bluuebunny/crossref_metadata_2025 huggingface dataset:
The rabbit properdin system: I. Identification of a new factor and purification of rabbit properdin.
Authors: Naff G B , Hedrick S W , Ratnoff W D , Novak M A , Smith M C , Steiner C , Todd E W
Published: December 2022

Pure preparations of rabbit properdin were obtained from rabbit serum by ion-exchange chromatography. These preparations functioned as properdin when they were measured with the zymosan assay or with a serum reagent selectively depleted of properdin by a specific immunoabsorbent. Properdin in these preparations was in its activated state. A new serum factor was required to measure properdin activity when purified preparations of rabbit properdin were tested with the zymosan assay. This factor was designated as ZBP, or zymosan-binding protein. ZBP appeared to be distinct from known components of the alternative complement pathway and the classical complement system, and it did not appear to be an immunoglobulin.
Characterization of responding cells in oxidative mitogen stimulation. I. Ia+ cells and Ly-1+2+ cells are required for the proliferative response.
Authors: Phillips M L , Wettstein P J , O'Brien R L , Parker J W , Frelinger J A
Published: December 2022

Addition of anti-Ia sera to cultures of mouse spleen cells stimulated with oxidative mitogens, neuraminidase/galactose oxidase (NaGO) or sodium periodate (NaIO4), inhibits the subsequent proliferative response 30 to 70%. Anti-H-2K or D sera were not specifically inhibitory. Similar inhibition was seen when cells were pretreated with anti-Ia sera and washed before exposure to the mitogenic enzymes. Treatment with anti-Ia serum and complement depletes greater than 89% of the NaGO and the NaIO4 responses but 2% or less of the phytohemagglutinin (PHA) response. The response to NaGO was sensitive to depletion with anti-Thy-1 serum, rabbit anti-mouse brain serum, anti-Ly-1, or anti-Ly-2 serum. Mixtures of Ly-1 and Ly-2-depleted populations did not restore responsiveness. Thus both an Ia+ cell and an Ly-1+2+ T cell are required for [3H]TdR incorporation in response to NaGO treatment.
Purification of Fc gamma receptor from rabbit alveolar macrophages that retains ligand-binding activity.
Authors: Kulczycki A , Krause V , Killion C C , Atkinson J P
Published: December 2022

The Fc gamma receptor of rabbit alveolar macrophages was purified by affinity chromatography by using rabbit gamma-globulin (Rab gamma G) coupled to Sepharose. Macrophage preparations were efficiently labeled with 125I by using a modified lactoperoxidase method. After incubation of NP-40 cell lysates with Rab gamma G-Sepharose, elution at 4 degrees C with 0.5 N acetic acid containing 1% NP-40 and rapid neutralization allowed recovery of active Fc gamma receptor. Purified Fc gamma receptor retained its ligand-binding activity, since approximately 41 to 72% of labeled material specifically rebound to Rab gamma G-Sepharose. Active receptor also rebound to human IgG- and rat IgG-sepharose. Active Fc gamma receptor did not bind to Sepharose coupled to rabbit Fab, rabbit F(ab)'2 or human F(ab)'2 fragments, nor to Sepharose coupled to chicken IgG. Analysis of Fc gamma receptor by SDS polyacrylamide gels demonstrated a broad peak of radioactivity in the apparent m.w. range of 50,000 to 70,000 in 5.6% acrylamide gels and 35,000 to 55,000 in 9% gels. Labeled receptor with similar structural characteristics and ligand-binding activity was also obtained from highly purified adherent cell populations and from macrophages biosynthetically-labeled with [14C]glucosamine in culture.
Characterization of the oligosaccharide units of the fourth component of complement (Ss protein) synthesized by murine macrophages.
Authors: Roos M H , Kornfeld S , Shreffler D C
Published: December 2022

The glycosylation of murine C4 (Ss protein) synthesized by peritoneal macrophages has been investigated. Both the intracellular precursor, P-C4 (185), and the C4 alpha- and beta-chains that were secreted into medium were found to be glycosylated; however, no carbohydrate units were detected on the gamma-chain. Analyses of the oligosaccharide units showed that P-C4 (185) appears to contain both a "complex" and a "high mannose" carbohydrate group, the alpha-chain a "complex" group and the beta-chain a "high mannose" carbohydrate unit.
Interaction between Schistosoma mansoni and the complement system: binding of C1q to schistosomula.
Authors: Santoro F , Ouaissi M A , Pestel J , Capron A
Published: December 2022

In earlier studies we have found that activation of the classical complement pathway (CCP) by the immature schistosomes involves the presence of IgG. By investigating the first step of this activation we have demonstrated in the present work that binding of C1q to schistosomula can occur by two different routes: 1) directly, by specific C1q receptors, and 2) indirectly through the IgG previously attached to Fc receptors present on the parasite surface. Only this second mechanism appears to be involved in CCP activation by schistosomula. Moreover, certain low m.w. schistosome antigens (less than 20,000), which activate CCP, also directly fixed C1q. In this case, IgG are not required for C activation. The presence of receptors for host protein, essentially in 2- to 3-hr-old schistosomula, i.e., the life stage of Schistosoma mansoni that are first in contact with the host, could be the first mechanism by which the schistosomes evade the immune attack.
Macrophage accumulation in mice is inhibited by low molecular weight products from murine leukemia viruses.
Authors: Cianciolo G J , Matthews T J , Bolognesi D P , Snyderman R
Published: December 2022

