bluuebunny/crossref_metadata_2025 huggingface dataset:
Demonstration of a Surface Antigen on Epstein-Barr Virus Genome-Carrying Lymphoid Cells: Distinction from the Virus-Determined Membrane Antigen
Authors: Sakamoto Kiyoshi , Hinuma Yorio
Published: January 2023

A surface antigen (SA) was detected on Epstein-Barr virus (EBV)-carrying lymphoid cell lines by indirect membrane immunofluorescence with an antiserum from a rabbit immunized with Raji cells; the antiserum had been extensively absorbed with normal human blood and tonsil cells. The SA was not detected on normal human umbilical cord and adult peripheral blood lymphocytes or EBV-negative cell lines. Incidences of the SA and EBV-determined membrane antigen (MA) on certain EBV-carrying cell lines were not compatible. Antibody against SA was differentially absorbed by the SA-positive MA-negative cell lines whereas MA antibody was absorbed by MA-positive SA-negative cell lines. The results of cross-absorption tests of antiserum against Raji cells or P3HR-1 cells suggested that SA may contain more than one antigenic determinant.
The C5 Chemotactic Fragment Isolated from Activated Human Serum
Authors: Beebe D. , Goralnick S. , Gerard C. , Ozols J. , Ward P. A.
Published: January 2023

A chemotactic factor for rabbit and human polymorphonuclear leukocytes antigenically related to C5 has been isolated from human serum activated by zymosan in the presence of ε-amino caproic acid (EACA). Antiserum to the purified chemotactic factor as well as antiserum to human C5, inhibitis the chemotactic activity in human serum activated by zymosan, aggregated IgG, immune complexes, or bacterial lipopolysaccharide. The chemotactic activity of bacterial (E. coli) factor is not inhibited by either antiserum. The C5 chemotactic factor is purified by a combination of gel filtration and ion exchange gel chromatography. Analysis for anaphylatoxin activity in fractions from each step of the procedure indicates that the muscle-contracting activity is separated from the bulk of the chemotactic activity in the anion exchange step. The purified chemotactic factor migrates as an α globulin as assessed by elution activity in agarose.
Antibody-independent Complement-Mediated Killing of a Subpopulation of Thy-1-bearing Rat Lymphoid Cells
Authors: Budzko Delia B. , Kierszenbaum F.
Published: January 2023

Normal guinea pig serum (GPS) kills subpopulations of rat thymus and bone marrow cells. The nonspecific cytotoxic reaction can be abrogated by heating the serum at 56°C or by adding either 0.01M EDTA or cobra venom factor and is, therefore, complement (C) dependent. C activity was found to be provided via the alternative pathway since serum from C4-deficient guinea pigs was also effective, and heating at 50°C for 20 min to destroy the activity of factor B inhibited its cytotoxicity. Furthermore the reaction was Mg++ but not Ca++ dependent.

Absorption with rat thymocytes in the presence of 0.01M EDTA failed to affect the cytotoxicity of GPS tested after restoration of Mg++. Similar absorptions performed in the presence of Mg++ did remove the cytotoxic activity. Gammaglobulins isolated from GPS lacked cytotoxicity when tested in the presence of normal rat serum as a source of C. These results are consistent with an antibody-independent mechanism.
Physical Characterization of the Effect of Heat on Factor B Of the Properdin System
Authors: Chapitis Jane , Lepow Irwin H.
Published: January 2023

Purified factor B heated at 50°C for 30 min (ΔB) at physiological concentration (200–400 µg/ml) or higher sedimented as at least 4–5 species in linear sucrose density gradients. The lightest species of ΔB possessed slightly lower sedimentation rate, 5.3S, than native B, 5.8S. Consecutive heavier species differed by ∼ 2.6S. Serum fortified with radiolabeled 131I-B was heated; 131I-ΔB distributed broadely in the gradient. In analytical polyacrylamide disc gel electrophoresis (PAGE), ΔB migrated as multiple bands with the same or slower mobility compared with B, indicative of a polymerization phenomenon. Prior to PAGE, samples of ΔB were treated overnight at room temperature with 1% sodium dodecyl sulphate (SDS) with or without 8 M urea (Ur). This reduced the intensity of the slow bands and, concomitantly, increased the quantity of the fastest band. Upon additional treatment with 1% beta-mercaptoethanol (2-ME), ΔB migrated as a single band with the same mobility as B.
Reconstitution of C1 in Native Proenzyme Form and Analysis of the C1 Activation Process
Authors: Cooper N. R. , Ziccardi R. J.
Published: January 2023

C1 may be reconstituted in macromolecular proenzymatic form by incubation of highly purified C1q, C1r and 125I-C1s together in the presence of calcium. Formation of C1 occurs very rapidly and is essentially complete after 5 min at 0°C. C1 reformed in this manner contains an equimolar ratio of C1 subcomponents and sediments in sucrose density gradients with the 16 S rate characteristic of C1 in serum. Reconstituted C1 is fully activatable as shown by cleavage of the 87,000 dalton polypeptide chain of C1s into disulfide linked subunits of 59,000 and 28,000 daltons, respectively, after incubation with C1 activators. The percentage of C1s conversion and thus the extent of C1 activation may be quantitated. As reformed activatable proenzyme is relatively stable at 0° or frozen, it may be used to quantitatively assess the C1 activating properties of various substances as well as to analyze the C1 activation process.
Description of an Acidic Fragment (C3e) of Human C3 Having Leukocytosis-Producing Activity
Authors: Ghebrehiwet B. , Müller-Eberhard H. J.
Published: January 2023

A low m.w. fragment capable of mobilizing leukocytes from bone marrow is generated in serum upon activation of complement. This fragment has been reported to be derived from C3 (Rother, K., Eur. J. Immunol. 2, 550, 1972).

