bluuebunny/crossref_metadata_2025 huggingface dataset:
Identification of a macrophage antigen-processing event required for I-region-restricted antigen presentation to T lymphocytes.
Authors: Ziegler K , Unanue E R
Published: December 2022

The mechanism of macrophage-antigen handling was studied using a system that involves the quantitation of the antigen-specific binding of Listeria monocytogenes-immune T cells to macrophages. Specific T cells did not bind to native antigen. Because the specific binding of T cells to macrophages could be measured during a short (5- to 15-min) interaction, it was possible to follow the temporal development of a T cell-binding substrate with increasing time of antigen-macrophage interaction. In contrast to the rapid (5-min) uptake of Listeria by macrophages, the development of T cell-binding ability required a 30- and 60-min period of antigen-macrophage interaction. During this processing period, Listeria organisms bound to the macrophage surface were ingested and partially catabolized. Unlike antigen uptake, antigen processing was a temperature-dependent and energy-requiring event. Although macrophages treated with paraformaldehyde before antigen processing did not develop T cell-binding activity, macrophages treated with paraformaldehyde after a 60-min antigen-processing period retained T cell-binding ability. The kinetics of antigen catabolism correlated with antigen processing, and inhibition of antigen catabolism was associated with a corresponding inhibition of antigen processing for T cell binding. Anti-Ia antibodies had no effect on Listeria uptake of catabolism. These results supply direct evidence for a macrophage-antigen processing event relevant to T cell recognition of antigen.
Immunosuppression in murine malaria: a soluble immunosuppressive factor derived from Plasmodium berghei-infected blood.
Authors: Khansari N , Segre M , Segre D
Published: December 2022

Mice infected with Plasmodium berghei have a depressed immune response to a variety of antigens. We report the extraction, purification, and characterization of a soluble immunosuppressive substance derived from P. berghei-infected mouse blood. A crude extract, prepared by solubilization of infected erythrocytes in a Parr cell disruption bomb, reduced the anti-DNP PFC response of mice injected with the extract 1 day before immunization. Purification of the immunosuppressant was accomplished by precipitation with 50% saturated ammonium sulfate followed by chromatography on Sephadex G-150 in the presence of 6 M guanidine hydrochloride. The immunosuppressive activity was recovered in the last fraction eluted from the Sephadex G-150 column that contained low m.w. components. The activity was abrogated by trypsin digestion, but not by periodate oxidation. Volume for volume, the purified immunosuppressant had a 100-fold greater activity than the crude extract from which it was derived. It suppressed the response to the T-dependent antigens DNP-KLH and SRBC, but not to the T-independent antigen DNP-Ficoll.
The human autologous mixed lymphocyte reaction. I. Suppression by macrophages and T cells.
Authors: Smolen J S , Sharrow S O , Reeves J P , Boegel W A , Steinberg A D
Published: December 2022

The autologous mixed lymphocyte reaction (AMLR) is a proliferative response of T cells to signals from autologous non-T cells. The AMLR has been an enigma to immunologists because spontaneous proliferation of cells removed from the body is usually substantially less than that observed with a strong AMLR. However, the AMLR is thought to represent an important in vitro function, since it has the attributes of other immune responses, and it is abnormal in a variety of disease states thought to have an immune basis. We reasoned that if the AMLR represented a fundamental immune phenomenon, it should be subject to regulation. In the present study, we present evidence for suppression of the AMLR by macrophages and by T cells. Macrophages inhibited the T cell proliferation to (B + null) cells in a dose-dependent fashion and throughout the time course of the AMLR. Elimination of suppressor T cells by a specific antiserum led to an increase in the AMLR, which was again suppressed in a dose-dependent way by addition of the suppressive T cells. It may be concluded that the AMLR itself is subject to immune regulation and that the suppressive influences observed probably strongly inhibit the AMLR in vivo. Removal of the suppressive principles allows the maximal expression of the AMLR in vitro. We believe that our demonstration of regulation of the AMLR should remove the enigma associated with it and lead to a better understanding of normal cell-cell interactions as well as the basis for abnormalities in a variety of immune-mediated diseases.
Cross-induction of predominant NPb idiotypic antibodies with derivatives of (4-hydroxy-3-nitrophenyl) acetyl.
Authors: Ju S T , Dorf M E
Published: December 2022

Immunization of C57BL/6 mice with bovine gamma-globulin (BGG) conjugated with (4-hydroxy-3-nitrophenyl) acetyl (NP) induced a population of anti-NP antibodies that bear predominantly lambda light chain, exhibit heteroclitic affinity for heterologous NP derivatives, and share NPb idiotype. The present study analyzes the idiotypes of antibodies induced with BGG conjugated with the iodo-, bromo-, or nitro-NP derivatives (NIP, NBrP, and NNP). NIP-BGG, NBrP-BGG, and NNP-BGG, induce specific antibodies bearing NPb idiotype in C57BL/6 or C57BL/10 congenic mice, but not in many other inbred strains. Furthermore, the quantity of NPb idiotype in immune sera from various mouse strains immunized with NIP-BGG, NBrP-BGG, and NNP-BGG was similar to that in sera from mice immunized with NP-BGG. Anti-idiotypic antisera against C57BL anti-NP, anti-NIP, or anti-NBrP antibodies exhibit extensive idiotype binding of specifically purified B6 anti-NP, -NIP, -NBrP, and -NNP antibodies. These purified antibodies contain a high percentage (greater than 70%) of lambda-chain-bearing molecules. The data indicate that an extensively shared repertoire composed of predominantly lambda-bearing NPb-positive idiotypic antibodies is used in response to NP and its derivatives in C57BL mice.
Positive correlation between degree of parasitemia, interferon titers, and natural killer cell activity in Plasmodium falciparum-infected children.
Authors: Ojo-Amaize E A , Salimonu L S , Williams A I , Akinwolere O A , Shabo R , Alm G V , Wigzell H
Published: December 2022

