bluuebunny/crossref_metadata_2025 huggingface dataset:
Human B cell alloantigens; alpha subunit variability.
Authors: Markert M L , Cresswell P
Published: December 2022

Human B cell alloantigens were studied by two-dimensional gel electrophoresis. The heavy (alpha) and light (beta) chains precipitated by xenoantisera were compared on B lymphoblastoid cell lines of different HLA-DR types. In accordance with the results of other investigators, we observed considerable electrophoretic variability of beta subunits. Significant electrophoretic differences between alpha subunits isolated from different cells were also observed through the use of a pH 5 to 7 gradient in the isoelectric focusing dimension. HLA-DR allelic products from a heterozygous line exhibited differences in beta subunit electrophoretic mobility but apparent identity of alpha subunits.
Stimulation of mouse lymphocytes by a mitogen derived from Mycoplasma arthritidis. II. Cellular requirements for T cell transformation mediated by a soluble Mycoplasma mitogen.
Authors: Cole B C , Sullivan G J , Daynes R A , Sayed I A , Ward J R
Published: December 2022

The mitogenic property of supernatants from M. arthritidis cultures (MAS) is shown to be nonsedimentable, nondialyzable, labile to 56 degrees C for 1 hr, and active against spleen cells from both normal and germfree mice. Both viable M. arthritidis and MAS were active for T lymphocytes because anti-Thy-1 antiserum and C eliminated responsiveness. Spleen cells enriched for T lymphocytes by passage over nylon columns lost responsiveness unless supplemented with a radioresistant adherent cell population that was shown to bear Ia antigens. Evidence is also presented that the genetic control of T lymphocyte responses to the mycoplasma mitogen was exercised at the level of the Ia-bearing adherent cells. Thus adherent cells from positive responder mouse strains, but not those from nonresponder mouse strains, restored the responses of T cells from F1 hybrids between responder and nonresponder strains.
Specific binding of leukocyte inhibitory factor to neutrophil plasma membranes.
Authors: Klempner M S , Rocklin R E
Published: December 2022

The interaction of leukocyte inhibitory factor (LIF), a lymphokine that acts as a cell-directed inhibitor of neutrophil locomotion, with the plasma membrane of its target cell was studied. LIF bound specifically to intact neutrophils and to neutrophil plasma membrane vesicles but not to intact macrophages, erythrocytes, or plasma membrane vesicles obtained from these cells. Although LIF adhered tightly to the neutrophil plasma membrane and was not removed by extensive washing, LIF activity could be eluted with N-acetyl-D-glucosamine. Elution with galactose, fucose, and N-acetyl-D-galactosamine did not remove LIF from the neutrophil plasma membrane. Similarly, N-acetyl-D-glucosamine, but not galactose, interfered with the binding of LIF to neutrophil plasma membrane vesicles. It is proposed that LIF binds to a high-affinity neutrophil plasma membrane site and that some intrinsic neutrophil locomotory abnormalities may represent tightly bound inhibitors of migration.
Trypanosoma cruzi: induction of microbicidal activity in human mononuclear phagocytes.
Authors: Nogueira N , Chaplan S , Reesink M , Tydings J , Cohn Z A
Published: December 2022

Antigen-stimulated peripheral blood mononuclear cells from 14 patients with chronic Chagas' disease were examined for their ability to generate soluble factor(s) capable of activating human macrophages to a microbicidal state. Mononuclear cell factors (MCF) from all but one patient were capable of inducing macrophages to a state where they were able to kill trypomastigotes of Trypanosoma cruzi. Macrophage microbicidal activity against this organism was nonspecific, because it could be induced by lymphokine from PPD-positive subjects exposed to heat-killed BCG or by concanavalin A stimulation of normal donors cells. A factor(s) generated by the stimulation of mononuclear cells from normal donors by T. cruzi antigen did not induce macrophage microbicidal activity. Opsonization of the organisms with specific IgG did not alter their fate in normal macrophages, but enhanced their killing in MCF-activated cells. Induction of macrophage activation in the human system differed from the results previously described in mice in a few features: 1) Optimal microbicidal activity did not require daily addition of the soluble factors. 2) The MCF dose-response curve was shifted to lower concentrations. 3) MCF activity generated by antigen-stimulated peripheral blood lymphocytes correlates with their proliferative responses to antigen. Half of the patients showed low proliferative responses and correspondingly lower MCF activity. Mitogen responses were normal in all patients. No correlation was found between low or high responses and clinical manifestations of disease.
A novel mitogen released by lipid A-stimulated bone marrow cells.
Authors: Gollapudi S V , Kern M
Published: December 2022

Lipid A induced bone marrow cells derived from lipopolysaccharide responder strain C3H/HeN to release a component to the extracellular fluid that enhanced DNA synthesis of splenocytes derived from the lipopolysaccharide nonresponder strain C3H/HeJ. The mitogenic component was not selected when C3H/HeN splenocytes were used instead of bone marrow. The target cell in splenocyte populations responding to the mitogenic component released by lipid A-stimulated bone marrow cells is a B cell, as judged by the corresponding of individual cells undergoing DNA synthesis determined by autoradiograph and the presence of surface immunoglobulin detected by immunofluorescence. The mitogenic factor is heat-labile, sensitive to trypsin, and intensive to RNase.
Enumeration of IL 2-secreting helper T cells by limiting dilution analysis, and demonstration of unexpectedly high levels of IL 2 production per responding cell.
Authors: Miller R A , Stutman O
Published: December 2022

