bluuebunny/crossref_metadata_2025 huggingface dataset:
Importance of immunoglobulin isotype in therapy of experimental autoimmune encephalomyelitis with monoclonal anti-CD4 antibody.
Authors: Waldor M K , Mitchell D , Kipps T J , Herzenberg L A , Steinman L
Published: December 2022

Experimental allergic encephalomyelitis (EAE) is an autoimmune disease mediated by CD4+ T cells. Prior studies have established that monoclonal anti-CD4 antibodies can reverse EAE. To determine whether immunoglobulin isotype plays a role in the therapy of EAE with anti-CD4 antibody, an isotype switch variant family of the mouse IgG1 anti-rat CD4 antibody W3/25 was isolated with the fluorescence-activated cell sorter. The IgG1, IgG2b, and IgG2a W3/25 isotype variants all had identical binding capacities for rat CD4+ T cells. Although all three W3/25 isotypes showed some beneficial effects in the amelioration of EAE, the IgG1 and IgG2a W3/25 antibodies were superior to the IgG2b W3/25 in the treatment of EAE. Multiparameter fluorescence-activated cell sorter analysis of T cell subpopulations from treated rats showed that none of the antibodies of the W3/25 isotype switch variant family substantially depleted CD4+ target cells in vivo. These experiments demonstrate that immunoglobulin isotype is important in the monoclonal antibody therapy of autoimmune disease. They indicate that therapy of EAE may be successful without a major depletion of CD4+ lymphocytes. Immunotherapy may be optimized by selecting an appropriate isotype of a monoclonal antibody.
Activated lymphocytes during acute Epstein-Barr virus infection.
Authors: Tomkinson B E , Wagner D K , Nelson D L , Sullivan J L
Published: December 2022

Activated lymphocytes, as identified by HLA-DR expression, associated with acute Epstein-Barr virus (EBV)-induced infectious mononucleosis (IM) were shown to be a heterogeneous population containing significantly elevated cytotoxic/suppressor (CD8) T cells, natural killer (CD16) cells and helper (CD4) T cells. CD8 T cells were the primary activated population representing 24.5% of the total lymphocyte population. The activated CD4 T cells and natural killer cells accounted for 6.7% and 3.5% of the total lymphocyte population, respectively. Analysis of serum soluble interleukin 2 receptors (IL-2R) demonstrated significantly (p less than 0.001) elevated levels in the serum of acute IM patients compared with normal controls. Elevated levels of serum IL-2R were correlated (r = 0.67) with increased percentages of Leu 2a+/HLA-DR+T cells (i.e., activated CD8 T cells). Patients with X-linked lymphoproliferative syndrome and virus-associated hemophagocytic syndrome, two syndromes associated with severe acute EBV infections, demonstrated the most dramatic increase in serum IL-2R levels. These data demonstrate that EBV is associated with intense immune stimulation and that during acute IM activated lymphocytes, other than the CD8 T cells, may contribute to the immune response to EBV.
T cell recognition of listeriolysin O is induced during infection with Listeria monocytogenes.
Authors: Berche P , Gaillard J L , Geoffroy C , Alouf J E
Published: December 2022

During bacterial multiplication, Listeria monocytogenes (strain EGD) secretes sulfhydryl-dependent cytotoxin, termed listeriolysin O, a virulence factor presumable promoting intracellular growth of this ubiquitous pathogen. The role of this exotoxin in the process of T cell activation was studied in vivo during the course of an experimental infection in the mouse. By using highly purified listeriolysin O, it was found that infection with viable, replicative bacteria induced in vivo the emergence of T cells specifically reacting against this exotoxin, as demonstrated by eliciting the expression of delayed-type hypersensitivity to listeriolysin O in Listeria-immune mice. The kinetics of this inflammatory reaction followed the same pattern as that observed with crude Listeria antigenic preparation classically used for the detection of delayed-type hypersensitivity, with a peak of expression by day 6 and a slow decline over the next 3 wk to a residual level, indicating the presence of memory T cells reacting with the exotoxin. This result, therefore, allowed us to identify for the first time that a pure immunogenic molecule secreted by L. monocytogenes is specifically recognized by sensitized T cells induced during the course of infection by L. monocytogenes. The expression of T cell-mediated immunity to listeriolysin O was generated by very low amounts of replicative bacteria, indicating that the exotoxin released in host tissues during the process of intracellular growth is highly immunogenic. Our data favor the view that the binding of listeriolysin O to the membrane cholesterol might be a critical event potentiating the in vivo expression of delayed sensitivity against this exotoxin. Indeed, the insertion of listeriolysin O into the cell membrane induced resistance to enzymatic proteolysis and membrane-bound listeriolysin O was significantly more effective in inducing delayed inflammatory reaction in Listeria-immune mice.
Analysis of the idiotypic network in tumor immunity.
Authors: Raychaudhuri S , Saeki Y , Chen J J , Kohler H
Published: December 2022