We have isolated a fragment (C3e) of human C3 that has a m.w. of about 10,000 daltons and consists of 101 amino acid residues, according to computer analysis of amino acid composition data. C3e was generated in two ways: by incubation of isolated C3 with 2% (w/w) trypsin for 120 min at 37°C, or by aging serum at 37°C for 5 days. C3e preparations obtained by the two methods were virtually indistinguishable with respect to molecular size, amino acid composition and antigenicity. The electrophoretic mobility of C3e at pH 8.6 is greater than that of albumin. Anti-C3e reacts with C3e, C3, C3b and C3c, but not with C3a or C3d.
Interactions Between Complement Proteins and Cell Membranes: The Chemical Nature of the Bond Formed Between C3b and Cell Surface Macromolecules
Authors: Law S. K. , Levine R. Paul
Published: January 2023

C3, when activated via either the classical or alternative pathways to C3b, binds to membrane surfaces and particulate objects like zymosan. The interaction between C3b and such surfaces is apparently covalent in nature, for it cannot be disrupted under extreme denaturing conditions including heating at 90°C in a solution containing 2% SDS, 10 M urea, and 2% mercaptoethanol for 15 minutes. However, nucleophilic agents such as 1 M hydroxylamine at pH 9 are able to release C3b from its “receptors”, suggesting that C3b might bind via an ester bond. [Law and Levine, PNAS 74:2701 (1977)] Cleavage of ester bonds with hydroxylamine will yield hydroxamate derivatives, and if indeed C3b binds to its receptive surfaces via an ester bond, there is a 50% chance that a hydroxamate group will be found on C3b after its release from zymosan with hydroxylamine.
Interactions Between Complement Proteins and Cell Membranes: Resealability As Evidence that the Functional Complement and Osmotic Membrane Lesions Are Distinct
Authors: Li C. K. N. , Levine R. Paul
Published: January 2023

Cytolyis induced by the activated complement sequence and lysis of cells in hypotonic solution have many common characteristics. The demonstration of whether or not the functional complement lesion is identical to the membrane lesion produced in hypotonic lysis would seem a basic step in elucidating the mechanism of complement action. We evaluated the equivalence of the two membrane lesions by asking whether complement-impaired and hypotonically-damaged membranes reseal (i.e., regain selective solute permeability) under the same conditions. Osmotically lysed ghosts were prepared by suspending sheep erythrocytes in hypotonic sodium phosphate. Complement-lysed ghosts were prepared either by treating sensitized ghosts with human serum or by treating sensitized erythrocytes with serum and collecting the lysed cells. Resealing was induced by incubating ghosts in phosphate-buffered sodium chloride for 45 min at 37°C. By virtue of their ability to retain solutes and, hence, intracellular water, resealed ghosts possess buoyancy when centrifuged.
Radioimmunoassay for the Third Component of Human Complement
Authors: Lorenz P. E. , Tack B. F. , Schechter A. N.
Published: January 2023

The third component of human complement (C3) was purified to homogeneity by the method of Tack and Prahl (Biochem. 15: 4513, 1976). Sheep and rabbits were made hyperimmune with C3, as well as with activation fragments C3b, C3c, and C3d, as determined by standard double-diffusion assays. Radiolabeling of C3 and each of the fragments was performed by reductive alkylation with tritiated sodium borohydride (10 Ci/mmol) and formaldehyde. This method, which effects the methylation of free amino groups, allowed labeling to specific activities of ∼ 4 × 105 cpm/µg, with minimal change in function as determined by the hemolytic activity assay for C3. Competitive binding studies were conducted by incubation of the labeled and native C3 proteins with a 1/10,000 dilution of the sheep antiserum; free protein was separated from bound with a burro anti-sheep IgG antiserum. This radioimmunoassay indicated an affinity constant of about 5 × 109 liters/mole and with 100-µl samples could be used quantitatively in the range from 2 to 80 ng of C3.
The Role of Sialic Acid in the Functional Activity and Catabolism of C1̄-INH
Authors: Man Doreen P. , Minta Joe O.
Published: January 2023

Human C1̄-INH is a 4S neuraminoglycoprotein in normal serum that complexes stoichiometrically with and thereby inhibits the enzymatic activities of C1̄s, C1̄r, kallikrein, plasmin, activated Hageman factor, anaphylatoxin inactivator. Inherited deficiency of C1̄-INH activity has been associated with the clinical syndrome of hereditary angioneurotic edema. In this study, the effect of the enzymatic removal of sialic acid from C1̄-INH on its functional activity and metabolic behavior was evaluated. C1̄-INH was isolated from normal human plasma by column chromatography and preparative polyacrylamide gel electrophoresis. The highly purified protein was shown by SDS polyacrylamide gel electrophoresis to be comprised of a single polypeptide chain, m.w. 90,000. Incubation of C1̄-INH, at pH 7.4 with Vibrio cholerae neuraminidase at a ratio of 10:1 (wt/unit) for 60 min at 37°C resulted in the release of about 12% of the total sialic acid content. This treatment did not result in any gross alteration of the structure of C1̄-INH as assessed by its antigenicity, m.w. and C1̄s inhibitory activity.
Characterization of the Complement Lesion: The Formation of Trans-Membrane Channels and Their Mechanism of Assembly
Authors: Michaels David W. , Abramovitz Aaron S. , Hammer Carl H. , Mayer Manfred M.
Published: January 2023

Planar lipid bilayer membranes (BLM) have been used to study three features of the C5b-9 membrane attack sequence, namely: 1) whether the C5b-9 complex is assembled outside or within the membrane, 2) whether membrane thickness plays a role in the action of the cytolytic sequence, and 3) whether the terminal components increase membrane permeability in discrete steps, i.e., quanta, which would suggest trans-membrane channels.