We describe here a method for estimating the frequency of alloantigen-responsive precursors of interleukin 2-(IL 2) secreting mouse T helper cells in spleen cell populations, and for measuring the amount of IL 2 generated by the progeny of each responsive cell over a 5-day culture period. Depending on the particular stimulus, about 1 T cell in every 30 to 300 can generate detectable levels of IL 2. Mls-locus incompatibilities activate a higher fraction of cells than do differences at the H-2 complex. The responder cell is sensitive to anti-Thy-1.2 antibody and complement, and is highly enriched in Lyt-2- populations as compared to positively selected Lyt-2+ cells. The dilution curve obtained is consistent with the idea that IL 2 production depends on a single class of T cell. The amount of IL 2 produced in these limiting dilution cultures is unexpectedly high; about 30-fold greater than the levels predicted by extrapolation from conventional mixed lymphocyte cultures. These results suggest that conventional cultures may be very responsive to regulatory events that do not occur at very low responder cell concentrations. Thus, limiting dilution analyses will provide insights into the effects of drugs, age, subset manipulation, etc., on the IL 2-producing cell itself, information that cannot be provided by conventional methods alone.
Fc receptors for IgE on mouse macrophages and macrophage-like cell lines.
Authors: Boltz-Nitulescu G , Plummer J M , Spiegelberg H L
Published: December 2022

Murine alveolar and peritoneal macrophages (AM phi, PM phi) and M phi-like cultured cell lines were analyzed for IgE Fc receptors by rosette formation with mouse IgE-sensitized red cells and by binding of radiolabeled mouse IgE. A mean of 90.4% AM phi, 56.9% PM phi, 93.4% P388D1, 81.2% J774.1, 15.6% WEHI3, 54.7% WR19M.1, 52.3% RAW264.7, and 19.5% RAW309Cr.1 M phi-like cells formed IgE rosettes. The rosettes were specific for native mouse IgE and were inhibited by mouse IgE but not mouse IgG, IgA, IgM, or heat-denatured mouse IgE. Rat IgE, but not human IgE, induced rosettes and inhibited mouse IgE rosettes. Trypsin treatment of the M phi abolished IgE rosette formation. Mouse IgE bound to P388D1 M phi-like cells with a KA of 7.6 +/- 0.2 X 10(6) M-1 to 3.3 +/- 0.9 X 10(5) binding sites. After 30 min of incubation at 37 degrees C, 30 to 45% of AM phi, P388D1, and J774.1 M phi-like cells ingested erythrocytes sensitized with IgE but not unsensitized erythrocytes. The data indicate that mouse M phi bear Fc receptors specific for IgE that mediate phagocytosis of IgE-sensitized erythrocytes.
Structural and functional characterization of an incompletely processed form of murine C4 and Slp.
Authors: Karp D R , Capra J D , Atkinson J P , Shreffler D C
Published: December 2022

The properties of a 128,000-dalton polypeptide, corresponding to the uncleaved alpha- and gamma- chains of the fourth component of murine complement (C4), were studied. A fragment of similar size (137,000 daltons) from the structurally related sex-limited protein (Slp) was also found. These polypeptides have methylamine and iodoacetamide binding sites. suggesting that they, like the alpha-chains of C4 and Slp, possess an internal thiolester. In tryptic peptide map analysis, extensive homology is seen between the 128,000-dalton fragment and native C4 alpha- and gamma-chains. N-terminal sequences for this fragment and C4 alpha are identical, as are those for the 137,000-dalton Slp fragment and Slp alpha. Although the alpha-gamma fragment, like C4 alpha, undergoes denaturation-dependent autolytic cleavage, unlike C4 alpha, it cannot be cleaved by C1 This indicate that some of the properties of C4 do not require the native three-chain structure, whereas others do require it. These findings suggest that the alpha-gamma fragments represent an intermediate step in the processing of the C4 and Slp precursor polypeptides.
Interaction of very low density lipoproteins (VLDL) with rabbit C-reactive protein.
Authors: Cabana V G , Gewurz H , Siegel J N
Published: December 2022

Rabbit CRP is similar to human CRP in structure, kinetics of appearance, and binding reactivities to phosphate esters and cationic polymers. CRP in rabbit acute-phase serum migrates either with gamma or with beta, pre-beta electrophoretic mobility, and distinct gamma- and beta-migrating species can be observed simultaneously in some sera. The present study shows that beta-CRP in serum is converted to gamma mobility during isolation and purification. Normal, acute-phase, or CRP-depleted acute-phase rabbit serum restores the beta mobility of purified gamma-CRP, a conversion that does not occur in the presence of EDTA. Serum CRP fails to adsorb to DEAE-cellulose but does adsorb to CM-cellulose, from which it elutes as gamma-mobility antigen. Chelation by EDTA or flotation and removal of lipoproteins from acute phase rabbit serum produces a gamma-mobility CRP that adsorbs to the anion-exchange resin. Lipid-containing fractions from ion-exchange columns as well as VLDL (but not LDL or HDL) isolated by ultracentrifugation change the mobility of purified CRP from gamma to beta, pre-beta. These changes in mobility are not observed in the presence of EDTA or phosphocholine. In acute-phase rabbit serum with CRP of both beta and gamma mobility, the beta form has a higher m.w. and is lipid-associated, whereas the gamma form is a lower m.w., lipid-poor molecule. These results suggest that in serum the association of CRP with lipoproteins, particularly VLDL, is responsible for its beta, pre-beta electrophoretic mobility. Further studies of the association of CRP with lipoprotein in relation to lipoprotein metabolism may provide insight into the biological role of CRP.
IgA-producing hybridomas are readily derived from gut-associated lymphoid tissue.
Authors: Komisar J L , Fuhrman J A , Cebra J J
Published: December 2022

