bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunoprecipitation analysis of radiolabelled protein antigens biosynthesized in vitro by S. mansoni. I. Identification of antigens uniquely recognized by protective antibodies.
Authors: Barker R H , Srivastava B S , Suri P , Goldberg M , Knopf P M 
Published: December 2022

Abstract
Protein antigens from 4-wk worms were metabolically radiolabelled with [3H]leucine or [35S]methionine. Three freeze-thaw cycles released a large proportion (50% to 60%) of the TCA-precipitable radioactivity from the worms. Immune serum from twice-infected Fischer rats (F-2x), which was shown to confer resistance in a passive immunization assay, and immune serum from twice-infected Wistar Furth rats (W-2x), which does not confer resistance, were used for analyzing antigens in this worm fraction. Antibodies in these antisera differed in their titers to the freeze-thaw released antigens (W-2x greater than F-2x) and in their relative affinities for these antigens (F-2x greater than W-2x). Gradient slab gel electrophoresis of immunoprecipitates of radiolabelled antigens under denaturing conditions revealed many components, which could be categorized into two main types: unique antigens, recognized only by F-2x antibodies, and nonunique antigens, recognized by both F-2x and W-2x antibodies. The potential relevance of these antigens in resistance was further examined by antibody absorption experiments in which 4-wk worms were used as an immunoabsorbent to remove 90% to 95% of the immunoprecipitating activity and 65% to 70% (p less than 0.005) of the capacity to confer resistance in a passive immunization assay. It was concluded that loss of both anti-schistosome activities was specific since antigen released by worms during absorption could account for only 16% of the reduction in antigen-binding capacity and the titer of antibodies directed against beta-galactosidase did not significantly change during absorption. Antigens recognized uniquely by F-2x antibodies are therefore candidates for immunization studies examining induction of resistance against Schistosoma mansoni.
Hemagglutination assay of polypeptide coded by the pre-S region of hepatitis B virus DNA with monoclonal antibody: correlation of pre-S polypeptide with the receptor for polymerized human serum albumin in serums containing hepatitis B antigens.
Authors: Okamoto H , Imai M , Usuda S , Tanaka E , Tachibana K , Mishiro S , Machida A , Nakamura T , Miyakawa Y , Mayumi M 
Published: December 2022

Abstract
The receptor for polymerized human as well as chimpanzee serum albumins has been identified on the 55-amino acid polypeptide coded by the pre-S region of hepatitis B virus DNA. Monoclonal antibodies were raised against a synthetic polypeptide of 19 amino acid residues representing a hydrophilic region of the pre-S amino acid sequence deduced from hepatitis B virus DNA. Sheep erythrocytes fixed with glutaraldehyde were coated with monoclonal antibody against the synthetic polypeptide to develop a hemagglutination assay for pre-S polypeptide. The pre-S polypeptide was detected in the serum containing hepatitis B surface antigen particles along with hepatitis B e antigen, with titers in parallel with those of the receptor for polymerized human serum albumin.
Protection and recovery in influenza virus-infected mice immunosuppressed with anti-IgM.
Authors: Kris R M , Asofsky R , Evans C B , Small P A 
Published: December 2022

Abstract
BALB/c mice, immunosuppressed from birth with goat anti-mouse IgM, were able to recover from influenza virus infection in the absence of detectable serum and nasal antibody. Recovery was delayed a few days when compared with control animals. Antibody-deficient mice, that had recovered from an initial influenza virus infection, i.e., convalescent mice, were subsequently rechallenged with homologous influenza virus in order to study the importance of nasal and serum antibody in prevention of infection. Convalescent mice were susceptible to reinfection when nasal and serum antibody were not detectable. The mice were resistant to reinfection when serum and/or nasal antibody was detectable by radioimmunoassay. Normal mice that were passively immunized with high titer mouse anti-influenza virus serum were susceptible to challenge with homologous influenza virus. The serum antibody levels in these mice were higher than most of those found in the immune convalescent mice suppressed with anti-IgM, thereby suggesting that the serum antibody, found in convalescent suppressed mice, is not protective. We conclude that 1) mice can recover from influenza virus infection in the absence of detectable levels of nasal and serum antibody, thus indirectly confirming the role of cell-mediated immunity in recovery; 2) serum IgM, IgG2A, IgG2B, IgG3, and probably IgG1 antibody levels are not responsible for protection against influenza virus infection of the upper respiratory tract; and 3) nasal IgA antibody correlates best with protection against reinfection of the upper respiratory tract, but some other locally protective agent cannot be excluded.
Inhibition of human tumor growth by IgG2A monoclonal antibodies correlates with antibody density on tumor cells.
Authors: Herlyn D , Powe J , Ross A H , Herlyn M , Koprowski H 
Published: December 2022

