bluuebunny/crossref_metadata_2025 huggingface dataset:
A 19-kDa human erythrocyte molecule H19 is involved in rosettes, present on nucleated cells, and required for T cell activation. Comparison of the roles of H19 and LFA-3 molecules in T cell activation.
Authors: Groux H , Huet S , Aubrit F , Tran H C , Boumsell L , Bernard A
Published: December 2022

We have previously described a molecule on the SRBC surface which, in addition to the sheep equivalent of LFA-3, is involved in the process of rosette formation. It is made of a single, 14- to 19-kDa, polypeptide chain, and we termed this molecule S14. We have now identified, on the human E a molecule with a similar Mr albeit somewhat higher (19 kDa). The mAb against H19 efficiently block autologous or homologous rosettes by binding to human E. In addition, purified H19 molecules block rosettes made with human E and SRBC in a dose-dependent manner. The H19 molecule, like LFA-3, is not limited to the E surface, but is also present on many nucleated cells, including T cells and monocytes. Moreover H19, like LFA-3, is required for T cell activation: when we stimulated whole PBMC anti-H19 blocked [H3]TdR incorporation triggered via CD3, but not via CD2, in contrast to anti-LFA-3 that inhibited activation via both pathways. When a mixture of highly purified T-PBL and autologous paraformaldehyde fixed accessory cells (AC) was cultivated, anti-H19 or anti-LFA-3 mAb bound to AC blocked T cell proliferation. When high amounts of rIL-1 (100 U/ml) were added to purified T-PBL, no AC were required to sustain their proliferation upon stimulation via CD2, contrary to stimulation via CD3. When lower amounts of rIL-1 (10 U/ml) were used, fixed AC were still necessary to sustain proliferation via CD2. In this latter situation, anti-H19 mAb bound to AC could no longer inhibit T cell proliferation, whereas the anti-LFA-3 mAb was still inhibitory. When T-PBL were stimulated via CD2 in the presence of 100 U/ml of rIL-1, anti-LFA-3 did not induce any inhibition. Thus the inhibitory effect of anti-H19 and anti-LFA-3 mAb can both be accounted for by an effect on the AC molecules only, and not on the T cell molecules. F(ab')2 fragments of anti-H19 mAb produced the same pattern of inhibition as the whole Ig molecule, excluding an effect via the FcR. Moreover, purified preparations of the H19 molecules also produced inhibition.(ABSTRACT TRUNCATED AT 400 WORDS)
Anti-DNA antibodies bind directly to renal antigens and induce kidney dysfunction in the isolated perfused rat kidney.
Authors: Raz E , Brezis M , Rosenmann E , Eilat D
Published: December 2022

The pathogenesis of SLE is commonly attributed to the deposition of circulating immune complexes consisting of DNA and anti-DNA autoantibodies. However, recent work has shown multiple cross-reactions between anti-DNA antibodies and a variety of cellular and extracellular Ag. To test the possibility that these antibodies interact directly with glomerular Ag and induce kidney dysfunction, we applied mouse and human anti-DNA IgG to the isolated perfused rat kidney. The NZB/NZW mouse monoclonal anti-DNA bound to glomerular Ag with a concomitant induction of proteinuria and a decrease in inulin clearance. The albumin excretion was 2301 +/- 734 micrograms/min at 160 min of perfusion, as compared with 85 +/- 21 micrograms/min in controls (p less than 0.001). The inulin clearance was reduced to 0.17 +/- 0.02 ml/min as compared with 0.28 +/- 0.09 ml/min in controls (p less than 0.05). Polyclonal anti-DNA IgG obtained from patients with lupus nephritis bound to rat glomeruli and induced albumin excretion of 542 +/- 217 micrograms/min at 160 min of perfusion, as compared with 163 +/- 77 micrograms/min in controls (p = NS). The addition of plasma as a source of C to the human IgG increased the proteinuria markedly (albumin excretion of 1115 +/- 195 micrograms/min at 160 min of perfusion, p less than 0.02), probably due to C activation. Preincubation of the reactive mouse and human IgG with DNA completely abolished their binding to renal tissue and its physiologic consequences. These results suggest that direct binding of anti-DNA antibodies to renal Ag may play an important role in the induction of lupus nephritis.
Activation by IL-2, but not IL-4, up-regulates the expression of the p55 subunit of the IL-2 receptor on IL-2- and IL-4-dependent T cell lines.
Authors: Jankovic D L , Gibert M , Baran D , Ohara J , Paul W E , Theze J
Published: December 2022

We have investigated the effects of IL-2 and IL-4 on different parameters of T cell activation using three T cell lines. The Th cell line L14 and the cytotoxic T cell line C30.1, both grown in IL-2-containing medium, and a line derived from C30.1 cells (line 1) cultured in IL-4 for a prolonged period were studied. All three cell lines could be activated with IL-2 or IL-4. T cell stimulation by either IL-2- or IL-4-induced identical patterns of cell size enlargement and transferrin receptor expression. However, only IL-2 up-regulated cell-surface expression of the p55 subunit of the IL-2R (p55 IL-2R) as measured by flow cytometry and RIA. This difference was also reflected by the accumulation of soluble p55 IL-2R in the culture medium. No significant increase in expression of membrane or soluble forms of p55 IL-2R was detected after IL-4 stimulation. mAb specific for p55 IL-2R which block IL-2-induced T cell growth did not affect IL-4-mediated T cell proliferation indicating that p55 IL-2R is not involved in IL-4-mediated T cell growth. Analysis of IL-4R expression performed on line 1 using biotinylated IL-4 revealed that IL-4, but not IL-2, is capable of increasing IL-4R expression. Together these results suggest that during IL-2- or IL-4-induced T cell proliferation, each lymphokine specifically up-regulates its own receptor.
Characterization of the baboon erythrocyte C3b-binding protein.
Authors: Birmingham D J , Cosio F G
Published: December 2022