Herein we have analyzed the expression of idiotopes associated with a monoclonal anti-tumor-associated antigen (TAA) antibody in DBA/2 mice which have progressively growing tumors or resist tumor growth. A panel of eight monoclonal antiidiotypic antibodies raised against a monoclonal antibody which reacts with a mouse mammary tumor virus cross-reactive qp52 envelope protein (TAA) of the L1210/GZL lymphoma was used to measure the expression of idiotopes in sera from different treatment groups. Significant correlations between the expression of certain idiotopes and the growth of the tumor or the establishment of anti-tumor immunity are seen. 1) Idiotypes detected by anti-idiotype D11 are high in anti-idiotype immunized progressor or tumor-susceptible mice and low or absent in regressor mice, i.e., the mice immunized with the protective 2F10 anti-idiotype; 2) the 3A4-detected idiotypes are less frequent or absent in irradiated tumor-immunized regressor mice than in untreated mice challenged with live tumor or progressor mice; 3) no difference in the anti-TAA titers is seen in mice in which the tumor growth is inhibited and in mice in which the tumor grows; 4) no difference in 11C1 idiotype + anti-TAA titer was observed between regressor and progressor mice; and 5) mice with normal or accelerated tumor growth have higher titers of idiotypes detected by a polyclonal anti-idiotype. These findings provide evidence for a regulatory idiotype network induced by the growing L1210/GZL tumor or by anti-idiotypic immunization. The titer of anti-TAA antibody does not correlate with the biology of tumor growth, but certain idiotopes correlate with either progressive or regressive tumor behavior. Therefore, the target of the idiotype regulation is likely to be anti-tumor T effector cells. Effective idiotype therapy of tumors must deal with the complexity of idiotype regulation induced by the tumor itself and is unlikely to be successful if anti-idiotypes are used only as internal mimicry of a TAA.
Cerulenin is a potent inhibitor of antigen processing by antigen-presenting cells.
Authors: Falo L D , Benacerraf B , Rothstein L , Rock K L
Published: December 2022

Cerulenin is an antibiotic that inhibits eukaryotic lipid and sterol synthesis and blocks lipid modification of proteins. The effect of cerulenin on the ability of accessory cells to present antigen to T cells was investigated. This antibiotic strongly inhibits the ability of accessory cells to present antigen to murine T-T hybrids. This effect is observed for multiple distinct antigens including L-glutamic acid60-L-alanine30-L-tyrosine10, bovine insulin, L-glutamic acid56-L-lysine35-L-phenylalanine9, and ovalbumen. Presentation by both macrophage and B lymphoblastoid cell lines is inhibited. The ability to effectively pulse these cells with antigen is inhibited but not the ability of these same cells to present antigen that they have previously processed. Furthermore, this inhibition is selective as it can occur without significant inhibition of the antigen-presenting cell protein or DNA synthesis. Cerulenin does not inhibit antigen uptake or catabolism as assessed with labeled antigen. By these criteria this drug is shown to interfere with an antigen-processing step. The ability of cerulenin to block processing was compared with other known inhibitors. Although cerulenin was effective with all antigens tested, at least one inhibitor was not. Taken together, these results suggest that the effect of cerulenin may define a distinct step in antigen processing and provides evidence that some other processing events are not universally required. The ability of cerulenin to interfere with antigen processing is discussed in the context of the known actions of this antibiotic and events of antigen processing and presentation.
Peyer's patches export lymphocytes throughout the lymphoid system in sheep.
Authors: Pabst R , Reynolds J D
Published: December 2022

The lymphocyte output from small intestine containing either the long continuous ileal Peyer's patch (PP) or several smaller jejunal PP was examined in young lambs. Most studies were done in 2-mo-old lambs, 1 mo after removal of mesenteric lymph nodes (MLN). Extracorporeal perfusion of part of the intestine and addition of fluorescein isothiocyanate to the perfusate led to the labeling, in their normal microenvironment, of a regionally defined population of cells. One day later considerable numbers of emigrant lymphocytes were identified by fluorescence microscopy in the spleen, MLN and peripheral lymph nodes, jejunal PP, and bone marrow. In nonperfused ileal PP and thymus the labeling indexes were low. The highest labeling index was in the blood where 3.7% of the lymphocytes were labeled. A similar organ distribution of emigrant cells was found on day 3. When MLN were included in the perfused region more emigrants were identified. In some animals the intestinal lymphatic draining the perfused ileum was cannulated. Continual lymph drainage caused a dramatic decrease in the labeling indexes in other lymphoid organs. A substantial number of lymphocytes leave both ileal PP and jejunal PP via lymphatics and travel to all other lymphoid organs. However, the number of emigrant lymphocytes compared with the total number of labeled lymphocytes in the perfused tissue was about 10 times greater after perfusing gut with the jejunal PP than after ileal PP perfusion. We conclude that relatively more lymphocytes emigrate from the jejunal PP than from the ileal PP.
Immunochemical studies of Lolium perenne (rye grass) pollen allergens, Lol p I, II, and III.
Authors: Ansari A A , Kihara T K , Marsh D G
Published: December 2022

It was reported earlier that human immune responses to three perennial rye grass (Lolium perenne) pollen allergens, Lol p I, II, and III, are associated with histocompatibility leukocyte antigen (HLA)-DR3. Rye-allergic people are often concordantly sensitive to all three of these allergens. Since earlier studies suggested that these antigens are non-cross-reactive, their immunologic relatedness by double antibody radioimmunoassay (DARIA) was studied in order to understand further the immunochemical basis for the concordant recognition of the three allergens. Direct binding DARIA studies were performed with human sera from 189 allergic subjects. Inhibition DARIA studies were carried out with 17 human sera from grass-allergic patients who were on grass immunotherapy, one goat anti-serum, and six rabbit antisera. None of the sera detected any significant degree of two-way cross-reactivity between Lol p I and II, or between Lol p I and III. However, the degree of two-way cross-reactivity between Lol p II and III exhibited by individual human and animal antisera varied between undetectable and 100%. In general, the degree of cross-reactivity between Lol p II and III was higher among human sera than among animal sera. Taken together with earlier findings that antibody responses to Lol p I, II and III are associated with HLA-HDR3, and that most Lol p II and III responders are also Lol p I responders, but not vice versa, our present results suggest the following: the HLA-DR3-encoded Ia molecule recognizes a similar immunodominant Ia recognition site (agretope) shared between Lol p I and Lol p II and/or III; in addition, Lol p I appears to contain unique Ia recognition site(s) not present in Lol p II and III. However, further epitope analyses are required to investigate these possibilities.
Distribution of ecto-5'-nucleotidase on subsets of human T and B lymphocytes as detected by indirect immunofluorescence using goat antibodies.
Authors: Thompson L F , Ruedi J M , Low M G , Clement L T
Published: December 2022

