bluuebunny/crossref_metadata_2025 huggingface dataset:
A Quantitative Fluorometric Assay for Detection and Characterization of Fc Receptors
Authors: Schreiber Alain B. , Hoebeke Johan , Bergman Yehudit , Haimovich Joseph , Strosberg A. Donny
Published: December 2022

A new quantitative fluorometric binding assay that uses fluoresceinated aggregated IgG is proposed for the study of Fc receptors. The method was compared with a radiolabeling binding assay on three well characterized murine cell lines (38C-13, EL4, and BW). The apparent association constant of the binding and the amount of aggregated IgG bound per cell at saturation were calculated. The fluorometric assay enables the detection of 5 × 10-10 M bound aggregated IgG. Inhibition studies with monomeric IgG, reduced and alkylated aggregated IgG, and aggregated F(ab′)2 fragments of IgG confirmed the specificity of the assay. Staphylococcal protein A inhibited the binding of the aggregated IgG to Fc receptors.
IgE-B Cell-Generating Factor from Lymph Node Cells of Rats Infected with Nippostrongylus Brasiliensis
Authors: Urban Joseph F. , Ishizaka Teruko , Ishizaka Kimishige
Published: December 2022

Culture supernatants of mesenteric lymph node cells obtained from Nippostrongylus brasiliensis (Nb)-infected rats have the ability to increase the proportion of IgE-bearing cells in normal bone marrow cell cultures. In order to determine the cell source of the active substance, mesenteric lymph node cells and thoracic duct cells from Nb-infected rats were fractionated by various methods, and culture supernatants of each fraction were examined for the ability to generate IgE-bearing cells in normal bone marrow cell cultures. It was found that culture supernatants of the B cell-enriched fraction were substantially more active than those of the unfractionated cells or T cell-enriched fraction. Residual activity in the culture supernatant of the T cell-enriched fraction was eliminated by prior removal of contaminating immunoglobulin (Ig)-bearing cells in the fraction. The mesenteric lymph node cells depleted of IgE-bearing cells by rosette technique failed to produce IgE-B cell-generating factor. The results indicated that a major source of the soluble factor is IgE-bearing B cells. This conclusion was supported by the fact that treatment of mesenteric lymph node cells with antibodies specific for IgE accelerated the formation of IgE-B cell-generating factor in culture fluids. Formation of IgE-B cell-generating factor in culture fluids. Formation of IgE-B cell-generating factor by the mesenteric lymph node cells was reduced by pretreatment of the cells with pactamycin but not with mitomycin C, indicating that DNA synthesis is not required for the formation of the factor. The appearance of IgE-B cell-generating activity in the culture fluids of mesenteric lymph node cell cultures was inhibited in the presence of dibutyryl cyclic AMP or aminophilline but not by cyclic GMP.
Strain Variations in Murine MIF Production
Authors: Adelman Nancy , Cohen Stanley , Yoshida Takeshi
Published: December 2022

Stimulation of murine lymphocytes with antigen or mitogen in vitro can lead to the production of macrophage migration inhibition factor (MIF). In this study, variations in MIF production were examined in various inbred strains of mice. When BALB/c (H-2d) and AKR (H-2k) splenic lymphocytes were cultured with concanavalin A (Con A) in serum-free medium, good MIF production resulted within 24 to 48 hr. C3H/He (H-2k) cells cultured under identical conditions produced low levels of MIF and DBA-2 (H-2d) and C57BL/6 (H-2b) cells made no MIF response. Interestingly, however, C57BL/6 cells could make a good MIF response when the cell cultures were supplemented with 2% fetal calf serum (FCS) or if FCS was added to the supernatants after incubation. A similar pattern was observed with the cultures stimulated with specific antigen. This pattern of reactivity demonstrates that variation in MIF production is not directly related to differences in the H-2 complex.

The ability of preformed MIF from one strain to react with target cells from different strains was also examined. It was found that MIF produced by Con A-stimulated lymphocytes of a given strain was capable of inhibiting the migration of allogeneic macrophages as effectively as macrophages from the MIF producing strain. Furthermore, immunoadsorption of MIF-active supernatants with alloantisera directed against H-2 regions failed to remove MIF activity. Taken together, these results suggest that MIF activity as well as production are not under direct H-2 control and that the MIF molecule does not share antigenic determinants coded by the murine major histocompatibility complex.
Immunologic Tolerance in the Chicken
Authors: Morgan Edward L. , Rodrick Mary L. , Tempelis Constantine H.
Published: December 2022

Serum from 14-day-old chickens rendered tolerant at hatching with 1250 mg bovine serum albumin (BSA)/KBW was found to suppress an adoptive secondary response to BSA and an in vitro response to sheep red blood cells (SRBC). Chromatographic separation resulted in three fractions: I, II, and III. The suppressive activity was found to be contained in fraction I (m.w. >1 × 106) and fraction III (m.w. <2.5 × 104). Analysis of fraction I by affinity chromatographic techniques revealed that it was composed of soluble BSA-antibody complexes and their removal removed the suppressive activity. Analysis of peak III revealed that the suppressive activity could only be removed by BSA and anti-Line 3 antiserum columns.
The Induction of Macrophage Proliferation in Vitro by a Lymphocyte-Produced Factor
Authors: Hadden John W. , Sadlik John R. , Hadden Elba M.
Published: December 2022