In the first study involving “CIS/TRANS” experiments, we examined the process of C5b-9 assembly with respect to “sidedness”. The results show that the cytolytic sequence is divided into two reaction pairs, C5b, 6 plus C7 and C5b-8 plus C9. The reaction between the partners of each pair requires their presence on the same side of the membrane. However, the coupling between the pairs, i.e., between the C5b, 6, 7 complex and C8, can occur from opposite sides of the membrane, indicating that it occurs within the lipid interior of the bilayer.
Studies on the Lytic Sensitivity of Paroxysmal Nocturnal Hemoglobinuria (PNH) Erythrocytes (E)
Authors: Packman C. H. , Rosenfeld S. I. , Jenkins D. E. , Leddy J. P.
Published: January 2023

PNH E have an unexplained membrane defect making them highly susceptible to complement (C) lysis. Studies by others have found: 1) equal binding of antibody (Ab), C1 and C4, and similar C2 Tmax and decay, on PNH and normal human E; 2) markedly increased C3 binding by PNH E relative to Ab or C4 binding; 3) supranormal lysis per unit of C3 bound; 4) comparable numbers of 10nm electron microscopic (EM) ring lesions on lysed PNH and normal E membranes; and 5) in the presence of fluid phase and C5–C9, increased lysis of and C5 binding to PNH E, but equal lysis of PNH and normal E for a given quantity of C5 bound.

Our studies sought to further define the lytic behavior of PNH E. The PNH patients studied included cases with predominant populations of highly C-sensitive E (“type III”), or with intermediately sensitive E (“type II”), or with mixtures of E types.
Molecular Interactions of the Control Proteins C3b Inactivator and β1H with Various Complement Intermediates
Authors: Pangburn M. K. , Schreiber R. D. , Müller-Eberhard H. J.
Published: January 2023

Radioiodinated β1H was demonstrated to bind to sheep EAC4b, EAC4,2,3b and EC3b, but not to E, EA, EAC4,2 or to C3bINA and β1H treated EC3b. This binding was dependent upon the C3b concentration on the surface of the cells and could be inhibited by unlabeled β1H, free C3b or high concentrations of Factor B. The presence of activated properdin on EC3b cells did not affect β1H binding. Binding of radioiodinated C3bINA was demonstrated by stabilizing the enzyme substrate complex EC3b, βIH, C3bINA at 0°C. Binding of 125I-C3bINA to EC3b in the presence of β1H was 30-fold greater than in the absence of this cofactor. C3bINA binding was approximately stoichiometric with respect to bound β1H and this interaction had an apparent binding constant at 0°C of 108 M-1.

Fearon and Austen (J. Exp. Med. 146: 22, 1977) have reported that C3b on rabbit erythrocytes is protected from C3bINA and β1H action.
Enzymatic Inactivation of Complement by Mouse Saliva
Authors: Weill J. C. , Girard J. F. , Leca G. , Ayed K.
Published: January 2023

While searching for lymphocyte surface antigens in mouse saliva, we have observed that this secretion prevented the cmediated lysis of lymphocytes in a microlymphocytoxicity test (Terasaki plate). Mouse saliva has a preferential action on the C3 and C5 molecule which are degraded within 1 min in whole human serum, and then acts later on C2 and C4. Mouse saliva has no action on C1 and late components C6 to C9. With purified components the kinetic action of mouse saliva is slowed down. The action of saliva is inhibited by PMSF, TCLK, and aprotinine which indicates the role of a tryptic-like enzyme. When mouse saliva is injected i.v. into rats, the hemolytic capacity of their C is completely abolished in the first 24 hr and then recovers to its normal level on the 3rd day after injection. This inhibition of the C reaction is also obtained with rat and rabbit saliva but never with any of the human saliva tested.
Identity of Murine C4 and the MHC-Associated S Region Antigens
Authors: Wilde Charles E. , Capra J. Donald
Published: January 2023

As part of ongoing studies on the alloantigens of the murine major histocompatibility complex, the structures of the Ss and Slp antigens are being elucidated. These serum proteins exhibit m.w. of 200,000 daltons on SDS-polyacrylamide gels. Following reduction and alkylation, three subunits of 93,000, 78,000, and 35,000 daltons are generated. These subunits (molecular structures) are similar in size to the subunits of the human C4 C component as determined in our laboratory and by others. Furthermore, serologic cross-reactivity has been demonstrated between the murine S region antigens and human C4, with various antisera. The S region antigens are extremely labile, and are degraded by an activity in murine serum in a pattern similar to that generated by the action of C4b inactivator on human C4. Initial functional studies indicate that the ability to reconstitute the lytic capability of C4-deficient guinea pig serum co-purifies with the Ss antigenic activity.
The in Vitro Suppression of Spontaneous Erythrocyte Autoimmune Responses with Lymphocytes Activated with Concanavalin A
Authors: Ramshaw Ian A. , Woodsworth Mary , Eidinger David
Published: January 2023