E from primates demonstrate type 1 CR (CR1) with binding specificities for C3b and C4b. In the present study we characterized the E C3b-binding protein of baboons. We showed that three out of four mouse mAb and one polyclonal antiserum, raised against human E CR1, cross-reacted with baboon E. In addition, one anti-human CR1 mAb (1B4) and a polyclonal anti-human CR1 inhibited the binding of C3b opsonized immune complexes to baboon E. Finally, a mAb to human CR1 (E11) recognized epitopes on E of a variety of nonhuman primates, including baboons. SDS-PAGE analysis of biochemically purified baboon E membrane fractions reactive with E11 demonstrated a 65-kDa protein as a major component. Affinity absorption and elution experiments verified this protein to be E11 reactive as well as a C3b binding protein. E surface radiolabeling, followed by C3i affinity purification, confirmed that this 65-kDa protein is the only C3b-binding protein present on the baboon E membrane. We postulate that the baboon E 65-kDa protein is the equivalent of the human E CR1. In addition, there appear to be antigenic similarities between the baboon E 65-kDa protein and the human E CR1.
Structural and idiotypic characterization of the L chains of human IgM autoantibodies with different specificities.
Authors: Goñi F R , Chen P P , McGinnis D , Arjonilla M L , Fernandez J , Carson D , Solomon A , Mendez E , Frangione B
Published: December 2022

We have determined the V region amino acid sequence and/or serologic markers (kIIIb, PSL2, and PSL3) of 24 IgM monoclonal autoantibodies with specificities of anti-gamma-globulin (RF), anti-I (cold agglutinin), anti-low density lipoprotein and anti-intermediate filaments. The data emphasize the overwhelming selection of the HumKv325/VkIIIb L chain for this family of autoantibodies. The few amino acid substitutions found within the VL regions were mainly concentrated in the complementarity-determining region 1. JK and CK genes did not show the same pattern of restriction. There is a good correlation between the amino acid sequence and the presence of the kIIIb marker. The idiotypic marker PSL2 was present in 34 out of 35 kIIIb L chains analyzed (97%) and the PSL3 in 27 (80%). Moreover, the hydrophilicity and antigenic profiles of these L chains corroborate the presence of the epitopes detected by the anti-CRI. These results demonstrate a restricted selection of the Vk genes used by a family of self reacting proteins, and an unusual evolutionary conservation of the idiotypic structure that may be involved in the network regulation.
Fungicidal activity of IFN-gamma-activated macrophages. Extracellular killing of Cryptococcus neoformans.
Authors: Flesch I E , Schwamberger G , Kaufmann S H
Published: December 2022

Cryptococcus neoformans is an encapsulated yeast-form fungus which causes pulmonary and meningeal infections preferentially in the immunocompromised host. It is thought that cell-mediated immunity is important for acquired resistance against cryptococcosis with activated macrophages as the final effector cells. However, specific polysaccharides in the capsule of C. neoformans protect the fungus from adherence to phagocytes and from subsequent phagocytosis. We have studied extracellular killing of C. neoformans by IFN-gamma-activated macrophages and their products. Murine bone marrow-derived macrophages stimulated with rIFN-gamma for 24 h were able to effectively suppress the growth of C. neoformans and the effect of IFN-gamma was augmented by LPS. Killing of C. neoformans was also achieved by cell-free supernatants from bone marrow-derived macrophages stimulated with IFN-gamma plus LPS. Our results indicate that killing of C. neoformans by activated macrophages is independent from toxic oxygen radicals and mediated by secreted protein(s) of apparent molecular mass of 15 and 30 kDa. These findings indicate that activated macrophages play a major role in host defense, although the fungus resists phagocytosis and remains in the extracellular milieu.
A monoclonal antibody to the IL-1 beta peptide 163-171 blocks adjuvanticity but not pyrogenicity of IL-1 beta in vivo.
Authors: Boraschi D , Volpini G , Villa L , Nencioni L , Scapigliati G , Nucci D , Antoni G , Matteucci G , Cioli F , Tagliabue A
Published: December 2022

The synthetic fragment VQGEESNDK, corresponding to the amino acid sequence in position 163-171 of human IL-1 beta, possesses the immunostimulatory but not the pyrogenic activity of the mature IL-1 beta polypeptide in vivo. To assess the relevance of this domain of IL-1 beta for its biologic activities, a mAb was raised against the synthetic peptide 163-171. The mAb Vhp20 could effectively recognize human rIL-1 beta in RIA and immunoblotting. In vivo, the mAb Vhp20 was able to selectively inhibit the immunostimulatory activity of IL-1 beta, but it could not affect the fever-inducing capacity of IL-1 beta. It is proposed that functional domains could be identified in the human IL-1 beta protein and that the fragment in position 163-171 is of major importance for the adjuvant capacity of the entire molecule, but irrelevant to its pyrogenic activity.
Expression of I-A by macrophages from Bcgr and Bcgs mice. Transient expression of I-A is due to degradation of MHC class II glycoproteins.
Authors: Vespa L , Zwilling B S
Published: December 2022

