IL 2R mRNA accumulation. Similarly, IFN-gamma mRNA accumulated rapidly, simultaneously with IL 2 mRNA. This early peak of IFN-gamma mRNA, therefore, is likely to be independent of IL 2 action. Both IL 2 and IFN-gamma mRNA then showed later peak times of accumulation. IL 2 mRNA levels peaked at 5 hr after mitogen stimulation, whereas IFN-gamma mRNA levels peaked at 20 hr. IL 2R mRNA continued to accumulate for the full 40 hr of these kinetic experiments. The later accumulations of IFN-gamma and IL 2R mRNA and the resulting expression of the corresponding proteins may therefore be dependent on the earlier production of IL 2 and its subsequent interaction with the IL 2R on the surface of such activated T cells.
Interleukin 1 alpha and interleukin 1 beta bind to the same receptor on T cells.
Authors: Kilian P L , Kaffka K L , Stern A S , Woehle D , Benjamin W R , Dechiara T M , Gubler U , Farrar J J , Mizel S B , Lomedico P T
Published: December 2022

Pure, E. coli-derived recombinant murine interleukin 1 alpha (IL 1 alpha) was labeled with 125I and used for receptor binding studies. The 125I-IL 1 binds to murine EL-4 thymoma cells in a specific and saturable manner. Scatchard plot analysis for binding studies carried out at 4 degrees C reveals a single type of high affinity binding site with an apparent dissociation constant of approximately 2.6 X 10(-10) M and the presence of approximately 1200 binding sites per cell. The rate of association of the 125I-IL 1 with EL-4 cells is slow, requiring more than 3 h to reach apparent steady state at 4 degrees C. Cell-bound 125I-IL 1 cannot be dissociated from EL-4 cells upon removal of unbound 125I-IL 1 and incubation of the cells at 4 degrees C in the presence or absence of unlabeled IL 1. Unlabeled recombinant murine IL 1 competes for 125I-IL 1 binding in a dose-dependent manner, whereas interferon-alpha A, interleukin 2 (IL 2), epidermal growth factor, and nerve growth factor have no effect. The 125I-IL 1 binding site is sensitive to trypsin, suggesting that it is localized on the cell surface. We have also examined the ability of purified recombinant human IL 1 alpha and IL 1 beta to compete for binding of the radiolabeled murine IL 1 to its receptor and to stimulate IL 2 production by EL-4 cells. Previous reports have shown that human IL 1 alpha is approximately 60% homologous in amino acid sequence with murine IL 1, but that human IL 1 beta is only about 25% homologous with either murine IL 1 or human IL 1 alpha. Despite these marked differences, however, we report here that both human IL 1 proteins are able to recognize the same binding site as mouse IL 1. In addition, murine as well as both human IL 1 proteins stimulate IL 2 production by EL-4 cells.
Bacterial lipopolysaccharide-induced interferon-gamma production: roles of interleukin 1 and interleukin 2.
Authors: Le J , Lin J X , Henriksen-DeStefano D , Vilcek J
Published: December 2022

Bacterial lipopolysaccharide (LPS) induced human peripheral blood mononuclear cells (PBMC) to produce interferon-gamma (IFN-gamma). Monocytes play a mandatory accessory role in this process, because purified T lymphocytes failed to produce IFN-gamma in response to LPS and the addition of 2% monocytes to T cell cultures resulted in an optimal LPS-induced IFN-gamma production. IFN-gamma production was abolished in the presence of monoclonal antibodies specific for HLA-DR antigen. Addition of exogenous interleukin 2 (IL 2) markedly enhanced IFN-gamma secretion by PBMC induced with LPS. The addition of anti-Tac antibody specific for IL 2 receptors abrogated IFN-gamma production, suggesting that an interaction of IL 2 with IL 2 receptors was involved. By using a specific antibody binding assay, LPS was shown to amplify IL 2 receptor expression on PBMC, whereas exogenous IL 2 showed only a negligible enhancing effect on the expression of its own receptors. Interleukin 1 (IL 1), a product of LPS-stimulated monocytes, potentiated IL 2-induced IFN-gamma production in the absence of LPS. Neither IL 1 nor IL 2 alone induced IFN-gamma production in purified T lymphocyte cultures. When added together, however, substantial levels of IFN-gamma were induced. An enhanced IL 2 receptor expression on T cells was also demonstrated as a result of the combined action of IL 1 and IL 2. These results suggest that induction of IFN-gamma by LPS is due mainly to the generation of IL 1 and an enhanced expression of IL 2 receptors.
Production of B cell growth factor by normal human B cells.
Authors: Jurgensen C H , Ambrus J L , Fauci A S
Published: December 2022

