bluuebunny/crossref_metadata_2025 huggingface dataset:
Antigen presentation by guinea pig alveolar macrophages.
Authors: Lipscomb M F , Toews G B , Lyons C R , Uhr J W
Published: December 2022

The role of alveolar macrophages (M phi) in the induction of immune responses within the lung was investigated. Guinea pig alveolar M phi obtained from bronchoalveolar cells (BAC) were found to function as well as peritoneal exudate M phi in supporting proliferation of purified lymph node lymphocytes (LNL) induced by both soluble antigens and mitogen (Con A). Several lines of evidence indicate that the alveolar M phi is an effective antigen-presenting cell. 1) Washed alveolar M phi, previously "pulsed" with antigen, replaced both soluble antigen and BAC in the stimulation of immune LNL. 2) The interaction of alveolar M phi, over 80% of which were Ia positive, with lymphocytes was genetically restricted, i.e., only antigen-pulsed alveolar M phi that shared I region-encoded antigens with the antigen-specific T lymphocytes stimulated their proliferation. Furthermore, removal of Ia-positive alveolar M phi abrogated this response. 3) Antigen-pulsed alveolar M phi specifically bound immune T lymphocytes. In contrast, no evidence was obtained for immunosuppression by alveolar M phi. Thus, alveolar M phi failed to suppress specific LNL proliferation even at ratios of alveolar M phi to LNL of greater than 20:1, ratios that often exist locally within the lung. The possible role of antigen-bearing alveolar M phi in inducing local immunity and also in focusing a systemic response are discussed.
Inhibition of murine humoral immune responses by substances derived from trypanosomes.
Authors: Albright J W , Albright J F
Published: December 2022

Previous studies of depressed immune responses in mice infected with the mouse-specific Trypanosoma musculi have produced no evidence of major involvement of typical suppressor lymphocytes or macrophages. We continue this line of investigation in the present report by demonstrating that: a) T. musculi strongly suppress the responses of nude mouse spleen cells to the T-independent antigen, TNP-LPS; b) spleen cell preparations of infected mice display a substantial proportion of cells bearing trypanosome-derived substances (TDS) demonstrable by specific rabbit antibody against T. musculi (RATS); c) treatment of spleen cells from infected mice with RATS plus C eliminates the inhibitory effect of these spleen cells on the immune responses of co-cultivated normal spleen cells; d) incubation in vitro of normal spleen cells with an extract of T. musculi results in progressive loss of the cells to respond to antigens and, in addition, confers on the treated cells to respond to antigens and, in addition, confers on the treated cells the property of inhibiting the responses of co-cultivated normal spleen cells; e) T. lewisi, the rat-specific trypanosome, fails to inhibit murine immune responses. We conclude that the immunoinhibitory effects of T. musculi on murine immune responses are associated with the cytophilic binding of TDS (possibly in the form of immune complexes) and that this vigorous mechanism of inhibition will be shown to involve nonspecific mitogenic and/or biosynthetic activation of lymphocytes.
Continuous cytotoxic T cell lines reactive against murine plasmacytoma tumor-associated antigens.
Authors: Giorgi J V , Warner N L
Published: December 2022

Continuous cytotoxic T cell lines against murine tumor-associated antigens (TAA) were generated from normal BALB/c and (C57BL/6 X BALB/c)F1 spleen lymphocytes by sensitizing these cells in vitro to the BALB/c plasmacytoma (PCT) MPC-11. These cytotoxic T cell lines (CTLL) were maintained for periods of over 1 yr in T cell growth factor from cultures of mitogen-stimulated rat spleen cells. The lines were highly cytotoxic against the immunizing tumor, as well as against a select number of other tumor cell lines, and the patterns of reactivity of 3 of these lines against the various tumor cell targets indicated that these lines each recognized different PCT TAA. The antigens recognized included an MHC-restricted PCT antigen, an antigen shared by PCT and T lymphomas, and an MPC-11 unique PCT antigen. phenotypic characterization of the CTLL populations for cell surface marker expression indicated that they were largely homogeneous with respect to their differentiation state, and expressed Thy-1.2, Lyt-2, Lyt-3.2, and T30 antigens on their cell surface. In addition, 1 of the lines demonstrated variable low-level expression of Lyt-1. Thus, the populations were characteristics of mature T cells, and did not express cell surface markers characteristic of other lymphocyte subpopulations.
Interferon-induced resistance of fibroblasts to cytolysis mediated by natural killer cells: specificity and mechanism.
Authors: Trinchieri G , Granato D , Perussia B
Published: December 2022