Low m.w. extracts from three known oncogenic viruses, Friend, Moloney, and Rauscher, inhibited the accumulation of macrophages at sites of delayed inflammatory reactions in mice. The potential biologic significance of these proteins is suggested by their potency: as little as 1.2 ng of viral protein inhibited (p less than 0.02) macrophage accumulation when injected at a site distant to the inflammatory reaction. A virus envelope protein fraction of 15,000 daltons (p15E) was likewise found to inhibit macrophage accumulation and may in part represent the active factor of the virus extracts. Certain oncogenic viruses may thus exert their immunosuppressive activity by release of potent inhibitors of systemic macrophage function.
T cell responses to alloantigens. I. Studies of in vivo and in vitro immunologic memory and suppression by limit dilution analysis.
Authors: Burton R C , Fortin J L , Russell P S
Published: December 2022

A limit dilution technique was used to study the frequency of cytotoxic T cell precursors (f pre Tc) in the peripheral blood lymphocytes (pbl) of naive and alloimunized mice. It was found that alloimmune mice showed a 2- to 5-fold specific increase in the f pre Tc reactive to the immunizing alloantigens. This technique was further adapted for use as a sensitive in vitro assay for alloantigen-specific suppressor T cells. It was found that nonimmunosuppressed B6AF1 mice bearing surviving B10.BR cardiac allografts had circulating alloantigen-specific suppressor cells. In vitro it was shown that the culture of heat-inactivated B10.D2 spleen cells with B6AF1 spleen cells gave rise to alloantigen-specific B6AF1 suppressor cells.
Identification of leukotriene C-1 as a major component of slow-reacting substance from rat mononuclear cells.
Authors: Bach M K , Brashler J R , Hammarström S , Samuelsson B
Published: December 2022

Slow-reacting substance (SRS) was produced by rat peritoneal mononuclear cells after stimulation with the ionophore A23187. The SRS consisted of two main components as judged by high-pressure liquid chromatography (HPLC) on Florisil. The larger and more polar component consisted mainly of leukotriene (LT) C-1 as judged by ultraviolet spectroscopy, mass spectrometry (after desulfurization), amino acid analysis, and conversion by soybean lipoxygenase. Comparisons with authentic LTC-1 showed identity on reverse phase HPLC and guinea pig ileum bioassay. The latter methods are known to distinguish between LTC-1 and stereoisomers of LTC-1.
In vitro actions of glucocorticoids on murine macrophages: effects on glucose transport and metabolism, growth in culture, and protein synthesis.
Authors: Norton J M , Munck A
Published: December 2022

In vitro exposure of homogeneous monolayer cultures of thioglycollate-elicited mouse peritoneal macrophages to glucocorticoid hormones for up to 96 hr produced a progressive, dose-related inhibition of cell growth and protein synthesis. The reductions in cell protein, incorporation of radiolabeled leucine, and intracellular water space were specific to steroids with glucocorticoid action, with half-maximal inhibition occurring at about 10(-9) M for dexamethasone. Similar dose-related, glucocorticoid-specific decreases in net glucose uptake, lactate production, and 14CO2 production were observed that were only partially explained by the decrease in cell mass. A decrease in the monosaccharide transport system Vmax was also noted but could be completely accounted for by the reduction in cell surface area and the resulting proportional loss in transport sites. No effect on transport system affinity could be demonstrated. The suggestion was made that such long-term culture of macrophages in the presence of glucocorticoids reverses the biochemical and functional changes that comprise the "activated" state of mononuclear phagocytes.
Generation of suppressor cells by concanavalin A: a new perspective.
Authors: Fernandez L A , Macsween J M
Published: December 2022

Significantly lower mitogenic responses of fresh cells co-cultured with Con A-stimulated cells were found when compared with the responses of fresh cells co-cultured with preincubated control cells. We do not agree with the interpretation that this effect represents the generation of suppressor cells by Con A, since the responses of fresh cells cultured alone were also significantly less than when co-cultured with control cells and the same as when co-cultured with the Con A-stimulated cells. Treatment with mitomycin C was sufficient to prevent the preincubated cells from contributing to the mitogenic response of the fresh cells. The increased responses of fresh cells when co-cultured with preincubated cells seems analagous to the increased mitogenic responses of cells aged in vitro by preincubation without mitogen. This effect seems to be transferable to fresh cells in the absence of cell division. Although preincubation in the presence of Con A abrogates this effect, we do not interpret this as the generation of suppressor cells.
Multiple CTL subsets generated by H-2.L locus products stimulation: evidence for an antigenic determinant private to H-2.Ld.
Authors: Vazquez A , Senik A , Neauport-Sautes C
Published: December 2022

Analysis of the fine specificity of CTL subpopulations raised by an H-2.L locus products stimulation (H-2dm2 anti-H-2d) was performed by absorption experiments by using monolayers of macrophages of H-2m, H-2q, H-2b, and H-2k haplotypes. The results show the existence of four CTL subsets. The pattern of reactivity of three of them could be correlated with that of antibodies present in H-2dm2 anti-H-2d antisera (anti-H-2.64, anti-H-2.65, and anti-H-2.Kk). The fourth CTL subset reacted with a specificity unique to H-2.Ld molecules (a private specificity?), absent on cells from H-2m, H-2q, H-2b, and H-2k haplotypes, and undescribed as yet by serologic methods. These data support the hypothesis that the H-2.L locus products are comparable in their antigenic properties to those of the H-2.K and H-2.D loci.
Alterations in expression of measles virus polypeptides by antibody: molecular events in antibody-induced antigenic modulation.
Authors: Fujinami R S , Oldstone M B
Published: December 2022