Natural killer (NK) cell activity and interferon levels have been measured in the peripheral blood of children acutely ill with Plasmodium falciparum infection. The NK cell levels were found to be raised in the malaria-infected children, with a positive correlation between the degree of parasitemia and lytic activity. Comparatively high titers of antiviral activity was discovered in sera from the majority of P. falciparum-infected children, again positively correlating with the degree of parasitemia and NK levels. The characteristics of the antiviral factor indicated alpha-type interferon to be the dominating agent involved. Addition of exogenous interferon in vitro potentiated the NK levels of PBL from normal children while having no significant impact on cells from malaria-infected children.
Generation of alloreactive cytotoxic T lymphocytes: production of T cell and macrophage helper factors in addition to IL 1 and IL 2 by peritoneal cells from mice immunized to Listeria monocytogenes.
Authors: Finke J H , Sharma S D , Scott J W
Published: December 2022

We investigate the production and biological activity of soluble helper factors produced by peritoneal T cells and macrophage derived from mice primed in vivo with Listeria monocytogenes. Supernatant fluids from co-cultures of these immune T cells and activated macrophages contained Interleukin 1 (IL 1) and Interleukin 2 (IL 2), and had the ability to assist the generation of cytotoxic T lymphocytes (CTL) from a population of nylon wool nonadherent spleen cells sensitized to allogeneic heat-treated thymocytes. The ability to assist CTL development involved T cell and macrophage factors in addition to IL 1 and IL 2. Immune T cells cultured alone produced a factor, devoid of significant IL 2 activity, that assisted CTL development only if adherent cells were present in the responding population. Activated macrophage produced a 38,000 dalton component, distinct from IL 1 on the basis of m.w., that assisted the development of CTL from nylon wool nonadherent splenic cells. Supernatants fluids from co-cultures of immune T cells and allogeneic, nonactivated macrophage contained a CTL helper factor but did not contain IL 1 or IL 2 activities. In contrast, supernatant fluids from co-cultures of immune T cells and syngeneic, nonactivated macrophage contained all 3 activities. This suggests a genetic restriction for the production of IL 1 and IL 2 that does not restrict the production of a CTL helper factor. These results demonstrate that T cell- and macrophage-derived helper factors distinct from IL 1 and IL 2 participate in the development of CTL.
Antigen-specific human T lymphocyte clones: induction, antigen specificity, and MHC restriction of influenza virus-immune clones.
Authors: Lamb J R , Eckels D D , Lake P , Johnson A H , Hartzman R J , Woody J N
Published: December 2022

Human peripheral blood lymphocytes from an HLA-Dw1,3 individual were primed in vitro with influenza A virus (A/Texas/1-77/x-49) and subsequently cloned by limiting dilution in TCGF. Of the 96 TLCs originally obtained, nine were characterized in detail. TLCs were antigen specific, responding to influenza A virus, not to influenza B, TGAL, GAT, tetanus toxoid, or KLH, and only when antigen was presented by cells unable to form rosettes with AET-treated SRBC. Presentation of antigen by unseparated PBL often resulted in significant "back stimulation," probably via production of growth factors. The MHC requirements for the induction of TLC proliferation were analyzed. Of four representative clones analyzed, three required Dw1;DR1 compatibility for successful presentation of viral antigens by a panel of antigen-presenting cells. In contrast, one TLC showed an unusual pattern of response that could not be correlated to a particular HLA haplotype. Monoclonal anti-T cell antibody analysis of the surface phenotype of two TLCs maintained in continuous culture for 5 mo indicated that they were OKT3+, 4+, and 8-, consistent with an inducer/helper phenotype. To confirm the clonal nature of TLCs, data on the functional properties of TLC subclones are also presented.
Cellular origin and interactions involved in gamma-interferon production induced by OKt3 monoclonal antibody.
Authors: Chang T W , Testa D , Kung P C , Perry L , Dreskin H J , Goldstein G
Published: December 2022

OKT3 monoclonal antibody, a human T cell mitogen, induced interferon production by cultured mononuclear cells at 10(-11) M concentrations. Interferon was secreted only under conditions wherein OKT3 was mitogenic, and production was correlated with cell proliferation. Thus, like mitogenesis, interferon secretion reached a peak 3 days after OKT3 stimulation, was inhibited by a factor(s) in human serum, and required 1000 times higher concentrations of Fab and F(ab')2 fragments of OKT3 for induction. The interferon was most likely of "gamma" (immune) type, because pH 2 and 56 degrees C treatments denatured it, whereas anti-alpha or -beta interferon antibodies did not. Mononuclear cells were fractionated into subpopulations that contained OKT4+ cells (helper/inducer T cells), OKT8+ cells (cytotoxic/suppressor T cells), and OKM1+ cells (monocytes) by combining sheep red blood cell rosetting and complement-mediated lysis using monoclonal antibodies against specific cell types. Both OKT4+ and OKT8+ cells proliferated upon OKT3 stimulation with the absolute requirement of OKM1+ cells. However, OKT4+ cells plus OKM1+ cells were necessary for the secretion of interferon. Studies with selective pretreatments with mitomycin C suggested that gamma-interferon was secreted by the OKT4+ cells and that the OKM1+ population subserved an accessory function.
Activation of rat B lymphocytes. II. Functional and structural changes in "aged" rat B lymphocytes.
Authors: Rosenberg J S , Gilman S C , Feldman J D
Published: December 2022