Interferons (IF) have been shown to have a complex regulatory effect on cell-mediated cytotoxicity. In this paper, we described our analysis of the protective effect of IF on human fibroblast target cells. Fibroblasts that have been preincubated with IF are not lysed by natural killer (NK) cells. This IF-induced protection is not observed in antibody-dependent cell-mediated cytotoxicity nor in complement-dependent lysis. Both types of leukocyte IF, viral and immune, and fibroblast IF protect fibroblasts from NK cell-mediated lysis. Electrophoretically purified viral type leukocyte IF also induces protection. Experiments of absorption of NK cells on target cell monolayers and analysis of cytotoxicity at the single-cell level in semisolid medium demonstrate that NK cells bind to both IF-treated and untreated fibroblasts but lyse only the latter. The cytotoxic ability of NK cells is inactivated after interaction with fibroblasts but not with IF-treated fibroblasts. Unlabeled normal fibroblasts, but not IF-treated fibroblasts, compete for the cytotoxicity mediated by NK cells on 51Cr-labeled target fibroblasts. Based on these findings, we propose a possible interpretation of the paradoxic existence of cells that can kill normal cells in the organism and still function in cell-mediated immunity to protect against virus-infected or tumor cells.
Detection of hybrid (combinatorial) Ia antigens using parent anti-F1 sera.
Authors: Yokota S , Lafuse W P , McCormick J F , David C S
Published: December 2022

Ia specificities 22 and 23 were initially identified by using conventional alloantisera and were mapped to the I-E subregion of k and d haplotypes on the basis of their reactivity with selected recombinants. Recently we found that Ia 22 and 23 are hybrid determinants on the basis of their expression on selected F1 cells, but absence from both parental cells. Initial attempts to detect hybrid Ia antigens by immunizing parents with F1 cells were unsuccessful. By utilizing lipopolysaccharide (LPS)-stimulated F1 spleen lymphoblasts as immunogens, 1 of the parents as recipient and the other parent cells for absorption of antisera, specific anti-Ia.22 and 23 antibodies were produced. The specificity of these parent anti-F1 sera was confirmed by cytotoxic and immunoprecipitation analyses.
Subpopulations of the T4+ inducer T cell subset in man: evidence for an amplifier population preferentially expressing Ia antigen upon activation.
Authors: Reinherz E L , Morimoto C , Penta A C , Schlossman S F
Published: December 2022

Prior studies demonstrated that Ia molecules were expressed on a fraction of human peripheral T4+ inducer cells upon stimulation by soluble antigen. In the present study, we utilized a fluorescence-activated cell sorter to separate antigen-activated T4+,Ia+ and T4+,Ia- populations and characterized their function. It was found that the T4+,Ia+ population contained the majority of proliferating T cells as assessed by tritiated thymidine incorporation. This proliferation largely appeared to be nonspecific. Despite macrophage repletion, elimination of the Ia+ subset of T cells with monoclonal anti-Ia antibody and complement treatment equally diminished subsequent proliferation to both the triggering antigen and an unrelated antigen. Moreover, the antigen-induced Ia+ subset of T cells alone produced a nonspecific helper factor, LMF. In contrast, the the T4+,Ia- population showed minimal proliferation to soluble antigen and did not generate LMF. Nevertheless, both T4+,Ia+ and T4+,Ia- inducer T cells were required to generate maximal immunoglobulin production by B cells in an antigen-driven system. We conclude that the human T4+ inducer T cell subset is comprised of at least 2 functionally distinct subpopulations, which are capable of acting in a synergistic fashion to provide help to B cells.
The role of immunoglobulins in alternative complement pathway activation by zymosan. I. Human IgG with specificity for Zymosan enhances alternative pathway activation by zymosan.
Authors: Schenkein H A , Ruddy S
Published: December 2022

Prior absorption of normal human serum (NHS) or C2-deficient human serum (C2D) with zymosan at 0 degrees C results in diminished consumption of C3 and factor B during subsequent incubation of the sera in Mg-EGTA buffer with zymosan at 37 degrees C for 30 min. An acid eluate from the zymosan restores the defect of absorbed NHS and C2D, and also enhances C3 and factor B utilization in hypogammaglobulinemic serum (H gamma S) in a dose-dependent fashion. The activity is specific in that the eluate from zymosan fails to enhance C3 and B depletion in H gamma S or absorbed NHS by lipopolysaccharide or Sepharose. The active component of th zymosan eluate emerges from both Sepharose 4B and Sephacryl S-200 in the region of molecules with m.w. of 150,000. Absorption with protein A-Sepharose removes the activity, demonstrating that it is IgG. Digestion of the IgG with pepsin fails to diminish activity, indicating that the Fc region is not required for activity; reduction to monovalent Fab' fragments, however, abrogates activity. When IgG antibody is bound to Protein A-Sepharose, it fails to enhance C3 depletion in H gamma S by Sepharose, indicating that binding of IgG antibody by the Fab region is necessary for enhancement of alternative pathway activity in human serum.
Murine T cell lines that help induction and generation of allospecific cytotoxic T cells from thymocytes.
Authors: Narimatsu H , Saito K
Published: December 2022