Murine peritoneal macrophages from mice that are resistant to Mycobacterium bovis (strain BCG) can be induced to continuously express MHC class II (Ia) glycoproteins. In contrast, macrophages from BCG susceptible mice will only transiently express Ia. The purpose of this investigation was to determine the biochemical basis of continuous or transient Ia expression. We therefore compared Ia biosynthesis by macrophages from C.D2Bcgr mice to that by macrophages from congenic BALB/c.Bcgs mice. We show that macrophages from both strains of mice synthesize Ia initially and that very little synthesis occurs after 5 days of in vitro culture. No differences in the amount of Ia synthesized by the macrophages was apparent as determined by quantitative immunoprecipitation and by ELISA. Despite the lack of synthesis, macrophages from C.D2Bcgr mice continue to express Ia. The results of pulse-chase experiments indicate that macrophages from BALB/c.Bcgs mice degrade newly synthesized MHC class II glycoproteins whereas the majority of Ia remains associated with macrophages from the C.D2Bcgr mice. The addition of chloroquine to cultures of macrophages from BALB/c.Bcgs mice prevented the degradation and prolonged the expression of Ia. The results of this investigation show that there are no differences in the synthesis of Ia by macrophages from the two congenic strains of mice. The transient expression of Ia by macrophages from BALB/c.Bcgs mice is due to its degradation.
Depletion of guanine nucleotides with mycophenolic acid suppresses IgE receptor-mediated degranulation in rat basophilic leukemia cells.
Authors: Wilson B S , Deanin G G , Standefer J C , Vanderjagt D , Oliver J M
Published: December 2022

In RBL-2H3 rat basophilic leukemia cells, Ag that crosslink IgE-receptor complexes stimulate the turnover of inositol phospholipids, the mobilization of Ca2+ from intra- and extracellular sources, the release of serotonin and other substances from granules and the transformation of the cell surface from a microvillous to a lamellar architecture. This study explores the role of GTP-binding proteins (G proteins) in the control of these biochemical and functional responses. We report that incubating RBL-2H3 cells for 4 h with 10 microM mycophenolic acid (MPA), an inhibitor of de novo GTP synthesis, reduces GTP levels by over 60% and causes an average reduction of 50% in Ag-stimulated serotonin release. This inhibition of secretion is associated with a 50% decrease in the rate of 45Ca2+ influx in MPA-treated cells. In contrast, Ag-stimulated inositol trisphosphate production is only slightly reduced, indicating that the phosphatidylinositol-specific phospholipase C can be activated by Ag in GTP-depleted cells. The membrane responses to IgE receptor cross-linking are unaffected by incubating cells with MPA. Exogenous guanine or guanosine protects the GTP pools in MPA-treated cells and permits normal ion transport and secretory responses to Ag; adenine does not. These results implicate a guanine nucleotide-binding protein in the control of IgE receptor-dependent signal transduction in RBL-2H3 cells. This protein may particularly control the Ca2+ influx pathway that is essential for secretion.
Administration of monoclonal anti-IFN-gamma antibodies in vivo abrogates natural resistance of C3H/HeN mice to infection with Leishmania major.
Authors: Belosevic M , Finbloom D S , Van Der Meide P H , Slayter M V , Nacy C A
Published: December 2022

C3H/HeN mice that are naturally resistant to cutaneous disease and systemic infections with the protozoan parasite, Leishmania major, were treated at the time of infection, and weekly thereafter, with mouse anti-rat IFN-gamma mAb or an irrelevant antibody of similar isotype. Anti-IFN-gamma-treated mice developed cutaneous lesions; parasites spread to the regional lymph nodes and then metastasized to spleens and livers. The course of disease in these animals was similar to that of genetically susceptible BALB/c mice. Two exceptions in the pathology of L. major infections were noted between BALB/c and anti-IFN-gamma-treated C3H/HeN mice: 1) BALB/c mice died of systemic complications, whereas C3H/HeN mice did not, and 2) multinucleated giant cells were observed in lymph nodes and spleens of infected BALB/c mice, whereas these cells were not observed in infected C3H/HeN mice. Control mice, those treated with either saline or irrelevant antibody of the same isotype as the anti-IFN-gamma monoclonal, showed no evidence of cutaneous disease (development of footpad lesions) or systemic infection (by histopathology). Total abrogation of the natural resistance of C3H/HeN mice could be achieved by treatment with as little as 0.5 mg/mouse/wk of anti-IFN-gamma antibody, or by a single dose of 1 mg/mouse anti-IFN-gamma antibody administered at the time of parasite inoculation. If antibody treatment was delayed for as little as 1 wk after parasite inoculation, the infections in treated animals resembled that of untreated or control antibody-treated mice: no cutaneous lesions (by footpad swelling or viable counts of leishmania in footpad tissue) or systemic disease (by microscopic analysis of touch preparations of internal organs, and histopathology of same). The production of IFN-gamma during the initial interaction of the parasite and host cells appears to be a major component of genetic control of natural resistance to infection with L. major in C3H/HeN mice.
Clonal characterization of the human IgG antibody repertoire to Haemophilus influenzae type b polysaccharide. II. IgG antibodies contain VH genes from a single VH family and VL genes from at least four VL families.
Authors: Scott M G , Tarrand J J , Crimmins D L , McCourt D W , Siegel N R , Smith C E , Nahm M H
Published: December 2022

