bluuebunny/crossref_metadata_2025 huggingface dataset:
Antibody-induced redistribution of Heymann antigen on the surface of cultured glomerular visceral epithelial cells: possible role in the pathogenesis of Heymann glomerulonephritis.
Authors: Camussi G , Brentjens J R , Noble B , Kerjaschki D , Malavasi F , Roholt O A , Farquhar M G , Andres G
Published: December 2022

In this study we analyze the ability of antibodies that produce passive Heymann glomerulonephritis to induce antigen redistribution on the surface of cultured glomerular visceral epithelial cells (GEC). Polyclonal antibodies produced by immunization with membrane vesicles prepared from proximal tubule brush borders (BB) and polyclonal (rabbit) and monoclonal (mouse) antibodies to a membrane glycoprotein (gp 330) purified from epithelial cells of rat proximal tubule were used. The study by immunofluorescence of GEC kept at 4 degrees C or fixed with paraformaldehyde showed that the three antibody preparations reacted with the plasma membrane in a punctate pattern known to be due to staining of coated pits or coated vesicles on the cell surface. At 37 degrees C and, at a slower rate, at 22 degrees C, the two polyclonal antibodies induced a rapid clustering of antigen-antibody complexes on the nonadherent surface of living cultured GEC with subsequent formation of patches and caps and, after prolonged incubation, with temporary disappearance of Heymann antigen from the cell surface, so-called antigenic modulation. Antigen redistribution and modulation were inhibited by sodium azide, indicating that these processes are energy dependent. Monovalent Fab fragments of antibodies to BB vesicles did not alter the distribution of Heymann antigen unless they were subsequently cross-linked. Monoclonal anti-gp330 induced a modest degree of antigen redistribution, which was increased by subsequent cross-linking. Exposure of glomerular epithelial cells to cytochalasin B, colchicine, or ionophore A23187 prevented or altered antigen redistribution at 37 degrees C. Furthermore, the antibody-induced antigen redistribution was associated with changes in distribution of cytoplasmic actin, myosin, and tubulin, indicating that it is related to the contractile activity GEC. LEW rats, given i.v. injection of IgG directed against BB membrane vesicles, developed passive Heymann glomerulonephritis (i.e., immune deposits in the lamina rara externa of the glomerular basement membrane). In contrast, the glomeruli of rats exposed for longer periods to larger amounts of Fab fragments of the same antibodies failed to develop immune deposits. These studies show that the antibodies to the nephritogenic antigen of Heymann glomerulonephritis may induce a redistribution of immune complexes (IC) in the membrane of glomerular epithelial cells that is similar to that produced by other plasma membrane antigen-ligand interactions.(ABSTRACT TRUNCATED AT 400 WORDS)
Modulation of c-myb transcription in autoimmune disease by cyclophosphamide.
Authors: Mountz J D , Mushinski J F , Smith H R , Klinman D M , Steinberg A D
Published: December 2022

This study explores the relationship between autoimmunity and the myb proto-oncogene, a gene important for T cell development. The lpr/lpr mice had very large amounts of myb RNA in the lymph node (LN) cells; but unexpectedly, they had abnormally low levels of myb RNA in the thymus, an organ normally rich in myb RNA. Mice with the gld/gld genotype had high myb RNA levels in peripheral LN, similar to lpr/lpr mice, but had normal thymic myb RNA levels. Both lpr/lpr and gld/gld mice and an AILD patient with lymphadenopathy and high myb RNA in peripheral blood cells were treated with cyclophosphamide (CY). In all cases, the CY eliminated the lymphadenopathy and corrected the abnormal myb expression. However, there were significant differences in the clinical and cellular responses to this drug. A single large dose of CY led to marked regression of the lymphadenopathy of gld/gld mice and long-term amelioration of their autoimmune syndrome. In contrast, similar treatment of lpr/lpr mice failed to alter either the lymphadenopathy or the disease process. Consistent with these clinical findings, LN myb was normalized in gld/gld mice by a single injection of CY, whereas there was no effect on myb expression in lpr/lpr mice. The AILD patient reacted much like the gld/gld mice in that myb RNA levels in the peripheral blood, and bone marrow returned to normal after only three doses of CY. The lymphadenopathy and high levels of LN myb mRNA of the lpr/lpr mice could be normalized; this occurred only after long-term treatment with CY. These events were accompanied by an increase in thymic myb mRNA from low levels. These studies have combined a molecular probe with CY therapy to provide insights into the cellular bases for lymphoproliferative autoimmune diseases.
Hyporesponsiveness to augmentation of murine natural killer cell activity in different anatomical compartments by multiple injections of various immunomodulators including recombinant interferons and interleukin 2.
Authors: Talmadge J E , Herberman R B , Chirigos M A , Maluish A E , Schneider M A , Adams J S , Philips H , Thurman G B , Varesio L , Long C
Published: December 2022