When normal mouse spleen cells are cultured in vitro, large numbers of cells develop that produce antibody toward antigens found on bromelain-treated mouse erythrocytes (BrMRBC). The in vitro culture also generates T cells that mediate DTH toward these antigens. We have suggested that under in vivo conditions, suppressor T cells maintain these immune responses at a low level but that this suppression wanes when the cells are cultured in vitro. The present study examines the effect of concanavalin A (Con A) on the in vitro development of humoral and cell-mediated immunity to BrMRBC. Mitogenic concentrations of Con A prevented the development of both the PFC and TDTH responses toward BrMRBC. The Con A-induced suppression was due to the induction of suppressor T cells; thus the addition of Con A-activated cells to fresh spleen cell cultures prevented the development of both the PFC and TDTH response against BrMRBC.
Allogeneic Placenta is a Paternal Strain Antigen Immunoabsorbent
Authors: Wegmann Thomas G. , Singh Bhagirath , Carlson George A.
Published: January 2023

A partially purified 125I-labeled antibody directed against the murine major histocompatibility complex and injected i.v. into pregnant females is selectively absorbed by the placenta when the fetus bears the appropriate target antigen. The placenta specifically absorbs the antibody at both 13 days and 17 days of gestation, and the differential uptake is found as early as 2 hr after injection and as late as 12 hr. It is also seen in 13-day placentas that have had the fetus removed surgically, indicating that fetal circulation is not essential for the absorption to take place. Specificity controls eliminate the possibility that the differential uptake is due to Fc receptor binding or undefined effects of hybrid vigor. This increase in binding is not seen in the livers, spleens, kidneys, or lungs of the pregnant females. There is a slight decrease in radioactivity in the serum. These results indicate that the placenta is a paternal antigen-bearing immunoabsorbent that could serve as a barrier between the maternal immune response and the semi-allogeneic fetus.
Spontaneous Cytotoxicity
Authors: Muchmore A. V. , Decker J. M. , Blaese R. M.
Published: January 2023

We have shown that human mononuclear cells become spontaneously cytotoxic to a variety of erythrocyte targets after 7 days of in vitro culture. This phenomenon of spontaneous cytotoxicity occurs in low concentration of either autologous serum or FCS and is independent of any known stimulant. It does not require exogenous antibody, mitogen, or antigen. Once expressed, the cytotoxic cell has little, if any, specificity. Monocytes appear to be responsible for this observed in vitro cytotoxicity. We now present evidence that the development of spontaneous monocyte-mediated cytotoxicity in vitro is completely reversed by the addition of optimally mitogenic doses of PWM. PWM appears to reverse monocyte-mediated killing by stimulating a potent cell-mediated suppressor. This suppressor cell is radiosensitive and its action is blocked by inhibitors of protein synthesis. In contrast to other mitogen-driven suppressor models, PWM will inhibit spontaneous monocyte-mediated cytotoxicity even when added as late as 6 hr before the end of a 7-day culture.
Histamine Release Due to Bivalent Penicilloyl Haptens: The Relation of Activation and Desensitization of Basophils to Dynamic Aspects of Ligand Binding to Cell Surface Antibody
Authors: Dembo M. , Goldstein B. , Sobotka A. K. , Lichtenstein L. M.
Published: January 2023

We study the time-dependent aspects of activation and desensitization of passively sensitized human basophils by a bivalent penicilloyl hapten, [BPO]2, in the presence or absence of a monovalent penicilloyl hapten, [BPO]1. Data presented in this and the preceding paper are found to be consistent with a simple kinetic model of the binding and cross-linking reaction between [BPO]1, [BPO]2, and cell surface IgE. It is shown that the rapid perturbation of cross-linked IgE by simple dilution or washing of cells or by addition of excess [BPO]1 causes re-equilibration of the rate of histamine release within a matter of seconds. This demonstrates that no stable antigenindependent “activated” state of basophils exists and that cross-linked antibody is necessary throughout the entire time course of histamine release.

In addition, we show that desensitization requires the continuing presence of cross-linked antibody on the cell surface and that the rate of desensitization is a monotone increasing function of the number of cross-linked IgE molecules per cell. The rate of desensitization also appears to be a saturable function of the number of cross-linked IgE antibodies.

In light of the kinetic model these data indicate that the binding and cross-linking reaction between [BPO]1, [BPO]2, and cell surface IgE approaches thermal equilibrium with a time constant on the order of 10 sec or less. This in turn implies that cyclic aggregates of [BPO]2 and IgE are unstable. Finally, since release and desensitization occur on a time scale of 100 sec or more, dynamic, as opposed to equilibrium, properties of the cross-linking reaction are unlikely to have any influence on [BPO]2-induced histamine release.
Langerhans Cells Trap Tick Salivary Gland Antigens in Tick-Resistant Guinea Pigs
Authors: Allen John R. , Khalil Hanaa M. , Wikel Stephen K.
Published: January 2023

In the infested skin of tick-resistant guinea pigs, indirect immunofluorescence techniques have revealed that antigens from the ticks' salivary glands are associated with discrete dendritic cells in the epidermis. Evidence is presented to support the suggestion that these antigen-retaining cells are Langerhans cells.
Suppression and Enhancement of the Rabbit Primary in Vitro Antibody Response with Anti-Allotype Antibody: Concurrent Effects on Thymidine Incorporation, Blastogenesis, and Cell Surface Ig
Authors: Roux Kenneth H. , Metzger Dennis W. , Dray Sheldon
Published: January 2023