Eight hybridomas secreting IgA monoclonal antibodies were obtained by using gut-associated lymphoid tissue as a primed plasmablast source. IgA secretors are obtained at higher frequencies by this technique than by conventional splenic fusions. This technique provides useful tools for the study of mucosal protection, and it demonstrates that exaggerated potential of gut-derived B cells, compared to splenic B cells, for IgA expression.
Inhibition of specific immune responses by feeding protein antigens. V. Induction of the tolerant state in the absence of specific suppressor T cells.
Authors: Hanson D G , Miller S D
Published: December 2022

The effect of CY pretreatment on the ability of OVA feeding to induce both tolerance and active suppression was examined in mice. CY-pretreated, OVA fed mice were fully unresponsive in both OVA-specific DTH and antibody responses, but, in contrast to untreated OVA-fed mice, did not transfer suppression to normal recipients via splenic lymphocytes. Restoration of Ts activity in CY-pretreated mice was accomplished by reconstitution with normal T cells before antigen feeding, indicating that the CY effect was at the Ts precursor level. In addition, it was found that certain OVA-specific immune parameters (DTH and splenic PFC responses) in recipient mice were susceptible to suppression by transfer of spleen cells from OVA-fed donors, whereas other measures (antigen-induced T cell proliferation and serum antibody titers) were not. The data suggest that CY-sensitive Ts are not necessary for either induction or maintenance of specific tolerance after OVA feeding.
Induction of immunoglobulin secretion by a simple nucleoside derivative.
Authors: Goodman M G , Weigle W O
Published: December 2022

8 bromoguanosine (8BrGuo), a low m.w. nucleoside derivative that rapidly traverses the lymphocyte membrane to the interior of the cell, is an extremely potent inducer of immunoglobulin production by B lymphocytes. It has recently been demonstrated that this same agent can initiate high level lymphocyte proliferation in vitro. Data in the current report demonstrate that 8Br-cGMP and other cGMP analogues are at best weak inducers of immunoglobulin secretion, being more than two orders of magnitude less effective (per molecule taken up) than 8BrGuo. Incubation of lymphocytes with 8BrGuo fails to elevate their intracellular concentrations of cGMP. Moreover, at equimolar concentrations, underivatized cGMP actually antagonized the induction of antibody production by 8BrGuo. These data, in concert with observations that many lymphocyte activators fail to alter cGMP content, that many agents that elevate cGMP fail to induce immunoglobulin synthesis, and that some cGMP-elevating agents even inhibit it, suggest that the induction of immunoglobulin production, like the induction of proliferation in B cells, is not primarily dependent upon cGMP. A simple nucleoside derivative is described, the use of which should prove to be a powerful probe for investigating the triggering mechanisms underlying the proliferative and differentiative B lymphocyte pathways at the molecular level.
T cell regulation of the IgG2a response to TNP-Ficoll: evidence that allotype congenic mice contain both helper cells that preferentially enhance IgG2a synthesis and suppressor cells that specifically suppress IgG2 synthesis.
Authors: Mongini P K , Paul W E
Published: December 2022

When unprimed C57BL T cells were transferred into C57BL nu/nu mice, a preferential enhancement of the IgG2a antibody response to TNP-Ficoll was observed. Unprimed splenic T cells from Igh allotype congenic (B.C8) mice were unable to enhance the IgG2a response. The failure of T cells from allotype congenic mice to augment IgG2a antibody production to TNP-Ficoll was due to the presence of a T cell that specifically suppressed IgG2a antibody synthesis. The suppressive activity could be demonstrated in nu/nu mice and nu/nu mice reconstituted with C57BL helper cells. The suppressive activity of the B.C8 T cell population could be abrogated by treatment with anti-Lyt-1 and anti-Lyt-2 antibodies and complement as well as by treatment of B.C8 T cells with anti-Lyt-2 alone. Removal of the T cells responsible for IgG2a suppression from B.C8 splenic T cell population unmasked a population of B.C8 T cells that could enhance IgG2a preferentially augment IgG2a antibody synthesis can be found in donor mice that differ in their Igh background from the responding B cells.
Asymmetrical surface IgG on MOPC-21 plasmacytoma cells contains membrane heavy chain and one secretory heavy chain.
Authors: Goding J W
Published: December 2022

Membrane proteins from the B lymphomas WEHI-231 and 2PK3 and from the plasmacytomas MPC-11 and MOPC-21 were radioiodinated in situ by the lactoperoxidase method and were subjected to two-dimensional (nonreduced, reduced) polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate. Few heavily labeled membrane proteins were composed of disulfide-bonded subunits. One such protein (m.w. 200,000 intact and 116,000 reduced) shared some properties with the PC-1 alloantigen, although it was not conclusively identified. A second major disulfide-bonded protein (m.w. 200,000 intact and 95,000 reduced) has been identified previously as the receptor for transferrin. Membrane immunoglobulins of WEHI-231 (IgM) and 2PK3 (IgG2a) had the expected subunit structure, whereas membrane immunoglobulin was not detected on MPC-11. In contrast, surface IgG1 of MOPC-21 appeared to consist almost entirely of hybrid molecules containing one membrane gamma 1 chain and one secretory gamma 1 chain. This hybrid IgG molecule appeared to exist in both monomeric and dimeric forms. It is concluded that i) the synthetic and assembly mechanisms of secretory and membrane IgG1 are shared; ii) there are no special mechanisms to prevent pairing of membrane and secretory gamma 1 chains; iii) the presence of one hydrophobic tail is sufficient for membrane insertion of gamma 1 chains; and iv) the C-terminal extension cysteine residues of membrane gamma 1 chains in hybrid IgG molecules are either unpaired or may allow the formation of hybrid IgG dimers.
Opsonic properties of C-reactive protein in vivo.
Authors: Nakayama S , Mold C , Gewurz H , du Clos T W
Published: December 2022