Murine T cell lines that help induction and generation of allospecific cytotoxic T cells (CTL) from thymocytes cultured together with allogeneic stimulator cells have been established. It was done by successively culturing T cell blasts obtained from mixed lymphocyte cultures (MLC) in the medium supplemented with T cell growth factor (TCGF). The helper function of the long-term cultured T cells was antigen specific, radiation resistant, and not H-2 restricted. The helper function has been retained for more than 8 mo by the cells continually proliferating in the TCGF-supplemented medium. The T stimulated responsiveness of thymocytes to T cell mitogens. CTL activity seen in the original MLC waned rapidly during successive culture of this T cell line in TCGF medium T cell blasts from MLC successively cultured in continual presence of TCGF and the stimulator alloantigens retained strong CTL activity against the allogeneic stimulator cells for about 3 mo. All these T cell lines proliferating in TCGF medium expressed Thy 1 antigen and showed the appearance of a large T cell blast. These T cell lines could not proliferate in the absence of TCGF and lost responsiveness to T cell mitogens intrinsically.
Immunoregulatory plasma low density lipoprotein: the biologic activity and receptor-binding specificity is independent of neutral lipids.
Authors: Curtiss L K , Edgington T S
Published: December 2022

A normal human plasma low density lipoprotein subfraction (LDL-In), recovered within the intermediate density lipoprotein subclass of density range 1.006 to 1.019 g/ml, has previously been demonstrated to bind to a specific cell surface receptor independent of the LDL receptor and to regulate inductive events in the triggering of lymphocytes. The constituents of LDL-In that are responsible for the biologic activity and receptor-binding specificity were examined with respect to the role of sterols and other neutral lipids. Partial delipidization of LDL-In with heptane in the presence of starch permitted selective extraction of greater than 98% of the neutral lipids from the native lipoprotein particle. These partially delipidated polar lipid:protein particles were compared with native LDL-In with respect to charge, apoprotein content, suppressive activity for lymphocytes, and specific binding to the lymphocyte LDL-In receptor. The cholesterol- and glyceride-depleted LDL-In retained all characteristics of the native lipoprotein. These observations indicate that the interaction of LDL-In particles with the lymphocyte and the suppression of lymphocyte function are independent of the neutral lipid content of this bioregulatory lipoprotein, and that mechanisms other than cholesterol loading of the cell or sterol exchange with the plasma membrane must be operative.
Immune response gene control of determinant selection. III. Polypeptide fragments of insulin are differentially recognized by T but not by B cells in insulin immune guinea pigs.
Authors: Thomas J W , Danho W , Bullesbach E , Föhles J , Rosenthal A S
Published: December 2022

Synthetic polypeptides corresponding to restricted regions of the B chain of insulin were used to evaluate immune response gene control of guinea pigs immune to native insulin. The amino acids necessary for recall of immune memory were assessed at the level of the T cell by use of peptides 8 to 16 amino acids in length, representative of the amino terminus of the insulin B chain to induce antigen-specific proliferation and help for antibody formation. A single histidine residue in the 10th position of the B chain is critical for T cell activation. In addition, immune response genes operating in the macrophage discern the presence or absence of this residue and activate the appropriate T cell clones. Although receptor V region sharing may exist for T and B cells immune to globular proteins, it cannot be demonstrated by antigen specificity, since T proliferation and generation of T helper cells in response to intact insulin can be elicited by synthetic fragments that do not correspondingly induce antibodies that recognize the native molecule.
T cell hybridoma-derived regulatory factors. I. Production of T cell growth factor following stimulation by concanavalin A.
Authors: Schrader J W , Clark-Lewis I
Published: December 2022