We have adapted an in vitro culture system to study the dose-dependent effects of purified anti-light chain allotype (b4 or b5) antibody on the primary Ab response of rabbit spleen cells to sheep erythrocytes. At high doses, anti-b4 or anti-b5 Ab suppressed the anti-SRBC response and the expression of cell surface immunoglobulins while stimulating blastogenesis and thymidine incorporation. At low doses, anti-allotype Ab markedly enhanced the immune response and, to a lesser extent, thymidine incorporation and blastogenesis. The mitogenic effect of anti-allotype Ab was observed in the absence of antigen only at the higher doses. When tested on heterozygous b4b5 SpC, the high and low doses of Ab selectively modulated the immune response with respect to cells bearing the target allotype. In vivo induced allotype suppression could not be reversed by culturing SpC with high or low doses of purified anti-allotype Ab directed against the expressed allotype. Our data support the concept that anti-Ig Ab reacts directly with B cell surface Ig to trigger a mitogenic response. This trigger, however, is not sufficient to induce differentiation to anti-SRBC secreting cells in the absence of the antigen.
F1 Hybrid Anti-Parental H-2k Cell-Mediated Lympholysis
Authors: Warner John F. , Cudkowicz Gustavo
Published: January 2023

H-2k-heterozygous F1 hybrid mouse spleen cells cultured with irradiated H-2k-homozygous stimulator cells generated specific anti-parent cytolytic effectors. The parental antigenic determinants recognized by responder cells during induction (afferent arm) and by effector cells during cytolysis (efferent arm) were coded for, or regulated by, the H-2K-Hh-3 region of the MHC, according to recombinant analysis. There were no detectable influences by other linked or unlinked genes on the phenotypic expression of parental antigens; however, the anti-parent responsiveness was modulated by background genes of responder cells. These experiments establish that the K end of H-2 controls determinants of F1 anti-parental H-2k CML, like the D end controls those of F1 anti-parental H-2b CML, thus confirming the basic symmetry of the H-2 complex. The relationship of this primary in vitro cell-mediated response with natural in vivo resistance to parental and allogeneic bone marrow grafts is discussed.
Immune reactivity and immunosuppressive intervention in experimental nephritis. II. Effect of TLI on the course of two models of nephritis in the inbred rat.
Authors: Lowry R P , Forbes R D , Carpenter C B , Gurley K E , Merrill J P
Published: January 2023

Fractionated high-dose (3400 rad) total lymphoid irradiation (TLI) induces a unique and prolonged state of immunologic unresponsiveness. The therapeutic efficacy of TLI in immune glomerular disease was explored in two animal models: the accelerated autologous form of nephrotoxic serum nephritis (AA-NTSN) and autologous immune complex nephritis (AICN). LEW rats with established AA-NTSN, subjected to TLI, manifest decreased levels of circulating antibody to the heterologous (sheep) immunoglobulin G (0.4 +/- 0.2 vs 1.2 +/- 0.3 mg/ml, mean +/- SE respectively, p less than 0.01) early post TLI in association with a reduction in histopathology and albuminuria (6.7 +/- 2.2 vs control 19.6 +/- 5.4 mg/24 hr, mean +/- SE, p less than 0.02). Administration of TLI to rats with established AICN effected significant (p less than 0.001) reduction in albuminuria (162 +/- 30 vs 315 +/- 27), serum creatinine (p less than 0.005), and the incidence of lipemia (p less than 0.01) vs controls. Adoptive transfer studies provided no evidence that the sustained beneficial effect of TLI in AICN was suppressor cell mediated. Thus, the observed therapeutic efficacy of TLI in the treatment of experimental nephritis, shown to be related to a reduction in the level of circulating antibody in AA-NTSN, provides a new model system for study of immunity and immunosuppression in primary glomerular disease.
Phenotypic expression of genetically-controlled natural resistance to Mycobacterium bovis (BCG).
Authors: Stach J L , Gros P , Forget A , Skamene E
Published: January 2023

Mycobacterium bovis (BCG), when maintained in vitro, readily incorporates [3H]uracil, the RNA precursor. The rate of [3H]uracil incorporation into bacilli is sharply reduced when the BCG is phagocytized by murine adherent resident peritoneal macrophages and subsequently released by the lysis of monolayers. Macrophages derived from mouse strains that are innately resistant to BCG infection in vivo (Bcgr) are able to inhibit the [3H]uracil incorporation into the bacilli in a significantly more effective way than macrophages from BCG-susceptible (Bcgs) strains. This difference is best demonstrated with a low rate of infection (BCG: macrophage ratio between 1:1 and 2:1), and is most pronounced at 4 to 5 days after in vitro infection of macrophage monolayers. In vivo interaction of BCG with peritoneal macrophages in situ results in the same pattern of enhanced inhibition of [3H]uracil incorporation by Bcgr macrophages. The use of Bcg-congenic mouse strains has confirmed that the Chromosome 1 Bcg (Ity, Lsh) locus is regulating the antimycobacterial activity of macrophages. We conclude that the resident macrophage is the cell population that expresses the phenotype of genetically determined resistance to BCG infection.
Aggressiveness of SJL/J lymphomas correlates with absence of H-2Ds antigens.
Authors: Rosloniec E F , Kuhn M H , Genyea C A , Reed A H , Jennings J J , Giraldo A A , Beisel K W , Lerman S P
Published: January 2023