Abstract
Eight monoclonal antibodies (MAb) of IgG2a isotype that were produced against human melanomas were tested for tumor growth-inhibiting properties in nude mice injected with human melanoma cells of various origins. Four of the eight MAb inhibited growth of these tumors, and all four of these antibodies reacted in antibody-dependent macrophage-mediated cytotoxicity (ADMC) assays in vitro. The MAb that were inactive in vivo also did not react in these assays in vitro. The number of antibody-binding sites per cell on the tumor cell surface was significantly higher for tumoricidal MAb as compared to unreactive MAb. On the other hand, the percentage of tumor cells binding the MAb and the binding affinity to these cells were the same for the two groups of MAb. Also, tumoricidal and nontumoricidal MAb bound with similar affinity and antibody density to Fc receptors on macrophages. The importance of the number of antibody sites on the tumor cell surface for tumor destruction by MAb was confirmed by the demonstration of tumoricidal effects of mixtures of MAb that were by themselves not tumoricidal. MAb binding to different molecules on melanoma cells were complementary in ADMC, whereas MAb directed to the same molecule but to different epitopes were not.
Tac antigen-positive T cells activated in autologous mixed lymphocyte reaction regulate the generation of killer T cells against hapten-modified autologous cells.
Authors: Kumagai S , Namiuchi S , Ozaki S , Sano H , Tsubata T , Suginoshita T , Imura H 
Published: December 2022

Abstract
T cells that proliferate in the autologous mixed lymphocyte reaction (auto-MLR) have been shown to acquire some suppressor or regulatory activities. In the present study, we examined the suppressive effects of T cells activated in the auto-MLR on the induction of hapten-specific cytotoxic T cells. NRFT (depletion of ARFT from UT) were used as the responder cells of TNP-MLR. After primary and secondary TNP-MLR, the cells were harvested and tested for their cytotoxic activities against TNP-modified autologous cells by 51Cr-release assay. When UT cells cultured for 1 wk in auto-MLR were added to primary TNP-MLR at the beginning of culture, the cytotoxic activity tested at the end of the culture was suppressed from 15.6% +/- 2.7 to 5.8% +/- 1.1 (percent cytotoxicity, mean +/- SE). However, these auto-MLR-activated UT cells had little suppressive activity against cytotoxic T cells when they were added to the final assay of TNP-CTR. Suppressive activities of these cells on the generation of cytotoxic T cells during secondary TNP-MLR were also tested. The addition of auto-MLR-activated UT cells to the secondary TNP-MLR at the beginning of the culture reduced the cytotoxic activities of NRFT from 23.8% +/- 2.3 to 9.7% +/- 1.7 after secondary TNP-MLR. Allo-activated T cells, PHA blasts, and fresh autologous T cells were used as the controls, but none of the cells had suppressive effects on the generation of CTL. Characteristics of these suppressor cells were examined. Auto-MLR-activated cells from ARFT fractions exhibit very powerful suppressor activity. Treatment of the auto-MLR-activated T cells with mitomycin C eliminated their suppressive effects on the generation of CTL; 21.2% +/- 6.3 of UT cells became anti-Tac positive after 1 wk of auto-MLR. Treatment of auto-MLR-activated UT cells with anti-Tac antibody plus complement eliminated their suppressive activities on the induction of CTL. Thus, T cells stimulated in auto-MLR were shown to have suppressive effects on the induction of cytotoxic T cells against TNP-modified autologous cells. These cells were mitomycin C sensitive. Because anti-Tac antibody is reactive to activated T cells, activation of T cells during auto-MLR was thought to be necessary for the acquisition of the suppressive activity.
Evidence for the role of class I and class II HLA antigens in the lytic function of a cloned line of human natural killer cells.
Authors: Kornbluth J , Spear B , Raab S S , Wilson D B 
Published: December 2022