A cloned T cell hybridoma (123) was shown to produce T cell growth factor (TCGF). Supernatants of cultures of hybridoma-123 that had been stimulated with concanavalin A caused T cell blasts or a cloned T cell line to proliferate, allowed a mitogenic response to concanavalin A by thymocytes and by lymph-node cells depleted of accessory cells by treatment with anti-Ia serum and complement, and permitted the generation of both polyclonal and antigen-stimulated cytotoxic T lymphocytes in cultures of thymus cells. These observations suggest that the hybridoma is producing a factor with an identical spectrum of activities to that associated with TCGF derived from mitogen-stimulated spleen cells and indicate that the T cell is the source of TCGF. Together with other evidence that the same hybridoma produces activity affecting B lymphocytes, myeloid progenitor cells, and pluripotential stem cells, these experiments confirm the role of the activated T cell as a regulator of hemopoietic and lymphoid systems. T cell hybridomas should prove invaluable for biochemical and genetic analysis of these factors.
Regulation of the production of immune interferon and cytotoxic T lymphocytes by interleukin 2.
Authors: Farrar W L , Johnson H M , Farrar J J
Published: December 2022

The activation of alloantigen-specific cytotoxic T lymphocyte precursors is dependent upon the presence of both macrophages and helper T cells or regulatory molecules derived from these facilitative cells. Three biochemically distinct helper factors have been identified: interleukin 1 (macrophage-derived), Interleukin 2 (T cell derived), and immune interferon. All 3 factors are found in supernatants of mixed lymphocyte cultures (MLC), however, the removal of macrophages from these cultures completely ablates the production of these factors as well as the induction of cytotoxic T lymphocytes (CTL). The addition of IL 2 to these macrophage-depleted MLC restores the ability of responder T cells to: 1) bypass the requirement for macrophage soluble function, 2) produce immune interferon, and 3) generate CTL. The kinetics and dose response of immune interferon production in response to IL 2 correlates with the generation of CTL. The production of immune interferon as well as the generation of CTL requires T cells, alloantigen, and IL2. Furthermore, the induction of CTL by IL2 was neutralized by the addition of anti-immune interferon. These data suggest that: 1) the regulation of immune interferon production is based on a T to T cell interaction mediated by IL 2, and 2) immune interferon production may be required for IL 2 induction of CTL. These findings are consistent with the hypothesis that the induction of CTL involves a linear cell-factor interaction in which IL 1 (macrophage-derived) stimulates T cells to produce IL 2, which in turn stimulates other T cells to produce immune interferon and become cytotoxic.
Plasminogen activation by normal B lymphocytes, a function associated with the cell membrane.
Authors: Maillard J L , Favreau C
Published: December 2022

When purified murine plasminogen was added to cultures of mouse spleen B cells, active plasmin progressively appeared in the supernatants. This reaction, resulting from the specific cleavage of the plasminogen by lymphocyte plasminogen activator (LPA), was measured in a fibrinolysis assay using 125I-fibrinogen. T cells were totally ineffective; under certain conditions, they could even antagonize the B cell action. Of the various B populations studied, i.e., obtained from spleen, lymph nodes, or blood of various mouse strains, all expressed the same property of plasminogen activation, which concerned mainly medium-sized B cells. Since only slight activities were detected in extracellular or intracellular compartments, a membrane-associated proteolytic enzyme may be responsible for plasminogen activation. Submitted to a series of group-specific antiproteases, the lymphocyte plasminogen activator essentially behaved as a serine-protease, with sensitivity to diisopropyl fluorophosphate, phenyl methyl sulfonyl fluoride, and nitro phenyl guanidino benzoate. The fast renewal of the enzyme in the membrane was also demonstrated by different techniques, using modifiers of cell physiology, like cycloheximide and dexamethasone, or following the reexpression of the enzyme by the cell kinetically.
Soluble suppressor supernatants elaborated by concanavalin A-activated human mononuclear cells. I. Characterization of a soluble suppressor T cell proliferation.
Authors: Greene W C , Fleisher T A , Waldmann T A
Published: December 2022

When activated with the mitogenic lectin, concanavalin A, a subset of human peripheral blood mononuclear cells differentiate into potent suppressor cells that negatively modulate both cellular and humoral immune reactions. In addition to inhibitory cell-cell interactions, these regulatory cells elaborate a soluble immune suppressor supernatant (SISS) containing at lest 2 distinct suppressor factors. One of these factors, SISS-T, inhibits mitogen- and antigen-stimulated T cell proliferation, whereas the other, SISS-B, inhibits B cell immunoglobulin production. Characteristics of the latter inhibitor are reported in the companion paper. Properties of the soluble suppressor of T cell proliferation (SISS-T) include: 1) a m.w. of 30 to 45,000, 2) inhibition by a noncytotoxic mechanism, 3) instability at 56 degrees C, 4) loss of activity in the presence of the monosaccharide N-acetyl-D-glucosamine and retention on N-acetyl-D-glucosamine affinity columns, 5) binding to the same surface glycoprotein receptors recognized by the lectins wheat germ agglutinin and Agaricus bisporus lectin, which produce similar inhibition of mitogen- or antigen-induced lymphocyte proliferation, 6) elaboration by cells irradiated with 500 and 2000 R but not 6000 R, 7) a minimum requirement for 24 hr of lectin stimulation for production, and 8) elaboration by adherent cells or alternatively cellular collaboration requiring the participation of adherent cells. These data indicate that human suppressor cells are capable of modulating T cell function via the production of a soluble saccharide-specific factor(s) that interacts with defined surface glycoprotein or glycolipid receptors. These same receptors recognized by the suppressive endogenous lectin are also activated by selected exogenous nonmitogenic lectins that produce similar inhibition of T cell metabolism.
Allergic neuritis: a neuritogenic peptide from the P2 protein that induces disease in rats.
Authors: Szymanska I , Ishaque A , Ramwani J , Eylar E H
Published: December 2022