Although it has been demonstrated that malignant human B cell lines are capable of producing B cell growth factor (BCGF), production of BCGF by normal B cells has not been shown. In this study, we demonstrate BCGF production by normal B cells, achieved by using human peripheral blood B cells prepared by a positive selection technique and stimulated with Staphylococcus aureus Cowan I (SAC) for 12 hr. SAC was removed from the supernatants by anti-SAC-coupled Sepharose. Supernatants absorbed with this antibody were functionally free of SAC, as demonstrated by their inability to activate resting B cells. B cells stimulated with SAC for 12 hr produced BCGF activity that was generally unmeasurable in supernatants by 36 hr. Characterization of BCGF produced by SAC-stimulated B cells revealed a m.w. of 32,000 by high-performance liquid chromatography sieving and sodium dodecyl sulfate-polyacrylamide gel electrophoresis; this BCGF was found to have an isoelectric point of 6.7. Furthermore, this BCGF lacked interleukin 1, interleukin 2, interferon, and B cell differentiation factor activity. This observation that BCGF can be produced by normal human B cells is significant because it demonstrates for the first time that normal B cells have the ability to provide their own growth factors or the growth factors for other B cells.
Administration of monoclonal anti-T cell antibodies retards murine lupus in BXSB mice.
Authors: Wofsy D
Published: December 2022

Murine lupus in BXSB mice is associated with B cell hyperactivity, monocyte proliferation, and impaired T cell function. However, the significance of these abnormalities, and the relationship among them, has not been clearly established. To examine the role of T cells in the pathogenesis of autoimmune disease in BXSB mice, we depleted specific T cell subsets from BXSB males by using rat IgG2b monoclonal antibodies (MAb) to either Thy-1.2 (on all T cells) or L3T4 (on "helper/inducer" T cells). A single injection of anti-Thy-1.2 (6 mg i.v.) at age 3 mo produced a sustained 40 to 50% reduction in circulating T cells for 6 mo. Treatment prevented monocytosis, reduced anti-DNA antibody concentration, and retarded renal disease, but it did not prolong life. Repeated injections of rat MAb to Thy-1.2 were precluded by the development of a host immune response to rat immunoglobulin (Ig) that can cause anaphylaxis in BXSB mice. In contrast, rat MAb to L3T4 stimulated little or no immune response to rat Ig. We therefore were able to treat BXSB mice weekly with anti-L3T4 (2 mg i.p.) from age 3 to 12 mo. Treatment reduced circulating L3T4+ cells beneath the level of detection by fluorescence analysis. It also significantly reduced monocytosis, anti-DNA antibody production, renal disease, and mortality. These findings establish that monocytosis and autoimmunity in BXSB mice are promoted by T cells. They extend our previous observation that MAb to L3T4 retard autoimmunity in NZB/NZW F1 mice. Our finding that treatment with MAb to L3T4 is effective in two strains of lupus-prone mice suggests that treatment with MAb to Leu-3/T4, the human homologue for L3T4, may be effective in people with systemic lupus erythematosus.
Expression of transfected human interferon-gamma DNA: evidence for cell-specific regulation.
Authors: Young H A , Dray J F , Farrar W L
Published: December 2022