Anti-mu, anti-gamma, and anti-delta antibodies induce proliferation of splenic B lymphocytes from young Lewis rats, measured by 3H-TdR uptake. In contrast, splenic B cells of aged Lewis rats respond poorly or not at all to these reagents. T lymphocytes or interleukin 2 (IL-2) of young or aged rats augment the uptake of 3H-TdR in cultures of "young" B cells responding to anti-Ig reagents or LPS and DxS, but have no significant effect on the responses of "old" B cells. Analysis of spleen cells of young and aged rats in a fluorescence-activated cell sorter indicates the density of mu, gamma, and delta isotypes is reduced in "old" B cells, and that B cells of aged rats are significantly larger than those of young rats. These results delineate anatomic and structural changes in B lymphocytes of aged rats.
B lymphoblast antigen (BB-1) expressed on Epstein-Barr virus-activated B cell blasts, B lymphoblastoid cell lines, and Burkitt's lymphomas.
Authors: Yokochi T , Holly R D , Clark E A
Published: December 2022

Two new cell surface antigens expressed on B lymphoblastoid cell lines (B-LCL) were defined with cytotoxic mouse monoclonal antibodies. One marker, BB-1 (for B lymphoblast antigen-1), was detected on human and nonhuman primate B-LCL, Epstein-Barr virus (EBV)-activated B cell blasts, most Burkitt's lymphomas, and Ia+ B lymphoblast-like myelomas. Polyclonal B cell activators such as pokeweed mitogen (PWM) and lipopolysaccharide (LPS) also induced the expression of BB-1 on immunoglobulin (Ig)-positive cells. In contrast, BB-1 could not be detected on normal lymphoid tissues by complement-dependent cytotoxicity and immunofluorescence (IF) assays or by analysis with a fluorescence-activated cell sorter (FACS). T cell blasts, T cell leukemias, and pre-B cell or erythroblastic leukemia cell lines were also BB-1 negative. Of particular interest was the finding that BB-1 was expressed on the Jijoye lymphoma but only marginally on a subline of Jijoye, P3HR-1, that lacks receptors for EBV and produces a defective virus incapable of transforming lymphocytes. A second lymphoblast antigen (LB-1) unlike BB-1, was present on both T and B cell blasts and virus-transformed T- and B-LCL but not on normal lymphoid tissues.
Suppression of transferred BXSB male SLE disease by female spleen cells.
Authors: Hang L , Izui S , Theofilopoulos A N , Dixon F J
Published: December 2022

The severe autoimmune disease from which BXSB males die at an early age (young) can be transferred into lethally irradiated female recipients by inoculating them with male spleen or bone marrow cells; similar recipients of female spleen or bone marrow cells develop the late-life disease typical of BXSB females. Using this syngeneic cell transfer model, we investigated the possible ability of female splenic and bone marrow cells to modulate the transferred male disease. We found that female spleen cells or the T-enriched subpopulation of such cells successfully retarded the transferred male disease, as observed by the decreased and delayed glomerulonephritis-associated mortality and lowered levels of serum IgG, autoantibodies, and immune complexes. Transfers of female bone marrow or thymus or female splenic T-depleted subpopulations were incapable of suppressing the accelerated male disease. These results indicate that abnormalities of the male spleen or bone marrow inocula responsible for the transferred early autoimmune disease can be modified by female spleen cells, in particular the female T cell component.
Genetic and regulatory contributions of the major histocompatibility complex to the developing cytolytic T lymphocyte repertoire.
Authors: Sherman L A
Published: December 2022

The specificity repertoire of H-2Kb-specific CTL derived from 10- to 14-day-old neonates was examined. Analogous to the adult repertoire, the neonatal repertoire is composed of a large number of receptor specificities, each of which is represented at a low frequency, as well as a small number of highly recurrent specificities, which thereby serve as repertoire markers. The expression of most specificities appears to be independently regulated during development, resulting in the expression of a different set of recurrent specificities for neonates and adults within the same strain. The neonatal and adult repertoires were also compared with respect to the influence of the MHC on repertoire. Unlike adults, neonates of MHC different congenic strains (B10.D2 and B10.BR) have in common approximately half their recurrent specificities. Additionally, most parental specificities are expressed codominantly in neonatal F1 hybrids. These results may be interpreted as indicating either that 1) some, but not all, receptor genes demonstrate MHC-linked polymorphism and both parental alleles are expressed in F1 neonates, or 2) T receptor genes are nonpolymorphic in MHC congenic strains and the observed MHC-related repertoire differences are attributable to a positive selection mechanism. Since adults of these same strains do not display significant repertoire similarity, it is suggested that this increased repertoire divergence may be the result of encounters with environmental antigens in association with self-MHC antigens.
Activity of concanavalin A-induced suppressor cells in human MLR: differential effects on primary MLR, secondary MLR, and memory cell precursors.
Authors: Goeken N E
Published: December 2022