Peptide CN1, a large 93 residue peptide, derived from residues 21-113 of the bovine and rabbit P2 protein of sciatic nerve myelin, induces severe allergic neuritis in Lewis rats. When complexed with phosphatidylserine and tested at 50 microgram dosage in Freund's complete adjuvant, it induces severe clinical and histologic signs (cellular infiltration and demyelination of the sciatic nerve) in most animals. It is as potent in disease induction as the P2 protein on a weight basis. In contrast, when not complexed with phosphatidylserine, Peptide CN1 induced only mild clinical signs and histologic lesions in 3 of 10 rats. CNBr peptides CN2 and CN3, derived from the carboxyl and amino terminal ends, respectively, were not active. Spleen and lymph node cells from rats sensitized to Peptide CN1 responded to both P2 and Peptide CN1 in culture in the mitogenic assay. These data show that the major neuritogenic domain for the rat resides in the CN1 region.
Spontaneous cytotoxicity against virus-infected cells: relationship to NK against uninfected cell lines and to ADCC.
Authors: Weston P A , Jensen P J , Levy N L , Koren H S
Published: December 2022

Cellular immunoadsorption and cold cell competition assays were used to examine the specificity of NK. Lymphocytes nonadherent to monolayers of cells persistently infected with Sendai virus (SV-HEp2) were almost totally depleted of NK against the uninfected tumor cell lines K562, MOLT-4, and HSB, as well as against SV-HEp2, when assayed immediately after separation. Lymphocytes adherent to SV-HEp2 monolayers were also partially depleted of NK against these targets. After overnight incubation, the nonadherent cells remained relatively depleted of NK against all targets, compared to controls. The adherent cells displayed a variable amount of activity, depending on the donor; in all cases, however, substantial NK activity was observed in this fraction against all targets, infected and uninfected. Exogenous interferon failed to augment the activity of the nonadherent lymphocyte fraction. Cellular immunoadsorption on monolayers of K562 or HSB was similarly found to partially deplete NK against SV-HEp2, as well as against the homologous cells. Cold cell inhibition studies showed that SV-HEp2 and, to a lesser extent, HEp2, could inhibit the lysis of K562; similarly, K562 could partially inhibit the lysis of SV-HEp2. We concluded that infected and uninfected target cells are lysed by overlapping populations of NK effector cells. In addition, the ADCC activity of SV-HEp2-adherent and nonadherent lymphocyte fractions was examined immediately after separation. Whereas the nonadherent lymphocytes were depleted of both ADCC and NK, the adherent lymphocytes were partially depleted of NK yet contained high levels of ADCC activity.
Delayed, relapsing experimental allergic encephalomyelitis in mice.
Authors: Lublin F D , Maurer P H , Berry R G , Tippett D
Published: December 2022

Immunization of female SJL mice with an emulsion of lyophilized mouse spinal cord, pertussis vaccine, and complete Freund's adjuvant produces a delayed and often relapsing form of experimental allergic encephalomyelitis (DR-EAE). The mice develop initial signs of disease an average of 6 mo after immunization. Relapses occurred 2 wk to 11 mo after the initial illness. Some animals had multiple relapses. Pathologic examination of the brain and spinal cord revealed perivascular infiltration of mononuclear cells with acute demyelination. Areas of subacute and chronic demyelination ("plaques") were also seen. This model produces a clinical course of relapsing-remitting disease with pathologic evidence of both recent and old inflammatory lesions at various levels of the central nervous system. It thus more closely resembles multiple sclerosis than acute EAE.
The transformation of adult but not newborn human lymphocytes by Epstein Barr virus and phytohemagglutinin is inhibited by interferon: the early suppression by T cells of Epstein Barr infection is mediated by interferon.
Authors: Thorley-Lawson D A
Published: December 2022