The studies presented indicate that sensitized guinea pig lymph node lymphocytes release on exposure to antigen a soluble mediator of 35 to 70,000 daltons, which induces proliferation of nonimmune oil-induced, monocyte-derived peritoneal and noninduced alveolar macrophages. Cell counts and nuclear labeling experiments indicate that this proliferation can be effectively assayed under conditions of monolayer culture by tritiated thymidine incorporation. The magnitude and the kinetics of the proliferative response of macrophages in this system are dependent upon the concentration and the time of addition of the soluble mediator. Influences that operate to limit proliferation in this system appear to be high macrophage density, the production of prostaglandin by macrophages, and other mediators present in the lymphokine preparation, such as MIF. We have tentatively termed the active soluble mediator macrophage mitogenic factor (MMF); however, its similarity to a fibroblast-produced macrophage growth factor (MGF) might indicate that, like the interferons, a term like Type II MGF would also be appropriate. The biology of this soluble mediator would appear relevant in terms of the marked proliferation and activation of macrophages known to occur during states of intense T lymphocyte-mediated immunity, as occurs during infection with facultative intracellular bacterial pathogens.
Suppressor T Cell Mechanisms in Contact Sensitivity
Authors: Miller Stephen D. , Sy Man-Sun , Claman Henry N.
Published: December 2022

We investigated the mechanism(s) by which MHC-restricted suppressor T cells (Ts) induced by i.v. injection of allogeneic DNP-modified lymphoid cells (alloinduced Ts) suppress the DNFB contact sensitivity response. It was shown that alloinduced Ts acted only during the early phases (afferent limb) of sensitization. They were incapable of suppressing previously sensitized recipients or of inhibiting the expression of DNFB-immune LN cells when co-transferred into normal recipients. The target of alloinduced Ts seems to be cell proliferation, i.e., inhibition of antigen-induced cell proliferation (DNA synthesis) in Ts recipient mice. The failure of recipients of alloinduced Ts to generate DNFB-immune LN cells capable of transferring contact sensitivity to normal recipients also suggests that these Ts act by preventing the development of an expanded clone of mature immune T cells. The suppressive effects of alloinduced Ts also were inhibited by prior in vitro treatment with anti-TNP serum. The data are discussed in terms of current models of suppression, and are compared to mechanisms of suppression in other contact sensitivity models.
The Role of Antibody in Recovery from Experimental Rabies
Authors: Miller Aaron , Morse Herbert C. , Winkelstein Jerry , Nathanson Neal
Published: December 2022

The avirulent high egg passage (HEP) strain of rabies virus produces an inapparent infection limited to the central nervous system (CNS) in intracerebrally inoculated adult mice. Heavy chain isotype (anti-µ antiserum) immunosuppression potentiates the infection, with a mortality of about 60% and with elevated virus titers in the brain. Anti-µ-treated mice fail to raise antibody responses to rabies virus although their T cell function is normal when measured by the concanavalin A response of splenic lymphocytes. This indicates that the B cell response plays an important role in clearance of rabies virus from the neuroparenchyma. Treatment with cyclophosphamide or by adult thymectomy, x-irradiation, and bone marrow reconstitution potentiates HEP infection to a greater extent than does isotype suppression. Since these suppressive techniques impair both T and B lymphocyte responses, the data suggest that cellular immune mechanisms may also contribute to host defenses against this central nervous system (CNS) virus infection.
Studies on the Interaction between Protein A and Immunoglobulin G
Authors: Langone John J. , Boyle Michael D. P. , Borsos Tibor
Published: December 2022

Staphylococcal protein A (PA) and IgG anti-Forssman immunoglobulin formed complexes that behaved functionally like IgM in their ability to lyse sheep erythrocytes (E) in the presence of whole guinea pig complement (GPC) and to fix purified guinea pig C1̄. Concanavalin A, a plant lectin that inhibited IgM but not IgG hemolytic activity, inhibited the hemolytic activity of IgG-protein A complexes that behaved like IgM but had no effect on complexes that behaved functionally like IgG. Since Con A is known to bind specifically to glucose and mannose residues, our results suggested that the interaction of protein A with the Fc region of IgG led to exposure of sugar moieties that may participate in complement (C) binding. The production of IgM-like complexes depended on the ratio of protein A to IgG and the empirical formula of these IgM-like complexes was found to be [(IgG)2PA]n. As the ratio of PA to IgG was increased, the resulting complexes tended to behave functionally like IgG but with reduced hemolytic activity and C1̄ fixing ability. Furthermore, the binding of C1̄ to EIgG was inhibited by PA and the binding of PA to EIgG was inhibited by C1̄ indicating that the binding sites for C1̄ and PA were located near each other or were identical. Our results offer a reasonable explanation for the reported effects of PA or mixtures of PA and IgG in vitro and in vivo.
Studies on the Interaction Between Protein A and Immunoglobulin G
Authors: Langone John J. , Boyle Michael D. P. , Borsos Tibor
Published: December 2022

The interaction between protein A (PA) and IgG immunoglobulin to Forssman antigen in solution results in the production of complexes that behave functionally like IgM in their ability to fix complement (C) and lyse sheep erythrocytes (E). Based on the results of hemolytic experiments carried out with specific anti-Forssman IgG and C, it appears that IgG not directed against the Forssman antigen can participate with specific antibody in the formation of hemolytically active (i.e., C fixing) IgM-like complexes. The ability of PA to increase the amount of 125I-labeled IgG fraction bound to E under the condition of limiting specific antibody supports this finding. Ultracentrifugation experiments carried out in a sucrose gradient and in the presence of either 125I-labeled PA or IgG was used to separate complexes formed between PA and IgG. By use of standards in these experiments, the molecular formula of the IgM-like complex was found to be [(IgG)2PA]2. Depending on the relative amounts of PA and IgG, complexes with molecular formulas corresponding to IgG2-PA and [IgG]3PA2 are also formed. These complexes may also be hemolytically active. The IgM-like complex, isolated by centrifugation is stable in terms of hemolytic activity for at least 96 hr at 4°C and at 37°C for at least 24 hr.