The capacity of CRP to alter the clearance and site of sequestration of erythrocytes was examined. Mouse erythrocytes, coated with PnC to provide a binding site for CRP, were radiolabeled and injected into homologous mice. The liver, spleen, kidneys, and lungs were removed and counted to assess the site of erythrocyte clearance. In the presence of CRP, an increase in splenic sequestration of E-PnC was observed along with a slight decrease in hepatic sequestration. This altered clearance pattern was dependent on both C activation and on the continued presence of CRP. The clearance of cells coated with IgM or IgG antibody to PnC was compared. In both cases, antibody caused an increase in sequestration by the spleen. However, IgM-coated cells required C for splenic clearance, whereas IgG-coated cells did not. We have shown in these experiments that CRP can affect the in vivo pattern of organ sequestration of cells to which it is bound in a manner similar to antibody.
Functional heterogeneity of culture-grown bone marrow-derived macrophages. II. Lymphokine stimulation of antigen-presenting function.
Authors: Lee K C , Wong M
Published: December 2022

The activation of immunostimulatory activity and Ia expression was studied in pure populations of murine macrophages (M phi) grown in vitro from bone marrow precursor cells in the presence of L cell-conditioned medium as the source of colony-stimulating factor. During exponential growth, the M phi developed maximal Ia-dependent antigen-presenting activity as detected by the induction of antigen-specific T cell proliferation, but the proportion of Ia+ M phi was low (less than 10%). Fractionation of the M phi according to size by velocity sedimentation resulted in concentration of the antigen-presenting cells in the smallest fraction, but the enrichment of Ia+ M phi in this fraction was less than twofold. All fractions also showed comparable degrees of antigen uptake regardless of their T cell-stimulating activity. Thus Ia and antigen, although obviously essential, are insufficient for full manifestation of antigen-presenting function. Activation of M phi with lymphokines from Mycobacterium-activated lymph node cells resulted in enhanced Ia expression in all fractions, but only small M phi showed an enhancement in antigen presentation. Large activation M phi were found to exert an immunosuppressive effect that probably neutralized any augmentation of stimulatory activity. thus heterogeneity can be demonstrated in i) the function of unstimulated M phi, ii) the responsiveness of subsets to stimulation, and iii) the manifestation of activated functions.
Fc gamma 2b receptor-mediated prostaglandin synthesis by a murine macrophage cell line (P388D1).
Authors: Nitta T , Suzuki T
Published: December 2022

The nature of signals transmitted by two types of Fc gamma receptors (one specific for IgG2b and the other for IgG2a) present on the surface of a murine macrophage cell line (P388D1) was investigated. Specific binding of IgG2b (presented as EA2b) to cell surface Fc gamma 2br triggered the release of 3H-arachidonic acid and 3H-prostaglandins (PG) from P388D1 cells that were prelabeled with 3H-arachidonate. The release of 3H-arachidonic acid, which increased in a dose-dependent manner, was enhanced by exogenous Ca++ (1.25 mM) and was completely blocked by ethylenediaminetetraacetate (EDTA) (4 mM) or a phospholipase A2 inhibitor, p-bromophenacylbromide (7 microgram/ml). A cyclooxygenase inhibitor, indomethacin (9 microgram/ml), reduced the 3H-arachidonic acid release and completely blocked the conversion of arachidonate into PG. Cytochalasin D (1 microgram/ml), which inhibited the phagocytosis of immune complexes by 90% of P388D1 cells, did not affect the Fc gamma 2bR-triggered release of arachidonic acid. Specific binding of IgG2a (presented as EA2a) to cell surface Fc gamma 2aR did not trigger the release of either 3H-arachidonic acid or 3H-PG from P388D1 cells. Our data demonstrate a signal for the activation of the arachidonic acid metabolic cascade is transmitted by Fc gamma 2bR, but not by Fc gamma 2aR, on the surface of P388D1 cells, probably through the initial activation of the phospholipase A2 activity associated with Fc gamma 2bR.
Tubulointerstitial nephritis and immunologic responses to Tamm-Horsfall protein in rabbits challenged with homologous urine or Tamm-Horsfall protein.
Authors: Mayrer A R , Kashgarian M , Ruddle N H , Marier R , Hodson C J , Richards F F , Andriole V T
Published: December 2022

Tubulointerstitial nephritis was produced in 19 of 23 New Zealand White rabbits challenged i.v. with adjuvant-free homologous urine for greater than or equal to 16 wk and 11 of 14 challenged with adjuvant-free rabbit Tamm-Horsfall protein for 2 to 24 wk. Lesions were identical in the two groups of rabbits and were characterized by focal mononuclear infiltrates and microscopic scarring localized to distal nephron segments identified as the thick ascending limb of the loop of Henle. Concomitant immunoglobulin deposition was not detected despite antecedent elevations in serum IgG antibody directed against Tamm-Horsfall protein in 17 of 19 and 10 of 11 affected rabbits, respectively. Peripheral lymphocytes from affected rabbits were found to be cytotoxic and underwent blast transformation in the presence of homologous urine or Tamm-Horsfall protein in vitro. These lymphocytes were shown to produce a soluble cytotoxic product upon exposure to Tamm-Horsfall protein. Neither tubulointerstitial nephritis nor this pattern of cellular and humoral immune response to Tamm-Horsfall protein was found in two age-matched control groups: one unchallenged, and the other challenged i.v. with urine that had been selectively depleted of Tamm-Horsfall protein by 95%. It is concluded that the tubulointerstitial nephritis produced in rabbits by injection of urine or Tamm-Horsfall protein is the result of a predominately cellular immune response directed against Tamm-Horsfall protein.
Human T cell hybridomas producing lymphokines. I. Establishment and characterization of human T cell hybridomas producing lymphotoxin and migration inhibitory factor.
Authors: Kobayashi Y , Asada M , Higuchi M , Osawa T
Published: December 2022