Augmentation of natural killer (NK) cell activity has been observed after the single administration of a wide variety of biological response modifiers (BRM); however, multiple injections of BRM have resulted in hyporesponsiveness to NK augmentation in both preclinical and clinical studies. In these studies, hyporesponsiveness to augmentation of NK cell activity occurred after multiple injections of interferon (IFN recombinant human IFN-alpha A/D and recombinant IFN-gamma) and interleukin 2 and was found to be systemic (lungs, liver, blood, and spleen). In contrast, hyporesponsiveness to augmentation by multiple injections of maleicanhydride divinyl ether (MVE-2) or Propionibacterium acnes was limited to the spleen and peripheral blood lymphocytes, with continued augmentation of NK cell activity in the peritoneum, lungs, and liver. Despite the hyporesponsiveness to augmentation of NK activity by multiple IFN injections, NK activity could still be augmented by a single injection of another BRM. The NK cell hyporesponsiveness induced in the spleen by MVE-2 was also reversed by a single administration of IFN or polyinosinic-polycytidylic and poly-L-lysine solubilized by carboxymethyl cellulose but not by OK-432 or P. acnes. These results demonstrate that the nature of the hyporesponsiveness to NK augmentation, which is induced by multiple treatments with BRM, varies with the type of agent. The noncytokine BRM that were studied induced hyporesponsiveness only in specific lymphoid compartments but not in major nonlymphoid organs, whereas cytokine BRM induced a systemic hyporesponsiveness. The hyporesponsive state induced by the different types of BRM, also varied in regard to the pattern of susceptibility to augmentation of NK activity by unrelated BRM.
Gamma-interferon enhances expression of Class I MHC antigens in the weakly HLA+ human choriocarcinoma cell line BeWo, but does not induce MHC expression in the HLA- choriocarcinoma cell line Jar.
Authors: Anderson D J , Berkowitz R S
Published: December 2022

PHA-activated lymphocyte supernatants and high doses of affinity-purified human gamma-interferon enhance the expression of apparently normal Class I histocompatibility antigens in a malignant human trophoblast cell line that expresses low amounts of these antigens under normal culture conditions. Another human choriocarcinoma cell line, Jar, which is normally HLA-, did not respond to this treatment. This system provides a model in which to study further the regulation and effects of MHC antigen expression in cells of trophoblastic origin.
The effects of vasoactive intestinal peptide on human natural killer cell function.
Authors: Rola-Pleszczynski M , Bolduc D , St-Pierre S
Published: December 2022

Vasoactive intestinal peptide (VIP) can be found at nerve endings in various tissues and has recently been shown to interact with human lymphocytes through an adenylate cyclase-linked receptor. Because various neuroendocrine factors are thought to influence immune responsiveness, we studied the effect of VIP on natural killer (NK) effector function. Human lymphocytes were incubated with 51Cr-labeled K562 target cells in a 4-hr cytotoxicity assay in the absence or presence of increasing concentrations of VIP. As expected from its activation of adenylate cyclase, VIP was inhibitory at 10(-6) to 10(-10) M. Interestingly, however, when lymphocytes were preincubated with VIP for 30 or 60 min, then washed and added to target cells, a significant augmentation of NK activity ensued. Binding studies revealed that preincubation with VIP resulted in increased numbers of effector-target conjugates, whereas cytotoxic activity in agarose was not affected at the single cell level. Studies with synthetic analogs of VIP revealed that the integrity of the 14-28 C-terminal amino acid sequence was essential for its activity in cytotoxicity. These data strongly suggest a functional role for VIP in modulating immune responses during neuroendocrine interactions with the immune system.
Immunogenicity of a synthetic glucosyl-alpha(1,3)-glucosyl protein conjugate.
Authors: Tittle T V , Mawle A , Cohn M
Published: December 2022

We compare antibody responses to nigerose [alpha(1,3) diglucoside] when it is presented as a hapten linked to keyhole limpet hemocyanin (N-KLH) or as a native constituent of dextran (B1355). In classic terms, N-KLH is thymus dependent (TD), whereas B1355 is thymus independent (TI). N-KLH only induced an in vitro antibody response in T-depleted splenic B cells when syngeneic, KLH-specific T helper cells (TH) were supplied. This need for H-2-restricted TH could not be supplanted by the addition of lymphokines (LK). In contrast, the response to B1355 only required the addition of LK. In vivo, N-KLH induced both kappa class and lambda class antibodies, unlike B1355, which induced a response that was restricted to the lambda class. N-KLH induced a substantial IgG response in vivo, with IgG1, IgG2a, and IgG2b subclasses increasing by two to three orders of magnitude over preimmunization levels. These isotypes were not found in the in vivo response to B1355. This is consistent with the TD and TI classifications of these immunogens. Antibodies induced by N-KLH were totally inhibited by the free alpha(1,3)-linked diglucosyl hapten, nigerose, as were those induced by B1355. In vitro, B1355 also induced a lambda predominant response in naive splenic B cells. However, prepriming with N-KLH resulted in a dramatic kappa class response to B1355. The data suggest that B cells can become responsive to TI antigens after TD activation.
Protein G: a powerful tool for binding and detection of monoclonal and polyclonal antibodies.
Authors: Akerström B , Brodin T , Reis K , Björck L
Published: December 2022

Protein G is an immunoglobulin (IgG)-binding bacterial cell wall protein recently isolated from group G streptococci. We have investigated the avidity of protein G for various monoclonal and polyclonal Ig of the IgG class, and compared it with the binding properties of protein A, the staphylococcal Fc-binding protein. Radiolabeled Ig were mixed with Sepharose-coupled protein G or protein A, and the amounts of radioactivity bound to the matrix-coupled bacterial proteins were determined. The avidity was found to be greater for protein G than for protein A for all examined Ig. Protein G bound all tested monoclonal IgG from mouse IgG1, IgG2a, and IgG3, and rat IgG2a, IgG2b, and IgG2c. In addition, polyclonal IgG from man, cow, rabbit, goat, rat, and mouse bound to protein G, whereas chicken IgG did not. The binding property of protein G was additionally exploited in the Western blot assay, in which iodine-labeled protein G was used successfully for the detection of a rat monoclonal antibody against ovalbumin, and for the detection of rabbit and goat polyclonal whole antisera against human urinary proteins. In these experimental situations, protein G was found to be a powerful reagent for the detection of IgG, and consequently the antigen against which these antibodies are directed.
Purification and N-terminal amino acid sequence of proliferating cell nuclear antigen (PCNA)/cyclin and development of ELISA for anti-PCNA antibodies.
Authors: Ogata K , Ogata Y , Nakamura R M , Tan E M
Published: December 2022