The ability of IgG to behave functionally like IgM in the presence of PA may account for the effects in vitro and in vivo attributed to PA interacting with IgG.
Anti-Tumor Immunity in B Lymphocyte-Deprived Mice
Authors: Brodt Penina , Gordon Julius
Published: December 2022

Immunity to a syngeneic methylcholanthrene-induced tumor was studied in (C57BL/6 × C3H)F1 males, treated continuously from birth with a rabbit anti-mouse IgM serum. Such mice have been shown to be selectively depleted of Ig-bearing lymphocytes and incapable of synthesizing antibodies. In the experiments reported, a heightened resistance of these mice to the syngeneic fibrosarcoma was demonstrated. This resistance was manifest in significantly slower tumor growth at the site of injection, as well as a lower incidence of spontaneous pulmonary metastasis.
Kinetic Assessment of Alternative Complement Pathway Activity in A Hemolytic System
Authors: Polhill Rutherford B. , Pruitt Kenneth M. , Johnston Richard B.
Published: December 2022

Rabbit erythrocytes (RaRBC) can serve as both the initiator and target of alternative pathway activity. We describe here a turbidimetric assay of RaRBC hemolysis that depends on the observation that, within the limits applied, absorbance at 700 nm of an erythrocyte suspension is directly proportional to cell concentration. Absorbance of multiple samples can be measured at frequent short intervals, which permits kinetic analysis. Sera to be studied are chelated with 0.008 M EGTA in the presence of 0.002 M Mg++, which prevents lysis of antibody-coated sheep erythrocytes through the classical pathway, even by concentrated serum. The time required to lyse one-half the RaRBC (t½) is directly proportional to the reciprocal of the serum dilution (1/S). RaRBC lysis by human serum appears to require factor B in that sera heated to 50°C for 30 min to inactivate this protein lost all activity in the assay, and activity could be restored in a dose-response fashion with purified factor B. Sera from two humans with homozygous C2 deficiency and approximately half-normal serum levels of factor B were mildly deficient in the assay; this abnormality could be removed by the addition of purified factor B but not C2. C4-deficient serum functioned normally. Serum from guinea pigs, mice, and chickens also demonstrated alternative pathway activity by this technique. The relationship between t½ and serum dilution can be expressed by a time-dependent von Krogh equation for complement-mediated lysis, which extends the usefulness of the assay in analyzing rate-limiting components of alternative pathway activation. The maximum rate of hemolysis reported for antibody-coated sheep erythrocytes is about 50-fold greater than that calculated by this equation for RaRBC lysis, in agreement with observations in other systems that biologic activity is generated more slowly through the alternative pathway than through the classical pathway.
Characterization of the Effects of Endotoxin on Macrophage Tumor Cell Killing
Authors: Weinberg J. Brice , Chapman Harold A. , Hibbs John B.
Published: December 2022

These studies demonstrate the potent effect of LPS on the induction of macrophage-mediated tumor cell killing and show, by using pure populations of cloned macrophages as effector cells, that LPS can act in the complete absence of contaminating lymphocytes. Macrophage differentiation toward the tumoricidal state parallels the responsiveness of macrophages to LPS. Normal macrophages will not kill even in the presence of 10 µg/ml LPS; peptone-induced normal macrophages (stimulated macrophages) are made tumoricidal by ≥500 mg/ml LPS; and nontumoricidal BCG-activated macrophages are made to kill tumor cells by 0.5 to 1.0 ng/ml LPS. The LPS effect is reproduced by lipid A. The effect is abolished by alkaline treatment of LPS or by the presence of polymyxin B. Nontumoricidal BCG-activated macrophages from the lipid A-nonresponder mouse strain C3H/HeJ require 250 times more LPS to become tumoricidal than do nontumoricidal BCG-activated macrophages from the C3H/HeN strain. LPS acts synergistically with MAF-rich peritoneal cell supernatants in causing macrophages to kill tumor cells. Although LPS can elicit MAF production by lymphocytes, it can also act directly on cells of lymphocyte-free macrophage colonies to render them tumoricidal. Reagents are frequently contaminated with LPS, and unless this is noted, valid interpretation of experiments investigating macrophage tumor cell killing is difficult. Means of detecting, detoxifying, and eliminating the LPS of experimental agents are discussed.
In Vitro Sensitization of Human Lymphocytes Against Histiocytic Lymphoma Cell Lines
Authors: Treves Abraham J. , Heidelberger Ellen , Feldman Michael , Kaplan Henry S.
Published: December 2022

Peripheral blood lymphocytes (PBL) from normal human donors were tested for natural killing (NK) activity and for two types of in vitro induced cytotoxicity against allogeneic diffuse histiocytic lymphoma (DHL) cell lines. Culture-induced cytotoxic (CIC) activity developed in cultures of unseparated PBL incubated in the presence of fetal bovine serum (FBS) but not in the presence of human serum (HS). The CIC mediating effector cells were removed by nylon wool adherence, whereas the NK cells were not. A second type of in vitro induced cytotoxicity was obtained by specific sensitization against DHL cells (SIC). The SIC effector cells were not retained by nylon wool. SIC was manifested after sensitization in medium containing HS but not in FBS-containing medium unless nylon wool adherent cells were removed before sensitization. The lack of SIC in the presence of FBS appeared to be due to nylon wool-adherent suppressor cells. Such suppressor activity was also removed by plastic adherence or elimination of phagocytic cells. CIC and suppressive activity were found to be mediated by different cell populations.
Structural Studies of the Protein Portion of the H-2-Linked Ia Glycoprotein Antigens of the Mouse: Tryptic Peptide Comparison of Products from the I-A and I-C Subregions of B10.HTT
Authors: Freed John H. , David Chella S. , Shreffler Donald C. , Nathenson Stanley G.
Published: December 2022