Human T and B lymphocyte subsets were characterized for ecto-5'-nucleotidase (ecto-5'-NT) expression by two-color immunofluorescence by using polyclonal goat antibodies to 5'-NT and murine monoclonal antibodies to T and B cell subsets. Anti-5'-NT antibodies were prepared by immunizing a goat with purified human placental 5'-NT. Lymphocyte surface 5'-NT was detected with F(ab')2 fragments of immune goat IgG followed by biotinylated F(ab')2 rabbit anti-goat IgG and fluorescein isothiocyanate-avidin. Lymphocyte cell surface antigens were detected with phycoerythrin (PE)-conjugated anti-CD3, anti-CD4, anti-CD8, anti-CD16, and anti-CD19. HB-4, an antigen present on a major subset of human peripheral blood B cells, was detected with murine monoclonal anti-HB-4 and PE-anti-mouse-kappa. Analysis showed that ecto-5'-NT was expressed on 32 +/- 7% of CD3+, 19 +/- 6% of CD4+, and 50 +/- 21% of CD8+ T cells, but not on CD16+ lymphocytes. Ecto-5'-NT was also expressed on 81 +/- 8% of adult peripheral blood B cells as defined by PE-anti-CD19; HB-4 was expressed on 84 +/- 7% of CD19+ cells. The two populations of B cells were not identical, however, because HB-4 was co-expressed on only 79 +/- 18% of ecto-5'-NT+ B cells. Two-color immunofluorescent staining of T cells from a patient with congenital agammaglobulinemia and low T cell ecto-5'-NT activity revealed reduced percentages of ecto-5'-NT+ cells in his CD3+, CD4+, and CD8+ populations. Thus, reduced ecto-5'-NT activity by enzyme assay was paralleled by reduced numbers of 5'-NT molecules on the cell surface. Two-color immunofluorescent staining of B cells from a patient with hypogammaglobulinemia and low B cell ecto-5'-NT activity also revealed markedly reduced expression of 5'-NT. HB-4 expression was normal, however, suggesting that the patient's B cells were blocked in maturation subsequent to the acquisition of HB-4 but prior to that of ecto-5'-NT. These results demonstrate that anti-5'-NT antibodies will be valuable tools for analyzing ecto-5'-NT expression and lymphocyte maturation in patients with immuno-deficiency diseases.
Direct demonstration of binding of anti-Leu 4 antibody to the 40 kDa Fc receptor on monocytes as a prerequisite for anti-Leu 4-induced T cell mitogenesis.
Authors: Ceuppens J L , Van Vaeck F
Published: December 2022

It has previously been demonstrated that about 30% of healthy Caucasian subjects are "nonresponders" in assays of the mitogenic activity of monoclonal mouse IgG1 (mIgG1) anti-CD3 antibodies (e.g., anti-Leu 4 and UCHT-1), and that this unresponsiveness is due to lack of monocyte helper function. In an immunofluorescence assay with fluorescence-activated cell sorter analysis, we studied the binding of phycoerythrin-conjugated anti-Leu 4 to monocytes from responders and nonresponders. Interaction was observed with monocytes from responders only, and was blocked by a murine monoclonal antibody (IV.3) directed to an epitope on the 40-kDa low affinity Fc receptor (FcRII). This indicates that the interaction represents binding of the Fc part of phycoerythrin-conjugated anti-Leu 4 to FcRII on responder monocytes. Indirect immunofluorescence with antibody IV.3 demonstrated, however, that monocytes from both responders and nonresponders express similar levels of FcRII. Thus, nonresponder monocytes apparently express a variant FcRII which is unable to bind the Fc part of mIgG1 antibodies. The anti-FcRII antibody completely blocked anti-Leu 4-induced (but not OKT3 (mIgG2a)-induced) T cell proliferation in cultures of peripheral blood mononuclear cells from responders. The results provide direct evidence that monocytes from anti-Leu 4 responders, but not monocytes from anti-Leu 4 non-responders, are able to bind the Fc part of mIgG1 to FcRII, and that this interaction with FcRII is essential for the mitogenic activity of mIgG1 anti-CD3 antibodies.
Binding of interleukin 2 to its 75-kDa intermediate affinity receptor is sufficient to activate Na+/H+ exchange.
Authors: Mills G B , May C
Published: December 2022

High affinity interleukin 2 (IL-2) binding sites are composed of two IL-2-binding molecules: one of 55 kDa, commonly called TaC, and another of 75 kDa. In the absence of the other IL-2-binding molecule, the 55-kDa molecule binds IL-2 with a relatively low affinity and the 75 kDa molecule binds IL-2 with an intermediate affinity. One of the earliest events following interaction of IL-2 with its receptor on the surface of cells is an increase in intracellular pH due to activation of the Na+/H+ antiport. In contrast to IL-2-induced proliferation of human IL-2-sensitive T cells, interaction of IL-2 with a low affinity binding site was sufficient to activate the Na+/H+ antiport. By determining the effect of IL-2 on cytosolic pH in cells that express one of the two IL-2-binding molecules in the absence of the other IL-2-binding molecule, we have demonstrated that interaction of IL-2 with the 75 kDa IL-2-binding molecule is sufficient to activate the Na+/H+ antiport and thus induce cytosolic alkalinization. This indicates that the 75-kDa IL-2-binding molecule, in the absence of the 55-kDa IL-2-binding molecule, forms a functional receptor that can transduce an activation signal across the cell membrane.
Interferon-gamma synergizes with tumor necrosis factor and with interleukin 1 and requires the presence of both monokines to induce antitumor cytotoxic activity in macrophages.
Authors: Chen L , Suzuki Y , Wheelock E F
Published: December 2022