Proliferating cell nuclear antigen (PCNA), also called cyclin, was purified from PBS extract of rabbit thymus by using a combination of ammonium sulfate fractionation, DEAE-Sephacel, HPLC ion exchange, and HPLC gel filtration column chromatography. PCNA was purified more than 600 times and was analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting. SDS-PAGE showed that a 36 kD protein was selectively isolated in this purification process, and this protein was identified as PCNA by immunoblotting. Other previously identified nuclear antigens, Sm, nRNP, SS-A/Ro, SS-B/La, histone, and DNA, were not detected in this preparation by counterimmunoelectrophoresis and enzyme-linked immunosorbent assay (ELISA). Purified PCNA was used as an antigen to develop ELISA for rapid and specific detection of anti-PCNA in human sera. For further purification, the 36 kD band was electrophoretically eluted from SDS gel slices. The amino acid composition and the first 25 residues from the N-terminus of the protein were determined by using electroeluted PCNA. This amino acid sequence was found to be unique and showed little sequence homology with existent proteins in the protein identification resources databank.
Factor I co-factor activity of CR1 overcomes the protective effect of IgG on covalently bound C3b residues.
Authors: Fries L F , Prince G M , Gaither T A , Frank M M
Published: December 2022

We have shown previously that C3b resides in a protected site when it is covalently bound to IgG (C3b-IgG). Such C3b displays a reduced affinity for factor H, with consequent enhanced survival in the presence of factors H and I and increased capacity for promoting alternative pathway consumption of C3. Because erythrocyte CR1 may be a major co-factor for factor I-mediated inactivation of immune complex-borne C3b in blood, we have examined the effect of covalently bound IgG on the C3b-CR1 interaction. Binding of monomeric C3b and C3b-IgG to human erythrocyte CR1 demonstrates identical ionic strength dependence for both species. Identical numbers of binding sites with indistinguishable affinities are detected by both ligands. Cleavage of the alpha'-chain of C3b and the alpha'-heavy chain of C3b-IgG proceeds at the same rate when erythrocyte CR1 serves as co-factor for factor I. Unlike factor H, CR1 supports a second cleavage of fluid-phase iC3b alpha'1 chain (free or bound to IgG) that generates C3c and a 33,000 m.w. fragment, which bears antigenic markers characteristic of C3g. Inactivation of C3b and C3b-IgG by CR1 and factor I also occurs at physiologic ionic strength, but proceeds very slowly relative to rates attainable with sub-physiologic inputs of factor H. CR1 does not recognize IgG-bound C3b as being in a protected site but, because of low binding affinity at physiologic ionic strength, is probably highly dependent on multivalent ligand-receptor interactions to efficiently exert its co-factor functions. Thus, inactivation of C3b-IgG heterodimers or small immune complexes bearing limited numbers of C3b residues may remain largely factor H-dependent in vivo, with resultant enhanced C3b survival.
Relationship among IgE-binding factors with various molecular weights.
Authors: Jardieu P , Moore K , Martens C , Ishizaka K
Published: December 2022

The rat-mouse T cell hybridoma 23B6 forms IgE-binding factors on incubation with IgE. The hybridoma cells incubated with IgE contained intracellular IgE-binding factors of 60K, 30K, 14K, and 10K daltons, and secreted the 60K, 30K, and 14K IgE-binding factors. Both intracellular and extracellular IgE-binding factors of 60K and 14K daltons selectively suppressed the IgE response, whereas the 30K and 10K factors failed to do so. Reduction and alkylation of the extracellular 60K IgE-binding factors yielded fragments of 30K, 14K, and 10K daltons with IgE-binding activity, and the same treatment of the 30K "inactive" IgE-binding factor yielded the 14K and 10K fragments. Among the fragments obtained by reduction and alkylation, only the 14K IgE-binding factors selectively suppressed the IgE response. Monoclonal antibody OX 3, which recognizes an Ia determinant, bound the 60K and 30K IgE-binding factor, and the 30K fragment obtained by reduction and alkylation. None of the 14K and 10K IgE-binding factors and fragments of comparable size obtained by reduction and alkylation contained the antigenic determinant. The results indicate that 30K, 14K, and 10K IgE-binding factors are derived from the 60K precursor molecules. Transfection of COS 7 monkey kidney cells with a single cloned cDNA, 8.3, which encodes rodent IgE-binding factor, resulted in the formation of IgE-binding factors of 60K and 11K daltons. Both species of the factors had affinity for lentil lectin and selectively potentiated the IgE response, but only the 60K IgE-binding factor bound to the monoclonal anti-Ia antibody. Reduction and alkylation of the 60K IgE-binding factors from the cDNA clone yielded an 11K fragment having the same properties as the 11K IgE-binding factor, with respect to the affinity for lentil lectin, and the biologic activities. Because the cDNA clone was constructed from mRNA of 23B6 cells, it appears that the 60K IgE-binding factor molecule from 23B6 cells is composed of a single peptide chain, and that the naturally formed 30K, 14K, and 10K IgE-binding factors are formed by post-translational modification of the 60K peptide.
Immunosuppressive effects of benzidine in mice: evidence of alterations in arachidonic acid metabolism.
Authors: Luster M I , Tucker A N , Hayes H T , Pung O J , Burka T , McMillan R , Eling T
Published: December 2022