Ia antigens from the I-A8 and I-Ck subregions of the B10.HTT (H-2t3) strain of mice were isolated by indirect immunoprecipitation of arginine-labeled, nonionic detergent-solubilized materials. After biochemical purification the electrophoretically homogeneous 28,000 dalton glycoprotein β chains from the Ia precipitates were digested with trypsin and the resultant radiolabeled tryptic peptides were compared by analytical ion exchange chromatography. These comparisons reveal that the β chains of Ia antigens from the A (I-A8) and C (I-Ck) subregions of B10.HTT share only two out of 12 to 14 of their arginine tryptic peptides. Thus these noncross-reactive Ia antigens are structurally quite diverse, and would possess sufficient structural variability to account for their lack of antigenic cross-reactivity.
Characterization of the Proteolytic Fragments of Bovine Colostral IgG1
Authors: Wie Siong I. , Dorrington Keith J. , Froese Arnold
Published: December 2022

Bovine colostral IgG1 was subjected to both papain and pepsin hydrolysis. Papain digestion appeared to be optimal at pH 7.4 in the presence of 0.01 M cysteine. The molecule was split at the COOH-terminal side of the interchain disulfide bond(s), and in addition to Fab fragments, two Fc fragments, designated Fc(I) and Fc(II), were obtained. Both Fc fragments had an identical NH2-terminal sequence, but differed in m. w. by about 10,000, with Fc(II) being the smaller one. Differences were also observed in their circular dichroism (CD) spectra and in their susceptibility to carboxypeptidase hydrolysis. These results suggested that the distinguishing characteristics of the two Fc fragments resided in the COOH-terminal parts of the molecules. Pepsin hydrolysis yielded the expected F(ab′)2 and pFc′ fragments. This hydrolysis was found to be dependent upon substrate concentration leading to aggregate formation at IgG1 concentrations below 3%.
Cytotoxic T Lymphocytes to Murine Plasmacytoma Cells in Allogeneic and Syngeneic Mice: H-2 Antigens Are Essential in the Induction and Effector Stages of Ctl
Authors: Kaneko Yukio , Natsuume-Sakai Shunnosuke , Migita Shunsuke
Published: December 2022

T cell-mediated cytotoxicity and transplantation immunity to immunoglobulin-producing and nonproducing mouse plasmacytoma cells have been investigated in allogeneic and syngeneic mice. By using the 51Cr-release assay it was found that cytotoxic activity was developed in vitro by culturing C57BL/6 spleen cells with immunoglobulin-producing plasmacytoma MOPC 11 (producer) cells that were susceptible to lysis by C57BL/6 anti-BALB/c cytotoxic T lymphocytes (CTL). In contrast, CTL were not induced when C57BL/6 spleen cells were cultured in vitro with immunoglobulin-nonproducing variant cells of MOPC 11 (nonproducer) that contained fewer H-2 antigens as revealed by the cytotoxic responses and cold inhibition tests of C57BL/6 anti-BALB/c CTL. MOPC 11 producer cells, when injected i.p. into C57BL/6 mice, were completely rejected, but the tumor was developed in C57BL/6 mice that had been previously inoculated with MOPC 11 nonproducer cells. When spleen cells from BALB/c mice that had been sensitized in vivo with MOPC 11 producer cells were restimulated in vitro with MOPC 11 producer cells, CTL could be generated to the tumor-associated antigens (TAA) of MOPC 11 producer cells.

No syngeneic CTL were induced against MOPC 11 nonproducer cells. Transplantation analyses showed that, although the anti-tumor immunity against MOPC 11 producer cells was observed when BALB/c mice were primed with MOPC 11 producer cells, MOPC 11 nonproducer cells failed to prime BALB/c mice either to MOPC 11 producer or nonproducer cells. The cytotoxic activity of syngeneic CTL generated against MOPC 11 producer cells was significantly inhibited by anti-H-2d serum, suggesting the involvement of H-2 antigens on the membrane of MOPC 11 producer cells in lysis by anti-TAA CTL. These findings, therefore, indicate: 1) H-2 antigens and TAA present on plasmacytoma cells are essential in the induction and effector stages of CTL and 2) H-2 restriction of CTL exists also in plasmacytoma systems.
Participation of the Humoral Immune System in the Myeloma-Specific Transplantation Resistance
Authors: Bridges Sandra H.
Published: December 2022

Studies are reported that examine the participation of humoral and cellular responses in the myeloma-specific transplantation resistance induced by preimmunization of BALB/c mice with purified myeloma protein M315. A plasmacytoma spleen colony-forming assay was used to provide a quantitative estimate of the tumor immunity in recipients of unfractionated spleen cells or serum from mice immunized four to seven times with M315. The primary findings were: 1) that the tumor immunity can be transferred by immune spleen cells provided that a boost of M315 is given to adoptive hosts, and 2) that passively transferred serum containing anti-M315 idiotype antibody (a-Id315) can also inhibit tumor growth. Adoptive transfer was successful in the presence of minute amounts of a-Id315, whereas passive transfer required relatively large amounts of activity. The passive transfer experiments involved an extended injection schedule and thus could not discriminate between direct effects of antibody or idiotype-specific humoral substances on tumor cells or inductive effects on the cellular immune system. Experiments examining the properties of the immune elements involved in the transplantation immunity demonstrated that, once established, they are resistant to acute radiation (to 800 R) and cortisone damage.
The C5b-6 Complex: Reaction with C7, C8, C9
Authors: Podack Eckhard R. , Biesecker Gregory , Kolb William P. , Müller-Eberhard Hans J.
Published: December 2022

The reaction of purified C5b-6 with purified C7, C8, and C9 was studied in cellfree solution. C5b-6 binds C7, C8, and C9 in a sequential manner and thereby forms hemolytically inactive complexes. Calculations of molar ratios indicate the binding of multiple C9 molecules per C5b-8 complex, which contains equimolar amounts of C5b, C6, C7, and C8.