Small concentrations of recombinant murine interferon-gamma (MuIFN-gamma), recombinant human interleukin 1 (HuIL-1), and recombinant murine tumor necrosis factor (MuTNF), added separately to cultures of thioglycolate-elicited peritoneal macrophages, produced no cytotoxic activity against L5178Y cells, a tumor cell line which is resistant to the direct toxic effects of these cytokines, either alone or in combination. However, small concentrations of MuIFN-gamma when combined with small concentrations of either HuIL-1 or MuTNF activated these macrophages to produce cytotoxic effects against L5178Y cells; small concentrations of HuIL-1 and MuTNF in combination had no macrophage activating activity. Specific antibody to MuTNF blocked the macrophage-activating synergistic effects of MuIFN-gamma + HuIL-1, and specific antibody to HuIL-1 blocked the macrophage-activating activity of MuIFN-gamma + MuTNF, indicating that MuTNF was induced in macrophage cultures treated with MuIFN-gamma + HuIL-1, and that murine IL-1 was induced in macrophage cultures treated with MuIFN-gamma + MuTNF. These results indicate that all three cytokines are required for induction of antitumor cytotoxic activation of macrophages. Experiments with a concentration of MuIFN-gamma which alone could activate macrophages revealed that both MuTNF and murine IL-1 were required for this activation. The demonstration that small concentrations of these three cytokines can act synergistically, but not separately, to activate macrophages indicates the importance of cytokine combinations in immunoregulation and in anti-tumor cell-mediated immune responses.
Interferon-gamma is produced by activated immature mouse thymocytes and inhibits the interleukin 4-induced proliferation of immature thymocytes.
Authors: Ransom J , Fischer M , Mosmann T , Yokota T , DeLuca D , Schumacher J , Zlotnik A
Published: December 2022

We have recently shown that interleukin 4 (IL-4) (formerly called BSF-1) is a potent stimulator of fetal and adult immature thymocyte proliferation and that adult L3T4-/Lyt-2-thymocytes can be stimulated by calcium ionophore (A23187) and phorbol ester to secrete IL-4 (Zlotnik, A., J. Ransom, G. Frank, M. Fischer, and M. Howard. 1987. Proc. Natl. Acad. Sci. (USA) 84:3856). This report shows that fetal thymocytes (day 15 of gestation) can also be activated to produce IL-4 suggesting that IL-4 may be a mediator of fetal as well as adult immature thymocyte proliferation. Furthermore, we demonstrate that interferon-gamma (IFN-gamma) inhibits the IL-4-mediated proliferation of both fetal and adult L3T4-/Lyt-2-thymocytes. The inhibition of proliferation is blocked by anti-IFN-gamma antibody and is unaffected by indomethacin suggesting that IFN-gamma directly inhibits immature thymocyte proliferation. IFN-gamma does not block the IL-4/phorbol myristate acetate-mediated proliferation of an adult thymocyte population, which is enriched for L3T4-/Lyt-2+ and L3T4+/Lyt-2- cells, suggesting that the inhibitory effect of IFN-gamma is limited to the immature thymocyte population. Both fetal (day 15) and adult L3T4-/Lyt-2--thymocytes can be activated to secrete an IFN-gamma like activity. This activity is neutralized by a monoclonal anti-IFN-gamma antibody indicating that the activity is due to IFN-gamma. mRNA analysis of adult L3T4-/Lyt-2- thymocytes stimulated with A23187 and phorbol myristate acetate confirms that mRNA for both IL-4 and IFN-gamma is induced in adult L3T4-/Lyt-2- thymocytes. These results indicate that IL-4 and IFN-gamma can regulate immature thymocyte proliferation.
C1 dissociation. Spontaneous generation in human serum of a trimer complex containing C1 inactivator, activated C1r, and zymogen C1s.
Authors: Laurell A B , Mårtensson U , Sjöholm A G
Published: December 2022

Activation of the C1 complex in the presence of C1 inactivator (C1 IA) is known to result in the formation of tetramer C1 IA-C1r-C1s-C1 IA complexes that are dissociated from C1q. Both C1r and C1s of the tetramers are present in their activated forms. The present investigation concerned the generation of trimer complexes containing C1 IA, activated C1r, and zymogen C1s (C1 IA-C1r-C1s). C1 IA-C1r-C1s were released from C1q and were formed in high concentration during prolonged incubation (1 to 3 days) of normal serum at 37 degrees C without addition of activators. By contrast, dissociation of C1 with formation of C1 IA-C1r-C1s-C1 IA was complete within 30 min at 37 degrees C, when the serum was treated with heat-aggregated IgG (1 g/liter). On size exclusion chromatography (TSK-4000), C1 IA-C1r-C1s and C1 IA-C1r-C1s-C1 IA emerged with apparent m.w. of 320,000 and 460,000, respectively. The composition of the complexes was examined by absorption of serum with F(ab')2 anti-C1s- or anti-C1r-coated Sepharose beads. Eluates were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis combined with immunoblotting. Under nonreducing conditions, heat-aggregated IgG-treated serum showed high concentrations of C1 IA-C1r (m.w. 202,000) and C1 IA-C1s (m.w. 194,000), while serum incubated at 37 degrees C without activators showed high concentrations of C1 IA-C1r but no C1 IA-C1s. Under reducing conditions, heat-aggregated IgG-treated serum showed m.w. 120,000 and 110,000 complexes of C1 IA and the C1r and C1s light chains, respectively. Uncleaved C1s and the m.w. 120,000 complex was found in serum that was incubated at 37 degrees C without activators. Consistent with results obtained by size exclusion chromatography, analysis by crossed immunoelectrophoresis and by electroimmunoassay showed that C1s could be released from C1 IA-C1r-C1s in the presence of EDTA.
In vivo inhibition of neutrophil function in the rabbit using monoclonal antibody to CD18.
Authors: Price T H , Beatty P G , Corpuz S R
Published: December 2022