The relative sensitivity of the MLR responses of freshly isolated human lymphocytes to Con A-induced suppressor cells (SC) was compared to that of lymphocytes that had been primed previously in vitro. Fresh and primed cells were suppressed 72 and 17%, respectively, when cultured under similar conditions (p less than 0.0005). Titration of SC indicated that equivalent suppression in the two populations would require greater than a 50-fold excess of SC in the primed cells. Neither preincubation of the primed cells for 24 or 72 hr with the SC before restimulation, addition of fresh autologous cells to the primed cells, nor preincubation of the SC with fresh cells before addition to the primed cells increased suppression of primed cells. SC added at the beginning of a primary MLC were, however, very suppressive for both the primary response (67% suppression) and the subsequent secondary response (81% suppression). These data indicate that although the human primary MLR and the precursor of the memory cell are both sensitive to the suppressors induced by Con A, the memory cell itself possess an intrinsic resistance to such suppressors that is not related to simple kinetic phenomena nor to the loss in vitro of an intermediate regulatory cell. Cell depletion experiments suggest that resistance to nonspecific suppression may occur at the level of the helper cell.
Clustering of antigenic determinants on H-2 molecules.
Authors: Lemke H , Håmmerling G J
Published: December 2022

The spatial relationship of individual antigenic determinants on H-2Kk and H-2Db molecules was investigated with seven different monoclonal anti-H-2Kk and seven anti-H-2Db antibodies. In these studies the binding of radiolabeled monoclonal anti-H-2 to target cells was competed by addition of various cold anti-H-2 antibodies. The results indicate that on both H-2Kk and H-2Db molecules the antigenic determinants are arranged in two spatially separated clusters. Thus, antibodies to determinants within a cluster show mutual inhibition of binding but do not block the binding of antibodies to the other cluster, and vice versa. Furthermore, in the case of H-2Db antigens it was observed that binding of antibodies to one cluster would considerably enhance the binding of antibodies to the other cluster. A preliminary Scatchard analysis indicated that the enhancing antibody did not alter the affinity of the radiolabeled antibody, but led to an increase of available binding sites on the cell membrane. In addition, binding inhibition studies revealed that the conventional private specificity H-2.2 of H-2Db consists of at least two independent sites on the molecule.
Histamine suppresses in vitro synthesis of precursor (pro-C5) of the fifth complement component (C5) by mouse peritoneal macrophages.
Authors: Ooi Y M
Published: December 2022

Soluble histamine added to mouse peritoneal macrophages in culture suppressed the synthesis of the functional and antigenic complement component C5. Synthesis of intracellular C5 antigen by resident macrophages was suppressed by 16 to 80%, and functional C5 activity by 13.6 to 87.2% at concentrations of histamine ranging from 10(-6) M to 10(-3) M, respectively; secretion of C5 protein was depressed by 18.3 to 85.5% and hemolytic C5 by 8 to 80%. In thioglycollate-stimulated exudates, intracellular synthesis of C5 protein was reduced by 3.3 to 72.3% and functional C5 activity by 7.6 to 73.5% using similar concentrations of histamine; secreted C5 protein was inhibited by 8.9 to 75.7% and functional activity by 4 to 78%. The suppression of C5 activity in resident and thioglycollate-stimulated cultures was dependent on the dose of histamine with maximal suppression occurring at a concentration of 10(-3) M. Experiments in which specific histamine agonists were used confirmed that the action was mediated by the H2 receptor. The inhibition of C5 antigenic protein synthesis paralleled that detected for functional C5. Immunochemical analysis of C5 antigen synthesized under the influence of histamine indicated that suppression of synthesis of pro-C5 was the major mechanism responsible for the depression of C5 produced under these conditions. The inhibitory effects produced by histamine were shown to be mediated by histamine type 2 receptors as indicated by abrogation of the inhibition by cimetidine (H2 antagonist).
Restoration of allograft responsiveness in B rats by interleukin 2 and/or adherent cells.
Authors: Clason A E , Duarte A J , Kupiec-Weglinski J W , Williams J N , Wang B S , Strom T B , Tilney N L
Published: December 2022

LEW X BN)F1 cardiac allografts survive 1 wk in unmodified LEW recipients (MST +/- SD = 8.3 +/- 1.2 days) but indefinitely (greater than 100 days) in B rats, produced by 750 R sublethal x-radiation 3 to 4 wk after adult thymectomy and reconstitution with syngeneic bone marrow cells from thymectomized thoracic duct-drained donors. Graft survival appears independent of blocking antibodies and is not mediated by suppressor cells or loss of graft immunogenicity. The unresponsive state is eventually reversed by adoptive transfer of 10(8) spleen cells from nonimmune (MST +/- SD = 27.5 +/- 4.7 days) or alloimmune (MST +/- SD = 21.5 +/- 1.9 days) syngeneic animals. In contrast, concomitant administration of 2 X 10(7) thioglycollate-stimulated peritoneal exudate adherent cells plus 10(8) alloimmune syngeneic spleen cells produced acute allograft rejection in 50% of B recipients within 10 to 12 days, while in every instance grafts underwent acute rejection (MST +/- SD = 10.0 +/- 1.4 days) in B recipients treated with interleukin 2 (IL 2) rich conditioned supernatant plus sensitized cells. In vitro studies revealed that adherent cells from B rats possessed less than 50% the capacity of adherent cells from normal animals either to support the Con A-stimulated uptake of 3H-thymidine by splenic T cells or to promote production of IL 2 by spleen cells depleted of adherent cells. Altered lymphocyte migration patterns in B recipients may also contribute to prolonged allograft survival secondary to adherent cell dysfunction.
A biochemical variant of human T cell growth factor produced by a cutaneous T cell lymphoma cell line.
Authors: Gootenberg J E , Ruscetti F W , Gallo R C
Published: December 2022