In a previous study, it was demonstrated that T cells from adult individuals were able to suppress the transformation of B cells after infection by EBV. In this paper, it is shown that this suppression is mediated by interferon. Thus, the suppression is abrogated by anti-interferon serum and mimicked by human leukocyte interferon. Furthermore, the interferon is released in response to the virus-infected B cell, not the virus alone. The relevance of these results to previous clinical evidence, indicating a role for interferon in recovery from EBV infection, is discussed. Interferon will also suppress the transformation of adult B lymphocytes by the mitogen phytohemagglutinin (PHA). However, interferon at concentrations 2 to 3 orders of magnitude higher was unable to suppress the transformation of neonatal B lymphocytes by either EBV or PHA. These experiments suggest that EBV and PHA induced transformation share a common interferon sensitive step. Lastly, the resistance of newborn lymphocytes to the protective effect of interferon may be an important consideration in the application of interferon as an antiviral or anti-tumor agent.
Cytolytic T lymphocyte precursor cells in congenitally athymic C57BL/6 nu/nu mice: quantitation, enrichment, and specificity.
Authors: Maryanski J L , MacDonald H R , Sordat B , Cerottini J C
Published: December 2022

A sensitive limiting dilution microculture system was used to obtain minimal estimates of the frequency of CTL precursor cells (CTL-P) in spleens from 5- to 14-mo-old C57BL/6 nu/nu mice. Frequency determinations of CTL-P directed against H-2d alloantigens ranged from 1/159,000 to 1/12,400. The relatively low frequency of CTL-P was enriched nearly 10-fold (to 1/2300) by passage of nude spleen cells over a column of nylon wool. After priming nude spleen cells for 7 days in conventional MLC, 1 to 3% of the MLC cells could be operationally identified as CTL-P. Furthermore, the progeny of MLC-primed nude CTL-P were specifically cytolytic for target cells of the strain used for priming. Such a system may be useful for analyzing the specificity repertoires of cells of the T cell lineage that have not undergone thymic influence.
Frequency analysis of immunoglobulin V-gene expression and functional reactivities in bone marrow B cells.
Authors: Benner R , Rijnbeek A M , Schreier M H , Coutinho A
Published: December 2022

Frequency of immunocompetent B cells in bone marrow has been determined in vitro under culture conditions that allow the development in vitro under culture conditions that allow the development of every growth-inducible B cell into a clone of IgM-secreting PFC. Three limiting dilution culture systems were employed: a specific helper assay with SRBC as antigen and using activated T helper cells, a nonspecific helper assay using Con A-induced factors as a source of help, and polyclonal activation with LPS. From unseparated, normal C57BL/6J bone marrow 1 in 2200 to 1 in 2820 B cells were induced to form a clone of PFC to SRBC in each of the 3 systems. This corresponds to a frequency of 1 SRBC-specific clone in every 900 IgM-secreting LPS-reactive clones. The frequencies of specific plaque-forming B cell clones in terms of LPS-reactive B cells was 1 in 36 for NNP1-SRBC, 1 in 58 for TNP30-SRBC, 1 in 75 for NIP1-SRBC, and 1 in 230 for TNP3-SRBC. These frequencies of v-gene expression in bone marrow B cells are of the same magnitude as the corresponding frequencies for splenic B cells. Bone marrow B cells are also fully susceptible to stimulation by antigen in combination with either specific or nonspecific T cell help, as well as polyclonal activation by LPS, since every 3rd Ig-positive cells in marrow could be induced to form a clone of IgM-secreting cells. There is thus no difference in immunocompetence between surface Ig-bearing B cells from bone marrow and spleen.
Requirement of a combination of a saturated and an unsaturated free fatty acid and a fatty acid carrier protein for in vitro growth of lymphocytes.
Authors: Spieker-Polet H , Polet H
Published: December 2022

Two FFA, 1 saturated and 1 unsaturated, and a FFA carrier protein are essential for in vitro growth of Con A-stimulated lymphocytes. Optimal growth was obtained with a combination of palmitic and oleic acid. As carrier proteins, serum albumin and beta-lactoglobulin served equally well. Palmitic and oleic acid could be replaced by other saturated and unsaturated FFA, respectively. The effectiveness of unsaturated FFA was influenced by the chain length, the number of double bonds, and the configuration at the double bond. The position of the double bond appeared to have no effect. 125I-HSA binds to lymphocytes in a specific and nonspecific way. beta-Iac competes with 125I-HSA for the SA-binding sites. The specific binding and the growth supporting ability of SA have a similar dose response.
Synergism between two helper cell subpopulations characterized by different radiosensitivity and nylon adherence.
Authors: Agarossi G , Mancini C , Doria G
Published: December 2022