To define the V gene family repertoire of human IgG anti-Haemophilus influenzae type b polysaccharide antibodies, we purified six IgG1 and nine IgG2 anti-Hib-PS antibodies to monoclonality from immune serum of six individuals and performed N-terminal amino acid sequence analysis. Of the 15 clonal antibodies we examined, all H chain V regions were of the VHIII family. In contrast, the L chains of these antibodies were clearly from at least four different VL families; VKI, VKII, VKIII, and V lambda. Interestingly. VL family expression correlated with the cross-reactivity of these antibodies to the capsular carbohydrate of Escherichia coli K100. VKII antibodies did not cross-react, whereas antibodies expressing V lambda, VKI, or VKIII generally cross-reacted. We conclude that L chain V regions are very important contributors to the limited heterogeneity in this antibody repertoire.
Macrophages and T cells do not express Mlsa determinants.
Authors: Molina I J , Cannon N A , Hyman R , Huber B T
Published: December 2022

In order to test the tissue distribution of Mlsa determinants, we have generated highly purified stimulator cell populations. First, Mlsa expression in bone marrow derived macrophages (M phi) of Mlsa genotype was tested in primary MLR and on Mlsa-specific T cell hybridomas (THy). Second, a similar experimental approach was used to analyze thioglycolate, peptone or Con A elicited peritoneal M phi. In all cases, these M phi cell populations were able to generate an excellent alloresponse, whereas no functional Mlsa determinants could be detected. Third, to further investigate whether the expression of Mlsa is lymphocyte specific, but dependent on expression of class II molecules, we have transfected I-Ek alpha and beta cDNA into a panel of thymomas of Mlsa genotype. Although we achieved a high level of surface I-Ek expression in all of these T cell tumors, none of them was able to trigger the Mlsa-specific THy. These results strongly suggest that Mlsa expression is limited to B cells. It is likely that Mlsa is a tissue-specific self-peptide that associates with class II molecules.
Immunodeficiency in graft-versus-host disease (GVHD). II. Effects of GVHD-induced suppressor cells on CD4+ T cell clones.
Authors: Wall D A , Hamberg S , Ferrara J L , Abbas A K
Published: December 2022

Lethally irradiated mice transplanted with H-2-matched, minor histocompatibility-disparate bone marrow develop graft-vs-host disease (GVHD) that is associated with severe immunodeficiency. Splenocytes from such mice contain radioresistant cells that profoundly suppress normal lymphocyte function. We now show that GVHD-induced suppressor cells also inhibit the proliferation of CD4+ T cell clones specific for different Ag and class II MHC determinants. These suppressors have a dominant anti-proliferative effect, because they inhibit DNA synthesis in response to receptor-mediated stimulation and growth-promoting lymphokines, without abolishing lymphokine secretion or lymphokine receptor expression by the cloned T cells. The implications of these findings, and the usefulness of T cell clones for studying immune suppression, are discussed.
T cell tolerance to self antigens in New Zealand hybrid mice with lupus-like disease.
Authors: Kotzin B L , Kappler J W , Marrack P C , Herron L R
Published: December 2022

We determined if self-reactive T cells are able to escape thymic tolerance in autoimmune New Zealand mice. T cells utilizing V beta 17a and V beta 11 encoded receptors have been shown to be clonally eliminated in nonautoimmune mice expressing I-E because of their potential self-reactivity. Similarly, V beta 8.1+ and V beta 6+ T cells are tolerized in the thymus of nonautoimmune mice that express Mls-1a. These T cell subsets were quantitated in the lymph nodes and spleens of (NZB x NZW)F1 and (NZB x SWR)F1 mice. In young mice from both autoimmune strains, deletion was similar to that observed in control animals matched for I-Ed and Mls-1a expression. Furthermore, older female autoimmune mice with elevated levels of IgG antinuclear antibodies and severe lupus-like renal disease did not demonstrate evidence of a global tolerance defect. We also found that the levels of residual V beta 17a+ cells in MHC-matched control F1 strains were further reduced by up to 80% in autoimmune (NZB x SWR)F1 mice. The greater in vivo elimination corresponded to an enhanced ability of NZB spleen cells, compared with other H-2d spleen cells, to stimulate V beta 17a+ hybridomas in vitro. The increased stimulation in culture could not be attributed to quantitative differences in I-E Ag expression. The results suggest that autoreactive T cells have been eliminated in these autoimmune mice by normal mechanisms of self-tolerance. Furthermore, the data demonstrate the existence of an NZB minor locus not present in other H-2d strains that influences T cell repertoire and enhances stimulation of T cells potentially reactive to self class II MHC Ag.
Heterogeneous distribution and transmembrane signaling properties of lymphocyte function-associated antigen (LFA-1) in human lymphocyte subsets.
Authors: Pardi R , Bender J R , Dettori C , Giannazza E , Engleman E G
Published: December 2022

The role of LFA-1, a member of the integrin supergene family, in intercellular adhesion, including lymphocyte-endothelial cell (EC) binding, has been established. We now demonstrate that differences in LFA-1 cell surface density are responsible for the variable adhesion efficiency of lymphocyte subsets to EC. Electrophoretic analysis revealed multiple glycosylated isoforms of both alpha and beta subunits, largely as a result of different degrees of sialylation, with variable expression among different lymphocyte subsets. Neuraminidase digestion before EC adhesion increased the binding efficiency of all lymphocyte subsets, although the relative increase in each subset was proportional to the initial LFA-1 sialic acid content. LFA-1 cross-linking resulted in phosphoinositide hydrolysis and a rise in [Ca2+]i when using anti-alpha but not anti-beta subunit antibodies. These findings indicate that the density of LFA-1 on lymphocyte subsets controls their adhesive properties, and that the LFA-1 alpha subunit has transmembrane signaling properties that may result in activation events after interaction with its natural ligands.
Activation of murine T cells by toxic shock syndrome toxin-1. The toxin-binding structures expressed on murine accessory cells are MHC class II molecules.
Authors: Uchiyama T , Tadakuma T , Imanishi K , Araake M , Saito S , Yan X J , Fujikawa H , Igarashi H , Yamaura N
Published: December 2022