Stable human T cell hybridomas were produced by cell fusion between PHA-activated human peripheral blood lymphocytes and human acute lymphatic leukemia cells of a CEM cell line whose proliferation had been inhibited by treatment with an irreversible protein synthesis inhibitor (emetine) and an irreversible RNA synthesis inhibitor (actinomycin D). Two hybrid cell lines (E10, F8) thus produced expressed OKT3-reactive antigen, HLA-A1 and -B8 antigens derived from CEM cells, and HLA-A2 antigen derived from PBL, and they have 10 more chromosomes than CEM cells. Furthermore, these cell lines continuously secreted lymphotoxin over 3 mo. E10 was found to produce MIF in addition to lymphotoxin. Cloning of E10 and the relationship between the functions and surface phenotypes of E10 sublines were examined. Lymphotoxin-producing hybrids (E10-15 and E10-37) express more OKT8-reactive antigen than OKT4-reactive antigen, while lymphotoxin and MIF-producing hybrids (E10-25, E10-42, and E10-43) express more OKT4-reactive antigen than OKT8-reactive antigen.
Effects of oxygen radical scavengers and antioxidants on phagocyte-induced mutagenesis.
Authors: Weitzman S A , Stossel T P
Published: December 2022

Phagocytic leukocytes from normal humans can produce mutations in bacteria. To define further the role of oxygen radicals in this mutagenic process, we performed experiments in which scavengers or antioxidants were added to the incubation of phagocytes and bacteria. We found that 1) superoxide dismutase, catalase, mannitol, and benzoate were all capable of inhibiting mutation, 2) sulfhydryl compounds and vitamin E were also inhibitory, and 3) the presence of vitamin C in the incubations increased the mutation frequency. These data suggest an important role for hydroxyl radicals in mediating phagocyte-induced mutations.
I-A antigens on cloned alloreactive murine T lymphocytes are acquired passively.
Authors: Lorber M I , Loken M R , Stall A M , Fitch F W
Published: December 2022

Cloned lines of alloreactive cytolytic and amplifier T lymphocytes have been examined for expression of I-A antigens. Using flow cytofluorometry and monoclonal antibodies, MHC antigens representing both I-A and H-2K or D determinants were reproducibly detected on the cell surface of these cloned T lymphocytes. All cloned lines examined expressed H-2K or D antigens representing the MHC haplotype appropriate to their strain of origin. However, I-A as well as H-2K or D antigens appeared to be acquired passively from the stimulating cell population. Within the lower limits of detection using the fluorescence-activated cell sorter, evidence suggesting endogenous synthesis of I-A antigens by these cloned T lymphocytes could not be demonstrated. Further, the observed binding appeared to be nonspecific, because material originating from allogeneic, syngeneic, or third-party stimulating cells could be observed under appropriate conditions.
A monoclonal antibody directed against the HLA-Bw6 epitope.
Authors: Radka S F , Kostyu D D , Amos D B
Published: December 2022

A cytotoxic monoclonal antibody, SFR8-B6, produced by immunizing KGH rats with partially purified glycoprotein from JY, a human B lymphoblastoid cell line, detects HLA-Bw6, a unique public antigen on the HLA-B molecule. By cytotoxicity, SFR8-B6 has complete concordance with the presence of Bw6 as defined by alloantisera, and its reactivity segregates with HLA in families. Because sera detecting Bw4 and Bw6 are rare, this monoclonal antibody has value as a perpetual standard. In addition, SFR8-B6 offers potential as a probe for investigating the molecular relationships of HLA antigens.
Effect of plicatic acid on human serum complement includes interference with C1 inhibitor function.
Authors: Giclas P C
Published: December 2022

In an earlier study, we presented evidence that plicatic acid (PA) activated C in normal human serum (NHS) by an immunoglobulin-independent mechanism that did not involve factor B of the alternative pathway and that required Ca++ for initiation. The present paper further verifies that PA acts through the classical pathway. In PA-treated NHS, titers of C1, C4, C3, and C5 decreased after incubation at 37 degrees C, but in C2-deficient serum, only the titers of C1 and C4 were decreased after identical PA treatment. Activation of purified precursor C1 did not occur when it was incubated with PA at concentrations that would have produced C1 consumption in serum. Thus, PA added to serum initiates activation of the classical pathway, but is incapable of activating C1 directly. PA added to a mixture of native C4 and activated C1s did not alter the kinetics or the extent of C4 inactivation by the C1s. However, when mixtures of C4, C1s, and C1-In were incubated with PA, the ability of the inhibitor to inactivate the C1s was markedly reduced. These data indicate that the mechanism by which PA activates C in serum may involve interference with the normal regulatory mechanism that controls C1 activity.
A high frequency idiotypic marker of anti-DNA autoantibodies in MRL-Ipr/Ipr mice.
Authors: Rauch J , Murphy E , Roths J B , Stollar B D , Schwartz R S
Published: December 2022