SJL/J lymphomas emerged as H-2Ds-negative variants upon transplantation of their respective H-2Ds-positive spontaneous tumors. Of nine spontaneous SJL/J lymphomas examined, only two contained detectable numbers of H-2Ds-negative tumor cells. Of seven successfully transplanted tumors, however, four emerged as predominantly H-2Ds-negative tumors by their second transplantation. Long term SJL/J lymphoma lines, RCS 5 and SJL/SJL, were also found to be H-2Ds-negative. The expression of H-2Ks and I-As were maintained on all tumor lines examined. H-2Ds-negative tumor cells were consistent stimulators of syngeneic lymphoproliferation, whereas tumors maintaining H-2Ds expression varied in their stimulatory capacity. Transplantation times required to achieve morbidity in syngeneic mice correlated with tumor cell expression of H-2Ds. Tumors maintaining H-2Ds expression were less aggressive and required 57 to 150 days to produce morbidity compared with highly aggressive H-2Ds-negative tumors that required only 7 to 10 days at one-quarter of the cell dose (10(7) cells). Growth curve analysis based on spleen weights (corrected for body weight) indicated that three types of SJL/J lymphomas could be identified based on their expression of H-2Ds and ability to stimulate syngeneic lymphoproliferation: 1) indolent, nonstimulatory H-2Ds-positive tumors; 2) indolent, stimulatory H-2Ds-positive tumors; and 3) highly aggressive, stimulatory H-2Ds-negative tumors.
A mitogenic factor, released by stimulated human mononuclear cells and distinct from interleukin 2 (IL 2), B cell growth factor (BCGF), and interleukin 1 (IL 1).
Authors: Kasakura S , Taguchi M , Watanabe Y , Okubo T , Murachi T , Uchino H , Hanaoka M
Published: January 2023

Two lymphocyte mitogenic factors, interleukin 2 (IL 2) and blastogenic factor (BF), are generated concomitantly in human mixed lymphocyte cultures (MLC). The latter mitogenic factor is directly mitogenic for unstimulated lymphocytes, whereas the former mitogenic factor acts only on previously activated lymphocytes. Both factors had a m.w. range, as determined by gel filtration, of 18,000 to 30,000. Thus, these two factors were inseparable on the basis of m.w. size. However, BF and IL 2 were separable during ion exchange chromatography on the DEAE cellulose and phenyl-Sepharose chromatography. In addition, BF activity in the supernatants of MLC reached a maximum after day 5, whereas IL 2 activity peaked at day 3, thus distinguishing BF from IL 2 kinetically. These results clearly indicate that BF activity is mediated by molecules distinct from IL 2. The biochemical relationship between B cell growth factor (BCGF) and BF was also examined. Because BF was readily separable from BCGF by Con A-Sepharose chromatography, BF is distinguishable from BCGF. No augmentation of PHA-stimulated C3H mouse thymocyte proliferation was associated with the preparation of partially purified BF, demonstrating that BF and IL 1 are distinct molecules. Taken together, these results indicate that BF is clearly distinct from IL 2, BCGF, and IL 1. BF-containing MLC supernatants have direct mitogenic activity on both T and B cells. Both T and B cell blastogenic activities copurified during ammonium sulfate precipitation, gel filtration, DEAE cellulose ion exchange chromatography, and hydrophobic chromatography. Thus, these two activities appear to be biochemically inseparable. Monoclonal anti-Tac, that has been suggested to recognize the receptor for human IL 2, was highly inhibitory to the T cell response to the phenyl-Sepharose preparations of BF (IL 2-free). In contrast, this antibody had minimal or no effect on BF-induced B cell proliferation. However, when MLC supernatants were absorbed with a cloned IL 2-dependent T cell line, only IL 2 activity, but not BF activity, was removed, demonstrating that BF and IL 2 have different binding specificities. The precise mechanism(s) by which anti-Tac inhibits BF-induced proliferation of T cells is unknown at present. Additionally, during the course of these experiments, we observed that Con A-Sepharose chromatography could be used as a simple one-step method of separating BCGF from IL 2.
IgE-binding factors from mouse T lymphocytes. III. Role of antigen-specific suppressor T cells in the formation of IgE-suppressive factor.
Authors: Jardieu P , Uede T , Ishizaka K
Published: January 2023

BDF1 mice were given three i.v. injections of ovalbumin (OA) to induce antigen-specific suppressor T cells. Incubation of spleen cells of OA-treated mice with homologous antigen resulted in the formation of IgE-suppressive factor. This factor was not derived from antigen-specific suppressor T cells, but suppressor T cells were essential for determining the nature of IgE-binding factors formed. In the spleen cells of OA-treated mice, antigenic stimulation of antigen-primed Lyt-1+ (helper) T cells resulted in the formation of inducers of IgE-binding factor, whereas Lyt-2+, I-J+ T cells released glycosylation-inhibiting factor (GIF), and these two factors, in combination, induced unprimed Lyt-1+ T cells to form IgE-suppressive factor. The role of GIF is to inhibit the assembly of N-linked oligosaccharides on IgE-binding factors during their biosynthesis, and thereby provide them with a biologic activity: suppression of the IgE response. Under the experimental conditions employed, GIF was released spontaneously from antigen-specific suppressor T cells. However, antigenic stimulation of the cells enhanced the release of the factor. GIF from antigen-specific suppressor T cells has a m.w. of 25,000 to 30,000, as estimated by using gel filtration, binds to anti-I-J alloantibodies and to a monoclonal antibody specific for lipomodulin, and has affinity for specific antigen. The possible relationship between antigen-specific GIF and antigen-specific suppressor factors is discussed.
Inhibition of class I and class II MHC-restricted antigen presentation by cytotoxic T lymphocytes specific for an exogenous antigen.
Authors: Rock K L , Rothstein L , Fleischacker C , Gamble S
Published: January 2023