The dissociation constants for the terminal components were calculated from Scatchard plots: KD (C7) = 0.2 to 2.9 × 10-12 M, KD (C8) = 0.9 to 8.6 × 10-12 M, and KD (C9) = 0.1 to 0.5 × 10-12 M. The free energy for C5b-9 formation from C5b-6, C7, C8, and C9 is estimated to be -50 kcal/mole.

Inactivation of C5b-6 by C7 is a rapid, time and temperature dependent process following second order kinetics. Complex formation at 37°C is diffusion controlled; at 4°C it is, in addition, controlled by activation energy requirement since the activation energy for complex formation was found to be 33.7 kcal/mole. Association of C5b-6 and C7 results in the formation of a labile membrance binding site, C5b-7*, which decays rapidly to yield C5b-7i. C5b-7 formation from its precursors C5b-6 and C7 is the rate limiting step, decay of C5b-7* to C5b-7i is rapid compared to the association reaction.

The following thermodynamic parameters were obtained at 30°C for the C5b-7i formation from C5b-6 and C7: ΔG = -17 kcal/mole, ΔH = +8.6 kcal/mole and ΔS = 77 e.u. The data are compatible with the interpretation that the protein-protein interactions occurring upon complex formation are accompanied by release of protein bound water or by conformational changes or both. C5b-7 formation results in acquisition of a labile binding site, a markedly anodal electrophoretic mobility, expression of a second neoantigen, and in aggregation in the absence of cells or the S-protein.
Genetic Polymorphism of Murine C3 Controlled by a Single Co-Dominant Locus on Chromosome 17
Authors: Natsuume-Sakai Shunnosuke , Hayakawa Jun-Ichiro , Takahashi Morinobu
Published: December 2022

Genetic polymorphism of murine C3 was demonstrated by a combined use of isoelectric focusing (IEF) in thin layer polyacrylamide gel and immunofixation. All 18 inbred strains, which were originally derived from the United States, showed a single C3 band of pI 6.1. In contrast, two strains (NC and NBr) derived from the Japanese fancy mouse and a strain (MoA), which was established from Japanese wild mouse (Mus musculus molossinus), showed a single but more anodal C3 band of pI 6.0. A mixture of plasma from two different strains, one from the Japanese mouse and another from the mouse of American origin, resulted in two discrete C3 bands; neither of these two bands can be distinguished from the C3 band observed in one of the unmixed plasmas. Breeding experiments established that the pI variation of mouse C3 is inherited as an autosomal co-dominant trait controlled by a single locus. Thus, the C3 gene segregated in the classical Mendelian ratio among second generation progeny from a cross between NC and one of the American strains, B10, BALB/c, or CBA. The locus controlling the pI variation of murine C3 was designated as C3-1 locus and its linkage with other genetic markers was studied. The C3-1 locus segregated relative to Albino, Agouti, Brown, Es-1, HC, and Id-1. However, the linkage of the C3-1 locus to two loci, Ce-2 and the S region of the H-2 complex was observed. Both of these two loci are localized to chromosome 17. The distances of the C3-1 locus from Ce-2 and S were estimated as 23 and 11 centimorgans, respectively. These values imply that the C3-1 locus is located outside H-2 of the chromosome 17.
Binding of IgG and Papain-Derived Fragments to Fc Receptors of the Fetal Rabbit Yolk Sac Membrane
Authors: Tsay David D. , Schlamowitz Max
Published: December 2022

Quantitative measurements of the in vitro binding of 125I-labeled rabbit IgG (IgGR), and its Fab-1, Fab-2, and Fc fragments to receptors on the fetal rabbit yolk sac membrane (YSM) were carried out by incubating equimolar solutions (1 × 10-5 M) of IgGR and of each of its fragments with formalin-fixed discs (3.5 cm2) of the YSM. It was found that 97, 4, 2, and 96 pmoles of IgGR, Fab-1, Fab-2, and Fc, respectively, were bound per YSM disc. Since the binding characteristics of intact IgGR were fully conserved in the Fc piece, the results establish that the YSM receptor for IgG is an Fc receptor. It was also shown that whereas IgGR retained its binding ability after exposure to stress (55°C, 10 min), free Fc did not. These findings, together with knowledge of the IgG structure, imply that the YSM receptor recognition unit of IgGR resides in the CH2 domain of its Fc piece.
Cell-Mediated Cytotoxicity Against Virus-Infected Target Cells in Humans
Authors: Santoli Daniela , Trinchieri Giorgio , Koprowski Hilary
Published: December 2022

The mechanisms by which human lymphocytes lyse virus-infected allogeneic fibroblast cultures were analyzed with particular consideration of the role of antiviral antibodies and interferon. Human cells infected with viruses were able to induce high levels of interferon upon contact with human lymphocytes. Interferon, whether produced by lymphocytes after direct infection with virus or induced upon exposure of lymphocytes to virus-infected fibroblasts, appeared to be responsible for enhancing the cytotoxic efficiency of the natural killer cell against the infected target. Activation of cytotoxic lymphocytes occurred as early as 6 hr after addition of interferon and increased up to 24 hr. Antibody-dependent cell-mediated cytotoxicity (Ab-CMC) could be easily induced by sensitization of infected target cells with antiviral antibodies and could be detected at 4 hr from the beginning of the cytotoxic test, before the effect of interferon on the natural killer cell was evident. However, the antibody-dependent effector cell was inactive after 4 hr of incubation. F(ab′)2 fragments of rabbit antihuman IgG completely inhibited Ab-CMC but did not at all affect the spontaneous cytotoxic activity of the effector cells against virus-infected target.
Human Monocyte Cytotoxicity to Tumor Cells
Authors: Shaw George M. , Levy Paul C. , Lobuglio Albert F.
Published: December 2022