Benzidine (4,4'-diaminobiphenyl), a known human bladder carcinogen used in the synthesis of dyes, was immunosuppressive in mice after subchronic exposure. Suppression, particularly of cell-mediated immunity, occurred at dose levels previously found to be subtumorigenic in mice, as evidenced by suppressed lymphoproliferative and delayed hypersensitivity responses. In addition, benzidine exposure was found to decrease host resistance, including resistance to the growth of transplantable tumor cells and infection with Listeria. These data suggest that the development of neoplastic disease may be facilitated by the ability of benzidine to alter the immune response. The mechanism(s) responsible for immunosuppression by benzidine, however, is probably not the same as that responsible for its direct carcinogenicity. The addition of benzidine in vitro to mitogen-activated lymphocytes mimicked the suppression of lymphocyte responsiveness in vivo. In vitro studies suggested that alterations in metabolites of the arachidonic acid/lipoxygenase pathway were responsible for the immune alterations. Benzidine and the lipoxygenase inhibitor NDGA inhibited arachidonic acid metabolism and the mitogen response in lymphocytes, whereas the cyclooxygenase inhibitor indomethacin was ineffective. Addition of 8brcGMP partially restored benzidine-suppressed responses, whereas arachidonic acid potentiated the suppression. These data are consistent with the hypothesis that alterations in lymphocyte functions may occur as a result of quantitative changes or depletion of conversion products in the arachidonate/lipoxygenase pathway induced by the addition of compounds that serve as co-oxidative substrates for hydroperoxidases, the prototype being benzidine.
Production of the lymphokine soluble immune response suppressor (SIRS) during chronic experimental schistosomiasis mansoni.
Authors: Aune T M , Freeman G L , Colley D G
Published: December 2022

Chronic schistosomiasis mansoni is a helminthic infection characterized by cell-mediated anti-egg granulomatous reactions and a variety of associated immunoregulatory phenomena. Soluble immune response suppressor (SIRS) is a lymphokine produced by activated suppressor T lymphocytes in various experimental settings. This report demonstrates the presence of SIRS in the sera of mice with chronic schistosomiasis mansoni (at least 20 wk of infection), but not in the sera of mice with earlier infections. Also, cultures of isolated, intact, hepatic, egg-focused granulomas from chronically infected mice released detectable levels of SIRS. These are the immunomodulated lesions characteristic of this infection. Large, intense, unmodulated granulomas obtained from acutely infected mice did not release SIRS. There is, therefore, a strong association between the presence of SIRS in the serum, the production of SIRS by intact lesions, and the chronic, immunomodulated stage of schistosomiasis mansoni.
Ubiquity of the repetitive epitope of the CS protein in different isolates of human malaria parasites.
Authors: Zavala F , Masuda A , Graves P M , Nussenzweig V , Nussenzweig R S
Published: December 2022

Sporozoites of the human malaria Plasmodium falciparum and Plasmodium vivax obtained from a large number of endemic areas were screened with species-specific monoclonal antibodies that recognize the repeated epitopes of the respective circumsporozoite (CS) proteins. By using a two-site immunoradiometric assay, it was determined that all the parasite isolates of a given species react with a single monoclonal antibody, indicating the presence of a common repeated epitope. Polyacrylamide gel electrophoresis, followed by Western blot, showed that the CS proteins of the various isolates differed in their apparent m.w.
The role of interleukin 1 (IL 1) in tumor-NK cell interactions: correction of defective NK cell activity in cancer patients by treating target cells with IL 1.
Authors: Herman J , Dinarello C A , Kew M C , Rabson A R
Published: December 2022

This study examined the importance of interleukin 1 (IL 1) in the large granular lymphocyte (LGL)-target cell interaction. K562 target cells when treated with highly purified human IL 1 for 1 hr bound greater numbers of LGL than untreated cells. LGL from patients with hepatocellular carcinoma (HCC) that bound few untreated K562 cells, attached to considerably increased numbers of IL 1-treated target cells. Cytotoxicity of LGL against target cells could similarly be increased by pulsing the latter cells with IL 1, and defective cytotoxicity of LGL from HCC patients could be corrected by treating the target K562 cells with IL 1. Lysis of PLC/PRF/5 cells, Yac-1 cells, and normal skin fibroblasts could also be increased by treatment with IL 1 for 1 hr. The enhanced binding and cytotoxicity of IL 1-treated target cells was only observed when the latter cells were preincubated with IL 1 at 37 degrees C, and was not evident at 4 degrees C. Furthermore, the IL 1-mediated effect could be abolished by treating the target cells with cycloheximide before the IL 1 pulse, or by adding rabbit anti-human IL 1 together with the IL 1. These results indicate that IL 1 affects a variety of target cells and increases their ability to bind and be lysed by enriched LGL. They demonstrate, furthermore, that defective natural cytotoxicity by the LGL of patients with advanced malignant disease can be corrected in vitro by treating the target cells with IL 1.
Evidence that lymphokine-activated killer cells and natural killer cells are distinct based on an analysis of congenitally immunodeficient mice.
Authors: Andriole G L , Mulé J J , Hansen C T , Linehan W M , Rosenberg S A
Published: December 2022