Ag in the extracellular fluids can be internalized, processed, and presented in association with class I MHC molecules on specialized APC in normal spleen. We examine the fate of these APC after they present Ag to a CTL. When splenocytes present exogenous OVA to CTL, their ability to subsequently present native Ag in association with both class I and class II molecules is inhibited. CTL do not inhibit the ability of splenocytes to present processing independent peptides with class I or class II molecules. Inhibition of Ag presentation is only observed in the presence of the specific Ag recognized by the CTL. This inhibition is MHC-restricted. In the presence of specific Ag, CTL inhibit the ability of APC to present unrelated Ag. However, bystander APC are not affected by activated CTL. Taken together these results indicate that when APC present exogenous Ag to CTL, they are inhibited or killed. The CTL that mediates this activity has a conventional CD4-CD8+ phenotype and utilizes a TCR-alpha beta. The potential significance of these findings and their possible relationship to phenomena associated with Ts cells are discussed.
IL-12 receptor. I. Characterization of the receptor on phytohemagglutinin-activated human lymphoblasts.
Authors: Chizzonite R , Truitt T , Desai B B , Nunes P , Podlaski F J , Stern A S , Gately M K
Published: January 2023

IL-12 is a 75-kDa heterodimeric cytokine composed of disulfide-bonded 35-kDa and 40-kDa subunits. Included among the biologic activities mediated by IL-12 is induction of proliferation of PHA-activated human PBL. The concentration of IL-12 required to stimulate maximum proliferation of PHA-activated lymphoblasts is 50 to 100 pM. In this study, highly purified 125I-labeled IL-12 (7 to 15 microCi/microgram; 50 to 100% bioactive) was used to characterize the receptor for IL-12 on 4-day PHA-activated lymphoblasts. The binding of 125I-labeled IL-12 to PHA-activated lymphoblasts was saturable and specific because the binding of radiolabeled ligand was only inhibited by IL-12 and not by other cytokines. The kinetics of [125I]IL-12 binding to PHA-activated lymphoblasts was rapid at both 4 degrees C and 22 degrees C; reaching equilibrium within 60 min. At 22 degrees C, the rate of dissociation of [125I]IL-12 was slow in the absence of competing IL-12 (t1/2 = 5.9 h) and more rapid in the presence of 25 nM competing IL-12 (t1/2 = 2.5 h). The kinetically derived equilibrium dissociation constant ranged from 10 to 83 pM. Analysis of steady state binding data by the method of Scatchard identified a single binding site with an apparent equilibrium dissociation constant of 100 to 600 pM and 1000 to 9000 sites/lymphoblast. The equilibrium dissociation constant for competing ligands and sites per cell calculated from unlabeled IL-12 competition experiments ranged from 164 to 315 pM and 1067 to 3336, respectively, which is in good agreement with the values determined from steady state binding. The variations in KD and sites per cell were dependent on the individual preparations of lymphoblasts. Although the steady state binding data were consistent with a single class of high affinity binding sites, the kinetic dissociation data indicates a cooperative interaction between receptors on PHA-activated lymphoblasts. Affinity cross-linking of surface bound [125I]IL-12 to PHA-activated lymphoblasts at 4 degrees C identified a major complex of approximately 210 to 280 kDa. Anti-IL-12 antibodies also immunoprecipitated a complex of approximately 210 to 280 kDa that was produced by cross-linking unlabeled IL-12 to 125I-labeled lymphoblast cell-surface proteins. Cleavage of this complex with reducing agent identified one radiolabeled protein of approximately 110 kDa. These data suggest that the IL-12 binding site on PHA-activated lymphoblasts may be composed of a single protein of approximately 110 kDa.(ABSTRACT TRUNCATED AT 400 WORDS)
IL-2 dependence of IL-9 expression in human T lymphocytes.
Authors: Houssiau F A , Renauld J C , Fibbe W E , Van Snick J
Published: January 2023

Human IL-9 is a T cell-derived lymphokine that is abundantly expressed upon activation with mitogens. The observation that IL-9 induction peaks as late as 28 h after stimulation suggested the involvement of secondary signals in this process. The finding reported here that IL-9 expression is blocked by cycloheximide strongly supports this hypothesis. Moreover, we identify IL-2 as the critical element controlling IL-9 expression in T cells. We show (i) that anti-IL-2R antibodies block IL-9 expression in T cells stimulated with PMA and anti-CD3 and (ii) that IL-2, of a panel of cytokines, is the only molecule that synergizes with PMA for IL-9 induction. The latter finding is confirmed in a T cell leukemia line. Finally, we demonstrate that IL-2 plays a regulatory role in the induction of other cytokines, such as IL-4, IL-5, IL-6, and granulocyte/macrophage-CSF, in fresh peripheral T cells.
Identification of two type IIa IgG-binding proteins expressed by a single group A streptococcus.
Authors: Otten R A , Raeder R , Heath D G , Lottenberg R , Cleary P P , Boyle M D
Published: January 2023

Functional heterogeneity associated with Ig-binding proteins expressed by group A streptococci is well documented. In this study we have demonstrated that treatment of group A streptococcal isolate 64/14 with CNBr resulted in the solubilization of two different sized proteins that displayed identical functional reactivity with human IgG1, IgG2, and IgG4 (characteristics of a type IIa binding protein). Monospecific polyclonal antibodies to each form of type IIa molecule were prepared and no antigenic cross-reactivity between the two m.w. forms of type IIa binding protein could be detected. The smaller m.w. protein was shown to be identical or closely related to the recombinant type IIa protein cloned from strain CS110. These studies provide further evidence for the heterogeneity of type II Ig-binding proteins expressed by pathogenic group A streptococci.
Cytotoxic T lymphocytes from HIV-1 seropositive individuals recognize immunodominant epitopes in Gp160 and reverse transcriptase.
Authors: Lieberman J , Fabry J A , Kuo M C , Earl P , Moss B , Skolnik P R
Published: January 2023