The CD11b/CD18 membrane antigen complex has been shown to be essential for normal neutrophil function in vitro, and patients lacking this antigen exhibit severe neutrophil dysfunction. Murine monoclonal antibody 60.3 (Ab 60.3), directed toward CD18, is a potent inhibitor of human neutrophil function in vitro. To determine whether Ab 60.3 might similarly inhibit neutrophil function in vivo, we measured the effect of antibody administration on neutrophil localization to polyvinyl sponges placed s.c., in rabbits. Studies in 25 animals showed that infusion of Ab 60.3 at the time of sponge insertion resulted in dose-dependent inhibition of in vivo neutrophil migration with almost complete paralysis of neutrophil migration at higher antibody doses. These studies confirm the functional relevance of CD18, demonstrate that neutrophil function can be profoundly inhibited in vivo by Ab 60.3, and suggest that substances such as AB 60.3 may be clinically useful as potent anti-inflammatory agents.
Inhibitory activity of interferons and interleukin 1 on the development of Plasmodium falciparum in human hepatocyte cultures.
Authors: Mellouk S , Maheshwari R K , Rhodes-Feuillette A , Beaudoin R L , Berbiguier N , Matile H , Miltgen F , Landau I , Pied S , Chigot J P
Published: December 2022

We have studied the effect of natural and recombinant human interferons (HuIFN-alpha, -beta, and -gamma), and interleukin 1 (IL-1) on development of sporozoites of Plasmodium falciparum in cultures of functional hepatocytes. HuIFN-gamma inhibits hepatic schizogony of P. falciparum at very low concentrations (0.1 to 10 international units/ml), the target being the hepatocyte. Application after sporozoite inoculation is effective, suggesting an intracellular mechanism. There is also an 84% inhibition after application from 4 to 6 days following inoculation so that by day 6, there was a disappearance of a significant number of schizonts previously present at day 4, indicating more than a parasitostatic effect, and probably a postassembly action. HuIFN-alpha and -beta were effective, but only at 1000-fold higher concentrations than HuIFN-gamma. IL-1 (5 U/ml) also inhibited hepatic development of P. falciparum sporozoites; however, IL-1 treatment was effective only when applied before sporozoite inoculation.
Antigen-stimulated lymphokines from patients with cutaneous leishmaniasis induce monocyte killing of Leishmania major intracellular amastigotes.
Authors: Passwell J H , Shor R , Trau H , Shoham J , Jaffe C L
Published: December 2022

The specific immune response of patients with cutaneous leishmaniasis including the ability of their lymphokines to enhance the monocytes' leishmaniacidal activity was studied. In 16 patients with cutaneous leishmaniasis, their concanavalin A-induced lymphocyte proliferative responses, interferon-gamma and interleukin 2 activities and the ability of their concanavalin A-induced lymphokines to kill monocyte intracellular amastigotes were not different from normal controls. Antigen-stimulated lymphocyte cultures showed that 13 of 13 patients had an increased lymphocyte proliferative response; 11 of 16 produced interleukin 2 and 12 of 13 produced interferon-gamma; in addition, 10 of 11 of these antigen-induced supernatants increased the monocytes' killing of Leishmania major amastigotes. Antibody levels to parasite membrane antigens determined by radioimmunoassay showed that 8 of 13 titers were greater than 10 and 4 of 13 titers were 2 to 10 times higher than control. Our findings demonstrate that patients with cutaneous leishmaniasis elicit a specific immune response to L. major antigens and part of this response is the production of lymphokine capable of promoting monocyte killing of intracellular amastigotes.
Production of tumor necrosis factor during murine listeriosis.
Authors: Havell E A
Published: December 2022

During a lethal murine infection with the gram-positive bacterium, Listeria monocytogenes, a factor appears in the serum that is capable of lysing certain tumor cells in vitro. The levels of this serum cytotoxic factor increase with the progression of morbidity. Neutralization of Listeria-induced cytotoxic factor activity with a monospecific antiserum to recombinant murine tumor necrosis factor (TNF) revealed that the cytotoxic factor was antigenically indistinguishable from natural TNF present in endotoxin-induced tumor necrosis serum. In contrast to a lethal infection, no TNF activity was detected in sera of mice throughout a sublethal infection. However, shortly after initiation of a sublethal infection, mice acquire a greatly enhanced capacity to produce serum TNF in response to an intravenous injection of endotoxin. Cultures of unfractionated spleen cells from mice with ongoing Listeria infections produced TNF when incubated in the absence, but not in the presence, of antibiotics. However, such antibiotic-treated cultures could be stimulated with endotoxin to produce substantially higher TNF yields than spleen cells of uninfected mice. It is also shown that intravenous infusion of anti-recombinant murine TNF IgG into sublethally infected mice results in increased Listeria proliferation in spleens and livers, and ultimately in death from an overwhelming infection.
Selective in vivo antitumor effects of monoclonal anti-I-A antibody on B cell lymphoma.
Authors: Bridges S H , Kruisbeek A M , Longo D L
Published: December 2022