The in vitro incubation of lymphoid cells in RIL 2 results in the generation of LAK cells that are broadly lytic to autologous, syngeneic, and allogeneic fresh tumor cells, but which do not lyse fresh, normal cells. Strains of mice with congenital immunodeficiencies were tested both for the presence of NK cells and for their capacity to generate LAK cells after in vitro incubation with IL 2. Splenocytes obtained from two immunodeficient mouse strains (NIH-Beige-Nude and NIH-Beige-Nude-XID) failed to generate LAK cells, but displayed significant activity. Splenocytes from another immunodeficient mouse strain (NIH-Beige-XID) generated LAK cells but did not display NK cell activity. This dissociation of activation of LAK cells from NK cells among the immunodeficient strains indicates that the LAK and NK cell lytic systems are distinct.
Active transformation of tolerogenic to immunogenic signals in T and B cells by 8-bromoguanosine.
Authors: Scheuer W V , Goodman M G , Parks D E , Weigle W O
Published: December 2022

The injection of deaggregated human gamma-globulin (DHGG) into A/J mice results in the establishment of a state of unresponsiveness to subsequent challenge with immunogenic aggregated human gamma-globulin (AHGG). Administration of the B cell activator 8-bromoguanosine (8BrGuo) 3 hr after administration of DHGG converts the tolerogen to an immunogen and results in an antibody response of even greater magnitude than the primary response elicited by AHGG alone. Adoptive transfer studies with separated populations of T and B cells demonstrated that although transformation of the tolerogenic signal to an immunogenic signal involves effects of 8BrGuo on both T cells and B cells, the major effect appears to be activation of antigen-specific T cells that would otherwise become tolerant. Modulation of T cell tolerance could conceivably be mediated either by direct or indirect mechanisms. Interestingly, optimal responsiveness of B cells from animals treated with DHGG and 8BrGuo is not a T cell-independent event, but requires antigen-reactive T cells. 8BrGuo is not able to override unresponsiveness when given 10 to 20 days after tolerance induction, at a time point when both T and B lymphocytes are tolerant. However, when given at day 60, when T cells (but not B cells) remain tolerant to this antigen, the nucleoside is able to terminate the tolerant state prematurely, possibly by providing an alternate T helper-like signal directly to B cells or by recruiting nonspecific functional T helper cells.
Suppressor T cells, distinct from "veto cells," are induced by alloantigen priming and mediate transferable suppression of cytotoxic T lymphocyte responses in vivo.
Authors: Owens T , Crispe I N
Published: December 2022

Primary and secondary cytotoxic T lymphocyte responses to minor alloantigens can be suppressed by priming host mice with a high dose (10(8) cells) of alloantigenic donor spleen cells (SC). Such suppression is antigen specific and transferable into secondary hosts with T cells. One interpretation of this is that antigen-specific host suppressor T cells (Ts) are activated. Alternatively, donor Lyt-2+ T cells, introduced in the priming inoculum, may inactivate host CTL precursors (CTLp) that recognize the priming (donor) alloantigens. Donor cells that act in this way are termed veto T cells. The experiments described here exclude veto T cell participation in transferable alloantigen-specific suppression, and demonstrate the operation of an alloantigen-specific host-derived T suppressor (Ts) cell. The origin of the Ts has been studied directly by using Thy-1-disparate BALB/c mice. The cell responsible for the transfer of suppression of a secondary CTL response to B10 minors was of the host Thy-1 allotype, and so originated in the host spleen and was not introduced in the priming inoculum. Secondly, antigen-specific Ts generated in CBA female mice against B10 minors could act on CTL responses to an unequivocally non-cross-reactive-third party antigen (H-Y), provided the two antigens were expressed on the same cell membrane. Such third-party suppression is incompatible with the operation of veto T cells. Depletion of Thy-1.2+ or Lyt-2+ cells from the suppression-inducing donor SC inoculum did not abrogate suppression induction in BALB/c mice; instead, suppression was enhanced. The demonstration of veto cell activity in similarly primed mice by other groups of investigators indicates that both types of suppression may operate. However, our results show that only antigen-specific Ts can mediate the transferable suppression of CTL responses to alloantigens.
Genetics of insulin-specific helper and suppressor T cells in nonresponder mice.
Authors: Jensen P E , Kapp J A
Published: December 2022

The role of insulin-specific helper and suppressor T cells in the H-2-linked genetic control of antibody responses to heterologous insulins was examined in vitro. These data demonstrate that pork insulin stimulates both primed helper T cells and dominant suppressor T cells in all nonresponder strains tested. Thus, the nonresponder phenotype is attributed to the activation of specific suppressor T cells rather than to an absence of helper T cell activity. Examination of the antigenic cross-reactivity patterns of pork insulin-primed helper and suppressor T cells in various strains demonstrates that fine specificity of the helper T cells differs from that of the suppressor T cells and that the patterns of antigenic cross-reactivity of these subpopulations are controlled by the H-2 gene complex. Furthermore, in a given strain of mice variants of insulin that stimulate helper T cells that cross-react with mouse insulin also stimulate dominant suppressor T cells that cross-react with mouse insulin. Such variants of insulin are perceived as nonimmunogenic. These observations raise the possibility that nonresponsiveness that is controlled by H-2 linked genes results from the activation of regulatory mechanisms involved in maintaining self-tolerance.
Mechanisms of suppressed cell-mediated immunity and impaired antigen-induced interleukin 2 production in granuloma-bearing mice.
Authors: Kobayashi K , Allred C , Yoshida T
Published: December 2022