Toxic shock syndrome toxin-1 (TSST-1)-binding structures present on murine lymphoid tissues were investigated by using 125I-TSST-1. T-depleted C57BL/6 spleen cells incubated with TSST-1 for 3 h at 0 degree C were mitogenic to splenic T cells, indicating that the former cells bind and present TSST-1 to T cells. TSST-1-binding activity was observed in C57BL/6 splenic B cells and L cells transfected with I-Ab genes, but not in splenic T cells and control L cells. Scatchard plot analysis showed that these B cells and transfectants bound TSST-1 with similar binding affinity. SDS-PAGE analysis showed that lysates of C57BL/6 spleen cells and the I-Ab-positive transfectants contain a single band which bound TSST-1 and comigrated with I-Ab heterodimers. TSST-1-binding activity observed clearly in C57BL/6. BALB/c, and C3H/HeN spleen cells and L cells transfected with I-Ab or I-Ak genes was not reduced by paraformaldehyde fixation. Binding of 125I-TSST-1 to the three spleen cells was markedly reduced by anti-I-A antibodies, but not by anti-I-E antibodies. C57BL/6, C3H/HeN, and (C3H/HeN x C57BL/6) F1 T cells were activated by TSST-1 to proliferate and produce IL-2 in the presence of FT6.2 cells, LT1-30-3 cells and either of them, respectively, but not in the presence of control L cells. These results indicate that I-A molecules function as the structures via that accessory cells directly bind TSST-1 on the cell surface and present a triggering signal of TSST-1 to T cells.
The antiinflammatory effects of essential fatty acid deficiency in experimental glomerulonephritis. The modulation of macrophage migration and eicosanoid metabolism.
Authors: Schreiner G F , Rovin B , Lefkowith J B
Published: December 2022

Dietary polyunsaturated fatty acid modulation exerts a beneficial effect in immune-mediated glomerulonephritis. To elucidate the mechanisms underlying this phenomenon, the effects of essential fatty acid (EFA) deficiency on the heterologous phase of nephrotoxic nephritis in rats (induced by the injection of a rabbit antiglomerular basement membrane antibody) were studied. The heterologous phase of nephrotoxic nephritis was characterized by an invasion of leukocytes into the glomerulus. Polymorphonuclear neutrophils predominated early on (3 h), whereas macrophages predominated at 24 and 72 h. EFA deficiency selectively prevented the influx of macrophages into the glomerulus. The invasion of polymorphonuclear neutrophils, in contrast, was unaffected. The influx of leukocytes into the glomerulus during nephritis was accompanied by a marked enhancement (10- to 40-fold) in glomerular thromboxane and leukotriene B4 production. EFA deficiency largely attenuated this change. Renal dysfunction during the heterologous phase of nephritis was manifested as azotemia, polyuria, sodium retention, and proteinuria. With EFA deficiency, polyuria, azotemia, and sodium retention were not seen. Proteinuria was reduced by approximately 85%. To address whether the lack of macrophage migration into the glomerulus in the context of nephritis with EFA deficiency might be due to a functional defect in macrophage migration, the chemotactic responsiveness of EFA-deficient macrophages was examined. EFA-deficient macrophages displayed normal chemotactic migration toward activated C. In sum, EFA deficiency prevents the invasion of macrophages into the glomerulus in nephrotoxic nephritis and attenuates the accompanying metabolic and functional alterations, but does not affect macrophage chemotactic responsiveness. Alterations in macrophage elicitation and lipid mediator generation by inflamed glomeruli thus appear to be central to the salutary effect of dietary polyunsaturated fatty acid modification on glomerulonephritis.
Transforming growth factor-beta inhibits the generation of cytotoxic T cells in virus-infected mice.
Authors: Fontana A , Frei K , Bodmer S , Hofer E , Schreier M H , Palladino M A , Zinkernagel R M
Published: December 2022

The immunoregulatory effects of human recombinant transforming growth factor (rTGF) beta 1 and human recombinant glioblastoma-derived T cell suppressor factor (rG-TsF)/TGF beta 2 was investigated in mice infected with lymphocytic choriomeningitis virus (LCMV) or vaccinia virus. Starting on the day of infection, i.p. injections of 1 microgram/day or rTGF-beta 1 or rG-TsF/TGF-beta 2 suppressed the generation of virus specific CTL. The effect of TGF-beta on CTL (day 8) was less pronounced when TGF-beta treatment was delayed for 3 days after LCMV infection. rG-TsF/TGF-beta 2 also has an inhibiting effect on CTL-mediated disease in LCMV-infected mice: it prolonged the survival time of mice infected with LCMV and reduced the local swelling reaction after infection into the footpad. These results indicate that rTGF-beta 1 and rG-TsF/TGF-beta 2 influence T cell immune reactivity in vivo.
1F7, a novel cell surface molecule, involved in helper function of CD4 cells.
Authors: Morimoto C , Torimoto Y , Levinson G , Rudd C E , Schrieber M , Dang N H , Letvin N L , Schlossman S F
Published: December 2022