Recent investigations examining mononuclear cell antibody-dependent cell-mediated cytotoxicity against tumor cell lines suggest that K lymphocytes and not monocytes are active in this cytotoxic reaction. We have found, however, that in an allogeneic assay system, human monocyte monolayers as well as lymphocytes mediate substantial lysis of 51Cr-labeled antibody-coated CEM lymphoblast tumor cells. This cytotoxicity is temperature-dependent and rapid, with most 51Cr release occurring in the first 4 hr of co-incubation. Interaction between target cell-bound antibody and the monocyte Fc receptor is necessary as demonstrated by the marked fall in antibody-dependent cell-mediated cytotoxicity (ADCC) produced by staphylococcal protein A, high concentrations of nonspecific immunoglobulin, and dilution of the target cell antiserum. Morphologic and functional characteristics of the monocyte-monolayer preparations establish their relative purity (>95%) and indicate that monocytes and not contaminating lymphocytes are responsible for tumor cell lysis. Furthermore, preincubation of monocyte and lymphocyte preparations with latex particles or low concentrations of immunoglobulin distinguished monocyte from lymphocyte ADCC. Thus, normal human monocytes have the capacity to carry out antibody-dependent cytotoxicity against nucleated malignant target cells.
Serologic and Immunochemical Characterization of HLA-A9 Xenoantisera
Authors: Allison James P. , Belvedere Mariaclara , Reisfeld Ralph A. , Pellegrino Michele A. , Ferrone Soldano
Published: December 2022

The specificity of A9 antiserum produced in rabbits immunized with high density lipoprotein-associated HLA-A9 from serum was investigated by using serologic and immunochemical approaches. After suitable absorption, the xenoantiserum No. 2958 is monospecific for A9 antigens in direct cytotoxic test. Data from lysostrip experiments and from blocking of cytotoxicity with Fab2 fragments indicate that the A9 xenoantiserum No. 2958 react with the same or closely associated antigenic structures recognized by A9 alloantisera. Immunoprecipitates obtained with the specific xenoantiserum No. 2958 and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis contained only proteins of the size of detergent-solubilized HLA and β2-microglobulin (45,000 and 12,000 m.w.). Immunodepletion experiments indicated that the precipitation was mediated by antibodies directed to the heavy chain, and not the light chain of the complex. These reaults indicate that monospecific HLA-A9 xenoantisera have the same discriminatory capacity of alloantisera and can be useful for the serologic and immunochemical characterization of HLA antigens.
Theory of Equilibrium Binding of Asymmetric Bivalent Haptens to Cell Surface Antibody: Application to Histamine Release from Basophils
Authors: Wofsy Carla , Goldstein Byron , Dembo Micah
Published: December 2022

We present a theory of the reversible binding of asymmetric bivalent haptens to cell surface antibody in the presence or absence of monovalent hapten. Bivalent haptens can link together bivalent antibodies to form linear chains or rings on cell surfaces. We show how to calculate the amount of any possible complex of bound bivalent hapten, monovalent hapten, and antibody.

We first treat the mixed hapten case, when the bivalent hapten is made up of two noncross-reacting haptenic groups, and the basophil has on its surface antibody against both haptenic groups. We further restrict our considerations to the situation where both antibody populations are homogeneous. For this case we show that the fraction of antibody on the cell surface that is involved in complexes of two more antibodies, i.e., the fraction of antibody which is cross-linked, possesses a number of general properties.

We use these theoretical results to interpret the experiments of Siraganian et al., (2) who, with the mixed hapten BPO-NH-(CH2)6-NH-DNP, studied the in vitro histamine release of basophils from allergic rabbits. We conclude that in these experiments the histamine release curves follow the cross-linking curves, i.e., the histamine release curves rise when cross-links are predicted to rise, are a maximum when cross-links are predicted to be a maximum, and fall when cross-links are predicted to fall.

We also treat the case, illustrated by DNP2-lysine, where the two haptenic groups have different affinities for a single homogeneous antibody population on the cell surface. Again we show that the fraction of antibody which is cross-linked possesses a number of general properties.
Serum from Lps Nonresponder C3H/HeJ Mice Does Not Support the Formation of Functional Eac Reagents
Authors: Hoffmann Michael K.
Published: December 2022

Serum from C3H/HeJ mice in contrast to serum from other mouse strains does not convert EA into EAC. A factor in supportive serum permits nonsupportive C3H/HeJ serum to produce a functional EAC-rosetting reagent. This factor is heat stable. Its concentration in serum parallels the sensitivity of mice to LPS. It is absent or inoperative when sensitivity is reduced on a genetic basis and increased when sensitivity is increased by treatment with BCG.
Activation of Distinct Helper and Suppressor T Cells in Experimental Trypanosomiasis
Authors: Jayawardena Anil N. , Waksman Byron H. , Eardley Diane D.
Published: December 2022