Pulmonary granulomas were induced in BALB/c mice immunized with methylated bovine serum albumin in complete Freund's adjuvant by the intratracheal injection of plain agarose beads or beads conjugated to specific antigen. Large hypersensitivity granulomas developed around antigen-coupled beads in immunized animals. Smaller but still prominent granulomatous reactions developed around plain beads in immunized mice. In nonimmunized animals, both plain and antigen conjugated beads produced very small granulomas. Granuloma formation in sensitized animals was associated with suppressed delayed-type hypersensitivity reactions induced by the footpad injection of specific and nonspecific antigens. Lymph node cells from sensitized granuloma-bearing mice with cutaneous anergy showed suppressed specific and nonspecific antigen-induced proliferative responses in vitro. These cells also showed suppressed interleukin 2 production in response to specific antigen. Although no soluble suppressive factor was detected in granuloma extracts, suppressor cells were found in lymph nodes of granuloma-bearing mice, which could inhibit antigen-induced production of interleukin 2 by lymph node cells from immunized mice. Antigen-specific immunoglobulin G antibody production was not suppressed in immunized granuloma-bearing mice. Previous studies from our laboratory have demonstrated migration inhibition factor and interleukin 1 activities in aqueous extracts prepared from granuloma-bearing lungs of immunized mice. These results and the findings reported here indicate that granuloma formation and the associated anergy observed in this system are primarily expressions of cell-mediated immunity; selective suppression of in vivo and in vitro expressions of cell-mediated immunity in granuloma-bearing mice may be due to impaired antigen-induced interleukin 2 production; and such impairment is caused by suppressor cells.
Mouse skin graft prolongation with donor strain bone marrow and anti-lymphocyte serum: surface markers of the active bone marrow cells.
Authors: De Fazio S , Hartner W C , Monaco A P , Gozzo J J
Published: December 2022

The survival of C3H/HeJ skin grafts on B6AF1 mice treated with anti-lymphocyte serum (ALS) can be significantly prolonged by the injection of the host with C3H/HeJ bone marrow. Although the prolongation is apparently due at least in part to the ultimate presence in the host of specific suppressor cells of donor origin, little is known about the nature of the cells in the marrow inoculum that are responsible for this effect. The present investigation was undertaken to characterize surface markers of the active bone marrow cells. Marker-positive populations were either depleted and enriched by panning techniques or depleted by killing with specific antibody and complement, and then were assayed for their ability to prolong graft survival. Cells that were adherent to anti-Ia-coated plates extended graft survival only slightly better than did treatment with ALS alone, whereas nonadherent (Ia-depleted) cells, as well as cells treated with anti Ia and complement, retained good prolonging activity. Similarly, panning on anti-immunoglobulin (Ig)-coated plates produced an active, Ig+-depleted population and an inactive adherent population, and killing of Thy-1+ cells with antibody and complement did not compromise the ability of the bone marrow inoculum to prolong graft survival. Complement receptor-positive (EAC+) and Fc gamma receptor-positive cells (EA+) were separated by panning on plates coated with sheep erythrocytes/antibody/complement and erythrocytes/7S antibody respectively. Adherent, EAC+-enriched cells were only slightly active, whereas the nonadherent, EAC-depleted population was fully active in graft prolongation. However, both Fc gamma R+ (EA+)-enriched and depleted populations were active, with the enriched fraction producing significantly better prolongation than the depleted population. Thus, the bone marrow cells that can prolong skin graft survival in ALS-treated mice appear to be Ia-, Thy-1+, largely complement receptor negative, and Ig-, but are largely positive for Fc gamma receptors.
G0 B cells activated by anti-mu acquire the ability to proliferate in response to B cell-activating factors independently from entry into G1 phase.
Authors: Proust J J , Chrest F J , Buchholz M A , Nordin A A
Published: December 2022

In the present studies we investigated the early steps in B cell activation and determined that activation could be separated from entry into cell cycle. Purified B cells from BALB/c nu/nu mice, activated under controlled conditions by affinity-purified rabbit IgG anti-mu or F(ab')2 fragments prepared from the same antibodies, were sorted according to size by flow cytometry. Approximately 80% of the B cells were small and were shown to be in Go state by quantitative RNA analysis and by [3H]uridine and [3H]thymidine incorporation studies. The sorted Go B cells, when again incubated in serum-free medium with the appropriate anti-mu preparations, remained in Go. However, Go B cells in the presence of anti-mu have undergone significant change(s), in as much as they were now able to proliferate in response to soluble mediators. The ability to develop a proliferative response to B cell-activating factor(s), acquired independently from entry into cell cycle, characterizes another important step in early B cell activation and also indicates that Go B cells characterized on the basis of cell size, density, and/or RNA content may be in an activated state.
HLA regulates postrenal transplant CML nonreactivity.
Authors: Goulmy E , Blokland E , Persijn G , Paul L C , Wilmink J , van Rood J J
Published: December 2022