We have developed a monoclonal antibody, anti-1F7, that inhibits soluble Ag-driven T cell proliferation as well as PWM-driven IgG synthesis. Anti-1F7 antibody reacts with approximately 57% of unfractionated T cells, 62% of CD4+ cells, and 54% of CD8+ cells. Although the 1F7 Ag is widely distributed among lymphoid cells, this Ag on CD4+ cells is preferentially expressed on the CDw29(4B4+) helper population. Moreover, anti-1F7 antibody further subdivides the CD4+CDw29+ cell subset into CDw29+1F7+ and CDw29+1F7- populations. The CD4+CDw29+1F7+ population of cells maximally proliferates to recall Ag such as tetanus toxoid, whereas helper function for PWM-driven IgG synthesis by B cells belongs to both the CD4+CDw29+1F7+ and CD4+CDw29+1F7- population of cells. The most prominent structure defined by this antibody is a 110-kDa molecule that is different from the 135-kDa, 160-kDa, and 185-kDa glycoproteins identified by anti-CDw29 antibody and the 180-kDa glycoprotein identified by UCHL-1 antibody. It is, however, related to the molecule recognized by anti-Ta1, an activation Ag on T cells. Furthermore, although the Ta1 molecule is recognized by anti-1F7 mAb, the 1F7 family of structures also includes molecules distinct from Ta1.
Perforin mRNA in primary peritoneal exudate cytotoxic T lymphocytes.
Authors: Nagler-Anderson C , Lichtenheld M , Eisen H N , Podack E R
Published: December 2022

Considerable evidence indicates that cloned CTL cell lines kill target cells by releasing toxic granules that contain a cytolytic protein, called perforin, and several serine esterases (granzymes A to F). However, primary CTL, such as the highly cytolytic peritoneal exudate lymphocyte (PEL) cell population, have been found by a hemolytic assay to have no perforin, or perhaps only borderline levels of that protein, suggesting that these cells use a different lytic mechanism. To determine whether or not primary CTL express the perforin gene, we have here compared mRNA from PEL CTL and from a cloned CTL cell line, 2C, by Northern blot analysis using a perforin cDNA probe. CD8+ PEL CTL contain approximately 30% of the amount of perforin message present in 2C. Moreover, depletion of CD8+ T cells from the total peritoneal exudate cell population removes both cytolytic activity and perforin message. We have previously shown that PEL CTL elicit the same changes in target cells as cloned CTL cell lines and are resistant to lysis by the toxic granules purified from these cells lines. Taken together these results are consistent with the view that primary CTL, as well as long term cloned CTL cell lines, exercise their cytolytic activity by means of perforin.
High-affinity antibodies to ssDNA are produced by CD-B cells in systemic lupus erythematosus patients.
Authors: Casali P , Burastero S E , Balow J E , Notkins A L
Published: December 2022

It was previously shown that human CD5+B cells are committed to the production of polyreactive "autoantibodies" that bind different self-Ag, including ssDNA, IgG Fc fragment, thyroglobulin, and insulin, as well as exogenous Ag, e.g., tetanus toxoid and other bacterial components. To define the contribution of the CD5+B cell subset to the production of antibodies to ssDNA in SLE, we quantitated, purified, and functionally characterized circulating CD5+ and CD5-B cells in patients and in healthy subjects. We found that in SLE patients circulating CD5+B cells were not increased in number, and both CD5+ and C5-B cells spontaneously secreted antibodies to ssDNA. Studies of the mAb we generated using CD5+ and CD5-B cells revealed that two types of antibody to ssDNA are produced in SLE. The first type, of the IgM class, is produced mainly by CD5+B cells and displays a moderate affinity for ssDNA (Kd, 10(-6) to 10(-7) mol/liter) and is polyreactive, not dissimilar to the autoantibodies inducible in the normal human B cell repertoire by polyclonal activation. The second type, mostly of the IgG and IgA class, is produced mainly by CD5-B cells and displays a higher affinity (Kd, 10(-8) mol/liter) for and reacts only with ssDNA. The functional features of the high affinity anti-ssDNA antibodies and the phenotype of their producing B cells mimic those characteristic of a "mature" Ag-driven response, such as that to tetanus toxoid in tetanus toxoid-vaccinated subjects.
Contribution of IL-6 to the antiproliferative effect of IL-1 and tumor necrosis factor on tumor cell lines.
Authors: Morinaga Y , Suzuki H , Takatsuki F , Akiyama Y , Taniyama T , Matsushima K , Onozaki K
Published: December 2022

The role of IL-6 in the antiproliferative effect of IL-1 for tumor cell lines was investigated using IL-1-sensitive cell lines. Human recombinant IL-1 alpha and IL-6 both inhibited the growth of an IL-1-sensitive cloned human melanoma cell line (A375-C6). However, IL-1 has greater maximum growth inhibitory activity than IL-6. Conditioned medium of the tumor cells that were treated with IL-1 contained IL-6 as determined by ELISA. Northern blot analysis revealed that IL-6 mRNA expression increased in IL-1-treated cells. In addition, antibody against human IL-6 neutralized about 50% of the antiproliferative effect of IL-1. The growth of an IL-1-resistant clone of A375 cells (A375-C5), which cannot be shown to express any detectable IL-1R, was inhibited by IL-6 to the same degree as A375-C6 cells. The A375-C5 cell line did not produce IL-6 or increase IL-6 mRNA after stimulation with IL-1. These results indicate that IL-6 mediates in part the antiproliferative effect of IL-1 on A375-C6 cells by acting as an autocrine antiproliferative factor. IL-1 also inhibited the growth of a malignant human mammary cell line (MDA-MB-415). IL-6 exhibited only slight growth inhibition in this cell line. Neither IL-6 production nor IL-6 mRNA expression was induced in this cell line by IL-1. Antibody against IL-6 did not neutralize the antiproliferative effect of IL-1. Therefore, for MDA-MB-415 cells IL-6 appeared not to be involved in the antiproliferative effect of IL-1. These results indicate that the antiproliferative effect of IL-1 involves at least two pathways, one IL-6 dependent and another IL-6 independent. The contribution of IL-6 to the antiproliferative effect of TNF was also examined. IL-6 appeared not to play a role in the antiproliferative effect of TNF in these cell lines.
Impaired macrophage activation in vitamin D3 deficiency: differential in vitro effects of 1,25-dihydroxyvitamin D3 on mouse peritoneal macrophage functions.
Authors: Gavison R , Bar-Shavit Z
Published: December 2022