Six hours after measles virus antibodies bind to the surface of HeLa cells acutely infected with measles virus, the expression of an external polypeptide F1, as well as internal polypeptides P and M are altered. The loss of F1 molecules during antibody-induced antigenic modulation explains the lack of cell-cell fusion and giant cell formation of infected cells cultured in the presence of antibody. The decrease in F1, P, and M viral polypeptides is specific, since the effect is only seen with antibodies directed against measles virus antigens expressed on the cell's surface and not with antibodies directed against nonviral antigens expressed on the surfaces of virus-infected cells. Since the P protein or its analog in other viral systems appears to be associated with transcriptive complex whereas the M protein is associated with nucleocapsid recognition and alignment at the plasma membrane, the alterations in these polypeptides might lead to aberrations in measles virus synthesis and maturation that are hallmarks of persistent measles virus infection.
Cell-cell interactions in the T cell proliferative response. I. Analysis of the cell types involved and evidence for nonspecific T cell recruitment.
Authors: Tse H Y , Schwartz R H , Paul W E
Published: December 2022

In the antigen-induced T cell proliferative response, it has been firmly established that antigen-specific T cell activation signals are provided by a specialized antigen-presenting cell (APC). However, the number of responding T cell populations involved has not been clearly delineated. This problem can be analyzed by plotting the logarithm of the number of cultured cells against the logarithm of the response. This yields a straight line, the slope of which indicates the minimum number of interacting cell populations that are required to give the response. In the antigen-induced T cell proliferative response, this number is 3. Based on their ability to shift the slopes of the log cell number-log response line, two of the populations were identified to be T cells. The third cell, which was present in irradiated spleens, possessed certain properties of the APC. Of the two T cells, one was antigen-specific and the other could come from normal unprimed animals. The frequency of antigen-specific proliferating T cells in primed animals was estimated to be only 1 in 1.3 x 10(3), and a large proportion of the proliferation was shown to be due to unprimed cells. Furthermore, without the need to use antigen-pulsed macrophages, this slope analysis demonstrated convincingly that the successful interaction between APCs and proliferating T lymphocytes is determined by products of the I-region immune response genes.
Pathogenesis of virus-induced osteopetrosis in the chicken.
Authors: Smith R E , Ivanyi J
Published: December 2022

Infection of chicken embryos with a nondefective avian leukosis virus MAV-2(0) induced bone hyperplasia and profound suppression of bursal and thymic lymphoid cell development within 2- to 3 weeks after hatching. A time-course study of infectivity during embryonal life showed a gradual loss of susceptibility between the 10th day of incubation and hatching. This finding suggests that an embryonal stem cell either before or early after seeding into the bone and primary lymphoid organs is a virus-susceptible target cell. Histologic observations of the bursa indicated only mild damage during the 1st week and severely impaired proliferation of follicular lymphoid cells during subsequent weeks of development. Thus, viral infection conferred a cytostatic rather than a cytolytic effect upon the lymphoid target cell. Infection of stem cells, which are progenitors of lymphoid cells as well as of bone osteoclasts, is compatible with the manifestations of the disease. A model of cellular disorders of the bone and lymphoid tissues is proposed. Adoptive transfer of lymphoid cells from adult MAV-2(0)-immunized chickens into histocompatible virus-infected juvenile recipients abrogated the manifestation of osteopetrosis. Passive injection of antiserum containing virus-neutralizing antibodies was also effective. Anti-gp85 viral surface glycoprotein-binding antibodies in sera from adoptively protected chickens receiving immune cells were exclusively of cell donor IgG allotype.
Analysis of the primary anti-(4-hydroxy-3-nitrophenyl) acetyl (NP) responsive B cells in BALB/C and B10.D2 mice.
Authors: Stashenko P , Klinman N R
Published: December 2022

The chain composition and fine specificity of the anti-(4-hydroxy-3-nitrophenyl) acetyl (NP) response was examined at the level of individual clones in BALB/c (Ig-1a allotype) and B10.D2 (Ig-1b) mice. The primary anti-NP serum response of B10.D2 is distinguished from that of BALB/c by its restricted heterogeneity and unusual heteroclitic fine specificity, which appear to be associated with antibodies bearing a unique allotype-linked idiotype(s) (NP-b) paired with lambda light (L) chains. At the clonal precursor level, the 10.d2 anti-NP primary response was found to be characterized by less diversity than that of BALB/c and is dominated by several clonotypes with the heteroclitic fine specificity. However, BALB/c also possess abundant heteroclitic precursors (53%), which are expressed but apparently obscured in its more heterogeneous serum response. Heteroclitic fine specificity in both strains is occasionally associated with clones bearing kappa as well as lambda L chains.
Murine lymphocyte alloantigens. I. The Ly-6 locus.
Authors: Potter T A , McKenzie I F , Morgan G M , Cherry M
Published: December 2022