Previous studies have shown that lymphocytes from renal allografted patients with a good functioning graft display donor-specific cell-mediated lympholysis nonreactivity (CML-NR) in vitro. To define whether the HLA system influences the occurrence of the CML-NR, immunogenetic studies were carried out. Posttransplant lymphocytes derived from CML-NR patients were stimulated in vitro with lymphocytes from unrelated healthy blood donors, who were selected for the presence or absence of kidney donor-specific HLA antigens. The presentation of kidney donor-specific HLA-B (and -C) antigens on the lymphocytes of unrelated blood donors resulted in cytolytic nonresponsiveness, whereas presentation of the kidney donor-specific HLA-A locus antigens on lymphocytes of the unrelated blood donors revealed no cytolytic nonresponsiveness. The results, as displayed by posttransplant lymphocytes of renal allografted patients, demonstrate that the kidney donor HLA-B (and -C) antigens are responsible for the in vitro-observed, donor-specific CML-NR. Consequently, presentation of cells from panel members matched to the kidney donor at the HLA-B locus suppresses the response towards HLA-A locus antigens. The in vitro-observed cytolytic nonresponsiveness appeared not to be due to an absence of specific cytotoxic T lymphocytes, because the nonresponsiveness can be abrogated by addition of exogenous IL 2.
Noncytotoxic functions of natural killer (NK) cells: large granular lymphocytes (LGL) produce a B cell growth factor (BCGF).
Authors: Procopio A D , Allavena P , Ortaldo J R
Published: December 2022

Highly purified human large granular (LGL), depleted of any detectable contaminant T and B cells or monocytes, were found to be potent producers in vitro of a soluble B cell growth factor (BCGF) able to sustain proliferation of B cells activated by anti-mu. Activation by lectins (phytohemagglutinin, PHA, concanavalin A, Con A; and pokeweed mitogen, PWM) was required to induce the production of high levels of this BCGF from cultured LGL. Production of BCGF was also detected after the binding of LGL with natural killer (NK)-sensitive (K562) but not with NK-resistant (RL male 1) target cells. In contrast to T cells, LGL did not need the additional presence of accessory cells to reach optimal production of BCGF by 72 hr of culture. The subpopulation of LGL responsible for the production of BCGF had phenotypic characteristics associated with NK cells (3G8+, HNK1+/OKT11+, DR-, OKT3-, Leu-M1-), and separated cells with these markers exerted high levels of NK activity. Selective production of BCGF also was obtained from cytotoxic clones derived from LGL. A partial characterization of the LGL-derived BCGF was performed by gel filtration. BCGF activity was detected in fractions with estimated m.w. of 20,000 and 45,000. The LGL-derived BCGF activity was resistant to reduction with 2-mercaptoethanol and was stable at -20 degrees C for months. Conversely, heating (56 degrees C for 1 hr) or digestion with trypsin greatly reduced the LGL-derived BCGF activity. These findings strongly suggest that LGL including those with NK activity can play an important positive role in the early events of the B cell-mediated immune response.
Synergy between B cell differentiation factors and interleukin 2, using a monoclonal system.
Authors: Mayer L , Crow M K , Thompson C
Published: December 2022

By using monoclonal B cell targets, cells derived from patients with chronic lymphocytic leukemia, and B cell differentiation factors (BCDF) derived from monoclonal human T cell hybridomas, we have demonstrated marked synergy for differentiation between interleukin 2 (IL 2) and BCDF. IL 2 alone had no effect on the proliferation of differentiation to immunoglobulin secretion in these cell populations; however, in conjunction with a variety of BCDF, differentiation to plaque-forming cells (PFC) was augmented 10- to 100-fold. There was no increase in proliferation as measured by [3H]thymidine incorporation. These effects could be demonstrated with concentrations of IL 2 as low as 5 U/culture, well within the physiologic range, by using either commercially available or recombinant IL 2. The addition of IL 2 to the B cell and BCDF cultures resulted in almost 100% expression of the IL 2 receptor, Tac, on the surface of these cells, and the augmented PFC response could be inhibited 70 to 80% by the addition of anti-Tac to the culture. Kinetic studies revealed that the addition of IL 2 to the B cell cultures could be delayed for up to 72 hr without a change in the PFC response, suggesting that IL 2 was acting as a secondary or synergistic signal for differentiation. Thus, it appears that IL 2 does have a role in B cell maturation mediated, in part, by IL 2 binding to the IL 2 receptor present on certain B cells.
Assembled topographic antigenic determinants of pigeon cytochrome c.
Authors: Hannum C H , Margoliash E
Published: December 2022

The specificity of the IgG fraction of the sera of several rabbits hyperimmunized with glutaraldehyde-polymerized pigeon cytochrome c was examined by fluorescence-quenching titration and a sensitive competitive plate-binding radioimmunoassay developed for the analysis of small amounts of antiserum. Four pigeon cytochrome c-specific Fab fragments were found to bind simultaneously to the immunogen. Competition assays, using an extensive set of naturally occurring, chemically prepared hybrid and enzymically modified cytochromes c, implicated in antibody binding all seven amino acid residues at which the immunogen differs from the homologous rabbit cytochrome c. Thus, rabbits produce small amounts of three antibody populations directed against the regions of serine 15, alanine 44, and glycine 89, respectively, on pigeon cytochrome c, and a large amount of the population which binds to an assembled topographic determinant composed of isoleucine 3, glutamine 100, alanine 103, and lysine 104. The latter four residues are from the amino-terminal and carboxyl-terminal alpha-helices, and cluster where the two helices cross each other on the back surface of the molecule. Antibodies against native pigeon cytochrome c reacted very poorly with the several cyanogen bromide-cleaved fragments of the molecule, consisting of residues 1 to 65, 1 to 80, 66 to 104, and 81 to 104.
The B10.A mouse B cell response to pigeon cytochrome c is directed against the same area of the protein that is recognized by B10.A T cells in association with the Ek beta:Ek alpha Ia molecule.
Authors: Hannum C H , Matis L A , Schwartz R H , Margoliash E
Published: December 2022