The present work extends our previous results on the radiosensitivity of the helper cell function. Two helper cell subpopulations, 1 radiosensitive and the other radioresistant, have been demonstrated in the spleen of mice at different times after priming with HRBC. The radiosensitive subpopulation increases with the increasing time interval between carrier-priming and irradiation. The 2 cell subpopulations have been further characterized by different nylon adherence properties: radioresistant helper cells adhere to nylon wool, whereas radiosensitive cells pass through. The 2 cell subpopulations were separated by x-irradiation and nylon wool filtration, and their helper activity was assessed separately or after recombination. The results favor the notion that 2 functionally independent helper T cells, as characterized by different radiosensitivity and nylon adherence, participate synergistically in the helper activity of primed spleen cells.
Functionally distinct helper T cells enriched under different culture conditions cooperate with different B cells.
Authors: Imperiale M J , Faherty D A , Sproviero J F , Zauderer M
Published: December 2022

Helper T cells selected from KLH-primed lymph node cells under different in vitro conditions were analyzed for the ability to cooperate in secondary hapten-specific antibody responses. It is shown that carrier-specific, MHC-restricted helper T cells selected in low-density cultures cooperate with equal efficiency in either PC-specific or DNP-specific responses. In the presence of both PC-specific and DNP-specific B precursors, however, such T cells are limited to participate in only one helper event in vitro. In contrast, the predominant helper T cell in a second population maintained in high-density lymph node cultures cooperates, presumably through a soluble factor, with multiple B precursors. These properties correspond to those previously described for specific and nonspecific effector functions. The experiments reported here further demonstrate that different B cells respond in vitro to carrier-specific and nonspecific helper signals.
The effect of T cell growth factor on the cell cycle of primate T cells.
Authors: Brown R L , Griffith R L , Neubauer R H , Rabin H
Published: December 2022

The effect of T cell growth factor (TCGF) on the cell cycle of four T cell lines that differed in their response to TCGF was studied. Activated normal marmoset T cells (OH-1) were totally dependent on the addition of TCGF for long-term proliferation. In the absence of TCGF, the cells were incapable of traversing the cell cycle and became arrested in G1. The addition of TCGF to arrested OH-1 cells stimulated them to enter the S phase after a lag phase of 24 to 33 hr. The TCGF-stimulated cells reached a maximum of cells in the S phase by 12 hr after the initiation of DNA synthesis. TCGF was required for a minimum of 18 hr before cells would enter the S phase. In the absence of TCGF, activated owl monkey (8I) and human (RG) lymphocytes displayed a TCGF-sensitive block; addition of TCGF stimulated these cells to enter the S phase after 12 and 16 hr, respectively. In contrast, an owl monkey tumor-derived T cell line (OMT-1), not dependent on exogenous TCGF for proliferation, was able to progress slowly through the cell cycle without a TCGF-sensitive block. These cells responded to TCGF by showing an initial increase in cells that entered the S phase after a lag of 6 hr and a continuing movement of additional cells into S over the course of the next several hours.
Regulation of macrophage suppression and cytotoxicity by interferon role of Ia-bearing macrophages.
Authors: Boraschi D , Niederhuber J E
Published: December 2022

Resident peritoneal M phi of C3H/HeN mice co-cultured with splenic lymphocytes suppressed proliferation to mitogens. This M phi-mediated suppression was significantly reduced by in vitro treatment of M phi with fibroblast interferon (IFN-beta). Conversely, M phi-mediated natural tumor cytolysis was augmented by M phi treatment with IFN-beta. Depletion of Ia-bearing (Ia+) M phi by means of anti-Ia serum and C treatment did not affect M phi-mediated suppression or M phi-mediated natural cytotoxicity. This suggested that Ia-negative (Ia-) M phi were responsible for the effector phase of these two M phi functions. The IFN-beta-induced increase in M phi cytolysis was not affected by depletion of Ia+ cells; however, modulation of suppressive activity by IFN-beta was found to be highly dependent on the presence of Ia+ M phi. This observation indicated that different M phi subpopulations were involved in the regulation of suppressive and tumoricidal activity. The results indicating different regulatory M phi were supported by experiments with C3H/HeJ mice. C3H/HeJ M phi do not develop high cytolytic activity in response to a variety of stimuli; however, M phi from C3H/HeJ mice were able to exert suppressive activity, which was reduced by treatment with IFN-beta.
Chemically related antigens compete for presentation by accessory cells to T cells.
Authors: Werdelin O
Published: December 2022