Anti-idiotypic antibodies were used to analyze relatedness of anti-DNA autoantibodies of MRL mice. The antiidiotypic antibodies, produced by immunization of rabbits with MRL-Ipr-derived hybridoma anti-DNA antibodies, were defined by their ability to inhibit specifically the binding of hybridoma anti-DNA antibody to DNA. One monoclonal anti-DNA antibody, H130, cross-reacted with two thirds of other hybridoma anti-DNA antibodies. The H130/anti-H130 system detected high amounts (up to 5 mg/ml) of immunoreactivity in sera of MRL-Ipr mice, whereas levels in MRL-+ sera were relatively low. The H130 family increased 10-fold in MRL-Ipr mice over the course of 5 mo, but its levels did not correlate chronologically with those of anti-DNA antibodies, cardiolipin-binding antibodies, or total serum immunoglobulins. H130 cross-reactivity was found, by quantitative immunoadsorption, in 40 to 60% of serum anti-DNA antibodies; however, a large excess of H130-related serum antibodies did not bind to DNA. The H130 family and anti-DNA antibodies therefore seem to constitute overlapping populations.
Detection of a common antigen on murine B cells and Lyt-2+ T cells by a rat monoclonal antibody, 14D10.
Authors: Kung J T , Sharrow S O , Mage M G , Paul W E
Published: December 2022

This paper reports the production of a rat monoclonal antibody, 14D10, which recognizes a determinant shared between B cells and Lyt-2+ T cells. Three subpopulations of spleen cells were defined based on the density of bound 14D10. They have been designated 14D10-SP (strongly positive), 14D10-WP (weakly positive), and 14D10-N (negative). Dual parameter immunofluorescence studies showed that 90% of 14D10-SP cells are IgM+ cells and more than 92% IgM+ cells are 14D10-SP. Of 14D10-WP cells, approximately 60% are Lyt-1+2+ T cells and less than 10% are IgM+ cells. However, most (greater than 90%) of Lyt-2+ T cells are reactive with 14D10. Staining of purified populations of Lyt-2+ and Lyt-2- T cells with fluoresceinated 14D10 also showed greater than 90% of Lyt-2+ T cells to be 14D10+, and fewer than 10% of Lyt-2- T cells are 14D10+. Mouse thymus contained very few (congruent to 5%) 14D10+ cells. Analysis of bone marrow cells shows almost all small cells to be 14D10+. Six Abelson virus-transformed cell lines all express the antigen recognized by 14D10.
H2Kk can influence whether cytotoxic T lymphocytes recognize trinitrophenyl in association with H2Dk unique or H-2Kk and H-2Dk shared self determinants.
Authors: Fujiwara H , Tsuchida T , Levy R B , Shearer G M
Published: December 2022

The present study investigates the effect of trinitrophenyl- (TNP) modified H-2Kk (TNP-Kk) antigens on the generation of anti-TNP-Dk restricted cytotoxic T lymphocyte (CTL) responses. C3H.OH mice were primed to TNP-self by skin-painting with trinitrochlorobenzene, and spleen cells from these primed mice were subsequently stimulated in vitro with TNP-self. The effector cells generated exhibited appreciable lysis of TNP-modified C3H.OH blast target cells. Cold target inhibition studies demonstrated the generation of two effector cell populations: one that recognizes TNP in association with unique Dk self determinants, and one that recognizes TNP in association with self determinants shared between TNP-Kk and TNP-Dk. This was in contrast to primed C3H/He spleen cells, which did not generate CTL that recognized TNP in association with unique Dk self determinants. When spleen cells from (C3H/He x C3H.OH)F1 mice primed to TNP were stimulated in vitro with TNP-C3H.OH cells, unique Dk self determinants were recognized in association with TNP. However, in vitro stimulation of the same F1 responding cells with TNP-C3H/He or TNP-F1 cells failed to elicit CTL that utilized these Dk-unique self determinants. The findings of this study demonstrate that unique or shared H-2Dk determinants can be differentially utilized by CTL populations, depending on the H-2 alleles expressed by the stimulator cells.
Prostaglandin-generating factor of anaphylaxis. II. Characterization of activity.
Authors: Steel L K , Bach D , Kaliner M A
Published: December 2022

Anaphylaxis of lung tissue leads to the generation of prostaglandins, thromboxanes, and hydroxyeicosatetraenoic acids. A portion of the prostaglandin generation is due to a unique oligopeptide termed "prostaglandin-generating factor of anaphylaxis (PGF-A)," which is generated during anaphylaxis. The activity of PGF-A on human and guinea pig lung was characterized: peak PG formation occurs within 5 to 10 min of the addition of PGF-A, calcium but not magnesium is required for PGF-A activity, and both physiologic pH and temperature are necessary for optimal activity. Human and guinea pig airway and parenchymal (lung) responses to PGF-A were similar (predominantely PGF2 alpha) but were not identical to each other (guinea pig parenchyma produces thromboxane as well). PGF-A is, thus, a novel, potent mediator generated during anaphylaxis of lung tissue that may contribute to the spectrum of tissue responses seen in allergic reactions.
Immunoglobulin secretion by cell lines derived from African and American undifferentiated lymphomas of Burkitt's and non-Burkitt's type.
Authors: Benjamin D , Magrath I T , Maguire R , Janus C , Todd H D , Parsons R G
Published: December 2022