In a study of the biologic consequences of using monoclonal antibodies (mAb) with specificity for I-A for the elimination of an I-A-bearing B cell lymphoma, it was found that, despite the presence of I-A on a number of normal cell types and the propensity of anti-I-A to induce modulation of I-A and I-E on normal cells in vivo, a substantial effect on lymphoma growth could be measured in mAb-treated hosts. Unlike I-A on normal cells, tumor I-A failed to modulate in vivo, and 50% of animals could be cured of lymphoma by multiple doses of anti-I-A mAb. With a sensitive spleen tumor colonization assay, it was shown that neither T lymphocytes nor natural killer cells were involved in tumor elimination by anti-I-A mAb. In addition, C3 depletion only minimally affected the ability of anti-I-A to inhibit tumor growth, suggesting that complement-dependent lysis of tumor cells was not a major mechanism. Spleen cells from long term survivors of tumor challenge and mAb treatment functioned normally as antigen-presenting cells and in the recognition of alloantigens, and serum Ig levels were somewhat higher than in untreated mice; thus, such therapy can be carried out without compromising the immune reactivity of long term survivors.
T cell tolerization in vitro: modulation of helper and suppressor cell activities.
Authors: Bleux C , Liacopoulos P , Couderc J , Kanellopoulos-Langevin C
Published: December 2022

This paper analyzes the conditions for in vitro tolerization of purified whole T cell populations and the consequences on helper and suppressor T cell functions. Highly purified splenic T cells from adult DBA/2 mice were incubated in vitro for 24 hr with high doses of trinitrophenyl coupled to human gamma-globulins (TNP-HGG). A profound inhibition of the TNP-specific helper function of these T lymphocytes was observed in a cooperative culture with normal purified splenic B cells and TNP-SRBC as antigen. This state of specific unresponsiveness was maintained after trypsin treatment of the cells, at the end of the 24-hr incubation with the tolerogen. We checked that this procedure removed the vast majority of F23.1 T cell receptor determinants from the cells. This result indicates that T cell receptors for antigen were not merely blocked by the tolerogen. In addition, B cells preincubated with tolerized T cells for 24 hr remained as responsive to TNP as B cells mixed with normal T cells in similar conditions. This demonstrates that the decreased response is not the result of secondary B cell tolerization. In addition, anti-Ia monoclonal antibodies were shown to block the induction of tolerance. We also showed that tolerized T cells significantly decreased the anti-TNP response of normal T and B cells in vitro, whereas the anti-SRBC response in the same cultures was unaffected. When tolerized T cells were separated into Lyt-2- and Lyt-2+ cells, it was found that tolerized Lyt-2- cells had lost about 75% of their helper activity and that Lyt-2+ cells suppressed 70% of the response of a normal T and B cell culture. Thus, in vitro induction of T cell tolerance results in a specific T cell unresponsiveness which is due to both helper T cell inactivation and induction of specific suppressor T cells.
Enhanced killing of Candida albicans by murine macrophages treated with macrophage colony-stimulating factor: evidence for augmented expression of mannose receptors.
Authors: Karbassi A , Becker J M , Foster J S , Moore R N
Published: December 2022

The effect of macrophage colony-stimulating factor (CSF-1) on killing of Candida albicans by murine peritoneal macrophages was determined. The killing capacity of resident peritoneal macrophages was unaffected by CSF-1. However, proteose-peptone-elicited peritoneal exudate macrophages that had been pretreated with CSF-1 (greater than or equal to 1000 U/ml) for 24 or 48 hr exhibited a significantly enhanced capacity to kill C. albicans. CSF-enhanced killing appeared to be independent of endogenously produced interferon-alpha/beta (IFN) in that enhancement by these two agents differed with regard to onset of the effect, target cell responsiveness, and duration of augmented killing. In addition, a highly specific anti-IFN antiserum that totally neutralized IFN augmentation of candidacidal activity had no effect on CSF-induced enhancement. Evidence was obtained indicating that CSF, unlike IFN, augmented mannose-inhibitable binding and ingestion of C. albicans, suggesting that augmented expression of mannose-receptors by CSF-treated macrophages was at least partially responsible for the enhanced killing.
Basic characteristics of human lung mast cell desensitization.
Authors: MacGlashan D , Lichtenstein L M
Published: December 2022

Human lung parenchymal mast cells displayed both specific and nonspecific desensitization. The kinetics of both release and desensitization were approximately equal to 3 times faster than human basophils, but a similar relationship between release and desensitization suggests similar biochemistries in basophils and mast cells. Arachidonic acid metabolite (PGD2 and LTC4) release was slower to desensitize (t1/2 of 8 min) than histamine release (t1/2 of 3 min), the ratio of which is similar to the ratio observed in basophils. Ionophore A23187-induced release was unaffected by desensitization to anti-IgE antibody, and calcium-45 uptake was inhibited by desensitization, suggesting that desensitization inhibits the early post-cross-linking "influx" of calcium that is necessary for mediator release in mast cells. In contrast to the above similarities in basophil and mast cell desensitization, mast cell desensitization, unlike that of basophils was not inhibited by diisopropylfluorophosphate.
Studies of IgE-dependent histamine releasing factors: heterogeneity of IgE.
Authors: MacDonald S M , Lichtenstein L M , Proud D , Plaut M , Naclerio R M , MacGlashan D W , Kagey-Sobotka A
Published: December 2022