Abstract
Monoclonal antibodies with specificity for HLA class I and class II antigens were generated which either inhibit or enhance the lytic activity of a cloned line of human NK cells. These antibodies were obtained from a fusion with spleen cells from mice immunized with NK clone 3.3. They affect the lytic function of that clone at the level of the killer cell; additional evidence suggests that the effect takes place during an early stage of lysis. Immunoprecipitation and cross-clearing experiments using MHC antibodies of known specificity demonstrate the reactivity of mAbs 131 and 164 with HLA class I antigens and mAbs 210 and 273 with HLA class II antigens. Binding studies indicate that these antibodies are probably recognizing nonpolymorphic MHC determinants. Although these antibodies bind to other NK effector cells tested, they have no effect on the lytic function of these bulk NK populations. Preliminary studies, however, indicate that they do affect the NK activity of a proportion of the clones within these bulk populations. To further assess the potential role of HLA gene products in the lytic function of NK3.3, several well-defined anti-MHC antibodies were tested for their effects on NK3.3 function. The anti-HLA class I and class II antibodies could each be grouped into functional categories based on their ability to enhance, inhibit, or not affect the lysis of NK-sensitive targets K562 and MOLT-4 by NK clone 3.3. These results demonstrate, for the first time, a potential involvement of MHC molecules with NK function.
Cell cycle-related expression of the receptor for a B cell differentiation factor.
Authors: Brooks K H , Uhr J W , Vitetta E S 
Published: December 2022

Abstract
Cloned, neoplastic B cells (BCL1) have been used to evaluate the expression of the receptor for the B cell differentiation factor, BCDF mu. These cells do not secrete IgM before stimulation with BCDF mu-containing T cell supernatants (SN). By inducing cell cycle synchrony in this homogeneous population, the expression of the BCDF mu receptor could be evaluated as a function of the cell cycle. Responsiveness to BCDF mu-containing SN is maximal when the cells are in S and G2 phases of the cell cycle, and a 2-hr exposure of cells to BCDF mu-containing SN during S/G2 results in optimal IgM secretion 5 days later. Cells in S/G2 are also maximally effective in absorbing BCDF mu activity from SN. These data support the hypothesis that B cells do not respond to differentiative signals until after they are committed to at least one round of cell division.
Non-cross-reactive monoclonal antibodies to human chorionic gonadotropin generated after immunization with a synthetic peptide.
Authors: Caraux J , Chichehian B , Gestin C , Longhi B , Lee A C , Powell J E , Stevens V C , Pourquier A 
Published: December 2022

Abstract
Noncross-reactive monoclonal antibodies specific for human chorionic gonadotropin (hCG) were obtained after pre-selection for submolecular specificity with a synthetic peptide immunogen. Mice were immunized with a synthetic peptide representing a segment unique to the beta-subunit of hCG (amino acid residues 109-145), conjugated to diphtheria toxoid. We then derived nine different hybridomas that secreted monoclonal antibodies reactive with both native hCG and isolated C-terminal peptide, after somatic cell hybridization of immune spleen cells with a nonsecretory myeloma cell line. None of the nine monoclonal antibodies, termed beta-hCG-CTPa1----a9, reacted with hLH, hFSH, or hTSH, although these pituitary hormones display extensive amino acid sequence homology with hCG. The noncross-reactive anti-beta-hCG monoclonal antibodies show apparent association constants on the order of 10(9) to 10(10) M-1. A sandwich-type enzyme-linked immunosorbent assay was set up with cut-off values of around 5 mIU/ml. These antibodies might have important implications for: a) improving the diagnosis and clinical management of pregnancy; b) monitoring the course of development of carcinomas which secrete the hormone, through in vitro assays or in vivo radioimmunodetection; c) evaluating the antibodies' therapeutic potential against such carcinomas; d) studying the biologic functions of the C-terminal segment of beta-hCG; and e) addressing the anti-fertility effect of antibodies raised against that segment.
Age-dependent changes in B lymphocyte lineage cell populations of autoimmune-prone BXSB mice.
Authors: Jyonouchi H , Kincade P W , Good R A 
Published: December 2022