Spleen cells taken from mice soon after infection with Trypanosoma brucei S 42 enhance the primary in vitro antibody response of normal spleen cells to sheep red blood cells (SRBC), but do not affect their response to DNP-Ficoll. Spleen cells harvested later in the infection (day 6 onwards) suppress the antibody response of normal spleen cells to both SRBC and DNP-Ficoll. The enhancing and suppressive effects of “infected” spleen cells are sensitive to treatment with anti-Thy 1.2 antiserum and complement, and can be mediated by nylon wool-purified populations of T cells. The enhancing T cell is sensitive to ALS, not lost within 4 weeks of adult thymectomy, and bears the Ly-1+, 23- phenotype. The suppressor T cell is insensitive to ALS, lost within 20 weeks of adult thymectomy, and bears the Ly-1+, 23+ phenotype. The significance of the activation of distinct helper and suppressor T cells is discussed in relation to the pathogenesis of trypanosomiasis.
Immunity to Plasmodium Berghei Yoelii in Mice
Authors: Weinbaum Fredric I. , Weintraub Jonathan , Nkrumah Francis K. , Evans Charles B. , Tigelaar Robert E. , Rosenberg Yvonne J.
Published: December 2022

The kinetics of various specific and nonspecific immunologic responses were examined in BALB/c mice infected with 17X nonlethal Plasmodium berghei yoelii (a self-limiting infection). The sequence of events after infection was characterized by rapid sensitization of splenic T cells to malaria antigen and polyclonal B cell activation, followed by a period of depressed splenic proliferative responses in vitro to mitogens (PHA and LPS) and malaria (specific) antigen. At the same time, suppressed primary in vitro splenic PFC responses to trinitrophenyl-aminoethylcarbamylmethyl-Ficoll (TNP-F) were seen. This suppression was an active process requiring adherent cells. During this period, levels of antimalarial antibody also increased exponentially. As the infection was cleared, splenic malaria antigen-specific proliferative responses were again observed and splenic PFC and in vitro mitogen responses returned to preinfection levels after variable periods of time. Both splenic proliferative responses to malaria antigen and antimalarial antibody responses remained persistently elevated.

In addition, some responses were examined in mice infected with 17X lethal P. b. Yoelii (a fatal infection); in comparison to the early responses of mice infected with the nonlethal substrain, there was a decrease and delay in the development of a splenic T cell response to malaria antigen and a blunted antimalarial antibody response.
Murine B Cell Leukemia Line with Inducible Surface Immunoglobulin Expression
Authors: Paige Christopher J. , Kincade Paul W. , Ralph Peter
Published: December 2022

A chemically induced leukemia of BDF1 mice, designated 70Z/3, was adapted to tissue culture in our laboratory. A minority of these cells displayed surface immunoglobulin (sIg) as detected by immunofluorescence with rhodamine-labeled class (IgM)-specific antibodies. Addition of the B cell mitogen, LPS, to the cultures induced sIg expression on all of these cells. The kinetics of this transition were dependent on the dose of LPS. As little as 0.1 µg/ml induced sIg on >97% of the cells within 36 hr. DxS also induced sIg whereas other mitogens (Con A, PPD) or inducing agents (DMSO, dimethyl formamide, butyric acid), tested over a wide range of concentrations, failed to induce sIg expression.

The cells bear H-2 antigens but lack IgD, IgG, IgA, Ia, and Thy 1.2. Exposure to LPS had no effect on the presence or absence of these structures. A small percentage of cells possessed receptors for complement and for the Fc portion of immunoglobulin. Cytoplasmic IgM was detectable within all of the cells, and constitutive production of small quantities of IgM was confirmed by SDS-polyacrylamide gel electrophoresis of serologic precipitates of cell lysates after pulsing with radioactive amino acids. Using similar methods, we failed to detect active secretion of immunoglobulin.

Thus, this cell line has properties similar to cytoplasmic Ig+, surface Ig- cells found in immature tissues and in bone marrow of mice and humans that are thought to be immediate precursors of sIg+ B lymphocytes. It may provide a model for studying the mechanism of LPS activation and the molecular events associated with externalization of cell surface receptors.
A Model for the Autosensitization Autoantibody Production Associated with Xenogeneic Thymic Rna
Authors: Nakamura Kunie , Nakamura Yoshiko , Kawahara Makoto
Published: December 2022

Normal C57BL/6 bone marrow cells cultured for 3 weeks with xenogeneic thymic RNA and syngeneic C57BL/6 antigens (immunoglobulin G or red blood cells) produced anti-immunoglobulin antibody or anti-mouse red blood cell antibody (hemolysin). Addition of both xenogeneic thymic RNA and autoantigens to bone marrow cultures was necessary to elicit autosensitization. Syngeneic thymic RNA would not substitute for xenogeneic RNA.

Normal recipients inoculated with syngeneic kidney or spinal cord homogenates and xenogeneic thymic RNA developed albuminuria or motor neuropathies within 10 days. Histologic examination of tissues from these animals revealed immunoglobulin deposits on glomerular or tubular basement membranes or on myelin sheaths. These changes were not observed in tissues from control animals inoculated with only the organ homogenates.

Normal mice injected with syngeneic bone marrow cells, which had been autosensitized in vitro against kidney or spinal cord homogenates, also developed albuminuria or motor neuropathies, respectively. These abnormalities were observed only if bone marrow cells had been cultured with both xenogeneic thymic RNA and autoantigens. Histologic examination of tissues from these mice also revealed immunoglobulin deposits in kidney or spinal cord tissues. These results demonstrate that xenogeneic thymic RNA can play important roles in the formation of autoantibodies.
A Comparison of the Effects of T and Macrophage-Like Suppressor Cells on Memory Cell Differentiation in Vitro
Authors: Klimpel Gary R. , Henney Christopher S.
Published: December 2022

An adherent, phagocytic, non-T cell present in the spleen of BCG infected animals was found capable of inhibiting both primary and secondary cytotoxic responses to alloantigen in vitro. BCG-spleen cells were compared to suppressor T cell populations induced either by culturing spleen cells in 10% fetal calf serum for periods up to 5 days or by stimulation of splenocytes for 48 hr with 5 µg/ml Con A. These comparative studies revealed that i) all suppressor cell populations were less effective at inhibiting secondary cytotoxic responses than they were at suppressing primary responses. ii) BCG-induced suppressor macrophages were as effective on a spleen cell basis as Con A-induced suppressor T cells. Both of these populations were superior to suppressor T cells induced by culture in the absence of added mitogen, which had little or no effect on secondary responses.