The Ly-6 locus and the Ly-6.2 specificity have been previously described, and we now further define this locus and the allelic specificities, Ly-6.1 and Ly-6.2. Back-cross studies and examination of several recombinant inbred (RI) lines demonstrate that Ly-6 is distinct from other loci determining CMAD, except for ALA-1 and evidence is presented for the identity of Ly-6 and ALA-1. The Ly-6 congenic strain C3H.B6-Ly-6b is described and was used to prepare antisera in combinations congenic for Ly-6. The allelism of the Ly-6.1 and Ly-6.2 specificities was confirmed by the reactivity of these antisera with a segregating F2 generation. Antisera can be prepared between the Ly-6 congenic strains, although the magnitude of the response is under the control of one or more genes in A strain, not linked to H-2 or Ly-4 loci. Absorption analysis using separated T and B lymphocyte populations demonstrate that Ly-6.2 does not have exclusive peripheral T cell representation as originally reported, but is also present on B cells in amounts one-fourth to one-eighth of that found on T cells and is found in greater quantities on T blast cells.
The role of human T cells (and T cell products) for monocyte tissue factor generation.
Authors: Edwards R L , Rickles F R
Published: December 2022

Monocytes generate the procoagulant material tissue factor (TF) when mixed mononuclear cell cultures are stimulated with antigens, mitogens, or bacterial endotoxin in vitro. Optimal monocyte TF production has been shown to require the presence of lymphocytes in the culture system. We have investigated the nature of this lymphocyte requirement by stimulating monocytes grown in the presence of varying numbers of T lymphocytes. In addition, some monocytes were grown in the presence of conditioned media prepared from T lymphocyte cultures. The results of these studies have demonstrated two pathways for monocyte TF generation: a relatively T cell-independent pathway that can be stimulated by endotoxin or PPD and a highly T cell-dependent pathway that can be stimulated by PHA. In addition, the lymphocyte requirement for PHA-induced monocyte TF generation may be replaced by conditioned media from T cell cultures.
Antibodies to double-stranded DNA: purification and characterization of binding specificities.
Authors: Gilliam A C , Lang D , LoSpalluto J J
Published: December 2022

Antibodies to double-stranded DNA are found almost exclusively in serum of patients with the autoimmune disease systemic lupus erythematosus (SLE). Very little is known about the nature of the antibody binding site(s) on DNA. We report here the affinity purification from SLE serum of a group of IgG and IgM antibodies that bind in nitrocellulose filter binding assays to entirely double-stranded radiolabeled DNA devoid of single-stranded regions. We have studied the specificities of these purified antibodies by competition with various unlabeled polynucleotides and have visualized their binding to double-stranded DNA by electron microscopy. From the competition studies we could identify a type of purified antibody that binds only to entirely double-stranded DNA and other types that bind to both double- and single-stranded DNA. We report also that purified antibodies that bind to double-stranded poly d(AT) bind well to single-stranded DNA. They appear to be different from those purified antibodies that bind to native double-stranded DNA; antibodies to poly d(AT) can be shown to bind independently of antibodies to native double-stranded DNA. Our results suggest that a heterogeneous group of antibodies to double-stranded DNA can exist in a single SLE serum.
Antibody-dependent cell-mediated cytolysis (ADCC) with antibody-coated effectors: new methods for enhancing antibody binding and cytolysis.
Authors: Jones J F , Segal D M
Published: December 2022

When P388D1 cells are incubated with anti-TNP IgG antibody and centrifuged through a mixture of dibutylphthalate and bis-(2-ethylhexyl)phthalate (1.5:1), large amounts of antibody remain cell bound for at least 20 hr after washing. Incubating cells with antibody in various concentrations of polyethylene glycol also enhances antibody binding compared with control cells incubated with antibody alone. P388D1 cells coated with anti-TNP antibody are potent killers of TNP-conjugated chicken erythrocytes (not coated with antibody). The cytolytic activity increases in proportion to the amount of antibody bound by the effector cells. Lysis is antibody dependent and hapten inhibitable. When mediated by antibody-coated effectors, lysis is less suceptible to inhibition by aggregated IgG than lysis of antibody-coated cells mediated by untreated effector cells.
Characterization of an auto-rosette inhibitory fraction in mouse serum.
Authors: Hsu K H , Ghanta V K , Duncan L A , Hunt C E , Hiramoto R N
Published: December 2022

Normal mouse sera inhibited auto-erythrocyte rosette formation by mouse thymus cells. Serum inhibitory factor was associated with high density lipoprotein (HDL) isolated from mouse sera with sequential flotation ultra-centrifugation techniques. Other portions of normal mouse sera, i.e., very low density lipoprotein (VLDL), low density lipoprotein (LDL), lipoprotein-free serum, and delipidated HDL had little or no inhibitory activity. A 20-fold purification with 68% recovery of total serum activity was obtained by this isolation procedure. HDL from the serum of BALB/c, C57BL/6, C3H, and NZB/BIN mice inhibited BALB/c auto-rosettes. Inhibition was observed when lymphocytes were preincubated with HDL and then washed before assaying, but there was no inhibition when erythrocytes were pretreated.
Production of lymphocyte-activating factor (Interleukin 1) by macrophages activated with colony-stimulating factors.
Authors: Moore R N , Oppenheim J J , Farrar J J , Carter C S , Waheed A , Shadduck R K
Published: December 2022

Murine peritoneal exudate macrophages incubated with medium conditioned by L929 cells were stimulated to produce lymphocyte-activating factor (LAF, Interleukin 1). This stimulatory activity was partially neutralized by antiserum prepared against partially purified L cell colony-stimulating factor (CSF) and comigrated upon gel filtration with the myeloproliferative activity. LAF-inducing activity of three different L cell CSF preparations, including one purified to homogeneity, was dependent upon the concentration of CSF. A minimum of 1,000 to 3,000 units of CSF activity was required to stimulate macrophagfes to produce LAF. Concanavalin A (Con A) stimulated splenic supernatants also contained CSF and LAF-inducing activities that co-eluted upon gel filtration. LAF-inducing activities co-eluting with the two Con A CSF peaks (apparent m.w. of 25,000 and 35,000) were effective at minimum dilutions containing 1,000 to 3,000 units of CSF activity correlating in potency with L cell-derived CSF. Based on these data, it is proposed that CSF, whether of L cell or lymphoid origin, not only has myeloproliferative activities but also is capable of stimulating macrophages to produce LAF.
Oscillations of IgM antibody affinity at the level of single immunocytes.
Authors: Pini C , Di Felice G , Neri R , Mancini C , Vicari G , Doria G
Published: December 2022