The production of interferon-gamma (IFN-gamma) has been limited to two specific cell types of the immune system, T cells and large granular lymphocytes. Interleukin 2 (IL 2) appears to be the primary physiologic stimulus for IFN-gamma production in vitro, but other agents, such as antigens, phorbol myristic acetate, concanavalin A, or other plant lectins, may also act as effective inducing agents for IFN-gamma production. Little is known, however, as to the role, if any, that genetic factors may play in the induction process. We now report that, on stable transfection of the genomic human IFN-gamma 8.6 Kb BamH DNA fragment into a mouse T lymphoblast cell line, both mRNA expression and synthesis of human IFN-gamma were stimulated by both the physiologic ligand IL 2 and phorbol ester. In contrast, we have been unable to induce with extracellular stimulants IFN-gamma production or cytoplasmic mRNA after introduction of this gene into NIH 3T3 fibroblasts, thus suggesting that the extracellular regulation of the expression of IFN-gamma may be controlled by a developmental mechanism(s) intrinsic for cells of lymphoid lineage.
Cytolytic interactions between murine macrophages, tumor cells, and monoclonal antibodies: characterization of lytic conditions and requirements for effector activation.
Authors: Johnson W J , Steplewski Z , Matthews T J , Hamilton T A , Koprowski H , Adams D O
Published: December 2022

Because of recent successes in inducing the effective rejection of neoplasms in vivo by administration of monoclonal antibodies (MAb), we analyzed lytic interactions in vitro that occur between macrophages and several combinations of tumor targets and MAb that can lead to such successful immunotherapy. Murine macrophages, interacting with MAb of the IgG1, IgG2a, IgG2b, and IgG3 isotypes directed against SW-1116 carcinoma cells, destroyed the tumor targets efficiently over 24 to 48 hr in vitro. Lysis was dependent on both concentration of the MAb and density of the macrophages. Binding and lysis of the targets in the presence of MAb of the IgG2a isotype was dependent on intact Fc gamma 2aR on the macrophages; target binding was necessary but not sufficient for subsequent lysis. The lytic step appeared to have an oxidative basis, at least in part, as shown by inhibition of lysis with a nonspecific scavenger of H2O2 or under either anaerobic or glucose-deprived conditions. TG-elicited or pyran-elicited macrophages, which are incompletely activated for antibody independent kill of tumor cells, were effective in mediating ADCC. By contrast, macrophages fully activated for direct cytolysis by administration of BCG or Propionibacterium acnes in vivo or by MAF and LPS in vitro, had diminished capacity for ADCC. A spectrum of five other tumor cells and antibodies, four of which are also involved in successful models of immunotherapy in vivo, were also killed over 48 hr more effectively by thioglycolate-elicited than by BCG-activated macrophages. Taken together, the data indicate that macrophages can lyse tumor cells in an ADCC reaction that has application to some models of the destruction of tumors in vivo, but that the lysis is slow and requires the macrophages to be activated in a specific way(s).
Anti-tumor properties of lymphocytes activated by the oxidizing mitogens.
Authors: Wang J , Suthanthiran M , Walle A , Lagman M , Schwartz R , Murthi V , Novogrodsky A , Stenzel K H
Published: December 2022

Human peripheral blood mononuclear cells when activated with the oxidizing mitogens, neuraminidase/galactose oxidase or sodium periodate, express cytolytic activity for freshly isolated tumor cells and for a variety of cell lines, including NK-resistant solid tumor lines. Normal lymphoid cells are not targets for cytotoxicity and do not inhibit lysis of susceptible targets mediated by the oxidizing mitogen-activated mononuclear cells. The cytotoxic response is rapidly generated and reaches peak levels at 48 hr. The oxidizing mitogens induce expression of IL 2 receptors on peripheral blood mononuclear cells. Combined treatment of cells with IL 2 and the oxidizing mitogens results in a marked enhancement of cytotoxicity. Enhancement is achieved at levels of IL 2 that alone result in minimal generation of cytotoxic cells. Growth of a human renal cancer cell line in nude mice was inhibited when the renal cancer cells were injected together with oxidizing mitogen-activated human mononuclear cells. These studies indicate that oxidizing mitogen-activated cells provide a potentially valuable source of material for the adoptive immunotherapy of tumors.
Activation of IL 1-dependent and IL 1-independent T cell lines by calcium ionophore and phorbol ester.
Authors: Zlotnik A , Daine B
Published: December 2022