Three cell lines of mature T cell origin established from patients with cutaneous T cell lymphoma-leukemia (CTCL) have been found to be constitutive producers of TCGF (L-TCGF). Biologically active L-TCGF can also be eluted from the plasma membranes of these cells. We have compared the biologic and biochemical properties of L-TCGF and TCGF derived from normal lymphocytes (N-TCGF). L-TCGF and N-TCGF share similar biologic activity: both support long-term growth of T cells that have undergone prior lectin or antigen stimulation, and have no effect on unstimulated T cells. However, L-TCGF is a more acidic (pI 4.5 vs 6.5 to 8.0) molecule than N-TCGF and elutes from DEAE-Sepharose at higher salt concentration (0.2 M NaCl vs 0.07 to 0.1 M NaCl). In addition, these two factors display differing mobilities on gel filtration. Treatment of L-TCGF with neuraminidase or alkaline phosphatase does not alter its pI, indicating that enzymatically vulnerable sialic acid or phosphate groups are not involved in the variation. The nature and significance of this biochemical variant remain unknown.
IgG1 antibody-dependent mediator release after passive systemic sensitization of basophils arriving at cutaneous basophil hypersensitivity reactions.
Authors: Mitchell E B , Brown S J , Askenase P W
Published: December 2022

When antigen is injected into a 24-hr cutaneous basophil hypersensitivity (CBH) reaction of an actively sensitized guinea pig, local basophils degranulate and release histamine. This reaction is called cutaneous basophil anaphylaxis and may be antibody mediated. We now report passive sensitization of basophils at CBH sites by systemic transfer of anti-picryl immune serum. Keyhole limpet hemocyanin- (KLH) immunized animals were skin tested with KLH to elicit 24-hr CBH reactions at day 7. Anti-picryl serum was injected i.v. at various times. On day 7, blue dye was injected i.v., and then 24-hr CBH sites vs nearby normal skin were challenged with 0.1 microgram picryl-human serum albumin (Pic-HSA). An immediate increase in vascular permeability (blueing) was noted at normal skin sites due to systemic passive cutaneous anaphylaxis (PCA), and augmented blueing occurred at CBH sites compared with normal skin. Systemic passive sensitization of CBH sites occurred when antiserum was administered as little as 1 hr before challenge of CBH site. However, local administration of anti-picryl serum (as in a local PCA reaction) was not able to sensitize tissue basophils, whether antigen was administered locally or systemically. The serum factor that mediated cutaneous basophil anaphylaxis was heat-stable (56 degrees C X 4 hr) 7S IgG1 antibody. Electron microscopy of Pic-HSA-challenged CBH sites in animals that received IgG1 antibody showed that local basophils undergo anaphylactic degranulation by exocytosis. These studies suggest that basophils arriving at CBH reactions are sensitized for anaphylactic function by antibody that can be acquired in the circulation, but possibly not at the local site.
Dynamics of B cell repertoire formation: normal patterns of clonal turnover are altered by ligand interaction.
Authors: Thompson M A , Cancro M P
Published: December 2022

The dynamics of B cell repertoire formation was examined by defining the kinetics and clonal composition of the influenza hemagglutinin- (HA) responsive BALB/c repertoire at 1 and 2 wk of age. Although the size and diversity of the HA-responsive repertoire remain constant during this period, the clonal composition changes significantly. These findings indicate a rapid and regular turnover of clonal specificities within the emerging primary repertoire. In addition, the effect of ligand exposure on this process was analyzed by characterizing the repertoire of 2-wk-old BALB/c mice that had been immunized with virus during their first week of life. This treatment markedly alters the normal kinetics and turnover of the emerging repertoire. First, many clonotypes that normally arise between 1 and 2 wk of age fail to be expressed in detectable numbers. Second, several clonotypes that are normally only transiently expressed at 1 wk of age are preferentially expanded and preserved within the responsive B cell pool. In conjunction, these results demonstrate that a) the primary repertoire is characterized by rapid and regular turnover in clonotype composition, b) antigenic exposure perturbs the normal kinetics and pattern of this turnover, and c) the exact effects of ligand exposure may depend on the developmental stage at which it occurs.
B cell growth factor and T cell growth factor produced by mitogen-stimulated normal human peripheral blood T lymphocytes are distinct molecules.
Authors: Muraguchi A , Kasahara T , Oppenheim J J , Fauci A S
Published: December 2022

Using a recently described assay for inducing and measuring the proliferation of normal human B cells in the absence of differentiation, we have demonstrated that B cell growth factor (BCGF) activity can be obtained from the culture of human peripheral blood mononuclear cells in the presence of mitogens. Using Sephacryl S-200 gel filtration, BCGF activity was demonstrated in the 20 to 30K m.w. fractions of mitogen-stimulated peripheral blood mononuclear cells. However, this fraction also showed substantial T cell growth factor (TCGF) activity. Despite this overlapping of m.w., BCGF activity could clearly be separated from TCGF activity by selective absorption of factor-containing supernatants with the interleukin 2 activity by using interleukin 2-dependent cells without any diminution of BCGF activity, strongly suggesting that these two factors may be distinct molecular entities.
Cyclic GMP as the second messenger in helper cell requirement for gamma-interferon production.
Authors: Johnson H M , Archer D L , Torres B A
Published: December 2022