1,25-Dihydroxyvitamin D3 (1,25(OH)2D3) is known to interact in vitro with mononuclear phagocytes. The purpose of this study was to determine the role of the steroid in macrophage activation in vivo. Peritoneal macrophages from normal and vitamin D3-deficient mice were obtained after i.p. injection of activating or eliciting agents. Cells obtained from vitamin D3-deficient mice exhibited defected capabilities to perform anti-tumor activities (cytostasis and cytolysis) and to form oxygen reduction products (H2O2 and O2-). On the other hand, the level of the lysosomal enzyme acid phosphatase was unaffected by vitamin D3 deficiency. In vitro, incubation of macrophages with 1,25(OH)2D3 enhanced their anti-tumor activities, but did not affect the cells' capacity to produce H2O2 and O2-, or acid phosphatase. Our results suggest that 1,25(OH)2D3 is essential for macrophage activation in vivo. However, in vitro, the hormone is only partially capable of affecting the macrophage functions, probably because of the maturation state of the cells.
MHC class II A alpha and E alpha molecules determine the clonal deletion of V beta 6+ T cells. Studies with recombinant and transgenic mice.
Authors: Anderson G D , Banerjee S , David C S
Published: December 2022

Interactions between MHC class II genes and minor lymphocyte stimulating (Mls) associated products are responsible for clonally deleting self-reactive T cells in mice. Here we demonstrate the role of the intact I-A and I-E molecules as well as the individual A alpha and E alpha chains in the deletion of cells bearing the V beta 6 TCR. DBA/1 (H-2q, Mls-1a) mice were crossed with various inbred congenic, recombinant, and transgenic strains and the F1's were screened for V beta 6 expression. All I-E+ strains were fully permissive in deleting V beta 6+ T cells. I-E- strains expressing I-A b,f,s,k,p permitted only partial deletion, while I-Aq strains showed no deletion. Recombinant I-Aq and I-Af strains which expressed E kappa alpha chain in the absence of E beta chain showed a decrease in V beta 6+ T cells as compared to their H-2q and H-2f counterparts. Furthermore, transgenic mice expressing E kappa alpha Aq beta gene in an H-2q haplotype (E kappa alpha Aq beta?) gave similar results to that of the recombinants in deleting V beta 6 T-cells. The role of the 1-A molecule was also shown by the partial deletion of V beta 6+ T cells in H-2q mice expressing transgenic I-Ak molecules. These results demonstrate that the E alpha chain is important in the deletion of V beta 6 T-cells in Mls-1a mice. The role of A alpha chain is also implied by the permissiveness of E kappa alpha Aq beta but not Aq alpha Aq beta molecules in the deletion of V beta 6+ T cells.
Adenovirus E1A products activate the Ig k-chain enhancer in fibroblasts. A possible involvement of the NF-kB binding site.
Authors: Shurman L , Sen R , Bergman Y
Published: December 2022

Proteins encoded by the early region 1A (E1A) regulate transcription of viral and cellular genes. The mechanism of this trans-regulation remains unclear but it is of considerable interest as an example of transcription regulation through cellular intermediates. We have therefore studied the effect of E1A products on the activity of the k-L chain gene enhancer. In our previous studies we have found that the k-chain enhancer is activated by E1A products in fibroblasts. Using in vivo competition experiments we found that the E1A regulatory effect involves trans-acting factors that can be titrated out by the k-chain enhancer sequences. Our transfection experiments suggest that the k3 enhancer fragment, encompassing the NF-kB binding site, is one of the sites through which the adenovirus E1A products exert their transactivation effect. The level of the nuclear factors that bind to the NF-kB binding site increases in fibroblasts that constitutively express E1A products. Understanding the mechanisms through which E1A regulates transcription should help to illuminate cellular mechanisms of gene control in normal and transformed cells.
Characterization of syngeneic antiidiotypic monoclonal antibodies to murine anti-human high molecular weight melanoma-associated antigen monoclonal antibodies.
Authors: Kusama M , Kageshita T , Chen Z J , Ferrone S
Published: December 2022

Hybridization with murine myeloma cells P3-X63-Ag8.653 of splenocytes from BALB/c mice immunized with syngeneic anti-human high molecular weight melanoma-associated Ag (HMW-MAA) mAb 149.53, 225.28, 763.74, and TP41.2 has resulted in the formation of antiidiotypic antibody-secreting hybridomas with a frequency ranging between 1.2% and 5.2%. No marked difference was detected in the frequency of antibody secreting hybridomas in the fusions generated from mice immunized with the four anti-HMW-MAA mAb, suggesting that the idiotopes expressed by each of them display similar immunogenicity in a syngeneic combination. The number of antiidiotypic mAb that did not inhibit the binding of immunizing mAb to melanoma cells was higher than that of those that died, suggesting that idiotopes not associated with the Ag-combining site are more immunogenic than those that are. The idiotopes recognized by mAb were not detected on a large panel of anti-HLA Class I mAb, anti-HLA Class II mAb, and anti-human melanoma-associated Ag mAb. The latter included also mAb that cross-inhibit the immunizing anti-HMW-MAA mAb. The idiotopes recognized by mAb were not detected on the isolated H and L chain of the immunizing anti-HMW-MAA mAb. Cross-blocking experiments with a selected number of antiidiotypic mAb identified three distinct idiotopes on mAb 149.53, 225.28, and TP41.2 and two on mAb 763.74. Three, 5, 2, and 5 antiidiotypic mAb to idiotopes within the Ag-combining site of mAb 149.53, 225.28, 763.74, and TP41.2, respectively, were tested for their ability to induce anti-HMW-MAA antibodies. Serological and immunochemical assays detected anti-HMW-MAA antibodies only in sera from BALB/c mice immunized with mAb MK2-23. Therefore, mAb MK2-23 can be classified as beta, while the remaining 14 can be classified as gamma.
The alpha 1/alpha 2 domains of class I HLA molecules confer resistance to natural killing.
Authors: Storkus W J , Alexander J , Payne J A , Cresswell P , Dawson J R
Published: December 2022