We have studied the activation of interleukin 1 (IL 1)-dependent and IL 1-independent T cell lines, specifically their capacity to produce and secrete interleukin 2 (IL 2). The IL 1-dependent T cell lymphoma LBRM33-1A5.47, which requires phytohemagglutinin (PHA) and IL 1 to produce IL 2, was compared with the IL 1-independent T cell lymphoma LBRM33-5A4 and T cell hybridomas DO-11.10/S4.4 and 3DO-54.8. The latter hybridomas do not require exogenous IL 1 to produce IL 2 in response to mitogens or ovalbumin (OVA)/I-Ad. Even though IL 1 is not required by these IL 1-independent T cell lines, we tested whether IL 1 could modulate their response but found no significant effect of exogenous IL 1. We then studied the activation of these T cell lines by the calcium ionophore A23187 and phorbol myristate acetate (PMA). In the case of the IL 1-dependent line LBRM33-1A5.47, there was a strong response when both A23187 and PMA were used simultaneously. We subsequently found that A23187 can replace PHA, and PMA can replace IL 1 in the activation of this cell line to IL 2 production. These observations suggest that the signal(s) provided by PHA and IL 1 involve at least in part a calcium flux, and activation of protein kinase C. Parallel experiments with the use of the IL 1-independent T cell lines showed a strong response to both agents when used simultaneously. A modest response observed to A23187 alone was always enhanced by the addition of PMA. No response was observed to PMA alone. IL 1-rich P388D1 supernatant could replace the enhancing effect of PMA in the response of the IL 1-independent T cell lines. We suggest that the activating signals provided by A23187 and PMA are at least part of the sequence of events that lead to production of IL 2 in either IL 1-dependent or IL 1-independent T cell lines. In IL 1-independent T cell lines, however, both of the activating signals studied may be delivered through stimulation of the Antigen-MHC T cell receptor.
Lipid composition of alveolar macrophage plasma membrane during postnatal development.
Authors: Ricardo M J , Small G W , Myrvik Q N , Kucera L S
Published: December 2022

This study was undertaken to define the age-related alterations in lipid composition that resident rabbit alveolar macrophages (AM) undergo during postnatal development. The eventual goal is to correlate these changes with the functional maturation of these cells. The number of AM recorded from total lung lavages rose markedly during the first 14 days of life, from 4.9 X 10(5) to 1.1 X 10(7). Adult lungs yielded 1.1 X 10(8) AM. A gradual but significant increase in fluorescence polarization (P) was observed during development when purified AM plasma membranes were tagged with the probe 1,6-diphenyl-1,3,5 hexatriene trimethyl ammonium. The rise ranged from a mean P value of less than or equal to 0.22 to 0.24 (p less than 0.001) for AM plasma membranes from rabbits 1- or 7-day-old to 30- or 150-day-old rabbits, respectively. This finding suggests that the fluidity of the AM plasma membrane decreased during postnatal development. Palmitic, stearic, oleic, and linoleic acids were the most prevalent fatty acids found in the neutral lipid fraction of the AM plasma membrane throughout development. The content of stearic acid rose from 10 to 16%, arachidonic acid rose from 2.8 to 9%, myristic acid decreased from 3.2 to 1.3%, palmitic acid decreased from 42 to 36%, and oleic and linoleic acids changed relatively little during the first 30 days of life. The levels of docosatetraenoic and docosapentaenoic increased gradually during the first 14 days of life, and by 30 days of life the levels declined to that observed at birth. The sum of these changes resulted in an increase in the ratio of unsaturated to saturated fatty acids (1 to 1.15) in the neutral lipid fraction. During the first month of life, the neutral lipid fatty acid pool in the total lipid fraction of AM plasma membrane increased from 12 to 18 mole %, cholesterol increased from 7 to 14 mole %, and total phospholipids decreased from 81 to 67 mole %. These changes resulted in increasing the cholesterol to phospholipid ratio from 0.09 at birth to 0.23 by 150 days of life. The levels of all three major lipid fractions were comparable at 30 days and 150 days of life. Adult levels of choline phosphoglycerides, the predominant phospholipid, were observed by 7 days of life to have decreased from 47 to 34.5 mole %, and the levels of ethanolamine phosphoglycerides and sphingomyelin increased from 17.5 to 25 mole % and from 9 to 13 mole %, respectively. Adult levels of lyso-bis-phosphatidic acid were reached by 30 days of life increasing from 8.2 to 17.8 mole %.(ABSTRACT TRUNCATED AT 400 WORDS)
Production of a fibroblast-stimulating factor by Schistosoma mansoni antigen-reactive T cell clones.
Authors: Lammie P J , Michael A I , Linette G P , Phillips S M
Published: December 2022