Abstract
BXSB mice, a recently developed autoimmune strain, develop a human lupus-like disease with B cell hyperplasia in peripheral lymphoid organs. Unlike other experimental models of autoimmunity and human lupus, BXSB male mice manifest accelerated autoimmune phenomena through the influence of a Y chromosome-linked enhancing factor. The present studies were performed to investigate the features of B lymphopoiesis in BXSB mice and to determine whether differences exist between BXSB males and females in this respect. B lineage cell populations in the marrow of BXSB mice were identified phenotypically by studying the cytoplasmic mu-heavy chains of IgM (c mu), and functionally by their ability to acquire clonability and sIg in short-term liquid cultures. Male BXSB mice became deficient in both the precursors of functional B cells and c mu + pre-B cells by the age of 8 to 12 wk. This followed a transient increase in this population, which peaked when the mice were 2 to 4 wk old. In females, substantial numbers of functional B cell precursors and c mu + cells were maintained until more than 4 mo of age. Cells lacking Ig but bearing a B lineage cell antigen (14.8) were elevated in numbers in both BXSB males and females until 16 wk of age when compared to normal strains of mice. At the time pre-B cells and functional B precursors were elevated in numbers, some sIg- cells were shown to form colonies in mitogen-stimulated semisolid agar cultures without a period of preculture. Most of these sIg- cells seemed to bear the B lineage cell antigen (14.8). They were independent of both G-10 adherent regulatory cells and Thy-1+ cells for their colony formation. These results indicate that B lymphocyte formation may be maintained in a hyperactive state in BXSB females, whereas males become deficient in B cell precursors very early in life. This early decline might be related to the accelerated development of autoimmune disease in BXSB mice. Bone marrow transplantation studies showed that these unusual characteristics of B lymphopoiesis were reciprocally transferable with unseparated bone marrow cells between BXSB males and females. This finding indicates that sex hormones are not a critical variable in abnormal B lymphocyte formation in this strain, and that the premature deficiency of immediate B precursors in males may be regulated by a genetic factor(s) located on the Y chromosome.
Epidermal cells synthesize a cytokine with interleukin 3-like properties.
Authors: Luger T A , Wirth U , Köck A 
Published: December 2022

Abstract
Interleukin 3 (IL 3) is produced by T lymphocytes and T cell lines (EL 4), as well as by a monomyelocytic cell line (WEHI 3), and it activates lymphocytes as well as mast cells. Recently we have demonstrated that epidermal cells (EC) perform monocyte/macrophage-like functions through the release of an interleukin 1-like immunomodulating mediator (EC-derived thymocyte activating factor; ETAF. Because mast cells predominantly are located in the skin, in the present study we investigated whether EC in addition to ETAF may produce IL 3. Normal as well as transformed keratinocytes were able to secrete an IL 3-like mediator (EC IL 3) that induces the proliferation of IL 3-dependent cell lines. Furthermore, both EC IL 3 and WEHI IL 3 have a similar m.w. of 30,000. In addition, an antibody against IL 3 also blocked EC IL 3 activity, suggesting that these molecules appear to be very similar. EC IL 3 production was greatly enhanced by the addition of concanavalin A, phorbol myristate acetate, lipopolysaccharide, and silica. Factor production was completely blocked by inhibiting protein synthesis. These findings demonstrate that keratinocytes synthesize an additional cytokine with the biologic and biochemical properties of IL 3, but distinct from ETAF. Thus, through the production of EC IL 3, EC may participate in the activation of mast cells and thereby mediate inflammatory as well as hypersensitivity reactions.
Augmentation of immunity to herpes simplex virus by in vivo administration of interleukin 2.
Authors: Rouse B T , Miller L S , Turtinen L , Moore R N 
Published: December 2022