Cyclic GMP and activators (acetylcholine, E. coli heat-stable toxin) of guanylate cyclase were capable of completely replacing the helper cell or interleukin 2 requirement for gamma-interferon (IFN gamma) production by Lyt-1-,2+ cells from C57BL/6 mouse spleen cells. The cyclic GMP help was independent of DNA synthesis or proliferation in the IFN gamma-producing cells, because cyclic GMP reversed mitomycin C blockage of IFN gamma production but did not reverse the inhibition of DNA synthesis. Thus, the findings presented here are unrelated to the question of the second messenger role of cyclic GMP in the activation of lymphocytes for DNA synthesis and cellular proliferation. The cyclic GMP help for IFN gamma production was antagonized by cyclic AMP and inducers (isoproterenol) of adenylate cyclase.
Animal toxicity of Shigella dysenteriae cytotoxin: evidence that the neurotoxic, enterotoxic, and cytotoxic activities are due to one toxin.
Authors: Eiklid K , Olsnes S
Published: December 2022

The lethal effect to rabbits and mice of Shigella dysenteriae toxin and the ability of the toxin to induce fluid accumulation in rabbit ileal loops were studied in relation to the cytotoxic activity. The relative concentrations of the three activities were approximately the same in a crude toxin preparation and in purified, electrophoretically homogenous toxin. The cytotoxic and lethal activities eluted identically from a high pressure liquid chromatography column and migrated at the same rate in polyacrylamide gel electrophoresis under nondenaturing conditions. The cytotoxic, lethal, and enterotoxic activities were inactivated to essentially the same extent upon incubation for few minutes at 80 degrees C and upon treatment with urea. Graded precipitation of Shigella toxin with different amounts of an antiserum to Shigella toxin in each case removed essentially the same fraction of the cytotoxic, the lethal, and the enterotoxic activity. The data indicate that one molecular entity is responsible for the three biologic effects of Shigella toxin studied. After i.v. injection, the LD50 dose was estimated to be 2.2 ng/kg in rabbits and 450 ng/kg in mice.
Primary amines inhibit the triggering of B lymphocytes to antibody synthesis.
Authors: Julian C , Speck N A , Pierce S K
Published: December 2022

Transglutaminase enzyme activity was demonstrated in murine splenic B lymphocytes. Preincubation of cell cultures with primary amines that are known substrates for transglutaminase inhibited the triggering of murine B lymphocytes to form clones of antibody-producing plasma cells. B cells could be rescued from this inhibition by incubating cultures with anti-immunoglobulin or multivalent antigens under nonstimulatory conditions. Rescue of B cells exhibited the same requirements as stimulation, which suggests that rescue is a dynamic process and not simply a receptor-ligand binding event. Primary amines appeared to inhibit an early, T cell-independent event in the B cell activation pathway, which was not sufficient to trigger B cells to form antibody-producing clones. Subsequent receptor-mediated events, required to further trigger B cells, were not inhibited by the presence of primary amines.
Stimulator cell requirements for allospecific T cell subsets: specialized accessory cells are required to activate helper but not cytolytic T lymphocyte precursors.
Authors: Czitrom A A , Sunshine G H , Reme T , Ceredig R , Glasebrook A L , Kelso A , MacDonald H R
Published: December 2022

Murine cortisone-resistant thymocytes were separated by staining with monoclonal anti-Lyt-2 antibody and FMF into Lyt-2- and Lyt-2+ subsets in order to analyze the nature of stimulator accessory cells required to activate each of these functionally distinct T cell subpopulations. The Lyt-2- fraction was able to proliferate but not to generate cytotoxic cells when stimulated by irradiated allogeneic spleen cells. Fractionation of the stimulator population showed that low numbers of dendritic cells and splenic macrophages, but not equivalent numbers of whole spleen cells or peritoneal macrophages, were able to stimulate the Lyt-2- population. On the other hand, the Lyt-2+ population, which showed little if any proliferation in response to irradiated spleen cells, contained all the precursors of cytolytic T lymphocytes. In contrast to the highly specific stimulator requirement of the Lyt-2- fraction, allospecific cytotoxic cells were generated from Lyt-2+ cells by any alloantigen-bearing stimulator cell provided interleukin 2 was present. This was confirmed by limiting dilution analysis: alloreactive CTL-P frequencies in spleen and thymus were not influenced by the nature of the stimulator cell. These data collectively indicate that heterogeneous Ia+ accessory cells are required to stimulate helper but not cytolytic T cell precursors.
Role of arachidonate metabolism in the immunoregulatory function of human leukocytic pyrogen/lymphocyte-activating factor/interleukin 1.
Authors: Dinarello C A , Marnoy S O , Rosenwasser L J
Published: December 2022

Leukocytic pyrogen (LP) is a polypeptide product of activated mononuclear phagocytes that has been established as the endogenous mediator of fever. Recent studies show LP may be identical to lymphocyte-activating factor (LAF or interleukin 1). In the present experiments, chromatographic separations of human LP indicate fractions that produce fever in rabbits and enhance phytohemagglutinin- (PHA) induced murine thymocyte proliferation (LAF activity) also stimulate human monocyte monolayers to release prostaglandin E (PGE). Ibuprofen, an inhibitor of the cyclooxygenase pathway of arachidonic acid metabolism, prevents PGE release from monocytes stimulated with LP and also brings about a rapid defervesence of LP-induced fever in rabbits. Concentrations of ibuprofen that block PGE production in vitro and in vivo, however, have no effect on LP-induced thymocyte proliferation. When the arachidonic acid analogue eicosa-5,8,11,14-tetraynoic acid was added to thymocytes in the LAF assay, a 50 to 70% decrease in LP-induced enhancement of proliferation was observed without a decrease in the background PHA response. Similar results were also observed with BW755C, a water-soluble inhibitor of the lipoxygenase pathway. The results of these studies suggest products of the cyclooxygenase pathway of arachidonate metabolism are not involved in the mechanism by which LP stimulates thymocyte proliferation. On the other hand, the results suggest products of the lipoxygenase pathway may mediate the thymocyte proliferative response induced by LP.
CBA/N X-linked defect delays expression of the Y-linked accelerated autoimmune disease in BXSB mice.
Authors: Golding B , Golding H , Foiles P G , Morton J I
Published: December 2022