Fibrosis in schistosomiasis is the terminal event of a complex pathophysiologic cascade involving interactions between fibroblasts and both host and parasite products. In the present study, the effect of lymphokines produced by cloned Schistosoma mansoni antigen-reactive T cells on the proliferation of murine fibroblasts was investigated. These T cells previously have been shown to proliferate, produce lymphokines, mediate delayed-type hypersensitivity responses, and generate in vitro granulomas in response to soluble egg antigen (SEA). T cells, co-cultured with irradiated antigen-presenting cells and pulsed with SEA, produced levels of fibroblast-stimulating factor (FSF) comparable to equivalent numbers of dispersed hepatic granuloma cells isolated from infected mice. Supernatants of cloned T cells pulsed with Con A (in the absence of macrophages) contained no detectable interleukin 1 activity, but did stimulate fibroblast activation and growth. T cell FSF activity was trypsin-sensitive, was stable at 56 degrees C but not to boiling, and was retained by Con A Sepharose. Activity was associated with HPLC fractions corresponding to an m.w. of 10,000 to 40,000. Neither recombinant interferon-gamma nor affinity-purified interleukin 2 was capable of stimulating fibroblast proliferation. In functional studies, the degree of fibroblast proliferation was related to the length of exposure to the factor. In addition, quiescent fibroblasts were maximally stimulated by T cell FSF only if a second co-factor such as insulin or epidermal growth factor was present. The synergism between T cell FSF and known progression factors suggests that FSF-T may provide a competence signal to fibroblasts. The present results suggest that a direct molecular link may exist between T cells and fibroblasts in schistosomiasis.
Comparative analysis of the priming effect of human interferon-gamma, -alpha, and -beta on synergism with muramyl dipeptide analog for anti-tumor expression of human blood monocytes.
Authors: Utsugi T , Sone S
Published: December 2022

Freshly isolated human peripheral blood monocytes from healthy volunteers were not cytotoxic to allogeneic A375 melanoma cells, but they were activated to the cytotoxic state by incubation in vitro with either des-methyl muramyl dipeptide (norMDP; minimal effective dose, 0.5 micrograms/ml) or recombinant human interferon-gamma (rIFN-gamma; minimal effective dose, 1 U/ml). A combination of subthreshold concentrations of these agents (norMDP, 0.5 micrograms/ml; rIFN-gamma, 10 U/ml) also induced significant cytotoxicity, indicating that the effects of norMDP and rIFN-gamma in monocyte activation are synergistic. Natural human IFN-gamma (nIFN-gamma) and norMDP also had similar synergistic effects. Pretreatment of rIFN-gamma with anti-IFN-gamma antibody completely inhibited its synergistic effect with norMDP in monocyte activation. Because pretreatment of rIFN-gamma and norMDP with polymyxin B did not interfere with their effects in monocyte activation, the preparations were not contaminated with lipopolysaccharide. Moreover, because pretreatment of monocyte monolayers with anti-Leu-11b antibody (anti-natural killer (NK) cell antibody) and complement did not interfere with the synergistic effects of norMDP and rIFN-gamma, whereas pretreatment with anti-Leu-M1 antibody (anti-monocyte antibody) caused complete inhibition of their effects, the observed tumor cytotoxicity of monocyte-rich monolayers was probably not due to a small number of adherent NK cells, but to the stimulation of the monocytes. Natural and recombinant IFN-alpha and IFN-beta at concentrations of greater than or equal to 100 U/ml also induced tumoricidal activity of monocytes, but unlike IFN-gamma, their effects were additive with norMDP, and they had less priming effect than IFN-gamma when they were added before norMDP to monocytes. These findings suggest that recombinant human IFN-gamma has much more synergistic potential with norMDP than IFN-alpha or IFN-beta, and this synergism of rIFN-gamma and norMDP for monocyte activation could be of clinical value in treatment of disseminated malignant diseases, because these compounds are readily available at standardized concentrations.
Murine T cells reactive to type II collagen. I. Isolation of lines and clones and characterization of their antigen-induced proliferative responses.
Authors: Hom J T , Stuart J M , Chiller J M
Published: December 2022