Abstract
The immune mechanisms responsible for recovery from herpesvirus infections are multiple and include a principle role for aspects of T cell immunity. Our investigations add further support for this notion. We show that the ability of immune lymphocytes from animals infected i.p. 6 wk previously with herpes simplex virus type one (HSV-1) clear virus more effectively when interleukin 2 (IL 2) is injected into recipients of the adoptive transfers. Mice were treated on two consecutive days with cyclophosphamide and infected in the pinnae with 4 X 10(6) plaque-forming units of HSV-1. Three hours post-infection lymphocyte populations were injected i.v., and after a further 3 days the pinnae were removed, homogenized, and the content of infectious virus assayed. Purified IL 2 obtained from EL-4 cells either was given i.v. 2 hr before and 24 and 48 hr after cell injection or was given subcutaneously 2 hr before and 3, 24, and 48 hr after cell injection. The latter three injections were given i.p. and suspended in 15% gelatin. The immune lymphocyte cell populations were splenocytes and were either injected immediately after preparation of cell suspensions or after 5 days in vitro secondary stimulation with HSV-1. This latter cell population showed greater viral clearance activity, a function shown previously to be a property of Lyt-2+ cells. The clearance activity of cells was markedly enhanced in animals given IL 2 but only with a regimen that included injections in gelatin, a procedure that enhances in vivo circulation time of IL 2. The cell involved in clearance was a T cell and principally the Lyt-2+ subset. Treatment of recipient mice with anti-asialo GM-1 did not affect the clearance efficiency, indicating that NK cells were not responsible for the observed effect. Our experiments indicate that IL 2 may provide an important regulator of immune function in vivo and may warrant its investigation as a therapeutic agent to enhance antiviral immunity in certain circumstances.
Natural killing target antigens as inducers of interferon: studies with an immunoselected, natural killing-resistant human T lymphoblastoid cell line.
Authors: Howell D N , Andreotti P E , Dawson J R , Cresswell P 
Published: December 2022

Abstract
The human T lymphoblastoid cell line CEM was subjected to immunoselection by co-culture with peripheral blood mononuclear cells (PBMC) for resistance to natural killer (NK) cell-mediated lysis. The NK susceptibility of the resulting subline, CEM.NKR, was 8.4 to 20.6% of that of CEM when PBMC or adherent cell-depleted PBMC were used as effector cells, and -7.1 to 12.1% of that of CEM when Percoll gradient-enriched large granular lymphocytes (LGL) were used. However, CEM and CEM.NKR exhibited comparable sensitivity to antibody-dependent cellular cytotoxicity. Unlabeled CEM was eight- to 32-fold more effective than unlabeled CEM.NKR in inhibiting the NK lysis of labeled CEM target cells, and CEM bound 1.9 to 3.9-fold more Percoll gradient-enriched LGL than CEM.NKR in single cell-binding assays, suggesting that the NK-resistant variant has lost the expression of NK target antigens. However, CEM.NKR was comparable to CEM in its ability to induce interferon (IFN)-alpha production by PBMC in vitro, and the NK-resistant variant maintained its susceptibility to the antiproliferative effects of IFN-alpha, indicating that these phenomena may be mediated by molecules other than NK target structures. Comparison of CEM and CEM.NKR by indirect immunofluorescence with monoclonal antibodies specific for leukocyte antigens and the transferrin receptor, and by microcytotoxicity typing for HLA-A and B specificities, revealed no major differences.
Effect of B cell differentiation factor (BCDF) on biosynthesis and secretion of immunoglobulin molecules in human B cell lines.
Authors: Kikutani H , Taga T , Akira S , Kishi H , Miki Y , Saiki O , Yamamura Y , Kishimoto T 
Published: December 2022

Abstract
Stimulation of human B lymphoblastoid cell lines, CESS and SKW6-CL4 with BCDF induced an increase in IgG- and IgM-secreting cells, as well as a slight increase in IgG and IgM expression on their respective surfaces. Biosynthetic labeling demonstrated that BCDF stimulation induced an increase in synthesis of secretory gamma- and mu-chains, as well as their precursors. A slight but significant increase in synthesis of membrane-bound gamma- and mu-chains and their precursors was also observed by BCDF stimulation. However, an increase in synthesis of secretory heavy chains was much higher than that in membrane-bound heavy chains in both cell lines. Pulse-chase experiments showed that increased synthesis of secretory heavy chains was not due to a decrease in degradation. BCDF stimulation induced a preferential increase in mRNA specific for secretory gamma- and mu-chains in CESS and SKW6-CL4 cells, respectively. These results suggest that BCDF induces an increase in the level of mRNA specific for secretory heavy chains, and then induces final maturation of B cells into immunoglobulin-secreting cells.