Nasal lavage fluids from unstimulated individuals contain a histamine-releasing factor (HRF) similar to those which we have previously described from macrophages, platelets, and from blister fluids obtained during the late cutaneous reaction. The nasal HRF was partially purified by ion-exchange chromatography and gel filtration. Although some m.w. heterogeneity was observed, the majority of the HRF eluted at an apparent m.w. range of 15,000 to 30,000. This partially purified HRF induced histamine release from basophils of certain individuals. Histamine release occurred via a mechanism which is IgE-dependent in that: basophils desensitized by exposure to anti-IgE in the absence of calcium no longer respond to HRF, and desensitization with HRF reduces responsiveness to anti-IgE; and removal of IgE from the basophil surface by using lactic acid renders cells unresponsive to HRF. We have further defined this IgE dependence and have shown that the reason that only selected basophil donors respond to HRF is due to a previously unrecognized, functional heterogeneity of IgE. Thus, passive sensitization using sera from responders restored the responsiveness of acid-stripped basophils and conferred responsiveness to basophils of a nonresponder with naturally unoccupied IgE receptors. Sera from nonresponders failed to do this even though similar numbers of IgE molecules were put onto the basophil surface in each case. This property of responder sera was due to IgE because both heating sera at 56 degrees C for 2 hr and passage of sera over anti-IgE-Sepharose (which removes greater than 90% of the IgE) markedly reduced the ability of sera to induce responsiveness, and because an excess of either purified IgE myeloma or purified penicillin-specific IgE antibody from a nonresponder competitively inhibited the ability of IgE from responder sera to induce responsiveness to HRF. We conclude that nasal lavage fluids contain an HRF which induces basophil histamine release in a specific, IgE-dependent fashion but only from individuals with the appropriate type of IgE. Because we have shown that basophils are recruited into the nose during the late-phase reaction, we suggest that nasal HRF may induce these cells to release histamine and other mediators which could contribute to the symptomatology of the late-phase reaction.
Induction of nitrite/nitrate synthesis in murine macrophages by BCG infection, lymphokines, or interferon-gamma.
Authors: Stuehr D J , Marletta M A
Published: December 2022

Macrophage synthesis of nitrite and nitrate after activation by BCG infection or by treatment in vitro with both T cell-derived (lymphokines (LK) or recombinant murine interferon-gamma (IFN-gamma] and bacterial (lipopolysaccharide (LPS) and heat-killed bacillus Calmette-Guerin (hk BCG] agents was studied by using macrophages from C3H/He and C3H/HeJ mice. Spleen and peritoneal macrophages isolated from BCG-infected donors that were producing nitrate continued to synthesize nitrite and nitrate in culture. LPS treatment in vitro (25 or 50 micrograms/ml) additionally increased this nitrite/nitrate synthesis. Thioglycolate-elicited macrophages from non-infected C3H/HeJ mice treated with LK also produced nitrite/nitrate, and concurrent LPS (0.1 to 50 micrograms/ml) treatment resulted in enhanced synthesis. Recombinant IFN-gamma also stimulated nitrite/nitrate synthesis by C3H/He and CeH/HeJ macrophages as did LPS (C3H/He only) and hk BCG. When given concurrently with either LPS or hk BCG, IFN-gamma enhanced C3H/He and C3H/HeJ macrophage nitrite/nitrate synthesis over that produced by macrophages treated with either LPS or hk BCG alone. Macrophages activated in vitro exhibited a 4 to 12 hr lag time before engaging in nitrite/nitrate synthesis, which then proceeded for 36 to 42 hr at linear rates. Daily medium renewal did not alter the synthesis kinetics but increased the total amount of nitrite/nitrate produced. Nitrate and nitrite were stable under the conditions of culture and when added did not influence additional macrophage synthesis. Taken together, these results indicate that T cell lymphokines and IFN-gamma are powerful modulators of macrophage nitrite/nitrate synthesis during BCG infection and in vitro, and nitrite/nitrate synthesis appears to be common property of both primed and fully activated macrophage populations.
Effects of bacterial lipopolysaccharide on the hydrolysis of phosphatidylinositol-4,5-bisphosphate in murine peritoneal macrophages.
Authors: Prpic V , Weiel J E , Somers S D , DiGuiseppi J , Gonias S L , Pizzo S V , Hamilton T A , Herman B , Adams D O
Published: December 2022

LPS and lipid A initiated enhanced hydrolysis of PIP2 in macrophages. When murine peritoneal macrophages were labeled with [2-3H]myoinositol and stimulated with either LPS or lipid A, a rapid (within 10 sec) rise in Ins(1,4,5)P3 was observed. The breakdown pattern of Ins(1,4,5)P3 was complex; this included breakdown of Ins(1,4,5)P3 and formation of Ins(1,3,4,5)P4 (approximately 10 to 30 sec), and ultimately formation of Ins(1,3,4)P3 (approximately 60 sec). Within 10 sec after treatment, LPS caused an average increase of about fourfold to fivefold in Ins(1,4,5)P3, which declined over 5 min. When the total isomers of InsP3 were measured, levels rose about twofold in response to LPS or to lipid A and remained elevated for as long as 5 min. Lipid A, in the concentration range of 0.1 to 10 micrograms/ml, induced elevated intracellular levels of Ca2+ as quantified by fluorescence with Quin 2 or with Fura 2. When single, adherent Fura 2-loaded macrophages were treated with lipid A, basal levels of calcium rose over 10 sec from approximately 55 nM to almost 600 nM. LPS, paradoxically, did not cause such substantial increases in intracellular calcium (i.e., increases of approximately 26 nM) when judged by Fura 2 fluorescence. LPS treatment led to enhanced phosphorylation of a characteristic set of proteins, similar to those induced by stimulating protein kinase C (PKC) with phorbol myristate acetate as previously reported. The enhanced phosphorylation of pp28, pp33, and pp67 in macrophages was evident by 15 min and optimal by 30 min. Taken together, these observations indicate that LPS and lipid A cause increased breakdown of phosphatidylinositol 4,5-bisphosphate, which led to enhanced intracellular levels of calcium and also to enhanced protein phosphorylation, presumably mediated by PKC. The data thus suggest that one major intracellular signal transduction mechanism, initiated by LPS and lipid A in macrophages, is the rapid breakdown of PIP2.
Expression patterns of MHC class II genes in rabbit tissues indicate close homology to human counterparts.
Authors: Kulaga H , Sogn J A , Weissman J D , Marche P N , LeGuern C , Long E O , Kindt T J
Published: December 2022