The expression of transfected HLA class I Ag has previously been shown to protect human target cells from NK-mediated conjugation and cytolysis. In this same system, transfected H-2 class I Ag fail to impart resistance to NK. In this study, we have mapped the portion of the HLA class I molecule involved in this protective effect by exploiting this HLA/H-2 dichotomy. Hybrid class I genes were produced by exon-shuffling between the HLA-B7 and H-2Dp genes, and transfected into the class I Ag-deficient B-lymphoblastoid cell line (B-LCL) C1R. Only those transfectants expressing class I Ag containing the alpha 1 and alpha 2 domains of the HLA molecule are protected from NK, suggesting the "protective epitope" is located within these domains. Since a glycosylation difference exists between HLA and H-2 class I Ag within these domains (i.e., at amino acid residue 176), the role of carbohydrate in the class I protective effect was examined. HLA-B7 mutant genes encoding proteins which either lack the normal carbohydrate addition site at amino acid residue 86 (B7M86-) or possess an additional site at residue 176 (B7M176+) were transfected into C1R. Transfectants expressing either mutant HLA-B7 Ag were protected from NK. Thus, carbohydrate is probably not integral to a class I "protective epitope." The potential for allelic variation in the ability of HLA class I Ag to protect C1R target cells from NK was examined in HLA-A2, A3, B7, and Bw58 transfectants. Although no significant variation exists among the HLA-A3, B7, and Bw58 alleles, HLA-A2 appears unable to protect. Comparison of amino acid sequences suggests a restricted number of residues which may be relevant to the protective effect.
Tumor necrosis factor stimulates transcription of HIV-1 in human T lymphocytes, independently and synergistically with mitogens.
Authors: Israël N , Hazan U , Alcami J , Munier A , Arenzana-Seisdedos F , Bachelerie F , Israël A , Virelizier J L
Published: December 2022

We have investigated the effect of TNF, a cytokine produced during most immunologic and inflammatory reactions, on HIV genome expression in human T lymphocytes. A CD4+ human T cell line (J.Jhan) was transfected with vectors permitting the expression of the chloramphenicol acetyl transferase (CAT) gene under the control of the long terminal repeat (LTR) of HIV-1. rTNF was found to induce HIV LTR transactivation as intensely as PHA or phorbol esters. PHA enhanced TNF receptor expression in J.Jhan cells and acted synergistically with TNF on HIV LTR induction. TNF was also shown to induce well expression of a whole HIV provirus genome transfected into J.Jhan cells. The use of various CAT constructs carrying fragments of the HIV LTR, combined with bandshift assays, showed that TNF stimulates HIV transcription by acting on the kB-like enhancer element of the LTR through induction and/or activation of an NF-kB-like protein factor. Such findings are compatible with the hypothesis that TNF production participates in the pathogenesis of AIDS by enhancing HIV replication in T lymphocytes.
T cell derived IL-6 is differentially required for antigen-specific antibody secretion by primary and secondary B cells.
Authors: Hilbert D M , Cancro M P , Scherle P A , Nordan R P , Van Snick J , Gerhard W , Rudikoff S
Published: December 2022

IL-6 (formerly PCTGF, HP-1, BSF-2, HGF, IFN-beta 2, 26 kDa) is a recently defined lymphokine demonstrating activity on multiple cell types, including hepatocytes, thymocytes, T cells, plasmacytomas, and B cells. The biologic effects of IL-6 on lymphocytes, particularly B cells, suggest this factor may be involved in the regulation of normal immune responses. Accordingly, we have investigated the role of IL-6 in Ag-specific responses of B cells from both naive and Ag-primed mice. When Ag-primed splenic T cells were used as a source of help, naive (primary) B cell responses specific for the hemagglutinin molecule of the influenza A virus (PR8) were fully inhibited by the addition of an anti-IL-6 antiserum, and are thus IL-6 dependent. In contrast, secondary B cell responses were essentially IL-6 independent, being unaffected by this antiserum even at concentrations 10-fold higher than required to completely inhibit primary responses. This differential IL-6 requirement was further investigated by using a panel of hemagglutinin molecule-specific Th clones. Consistent with the above findings, a Th1 clone secreting biologically active IL-6 enables antibody secretion by both primary and secondary B cells, whereas Th1 clones that do not produce IL-6 support secondary responses, but fail to help primary B cell responses unless exogenous IL-6 is added. These results provide the first instance of differential lymphokine requirements among primary vs secondary B cell responses, and suggest T cell-derived IL-6 plays a critical role during the regulation of humoral immune responses. Moreover, functionally distinct Th1 clones were identified that differed in IL-6 secretion and their corresponding ability to induce Ig secretion by primary and secondary B cells.