IgM antibody affinity was measured by hemolytic plaque inhibition assays on spleen cells from mice immunized with a single injection of DNP-dextran. Maturation of affinity was found to occur with time after 1 to 1000 microgram of immunogen and to be characterized by rapid oscillations independent from changes inFC number/spleen and in antibody secretion rate. Analysis of affinity heterogeneity showed that such oscillations occur in higher affinity PFC subpopulations. The origin of affinity oscillations was discussed in terms of interactions among antigen and the elements of the immune network.
Putative conformation of mouse Fc gamma-receptor.
Authors: Kahn-Perles B , Sire J , Boned A , Bourgois A
Published: December 2022

Three cell surface molecules (m.w. = 115,000, 90,000, and 70,000) binding to the Fc portion of complexed IgG have been isolated from the murine mastocytoma line P815. Various results suggested that the 90,000 and 70,000 dalton components are generated from the 115,00 dalton molecule by spontaneous proteolytic clevages and release of 23,000 dalton fragments. It was demonstrated that these cleavages occur during cell culture and not when freshly harvested mouse spleen cells are used as an Fc gamma R cell source. The survey of the Fc gamma R molecular forms obtained from P815 and spleen cells together with their reduction products led us to conclude that the mouse Fc gamma-receptor for complexed IgG is a single chain molecule (115,000 daltons) folded into five globular subunits (m.w. eta 23,000) linked by loose connecting regions accessible to proteolytic enzymes. Three of these subunits that compose the 70,000-dalton fragment are linked by di-sulfide bonds. Furthermore, a 140,000-dalton Fc gamma-binding molecule, not identified after cell surface labeling, could be detected after internal labeling. This component could be a cytoplasmic precursor of the Fc gamma R molecule. The structural model we present here might in addition shed some light on the discrepancy that appears through the various biochemical studies performed so far on Fc gamma-receptors.
The presence of two kinds of receptors for IgE on rat mast cells.
Authors: Froese A
Published: December 2022

Receptors for IgE from peritoneal mast cells (RMC) of six strains of rats were studied and compared with those of rat basophilic leukemia cells (RBL). Receptors were isolated from surface iodinated and detergent solubilized cells by means of IgE-Sepharose, IgE and anti-IgE, and a rabbit antiserum specific for the receptors of RBL cells (RAR). Like RBL cells, RMC from all rate strains were shown to be associated with two receptor molecules H and R, having apparent m.w. of about 55,000 and 45,000, respectively. THe presence of both molecules could be clearly demonstrated with RAR. When IgE-Sepharose was used, the presence of H could only be unequivocally shown if large numbers of IgE molecules were bound to the RMC.
Characterization of complement resistance in Escherichia coli conferred by the antibiotic resistance plasmid R100.
Authors: Ogata R T , Levine R P
Published: December 2022

We have examined the effect of the antibiotic resistance plasmid, R100, on the complement (C) mediated killing of Escherichia coli K-12 strains. The viabilities, in dilute normal rabbit serum (NRS), of 5 such strains were compared with the viabilities of the same strains harboring R100. For 1 strain, J6-2, we also measured the effect of R100 on viability in normal human serum (NHS) and in guinea pig serum (GPS); in NRS, NHS,and GPS devoid of classical C pathway activity; and in NHS devoid of alternative pathway activity. Finally, we compared the depletion of individual complement components in sera exposed to J6-2 and J6-2 harboring R100. Our results demonstrate that 1) R100 renders E. coli K-12 resistant to killing by NRS, NHS, and GPS; 2) the level of resistance, which ranges from 30- to 10,000-fold, is strain dependent and serum dependent; 3) R100 inhibits killing by both the classical and alternative C pathway. Resistance appears to involve a disruption on the C pathway subsequent to the activation of C5.
High anti-TNP plaque-forming cell potential of residual mIg+ cells in a T cell population.
Authors: Mond J J , Mage M G , Rothstein T L , Mosier D E , Herrod H , Asofsky R , Paul W E
Published: December 2022

In the course of experiments designed to study the immune response of purified populations of B lymphocytes to thymus-independent (TI) antigens, a variety of cell purification procedures were followed. In using anti-immunoglobulin-coated dishes to separate lymphocytes bearing membrane immunoglobulin (mIg) from mIg- lymphocytes, it was found that the nonadherent fraction, which was predominantly mIg-, complement receptor negative, and nonresponsive to the B cell mitogen lipopolysaccharide, gave very substantial anti-TNP plaque-forming cell responses to 2 TI antigens. These responses could be inhibited by incubation of such cells in the presence of anti-mu and thus appeared to be attributable to mIg+ cells. The evidence suggests the existence of a population of B lymphocytes that constitute a minor component of mIg+ cells having a high potential to make in vitro antibody responses. Users of techniques that utilize anti-Ig as a tool for separating B and T lymphocytes should carefully assess the extent to which residual B lymphocytes in the mIg- population contribute to antibody responses being studied.
Existence of T cells manifesting self-reactivity indistinguishable from alloreactivity.
Authors: Altman A , Katz D H
Published: December 2022