Mice of the DBA/1 strain develop arthritis after immunization with native chick type II collagen. Although both a humoral and a cell-mediated response specific to type II collagen are associated with the disease, the underlying immunologic basis remains to be established. As an initial step to analyzing the involvement of cellular immunity in collagen-induced arthritis, we isolated and characterized T cell lines and clones specific to type II collagen. Two sets of T cell lines were obtained by limiting dilution. One set was found to react exclusively with denatured type II collagen, whereas the other set responded to both native and denatured type II collagen. The specificity of such T cells was demonstrated by their inability to respond to other soluble proteins such as type I collagen, HGG, KLH, or OVA. Cells from these lines recognized type II collagen only in an MHC (H-2q)-restricted fashion. Furthermore, the collagen-specific T cells were found to respond to type II collagens obtained from various species, including chick, bovine, and rat. Finally, each set of cells displayed a phenotype characteristic of T helper cells, namely Thy-1+, L3T4+, Lyt-2-.
Antigen-induced T suppressor cells regulate the autoreactive T helper-B cell interaction.
Authors: Finnegan A , Hodes R J
Published: December 2022

The T suppressor (Ts) cell population that functions to regulate antigen-specific MHC-restricted T helper (Th)-B cell interactions also regulates the activation of B cells by cloned autoreactive Th cells. Activated Ts cells were generated by in vivo priming and restimulation in vitro with high concentrations of the specific priming antigen. Once generated, this Ts population inhibits the Th-dependent activation of primed B cells by both antigen-specific and autoreactive T cells in an antigen-nonspecific manner. This suppression requires the participation of both Lyt-1+2- and Lyt-1-2+ T cells. It was also demonstrated that accessory cells were required for the induction of Ts cells. Moreover, the generation of suppression was MHC-restricted and required the recognition by T cells of Ia antigens on accessory cells. These studies demonstrate that the same or a very similar Ts cell population can function to inhibit the activation of B cells by antigen-specific as well as autoreactive T cells.
Genetic restrictions in the development of antibody responses to L-glutamic acid60-L-alanine30-L-tyrosine10 by nude mice implanted with semiallogeneic thymus glands.
Authors: Lake J P , Kapp J A , Pierce C W
Published: December 2022

Athymic nude mice implanted with F1 thymus glands were used to investigate genetic restrictions regulating T cell-macrophage (M phi) interactions in the development of antibody responses to GAT. Spleen cells from conventional mice developed comparable primary plaque-forming cell (PFC) responses when stimulated by syngeneic and allogeneic GAT-M phi. However, spleen cells from strain A nude mice implanted with (A X B)F1 thymus glands were tolerant of strain B alloantigens and developed GAT-specific PFC responses to strain A GAT-M phi and allogeneic strain C GAT-M phi, but failed to respond to strain B GAT-M phi. The lack of primary GAT-specific PFC responses by spleen cells from (A X B)thy----A nude mice stimulated by strain B GAT-M phi was not due to detectable suppressor mechanisms. However, an allogeneic effect stimulated by H-2- or non-H-2-disparate GAT-pulsed or unpulsed M phi was able to overcome the inability of spleen cells from (A X B)F1 thy----A nude mice to respond to strain B GAT-M phi. Furthermore, the inability to respond to strain B GAT-M phi was overcome by the addition of supernatant fluids from independent cultures of H-2-disparate cells. These results 1) demonstrate that T cells from A nude mice implanted with (A X B)F1 thymus glands did not recognize nominal antigen in the context of B MHC antigens, and 2) suggested that the T cell repertoire was altered in strain A nude mice implanted with (A X B)F1 thymus glands, such that T cells that could recognize GAT in association with strain B MHC antigens were functionally deleted.