BXSB male mice spontaneously develop progressive autoimmune disease characterized by high serum immunoglobulins, including anti-nuclear antibodies (ANA), enlarged spleen and lymph nodes, and diffuse proliferative glomerulonephritis. Females develop symptoms at a much slower rate. The mechanisms underlying the autoimmune disease and the nature of the Y-linked accelerating factor have not yet been elucidated. We found that the male progeny of the cross between the non-autoimmune strain CBA/Ca and BXSB (CBA/Ca X BXSB)F1 showed progressing signs of autoimmunity starting at 6 to 7 mo. In contrast, the male progeny that resulted from BXSB males crossed with immune-defective CBA/N females (Xid) were devoid of splenic B colonies, were nonresponsive to TNP-Ficoll, and were free of autoimmune disease for at least 10 mo. At 18 mo, some of the (CBA/N X BXSB)F1 mice developed weak antinuclear antibodies, but no spleen or lymph node enlargement was seen. The same mice had low anti-TNP Ficoll responses but did not produce B colonies in vitro. The role of the X chromosome in regulating expression of autoimmunity in young and old BXSB mice is discussed.
Antigens on human plasma cells identified by monoclonal antibodies.
Authors: Anderson K C , Park E K , Bates M P , Leonard R C , Hardy R , Schlossman S F , Nadler L M
Published: December 2022

Two monoclonal antibodies that define distinct plasma cell-associated antigens, termed PCA-1 and PCA-2, were developed against human plasma cell leukemia cells. These antigens are strongly expressed on human myelomas, plasma cell leukemia, and plasmacytoma tumor cells, but are not detected on other lymphoid malignancies of B, T, null, or myeloid origin. PCA-1 and PCA-2 are not expressed on either normal T or B lymphocytes, but are weakly expressed on granulocytes and monocytes. When pokeweed mitogen is used to induce human B lymphocyte differentiation, PCA-1 is expressed when other B cell determinants are lost and plasmacytoid morphology, intracytoplasmic immunoglobulins, and surface T10 staining characteristic of plasma cells appear. In contrast, PCA-2 cannot be induced and may therefore appear later in the B cell differentiation scheme. These antigens may be of utility for the study and regulation of normal and abnormal plasma cell growth, traffic, and tissue distribution and may aid in understanding heterogeneity within plasma cell dyscrasias.
alpha-Interferon increases immunoglobulin production in cultured human mononuclear leukocytes.
Authors: Rodriguez M A , Prinz W A , Sibbitt W L , Bankhurst A D , Williams R C
Published: December 2022

Interferons (IFN) are known to modulate immune responses in either an inhibitory or a stimulating manner. The present study was initiated to investigate the mechanisms by which alpha-IFN modulates Ig production of human peripheral blood mononuclear cells (PBMC). IgG and IgM production was measured in pokeweed mitogen- (PWM) stimulated 7-day cultures of PBMC. Significant enhancement of IgM and IgG production was observed when alpha-IFN was added. Overnight preincubation followed by washing also produced significant enhancement. The effect of alpha-IFN was not obtained in the absence of PWM or T cells. The effect of alpha-IFN on cultures of B and T cells was not altered by irradiation of T cells (2000 rad). alpha-IFN was not shown to enhance the production of helper factor but did increase the responsiveness of B cells to helper factor if the B cells were preincubated with alpha-IFN. Finally, alpha-IFN did not increase the Ig production of PBMC induced by Epstein Barr virus (EBV), and the outgrowth of EBV-infected PBMC was not affected. Overall, these results show for the first time that the effect of alpha-IFN on PBMC is due to an enhanced responsiveness of B cells to helper factors produced by radioresistant T cells.
Requirement for human red blood cells in inactivation of C3b in immune complexes and enhancement of binding to spleen cells.
Authors: Medof M E , Lam T , Prince G M , Mold C
Published: December 2022

We showed previously that soluble immune complexes (IC) added to normal human serum and unseparated autologous blood cells bind predominantly to red blood cells (RBC) bearing C3b receptors. RBC-associated IC are processed both by C3b/C4b inactivator (I) cleavage of C3b and by alternative pathway-dependent C3b generation, and are returned to the serum in a modified form. In the present study, soluble IC were prepared by using 125I-BSA and guinea pig anti-BSA, and were treated with diluted human serum to optimize sustained C3b-dependent binding to human RBC. This binding to RBC could not be abrogated by preincubation of IC with heat-inactivated human serum or purified serum regulatory proteins, I and beta 1H (H), but after binding, pretreated IC dissociated. When IC were prepared with serum containing 125I-C3, treatment with I + H did not release labeled C3 from the complexes. Analysis by polyacrylamide gel electrophoresis in sodium dodecyl sulfate (SDS-PAGE) of 125I-C3b in IC showed similar labeled peaks whether IC were pretreated with buffer or with I + H or were bound to RBC without pretreatment. In contrast, when IC containing 125I-C3b were exposed to I + RBC, nearly 70% of the label was released from the IC. The released material analyzed by SDS-PAGE showed major 125I-C3 peaks corresponding in m.w. to free beta-chain and alpha 1 cleavage products of 30,000 to 33,000 daltons. IC in undiluted serum after incubation with RBC gave less binding to human polymorphonuclear leukocytes than after incubation without RBC, but notably more binding to guinea pig spleen cells and human lymphoblastoid cells. These findings argue that exposure to serum regulatory proteins does not prevent subsequent binding of experimental IC to RBC, that RBC binding promotes degradation of C3b in IC which proceeds beyond iC3b, and that this I-mediated breakdown renders IC reactive with spleen cells.
Local activation of the killing mechanism in PU5 antibody-dependent cell-mediated cytotoxicity effector cells.
Authors: Wei W Z , Lindquist R R
Published: December 2022