As part of an investigation of the cellular origins of undifferentiated lymphomas of the Burkitt's and non-Burkitt's types, we have examined immunoglobulin secretion by cell lines and biopsy samples from these tumors and have compared it with other lymphoblastoid cell lines. The majority of American lymphoma cell lines and a smaller fraction of African lymphoma cell lines secreted monoclonal IgM. No other Ig classes were secreted. Ig secretion by the tumor samples was also found to be exclusively IgM. The secreted IgM was polymeric and associated with J chain. Secretion of free light chain by most of the tumor cell lines was observed. Quantitation by immunoassay demonstrated that the American lymphoma cell lines secreted significantly more IgM than the African lymphoma cell lines. We have proposed that the lymphoma cells represent an early stage of B cell differentiation, during which antigen-independent secretion occurs.
Vasopressin replacement of interleukin 2 requirement in gamma interferon production: lymphokine activity of a neuroendocrine hormone.
Authors: Johnson H M , Farrar W L , Torres B A
Published: December 2022

The neuroendocrine antidiuretic hormone arginine vasopressin (AVP) was capable of replacing the interleukin 2 (IL 2) requirement for gamma-interferon (IFN gamma) production by Lyt-2+ cells from C57BL/6 mouse spleen cells. The AVP replacement did not stimulate DNA synthesis in the target lymphocytes. This suggested that AVP was capable of replacing an IL 2 function that did not involve stimulation of cellular proliferation or DNA synthesis. This was confirmed by the demonstration that mitomycin C inhibition of IFN gamma production was reversed by IL 2 or AVP without concomitant reversal of blockage of DNA synthesis. Oxytocin, which is structurally related to AVP, was also capable of replacing IL 2 requirement for IFN gamma production, whereas insulin was ineffective. The data show that the neuroendocrine hormones AVP and oxytocin are capable of lymphokine-like activity. This activity may involve the induction of a second messenger such as cyclic GMP.
The role of Ia molecules in the activation of T lymphocytes. I. The activation of an IL 1-dependent IL 2-producing T cell hybridoma by Con A requires an interaction, which is not H-2-restricted, with an Ia-bearing accessory cell.
Authors: Rock K L
Published: December 2022

A model of accessory cell-dependent lectin-mediated T cell activation was investigated by utilizing a mitogen-inducible T cell hybridoma. A continuous MHC-restricted antigen-specific T cell line was fused with the azaguanine-resistant AKR thymoma BW5147. A hybrid, RF1.16B, was identified that is minimally inducible by Con A stimulation alone but is stimulated by Con A in the presence of T cell-depleted accessory cells to produce interleukin 2. The accessory cell function can be replaced by the monokine interleukin 1. Thus the lectin is a sufficient trigger for the hybrid in the absence of MHC restriction elements. The accessory cell function from splenocytes is provided by a non-B, non-T, predominantly Ia-bearing radioresistant cell. The interaction between the RF1.16B hybrid and the accessory cell population is not H-2-restricted. Control experiments, including the use of a cloned source of accessory cells, ruled out contaminating T cells or direct lectin effects as an explanation for the lack of H-2 restriction. The finding that an Ia-bearing cell is required for activation in an MHC-nonrestricted manner is discussed, and a hypothesis is raised that Ia antigens may play a role in addition to that of being a restriction element.
Establishment of B cell hybridomas with B cell surface antigens.
Authors: Hamano T , Kim K J , Leiserson W M , Asofsky R
Published: December 2022

M12.4, one of several B lymphomas derived from BALB/c mice, was mutagenized with ethyl methanesulfonate in vitro. M12.4.1, a subline of the mutant cells, was sensitive to hypoxanthine-aminopterin-thymidine selective medium and was fused with normal splenic B lymphocytes of C57BL/6ByJ mice. The hybridomas obtained from this fusion were shown to express mu heavy chain, H-2KbDb, Iad, and Iab on the cell surface by analyses of flow microfluorometry and a cytotoxicity assay, although parental M12.4.1 lacked mu heavy chain on the cell membrane. These results demonstrate that the B cell hybridomas with B cell surface antigens have been established in vitro. IgM molecules on the cell surface of the hybridomas were shown to originate from normal B cells of C57BL/6ByJ mice by flow microfluorometry analyses after staining with fluorescein-labeled Bet 1, a monoclonal rat antibody that recognizes Igh-6.5, a mouse IgM allotypic determinant. These hybridomas could generate IgM-secreting cells at the high frequency (more than 10% of the cultured cells) when stimulated with bacterial lipopolysaccharide. On the other hand, parental M12.4.1 did not develop any IgM-secreting cells under the same conditions. These findings suggest that these B cell hybridomas with B cell surface antigens may be a good model for the study of B cell differentiation.
Cell cycle regulation of cloned cytolytic T cells by T cell growth factor: analysis by flow microfluorometry.
Authors: Sekaly R P , MacDonald H R , Zaech P , Nabholz M
Published: December 2022

In an attempt to better define the mode of action of TCGF we have investigated the effect of complete removal of TCGF on the cell cycle kinetics of a TCGF-dependent murine CTL cloned line (B6.1). Cells that had been cultured in the presence or absence of TCGF were stained with propidium iodide, a DNA binding dye, and the distribution of DNA content was analyzed by flow cytometry. Results indicated that the proportion of cells entering the S phase of the cell cycle started to decrease 6 hr after removal of TCGF from the culture medium. This fraction continued to decrease as a function of time, and after 30 hr without TCGF 93% of the cells were in the G1 phase of the cell cycle in comparison to 38% in control cultures containing TCGF. Direct evidence that B6.1 cells completed one cell cycle after removal of TCGF before they accumulated in the G1 phase was obtained with a technique combining the use of BUdR, a thymidine analog, and the DNA binding dye Hoechst 33342. When TCGF was added again to cultures of B6.1 cells that were arrested in the G1 phase, the majority of cells entered the S phase in a synchronous fashion after a lag phase of 10 to 12 hr. The duration of this lag phase was independent of the concentration of TCGF used to restimulate quiescent B6.1 cells. However, the number of cells entering S phase 10 hr after re-addition of TCGF was concentration dependent. Additional experiments indicated that the cytolytic activity was not dependent on TCGF, since no decrease in the activity of B6.1 cells was noted after these cells had been deprived of TCGF for up to 30 hr.
Discrepancy in expression ability of Tac antigen and Ia determinants defined by monoclonal antibodies on activated or cultured cord blood T lymphocytes.
Authors: Yokoi T , Miyawaki T , Yachie A , Ohzeki S , Taniguchi N
Published: December 2022