More importantly, both BCG and Con A-induced suppressor cells were capable of inhibiting the development of cytotoxic cells in cultures containing mitomycin C-treated “memory” cells. Thus, these suppressor cells can prevent nonproliferative events associated with cytotoxic T cell differentiation. It is therefore conceivable that the widely reported anti-proliferative action of suppressor cells is a secondary effect, resulting from suppression of a differentiative event that precedes cell proliferation.
Immunoglobulin-Independent Natural Cytotoxicity of Fc Receptor-Bearing Human Blood Lymphocytes to Mumps Virus-Infected Target Cells
Authors: Härfast Bengt , Andersson Torbjörn , Perlmann Peter
Published: December 2022

The natural cytotoxicity of peripheral blood lymphocytes (PBL) from healthy human donors to mumps virusinfected target cells was studied by a 51Cr-release assay. Neuraminidase-treated PBL were fractionated on columns charged with Helix pomatia A-hemagglutinin (HP) coupled to Sepharose. Cytotoxicity was found both in the fraction depleted of lymphocytes with HP receptors (HP+) but enriched in B and null cells and in two fractions containing HP+ cells, mainly considered to be T cells. The cytotoxic activity of the three fractions was well correlated with their content of lymphocytes with Fc receptors for IgG (FcR+). That FcR+ lymphocytes were indeed the effector cells in this system was further shown by fractionating the lymphocytes through columns charged with immune complexes (ovalbumin/rabbit anti-ovalbumin). Those columns that depleted the passed cell preparation of FcR+ cells also efficiently reduced cytotoxicity to the virus-infected target cells. In contrast, columns that were charged with F(ab′)2 fragments of rabbit anti-immunoglobulin and that completely removed sIg+ B cells did not significantly affect cytotoxicity. Taken together, the results indicate that the effector cells in this system are FcR+ sIg- cells and that a significant fraction of them appear to be T cells. However, some effector cells may lack T cell markers and may be null cells. This surface marker profile is very similar to that of antibody-dependent K cells as well as to that of lymphocytes displaying natural cytotoxicity to uninfected target cells (NK). We have previously shown that human NK cytotoxicity to uninfected target cells is frequently immunoglobulin dependent since it is strongly inhibited by addition of Fab fragments of purified rabbit antibodies to human immunoglobulin. Using this procedure we found that the natural cytotoxicity against the virus-infected target cells was not inhibited by Fab anti-immunoglobulin. In contrast, the strongly enhanced cytotoxicity obtained by inclusion in the experiment of a human anti-mumps serum was abolished. These results indicate that the eleyated natural cytotoxicity to mumps virus-infected target cells by lymphocytes from healthy donors is antibody independent, reflecting a virus-dependent but immunologically nonspecific activation of effector cells.
Fc-Receptors for IgG and IgM Immunoglobulins on Human T Lymphocytes: Mode of Re-Expression after Proteolysis or Interaction with Immune Complexes
Authors: Mingari Maria Cristina , Moretta Lorenzo , Moretta Alessandro , Ferrarini Manlio , Preud'Homme Jean Louis
Published: December 2022

The susceptibility to proteolysis and the mode of reexpression of receptors for IgM or IgG present on two different subpopulations of human T lymphocytes (T.M and T.G cells, respectively) have been investigated. The IgM receptor was highly susceptible to both trypsin and pronase, whereas the IgG receptor was resistant to trypsin and sensitive only to high concentrations of pronase.

The receptors have been removed by treating purified human T cells with pronase and their reappearance on the cell surface has been followed in vitro. The IgM receptors on the cell surface were detectable within 2 hr and the resynthesis was completed in 6 hr. IgG receptors were detectable in 4 to 6 hr and the resynthesis completed within 12 hr. When protein synthesis was inhibited by culturing the cells in the presence of cycloheximide for up to 12 hr, only the IgM receptor (which had a higher turnover rate) failed to be expressed. Whereas interaction of IgG immune complex with the IgG receptors was previously shown to induce a modulation of the receptors, contact with antigen-IgM antibody complexes did not alter the mode of expression of IgM receptors.
Activation of A Human T Cell Subpopulation Bearing Receptors for Autologous Erythrocytes by Concanavalin A
Authors: Fournier Catherine , Charreire Jeannine
Published: December 2022

Human lymphocytes from different lymphoid organs were examined for rosette formation with autologous erythrocytes. The autorosette-forming cells (A-RFC) were shown to belong to a T cell subset including less mature lymphocytes. When normal human peripheral blood lymphocytes were stimulated with how doses of the plant lectin concanavalin A (Con A), in the presence of autologous plasma, the A-RFC levels were strongly enhanced. This response gave rise to two peaks: the first one coincided with the peak of thymidine incorporation but the maximum increase occurred 5 or 6 days later when the proliferative response was impaired. Depletion of A-RFC before stimulation with Con A led to a clearcut decrease in autorosette levels at both peaks of the response. It is concluded that Con A, generally used for polyclonal activation against heteroantigens, may also result, in terms of A-RFC marker, in expansion of an autoreactive T cell population.