An analysis of the fine specificities of the primary and hyperimmune antibody responses of B10.A mice to pigeon cytochrome c showed that both were qualitatively very similar. Small amounts of antibody appeared to be directed against the regions of serine 15 and/or glutamic acid 44. The remaining antibodies (greater than 70%) bound to the same complex topographic determinant (including residues 3, 103, and 104) on the back surface of pigeon cytochrome c which had been found to dominate the rabbit antibody response to this protein, and to be involved in Ia-restricted T cell stimulation. The mouse antibodies reacted very poorly with fragmented forms of the immunogen or with tobacco hornworm moth cytochrome c, even though both of these antigens had been shown previously to strongly stimulate pigeon cytochrome c-primed T cells. The specificities of the primary IgG responses of seven other mouse strains were found to be very similar, but not identical, to that of B10.A mice. The cytochrome c-specific antibodies in the hyperimmune serum were shown to bind to determinants involving residues that vary between pigeon and mouse cytochromes c. Comparison of the binding of the antibodies to the immunogen and to the corresponding host protein enabled the calculation of the proportion of the overall binding energy contributed by the variant residues. This was as low as 19 to 35% for the primary response, rose to 25 to 46% for the hyperimmune mouse antibodies, and reached 40 to 63% for hyperimmune rabbit antibodies. The remaining energy of interaction (37 to 81%) was necessarily contributed by the surface of the protein surrounding the variant residues, which is the same for the immunogen and the host protein. These results illustrate the relatively subtle differences in binding affinities which can distinguish self from non-self recognition by antibody molecules.
Two distinct classes of IgG Fc receptors on a human monocyte line (U937) defined by differences in binding of murine IgG subclasses at low ionic strength.
Authors: Jones D H , Looney R J , Anderson C L
Published: December 2022

We have defined two distinct classes of IgG Fc receptors (FcR) on cells of a human monocytic line (U937) by analyzing the direct binding of murine IgG subclasses in medium of low ionic strength. Four lines of evidence support this contention. The binding of aggregated murine IgG2b (AggmIgG2b) to U937 and Daudi cells was enhanced at low ionic strength, whereas monomeric murine IgG2a (mIgG2a) did not bind to Daudi cells and its high affinity binding to U937 cells was unaffected by changes in ionic strength. Double reciprocal inhibition experiments with U937 cells indicated that the binding of both ligands was inhibited 30 to 135 times more efficiently by the homologous ligand than by the heterologous one. That is, the binding of 125I-AggmIgG2b was inhibited 50% by 3.5 micrograms/ml of AggmIgG2b and 100 micrograms/ml of mIgG2a. Similarly, the binding of 125I-mIgG2a was inhibited 50% by 2.5 micrograms/ml of mIgG2a and only 44% by 243 micrograms/ml of AggmIgG2b. A monoclonal antibody of the IgG2b subclass raised against an IgG FcR on K562 cells inhibited binding to U937 cells of AggmIgG2b but not of mIgG2a. Trypsinization of U937 cells abrogated by 32% the binding of mIgG2a but did not affect the binding of AggmIgG2b. Human IgG inhibited binding of both AggmIgG2b and mIgG2a to U937 cells. We propose that the newly recognized FcR that binds AggmIgG2b is the human homologue of the murine macrophage IgG2b/1 FcR (FcRII), and that the previously described 72,000 dalton high-affinity FcR on U937 cells that binds mIgG2a is the human equivalent of the murine macrophage IgG2a FcR (FcRI).
Phorbol ester induces tyrosine phosphorylation in normal and abnormal human B lymphocytes.
Authors: Nel A E , Navailles M , Rosberger D F , Landreth G E , Goldschmidt-Clermont P J , Baldwin G J , Galbraith R M
Published: December 2022

Tumor-promoting phorbol esters have been found to bind and activate phospholipid/Ca2+-dependent or C-kinase, and several of their effects, including proliferative responses in lymphocytes, have been assumed to be related to activity of this enzyme. However, phorbol esters have also recently been found to stimulate tyrosine phosphorylation in certain other cell types, and we therefore studied tyrosine kinase activity in normal and chronic lymphocytic leukemia (CLL) peripheral blood B lymphocytes stimulated with phorbol ester. High levels of tyrosine labeling were observed in unstimulated cells with major endogenous substrates of 75K, 66K, 43K, and 28K in Triton-soluble material, and of 56K to 61K in Triton-insoluble material; this profile was essentially similar in normal and CLL B cells. Treatment with phorbol ester for time periods varying from 20 min to 48 hr led to qualitative increases in tyrosine labeling of these phosphoproteins, as measured both in vitro and in intact cells "in vivo." Although the relative abundance of tyrosine phosphorylation as a percentage of total labeling was variable due to concomitant enhancement of serine and threonine phosphorylation, exogenous peptide substrate assays confirmed the increased tyrosine kinase activity quantitatively. Enhanced tyrosine phosphorylation was succeeded or accompanied in both normal and abnormal B cells by cellular activation, as judged by increased [3H]thymidine uptake, and terminal differentiation of CLL cells. These findings provide further evidence implicating tyrosine kinases in B lymphocyte activation.