T lymphocytes from cord blood and adults stimulated with mitogens and alloantigen were analyzed using monoclonal antibodies that detect Ia and Tac antigens associated with lymphocyte activation. Less than 5% of T cells freshly isolated or cultured without stimuli expressed Ia and Tac antigens assessed by the indirect immunofluorescence method. When both T cells from cord blood and adults were cultured with phytohemagglutinin (PHA), concanavalin A (Con A), pokeweed mitogen (PWM), or allogeneic cells, variable proportions of them expressed Tac antigen. The expression of Tac antigen on stimulated T cells increased in parallel with DNA synthesis, and was significantly correlated with the proliferative response of stimulated T cells. In contrast to Tac antigen, the expression of Ia antigens appeared to show some time lag behind the proliferative response. Although expression of Ia antigens was too weak to assess in PHA- or Con A-stimulated cultures, adult T cells were stimulated by PWM or allogeneic cells to express strongly Ia antigens in culture. However, the percentage of Ia+ cells in cord blood T cells stimulated with PWM or allogeneic cells was markedly lower as compared with that of adults. In addition, cord blood T cells grown in the presence of T cell growth factor showed the same degree of Tac antigen as adult ones did, whereas their expression of Ia antigens was negligible as compared with adult controls. These observations suggested that T cells in cord blood might be deficient by nature in their ability to express Ia antigens on activation. The inability to develop Ia+ T cells seemed to be characteristic of functional immaturity of T cells in early human ontogeny.
Antigen presentation by human B cells: T cell proliferation induced by Epstein Barr virus B lymphoblastoid cells.
Authors: Issekutz T , Chu E , Geha R S
Published: December 2022

T cell proliferation in response to antigen requires the presence of an antigen-presenting accessory cell. The accessory cell most commonly associated with antigen presentation has been the macrophage (Mo). This study demonstrates that B cells in the form of Epstein Barr virus-transformed B lymphoblasts (EBV-B) are able to present tetanus toxoid (TT) to human T cells and induce proliferation of these cells. T cells freshly isolated from peripheral blood were shown to undergo blast transformation and proliferation in response to TT and irradiated EBV-B cells. Furthermore, TT-reactive T cell blasts were shown to proliferate in the presence of EBV-B cells and TT, but not with other antigens. There was a progressive increase to a plateau in T blast proliferation with increasing numbers of EBV-B cells added to the culture. The concentration of TT required for optimal antigen presentation was similar for EBV-B cells and for Mo. TT-specific cloned T cells also proliferated in response to TT and EBV-B cells and could be continuously grown in culture with TT, interleukin 2-containing supernatant, and EBV-B cells in place of autologous Mo. EBV-B cells pulsed with TT could also act as antigen-presenting cells. The proliferative response of T cell clones to TT in the presence of EBV-B cells was inhibited by antiserum to human p29,34 glycoprotein but not by anti-beta 2-microglobulin. This inhibition was shown to result from interaction with Ia-like determinants on EBV-B cells. These results indicate that B lymphoblastoid cells in man are able, like Mo, to present antigen to T cells in the context of Ia-like determinants.
The binding characteristics of anti-Rho(D)-positive human and chimpanzee erythrocytes measured with 14C protein A.
Authors: Owens N A , Hui H L , Green F A
Published: December 2022

The relation of the human erythrocyte Rho(D) antigen to its chimpanzee counterpart is currently unresolved. To explore this relation, we prepared 14C protein A to compare the binding parameters between human anti-Rho(D) and Rho(D)-positive human and chimpanzee erythrocytes. Double reciprocal plots of the binding in each case exhibited a straight line with intercepts indicating approximately the same numbers of Rho(D) binding sites for human and chimpanzee erythrocytes but an affinity that was 20 times greater for the human. This would indicate that the human and chimpanzee each have a single class of sites whose primary structure is very similar but sufficiently different to give the large divergence in affinity as measured by the human isoimmune antiserum.
C4 does not bind to human and rabbit IgM during activation of the classical complement pathway on the red cell.
Authors: Circolo A , Borsos T
Published: December 2022

It has been known for many years that IgG-C4 complexes are generated during the activation of the classical complement pathway. Information regarding binding of C4 by IgM is not available. We studied the binding of human C4 by natural human and rabbit anti-hapten IgM under conditions in which the IgM was bound to hapten coupled to sheep red cells. We eluted the IgM by excess fluid phase hapten, reattached the eluted IgM to red cells coupled with hapten, and transferred the IgM from red cell-IgM-C4 complexes to red cells coupled with hapten. Analysis of the cells by radioimmunoassay and/or by hemolytic assays showed that no C4 was eluted from the cells with the IgM, that no C4 transferred from cell to cell with the IgM, and that the C4 remaining on the cells was hemolytically active. We concluded that in contrast to IgG, natural human and rabbit IgM at a cell surface failed to bind C4.