The studies reported here were designed to analyze the phenotypic characteristics of self-reactive T lymphocytes induced in culture by allogeneic effect factor (AEF), as well as the control of their functional activities by the major histocompatibility complex (MHC). Unprimed T cells cultured with AEF in the absence of exogenous stimulating target cells become activated against self-antigens, as evidenced by their ability to manifest two distinct activities. First, such cells could lyse syngeneic target cells. This cytolytic activity was directed against H-2K antigens and was mediated by Lyt-2+ T cells. Second, the AEF-activated T cells could be stimulated in a secondary culture to high levels of proliferative activity by irradiated syngeneic spleen cells. The stimulator cells in this syngeneic mixed lymphocyte reaction (MLR) were found to be Thy-1-negative, Ia-positive splenic adherent cells. Stimulation in the secondary syngeneic MLR was provided by I-region specificities, and the majority of the proliferating cells were Lyt-1+ cells. Finally, AEF-induced T cells were effective in serving as effectors of graft-vs-host reactions in vivo in syngeneic recipients. These results prove that, under appropriate conditions, murine T lymphocytes can display aggressive patterns of self-reactivity that are similar in both quantity and quality to the classical patterns of alloreactivity and may have great significance for our understanding of MHC recognition processes.
Interferon production by human and murine lymphocytes in response to alloantigens.
Authors: Perussia B , Mangoni L , Engers H D , Trinchieri G
Published: December 2022

The production of interferon (IF) by human and mouse lymphocytes sensitized to alloantigens in mixed lymphocyte cultures (MLC) was analyzed. During primary MLC, IF appeared in the culture fluid on day 2 and was maximal on day 5. Based on several biologic criteria, the IF produced is of the "immune" type. When lymphocytes sensitized to alloantigens were reestimulated in vitro, IF was produced within a few hours of culture. In all stimulated cultures, cell proliferation was observed in spite of the high concentrations of IF. The IF-producing cells in human MLC were identified as T lymphocytes lacking the receptor for the Fc fragment of IgG molecules (Fc gamma R(-)). Human MLC supernatants containing immune type IF mediate the enhancement of natural killer (NK) cell activity and protect NK target cells from lysis.
Generation of autoreactive cytotoxic lymphocytes by spontaneously established autologous lymphoblastoid cell line.
Authors: Sumiya M , Kano S , Gonda N , Oshimi K , Takaku F
Published: December 2022

Using spontaneously established autologous and allogeneic LCL as stimulator and target cells, we studied the generation of autoreactive cytotoxic T lymphocytes (CTL) in primary and secondary autologous MLC. In the primary autologous MLC, cytotoxic activity was detected on the 6th day and was found to be specific to autologous LCL. In the secondary autologous MLC, cytotoxic activity was detected earlier on the 3rd day, and was at a higher level than in the case of the primary autologous MLC. This cytotoxic activity was induced in both the primary and the secondary autologous MLC when T lymphocytes were used as responder cells. When autologous LCL-primed lymphocytes were used as responder cells in the secondary MLC, autologous LCL-specific CTL were not only generated by autologous LCL but also by allogeneic LCL, and the autologous LCL-specific CTL induced by allogeneic LCL was thought to be due to the nonspecific helper effect of allogeneic LCL-stimulation.
Effect of thymopoietin pentapeptide (TP5) on autoimmunity. I. TP5 suppression of induced erythrocyte autoantibodies in C3H mice.
Authors: Lau C Y , Freestone J A , Goldstein G
Published: December 2022

C3H mice (young and old), when immunized with the cross-reacting rat erythrocytes, produced erythrocyte autoantibodies that usually persisted for more than 10 weeks. I.P. injection of thymopoietin pentapeptide (TP5) once or thrice weekly accelerated the loss of erythrocyte autoantibodies 7 weeks after immunization; 10 ng of TP5 was the optimal dose. The rat agglutinin responses of these immunized mice were unaffected by TP5 during the whole period of study. Spleen cells from rat erythrocyte-immunized mice, when transferred to syngeneic recipients undergoing similar immunization schedules, delayed the appearance of erythrocyte autoantibodies in the recipients. A greater delay was observed when spleen cells were taken from mice that had also received TP5 treatment.
Analysis of receptor-mediated C1q binding to human peripheral blood mononuclear cells.
Authors: Tenner A J , Cooper N R
Published: December 2022

The binding of C1q to human peripheral blood leukocytes has been investigated. Studies with fluorescein conjugated F(ab')2 anti-C1q show that few (0 to 4%) normal leukocytes isolated in the presence of EDTA have C1q on their surface. However, approximately 26% of the mononuclear cell population is able to bind added C1q. Quantitative binding studies using 125I-C1q show that the binding to mononuclear cells is specific, saturable, and reversible. Scatchard plot analyses indicate an approximate equilibrium constant of 1.2 times 10(7) M-1. C1q binding appears to be mediated via the collagenous portion of the molecule in that 1) type I collagen inhibits this binding; 2) C1 reconstituted from purified C1q, C1r, and C1s does not bind to mononuclear cells, whereas the same amount of free C1q binds avidly; and 3) C1q enhances the binding of aggregated IgG to mononuclear cells.
Purification and physico-chemical characterization of rabbit tumor necrosis factor.
Authors: Ruff M R , Gifford G E
Published: December 2022