Genomic clones corresponding to five distinct major histocompatibility complex class II alpha-chains have been described for the rabbit; four of these encode complete, potentially functional alpha-chains. Hybridization analysis and preliminary sequence analysis indicate that one of these clones is structurally related to HLA-DP alpha, one to -DR alpha, one to -DQ alpha and one to -DZ alpha. Probes specific for the four class II genes were used to screen RNA samples from normal rabbit tissues to determine which of these genes are transcribed and whether expression of any particular gene is tissue specific. All four of the genes are transcribed, but there are variations in the levels of expression, in tissue distribution, and in transcript size. The highest levels of RLA-DR alpha, -DQ alpha, and -DP alpha transcription were found in lymphoid tissues. Lower levels of transcription were also detectable in several nonlymphoid tissues. Transcripts observed were about 1.3 kb, a size expected for these class II alpha-chain genes based on experience with their human homologues. The RLA-DZ alpha probe corresponding to HLA-DZ alpha hybridized weakly with a band of 3.6 kb; its expression could be detected only in lymphoid tissues. The size of the DZ alpha transcript, its tissue distribution, and partial sequence data confirm its homology with the human gene DZ alpha. In blots of total cellular RNA, a probe for a recently described human beta-chain, DO beta, hybridized to a transcript of about 1.3 kb in lymphoid tissues. These data indicate that RNA transcripts corresponding to all HLA class II loci described to date can be detected in rabbit tissues.
Tissue-specific expression and structure of a divergent member of a class I MHC gene family.
Authors: Ehrlich R , Lifshitz R , Pescovitz M D , Rudikoff S , Singer D S
Published: December 2022

The class I gene family of the major histocompatibility complex (MHC) of the miniature swine (SLA) contains seven members. Six of these are highly homologous, whereas the seventh, PD6, is only distantly related. A genomic clone containing PD6 has been isolated and characterized. The PD6 SLA gene, although only 55% homologous to the other SLA class I sequences, is still a member of the family; its size and exon/intron organization are similar to other class I genes. When aligned with other SLA genes, exons 1 to 6 of PD6 have open reading frames; exon 7 contains a termination codon. PD6 is transcribed in transfected mouse L cells where its expression is enhanced by interferon. In vivo expression of PD6 is observed in a variety of tissues, with the highest levels in mature lymphoid tissues. Peripheral T cells contain high levels of PD6-specific RNA relative to B cells, whereas no PD6 transcripts are detectable in thymocytes.
Conserved organization of the murine immunoglobulin epsilon gene region: restriction endonuclease maps and switch-region nucleotide sequence.
Authors: Gritzmacher C A , Liu F T
Published: December 2022

Various inbred mouse strains showed remarkable conservation of organization in the epsilon germline region as determined by restriction mapping. Restriction fragment length polymorphisms (RFLP) were seen in the epsilon gene region for only two of eight restriction enzymes tested. Furthermore, the RFLP did not correlate with the IgE-response phenotype for the murine strains SJL, SJA, C57BL/6, BALB/c, A/ST, and A/J. The IgE class-switch region (S epsilon) DNA from an SJL genomic clone was sequenced and was compared with S epsilon sequences from BALB/c mice. These S epsilon sequences were at least 95% homologous. Most of the S epsilon sequence differences observed between the two strains were single base pair substitutions, deletions, or insertions. The largest difference between the S epsilon sequences resulted from an insertion of seven contiguous bases seen in the SJL S epsilon region.
Absence of somatic mutation in the variable region of MPC 11 variants expressing a different heavy chain isotype.
Authors: Gilmore G L , Yang J Q , Marcu K B , Birshtein B K
Published: December 2022

Somatic mutation of immunoglobulin variable regions contributes to the diversity of the immune response. Some investigators have postulated that somatic mutation is coupled to isotype switching; others have presented evidence that the two processes are not linked. By using in vitro variants of the MPC 11 mouse myeloma cell line that produce heavy chains of different isotypes, we have examined several VH regions at the nucleotide level using a variety of different sequencing procedures. We have found no evidence of somatic mutation and conclude that the processes of somatic mutation and isotype switching may be independent.
Cell surface T3 expression requires the presence of both alpha- and beta-chains of the T cell receptor.
Authors: Saito T , Weiss A , Gunter K C , Shevach E M , Germain R N
Published: December 2022

We have identified a surface T3- Jurkat variant which has a defective alpha-chain but which possesses an intact beta-chain. The transfection of a functional mouse alpha-chain into this human T cell induces the expression of surface T3 molecules associated with mouse alpha-human beta-heterodimers detected by anticlonotypic antibodies. Treatment of the transfectant with anti-T3, anti-mouse Ti-alpha, or anti-human Ti-beta antibodies clears all Ti-T3 complexes from the surface. These results demonstrate that functional alpha- and beta-chains are both required for expression of T3 on the cell membrane, and that the Ti heterodimers present and associated with T3 on Jurkat cells involve only alpha- and beta-chains.