This study was undertaken to determine whether ADCC effector cells expressed their killing mechanism globally throughout the entire cell surface or locally in a restricted area. Nonantibody-coated erythrocytes were bound to PU5 ADCC effector cells by either Con A or protein A-Ig bridges, and the effector cells with the adherent nonspecific erythrocyte target cells were mixed with specific antibody-coated erythrocytes. Our results indicated that the Con A or protein A-Ig-linked erythrocytes were not destroyed while the effector cell was in the process of killing specific antibody-coated erythrocytes. Therefore, the ADCC killing mechanisms of PU5 cells require activation by the interaction of Fc receptor with specific antibody-coated erythrocytes, and these killing mechanisms, once activated, are expressed in a locally restricted area of the effector cells rather than globally throughout the entire surfaces of the ADCC effector cell. Previously, we investigated the expression of the killing mechanism in cytolytic T lymphocytes (CTL) and found that alloimmune CTL in the process of killing specific target cells did not kill nonspecific targets linked to the CTL by either wheat germ agglutinin or immunoglobulin bridges. Thus, with respect to the surface membrane expression of lytic activity, CTL and the PU5 ADCC effector cells are similar. Our findings support the view that the various effector killing cells have a common cytolytic pathway and differ only by the recognition and triggering mechanisms.
The migration of activated murine T lymphocytes in vitro. II. Evidence for differential locomotion of T cell subsets.
Authors: Hoffman R A , Ascher N L , Hanto D W , Simmons R L
Published: December 2022

Lymphocytes that were activated by various means (recovered from an in vivo allograft site, sensitized in mixed lymphocyte culture, or stimulated by Con A in vitro), were extremely motile in vitro when compared to unsensitized lymph node lymphocytes. Allosensitized lymphocytes generated in vitro and in vivo (harvested on days of peak cell-mediated cytotoxicity) were more motile than Con A-activated lymphocytes (harvested on the day of peak thymidine incorporation). Protein (bovine serum albumin, normal mouse serum, or alpha-casein) was chemokinetic for all of the lymphocyte preparations, especially those activated by alloantigen or Con A. When these bulk populations were used, no evidence was found to suggest these materials were chemotactic for activated lymphocytes; the various proteins promoted comparable chemokinetic effects. Treatment of allosensitized lymphocytes generated in vitro with Lyt-2 antisera and complement significantly reduced cell-mediated cytotoxicity, but had no effect on random motility. Conversely, treatment with anti-Lyt-1 antisera and complement impaired the motility of the residual cell population in response to chemokinetic normal mouse serum or alpha-casein. Within the bulk population of lymphocytes allosensitized in vitro, the cells that migrate most quickly are predominantly Thy-1.2, Lyt-1+2-, are not as cytotoxic, and do not incorporate thymidine as actively as the unseparated population. These experiments indicate that subpopulations of lymphocytes demonstrate locomotor heterogeneity. Studies designed to determine if a specific lymphocyte population can manifest directional motility (i.e., chemotaxis) will require the use of various antigen-sensitized lymphocyte clones at defined stages of the cell cycle.
Enhancement of natural cytotoxicity by beta-endorphin.
Authors: Mathews P M , Froelich C J , Sibbitt W L , Bankhurst A D
Published: December 2022

The role of enkephalins, beta-endorphin, or other neuropeptides produced by the nervous system in the alteration of immune responsiveness is generally unknown. The present studies were undertaken to investigate the role of these neuropeptides in the modulation of human spontaneous cytotoxicity induced by natural killer (NK) cells. Natural cytotoxicity was measured by using a standard 51Cr release assay with radiolabeled K562 cells. NK activity was significantly enhanced by both beta-endorphin (30.5 +/- 11.5%, M +/- SE, relative enhancement at 50:1, effector:target (E:T) ratio, 10(-14)M beta-endorphin) and methionine-enkephalin (met-enkephalin) (27.4 +/- 9.7% relative enhancement at 10(-9)M). The magnitude of relative enhancement significantly correlated with increasing concentrations of beta-endorphin. Leucine-enkephalin, alpha-endorphin, and morphine did not augment NK activity. The enhancement of NK activity with beta-endorphin increased at all E:T ratios tested. Naloxone inhibited the augmentation of NK activity produced by beta-endorphin and met-enkephalin. By using a combination of a standard 51Cr release and soft agarose single cell analysis assays, beta-endorphin increased both the number of E:T cell conjugates and the number of active killer cells among target-binding cells. The maximal effector cell recycling capacity was increased by 170%. These studies provide new insight into the mechanisms by which neuropeptides produced by the nervous system can alter immune responsiveness.