Rabbit TNF has been purified 2000-fold by a series of salt precipitations, gel filtrations, ion exchange chromatography, and lectin affinity chromatography to a single species on SDS-polyacrylamide gel electrophoresis (SDS-PAGE). TNF activity could be recovered from nondenaturing gel systems and has been shown to be an alpha-globulin with an isoelectric point of 5.1. The m.w. was estimated to be 68,000 d by SDS-PAGE, 55,000 by gel filtration, and 52,000 by glycerol gradient centrifugation. TNF activity was stable over the pH range of 6 to 10 and was relatively heat stable, not being inactivated at 70 degrees C for 1 hr. TNF activity was pronase sensitive, but relatively trypsin resistant. Neuraminidase and phospholipase C treatment did not destroy TNF activity. Partially purified TNF was still capable of eliciting hemorrhagic necrosis in susceptible tumors. Crude TNF serum had an interferon titer of 3000 U, whereas the partially purified sample had a titer of <30 U.
Regulation of lymphocyte activation: macrophage-dependent suppression of T lymphocyte protein synthesis.
Authors: Varesio L , Holden H T
Published: December 2022

We investigated the influence of macrophages on lymphocyte protein synthesis in C57Bl/6N mice. When activated macrophages recovered from MSV-induced regressing tumors or peritoneal macrophages induced by C. parvum injection were cultured for 6 hr with resting or Concanavalin A-stimulated normal spleen cells, a decrease of protein synthesis was observed. In contrast, peritoneal macrophages induced by injection of light mineral oil or a macrophage cell line, WEHI-3, were completely ineffective. When the mixed cultures of normal spleen cells and macrophages were fractionated, we found that Thy 1.2-positive, nylon-nonadherent cells, but not plastic adherent cells, had a depressed protein synthesis. The suppressor cells, on the contrary, were Thy 1.2 negative, adherent, and phagocytic. We concluded that activated macrophages are able to inhibit T cell protein synthesis. In comparative studies, we found that the macrophage-dependent suppression of protein synthesis correlated with the capacity of the macrophage to suppress production of a lymphokine, migration inhibitory factor, by in vitro stimulated lymphocytes. The possibility that an early block of protein synthesis is one mechanism through which suppressor macrophages inhibit the immune response is discussed.
Genetic control of the immune response to collagen. III. Coordinate restriction of cellular cooperation and antigen responsiveness by thymus-directed maturation.
Authors: Hedrick S M , Watson J
Published: December 2022

The H-2 restriction of T helper cells from thymus-reconstituted nude mice was examined. Hybrid athymic mice were bred from BALB/c.nu and C57BL/6.nu parental strains and reconstituted with fetal thymus tissue from either parental strain. T helper cells from these mice, immunized to SRBC, were restricted to cooperation with B cells of the thymic H-2 haplotype. These T helper cells were shown to have originated from the F1 host by functional sensitivity to antisera and complement. The H-2 restriction of thymus-reconstituted F1 nude mice was further investigated by examining expression of the Ir-collagen phenotype. Results showed that the level of antibody produced in response to type I calf collagen in thymus chimeras correlates with the H-2 haplotype (high responder or low responder) of the reconstituting thymus. These experiments indicate that the thymus environment of T cell maturation influences both the H-2 restriction and Ir-phenotype of a responding immune system.
Mechanism of immune suppression by murine neonatal fluids.
Authors: Suzuki K , Tomasi T B
Published: December 2022

Pretreatment of peritoneal exudate cells (PEC) for 24 to 48 hr with mouse amniotic fluid (MAF) results in a marked reduction in their ability to present antigen in a macrophage-T cell dependent antigen-induced lymphocyte proliferative assay. Since we showed that MAF did not inhibit the uptake of antigen by the antigen-presenting cells, presumably the site of action is either on "processing," T-macrophage interactions and/or on the secretion of soluble factors by macrophages. Whether suppression is the result of a direct effect on MAF on the antigen-presenting cell or indirectly via another cell type present in the PEC preparations was not established by this study. However, our data suggest that a major (although perhaps not sole) site of action of the suppressive factor(s) in MAF is at the level of the antigen-presenting cell. The biologic relevance of these in vitro observations is discussed in regard to the defects of immune function in fetal and neonatal animals.
Immunologic unresponsiveness after gastric administration of human gamma-globulin: antigen requirements and cellular parameters.
Authors: Vives J , Parks D E , Weigle W O
Published: December 2022

Gastric administration of human gamma-globulin (HGG) into adult A/J mice leads to the establishment of an antigen-specific unresponsive state to subsequent parenteral challenge with HGG. An unresponsive state is induced in both helper T and B lymphocyte populations. Unresponsiveness in helper T cells is of longer duration than in B cells, lasting at least 9 wk after intragastric intubation. Adoptive cell transfer of spleen cells from gastrically inoculated mice into healthy irradiated, syngeneic recipients revealed that the unresponsive state is stable upon cell transfer and that suppressor cells are present in the spleens of gastrically tolerized mice. The establishment of HGG-specific unresponsiveness is dependent upon both the dose and the form of the antigen adminstered. Soluble and deaggregated HGG are both more efficient than is heat-aggregated HGG in inducing unresponsiveness gastrically. The administered HGG is rapidly eliminated from the animal and only a small fraction reaches the circulation as immunoreactive protein. Although the cellular parameters of the systemic unresponsiveness induced by intragastric intubation with HGG appear similar to the parameters of parenterally induced unresponsiveness, the precise mechanisms by which gastric unresponsive states are established remain to be resolved.
Molecular relationships between large membrane proteins (LMP) expressed on T and B lymphocytes.
Authors: Dunlap B , Mixter P F , Koller B , Watson A , Widmer M B , Bach F H
Published: December 2022