The CTL response to HIV-1 is more vigorous than for any known human pathogen and may be a significant factor in preventing the progression to symptomatic disease. T cell lines, generated by non-specific stimulation with PHA and IL-2, may be reproducibly used to identify HIV-1 isolate-invariant epitopes recognized by the CTL of infected individuals. The CTL response in each of 12 infected individuals to envelope and reverse transcriptase (RT) is dominated by the recognition of one or two viral isolate-invariant epitopes. Seven subjects respond to a single gp160 epitope; three subjects recognize 2 gp160 epitopes. There is a significant increase in recognition of epitopes in the C terminal 104 amino acids of gp41 (p less than 0.002); in fact 40% of the subjects that respond to gp160 recognize the C terminal 20-mer. The CTL-mediated lysis of gp160-expressing targets is MHC restricted, but not all individuals that share the same serologically defined class I-restricting element respond to the same epitope. Recognition of the terminal 20mer is restricted by both A30 and B8. The response to RT in six subjects is distributed over the RT protein. The six subjects recognize four separate regions defined by truncated RT-vaccinia recombinants, but none of the subjects' CTL demonstrate significant recognition of the RT epitope identified in H-2k mice and some humans.
Mhc-DQB repertoire variation in hominoid and Old World primate species.
Authors: Otting N , Kenter M , van Weeren P , Jonker M , Bontrop R E
Published: January 2023

Comparison of 87 distinct Mhc-DQB sequences, obtained from 13 primate species, demonstrates that five out of eight trans-species Mhc-DQB allele lineages are at least 30 million years old and predate divergence of hominoid and Old World primate species. One lineage may be much older because its members are not only traced back in higher primates, but also are present in a New World primate species. Comparing Mhc-DQB repertoire variation in distinct species, allows one to pinpoint when certain polymorphisms were lost or gained in primate evolution. Heterogeneity observed among members of trans-species Mhc-DQB allele lineages can be explained in major part by point mutations, whereas intraexonic crossing-over is a potent mechanism in generating new allele lineages. The stability of Mhc-DQB polymorphisms is influenced by selective forces because distinct allele lineages appear to have accumulated nucleotide substitutions and amino acid replacements at different rates.
Evidence for the expression of non-HLA-A,-B,-C class I genes in the human fetal liver.
Authors: Houlihan J M , Biro P A , Fergar-Payne A , Simpson K L , Holmes C H
Published: January 2023

HLA class I Ag expression was investigated in the human fetal liver. By immunostaining, mAb to monomorphic class I Ag showed widespread reactivity with both epithelial and hemopoietic cells. By contrast, mAb to polymorphic determinants showed more restricted reactivity that was confined to a proportion of hemopoietic cells: the hepatic epithelium was essentially unreactive. This suggested that the developing liver might express nonclassical HLA class I. Class I Ag were examined in membrane and cytosol fractions of mid-trimester fetal liver. Because of its broad reactivity with HLA-A,-B, mAb Q1/28 was selected to identify classical class I Ag in these studies. Immunoprecipitations were carried out against radiolabeled glycoprotein extracts of fetal liver membranes. W6/32 detected a 40-kDa product characteristic of nonclassical class I proteins, as well as a 43-kDa product, in lysates immunodepleted with Q1/28. By immunoblotting, an anti-H chain antiserum (HC) identified a Q1/28- 40-kDa component and a 43-kDa Q1/28+ component in fetal liver membrane glycoproteins. The fetal liver cytosol fraction was found to contain a 42- to 43-kDa product by W6/32-chromatography. This component partitioned to the aqueous phase upon condensation in TritonX-114 detergent and by immunoblotting was reactive with monomorphic mAb HC10 but not with Q1/28. Total RNA and polymerase chain reaction amplified class I transcripts of fetal liver were probed using oligonucleotides specific for HLA-E, -F, and -G. HLA-F, was readily detected in total RNAs by Northern analysis. HLA-E, HLA-F, and HLA-G were all detected in fetal liver by polymerase chain reaction. Differential expression of these genes may occur between the first and second trimester of liver development. Overall therefore, the human fetal liver expresses multiple class I protein products and contains transcripts for non-classical class I genes; particularly HLA-F.
IL-7 up-regulates the expression of IL-8 from resting and stimulated human blood monocytes.
Authors: Standiford T J , Strieter R M , Allen R M , Burdick M D , Kunkel S L
Published: January 2023

Blood monocytes are important cellular sources of a vast array of bioactive substances, including regulatory and chemotactic cytokines. The regulation of these cytokines is of critical importance to the expression of acute and chronic inflammatory responses. IL-7, a T and B cell-activating cytokine, has recently been shown to have stimulatory effects on the expression of several monocyte-derived proinflammatory cytokines. We now describe the induction of IL-8 mRNA and extracellular protein from human blood monocytes by IL-7. The up-regulation of IL-8 mRNA by IL-7 was not altered by concomitant treatment with cycloheximide, suggesting that the direct stimulatory effects of IL-7 were not dependent upon de novo protein synthesis. In addition, IL-7 significantly potentiated the production of IL-8 from LPS-, TNF-, and IL-1-treated peripheral blood monocytes. Our findings suggest that IL-7 may play a critical role in the modulation of macrophage-derived cytokine expression and may function in vivo as an important proinflammatory cytokine.