Clones prepared from day 5 mixed lymphocyte cultures (MLC) were examined for the expression of large (170,000- to 200,000-dalton) membrane proteins (LMP), found on bulk cultures of resting and allogeneically activated T lymphocytes. Sodium dodecyl sulfate-poly-acrylamide gel electrophoresis (SDS-PAGE) of these proteins indicates both bulk populations and noncytotoxic clones express LMP of similar m.w. Peptide mapping further indicates that LMP of 187,000 (187K) and 200K daltons, found on T cells from bulk cultures or clones and the 220K dalton LMP from B cells, all appear to have a very similar peptide composition. This suggests a single protein (or series of closely related proteins) is differentially processed in functionally disparate populations, and hence may serve as a differentiation antigen for these populations.
Effects of metabolic inhibitors on spontaneous and interferon-boosted human natural killer cell activity.
Authors: Ortaldo J R , Phillips W , Wasserman K , Herberman R B
Published: December 2022

Human natural killer (NK) cell activity can be augmented by pretreatment with partially purified preparations of human interferon (IF). Studies have now been performed to determine the metabolic processes required for and involved in spontaneous NK activity and augmentation of cytotoxicity. A 4-hr 51Cr release cellular cytotoxicity assay was used to measure the NK activity, and peripheral blood leukocyte cells (PBL) were treated with: a) x-ray or mitomycin C; b) actinomycin D; or c) emetine, cycloheximide, pactamyhcin, or puromycin to assess the roles of DNA, RNA, and protein synthesis, respectively, in spontaneous NK activity and in boosting by IF. Prolonged incubation (18 hr) of PBL after blockage of synthesis of DNA almost completely abrogated NK activity; however, NK activity could be partially or totally restored to these populations by incubation of the effector cells for 1 hr at 37 degrees C with IF. Blockage of DNA synthesis for 1 hr had no effect on spontaneous NK activity or on boosting by IF. Inhibition of RNA synthesis also had no effect on spontaneous NK activity. Treatment of PBL with actinomycin before exposure to IF prevented boosting, but treatment with the RNA synthesis inhibitor after boosting with IF for 5 to 6 hr no longer had an appreciable effect on cytotoxicity. The effect of protein synthesis inhibitors on spontaneous NK activity was dependent on the inhibitor selected. Emetine and puromycin totally abrogated spontaneous NK activity at concentrations of inhibitor that blocked 3H-leucine incorporation 90% or more. In contrast, cycloheximide and pactamycin had only minimal effects on spontaneous NK activity but totally abrogated the boosting of IF.
Mutual recognition of parental and F1 lymphocytes. II. Analysis of graft-vs-host-induced suppressor cell activity for T cell-mediated lympholysis to trinitrophenyl self and alloantigens.
Authors: Polisson R P , Shearer G M
Published: December 2022

Spleen cells from (C57BL/10 x B10.A)F1 mice that had been injected 2 wk earlier with C57BL/10 (B10) or B10.A parental spleen cells were mixed with spleen cells from untreated F1 mice. The cell mixture was sensitized in vitro to trinitrophenyl-modified syngeneic cells (TNP-self) or alloantigens for a cell-mediated lympholysis (CML) response, and assayed for effector cell activity 5 days later. Cells from B10.A- but not B10-injected F1 spleens suppressed the CML of normal F1 spleens cells. In contrast, strong suppressive activity was obtained from irradiated B10-injected F1 mice. Thus, F1 mice were selectively resistant to GVH-associated immunosuppression induced by B10, but not by B10.A, parental spleen cells, and this F1 resistance mechanism appeared to be radiosensitive. The suppressive activity of spleen cells from irradiated, parental-injected F1 mice could be at least partially accounted for by cytotoxic activity of parental cells directed against alloantigens expressed by the F1. However, suppressor activity in intact parental-injected F1 mice appeared to be due to parental-induced F1 suppressor cells. The results are discussed with respect to: a) the use of this system as a possible model for investigating the selective resistance of F1 mice to parental T cell-induced GVH reactions, and b) the implications involved in the mutual recognition between F1 and parental lymphocytes, which may be relevant for immune surveillance against self-reactive T cell clones.
HLA-DRw alloantigens can be detected on peripheral blood T lymphocytes.
Authors: Mann D L , Sharrow S O
Published: December 2022

Antisera detecting HLA-DRw antigens (human Ia-like) react in cytotoxicity assays with peripheral blood B cells and monocytes but not T lymphocytes. Antisera detecting DRw specificities were used in flow microfluorometry studies to determine whether T lymphocytes express these antigens in quantities not detected by cytotoxicity. Peripheral blood lymphocytes depleted of monocytes were incubated with DRw antisera, reacted with fluoresceinated goat anti-human IgG, and analyzed on the fluorescence-activated cell sorter (FACS). Anti-DRw sera were found to be reactive on all of the lymphocytes as evidenced by a positive fluorescence signal. The reactivity was specific in that only those sera that detected DRw antigens on B cells and monocytes were reactive with the total lymphocyte population from the same donor. Reactivity of the antisera was removed by absorbing the antiserum with monocyte/B cells and T cells from a donor with the same DRw antigen as that found on the target cell of the donor tested. The results demonstrate the presence of DRw antigens on resting peripheral blood T lymphocytes. The implications of quantitative differences in DRw antigen expression on lymphoid cells are discussed.