Immune responsiveness of guinea pigs to dinitrophenyl-poly-L-lysine (DNP-PLL) and to the lysine-rich random copolymer of L-glutamic acid and L-lysine (GL) are both controlled by the "poly-L-lysine gene." We demonstrate that accessory cells of responder strains can be made incapable of presenting DNP-PLL to response T cells in assays for proliferation by in vitro exposure of the cells to GL before and during their exposure to DNP-PLL. The inhibition was not rapidly reversible, because GL preexposed accessory cells that were cultured for 2 hr in GL-free medium were still refractory to pulsing with DNP-PLL. In contrast, DNP-PLL had only a moderate inhibitory effect on accessory cell presentation of GL. Unconjugated poly- and oligo-lysines also inhibited the ability of accessory cells to present DNP-PLL, but inhibitory activity was displayed only by homopolymers containing eight to 12 or more residues in the chain. The homopolymers of D-lysine, L-arginine, and L-glutamic acid, and lysine-free glutamic acid-rich copolymers had little or no inhibitory effect. The results are interpreted to mean that antigens to which responsiveness is regulated by the same Ir gene compete for presentation by accessory cells. This may reflect a competition for the Ir gene product of the antigen-presenting cell.
Spleen cells from adult mice given total lymphoid irradiation (TLI) or from newborn mice have similar regulatory effects in the mixed leukocyte reaction (MLR). II. Generation of antigen-specific suppressor cells in the MLR after the addition of spleen cells from newborn mice.
Authors: Okada S , Strober S
Published: December 2022

Spleen cells from newborn BALB/c mice were added to the mixed leukocyte reaction (MLR) between a variety of responder and stimulator cells. The newborn cells nonspecifically suppressed the uptake of (3H)-thymidine and the generation of cytolytic cells regardless of the responder-stimulator combination used. Suppressor cell activity fell rapidly during the first 4 days after birth, and could not be detected by day 20. Newborn spleen cells inhibited the generation of nonspecific suppressor cells during the MLR but did not inhibit the generation of antigen-specific suppressor cells. Thus, newborn spleen cells exhibit a pattern of regulation of the MLR similar to that reported previously for spleen cells from adult mice given total lymphoid irradiation (TLI). These regulatory interactions provide a model that explains the ease of induction of transplantation tolerance in vivo in newborn mice and in TLI-treated adult mice.
Production of human suppressor T cell hybridomas.
Authors: Greene W C , Fleisher T A , Nelson D L , Waldmann T A
Published: December 2022

To study human T cell suppression of immunoglobulin (Ig) synthesis with homogeneous populations of immunoregulatory cells, human suppressor T cell hybridomas were prepared by somatic cell fusion of concanavalin A-activated peripheral blood T cells with hypoxanthine-guanine phosphoribosyltransferase-(HGPRT, EC 2.4.2.8) deficient human leukemic CEM T cells. After selection in hypoxanthine-aminopterin-thymidine (HAT) medium and cloning by limiting cell dilution, two human T cell hybridomas were identified that produced 60 to 80% suppression of in vitro polyclonal immunoglobulin production when cocultured with pokeweed mitogen- (PWM) stimulated peripheral blood lymphocytes. Further, one of the suppressor T cell hybridomas constitutively secreted a soluble suppressor factor(s) (TsF) of m.w. 70,000 to 85,000 daltons, which produced reversible noncytotoxic inhibition of lectin-activated B cell Ig production. In contrast, this TsF did not inhibit lectin- or antigen-induced T cell proliferation, nor did it interfere with the generation or effector function of cytotoxic T cells. Additional studies indicated that this Tsf acts directly on B cells or monocytes rather than indirectly modulating the activity of immunoregulatory T cells. In summary, these studies suggest that techniques of somatic cell fusion may provide a valuable approach to further study human immunoregulatory cell-cell interactions as well as provide a source of sufficient quantities of important lymphokines for further purification and characterization.
Binding of immunoglobulin E to the receptor on rat peritoneal macrophages.
Authors: Finbloom D S , Metzger H
Published: December 2022

The binding of radiolabeled monomers and chemically cross-linked dimers of rat immunoglobulin E (IgE) to peritoneal macrophages of rats was characterized. With either form, 40,000 to 50,000 molecules of IgE were specifically bound per cell under conditions where no endocytosis occurred. Monomeric IgE dissociated from macrophages within minutes, whereas dimers of IgE had a much slower rate of dissociation. Denatured rat IgE or native human IgE failed to inhibit the binding, but mouse IgE and, to a limited extent, rat IgG did. Oligomers of IgE by virtue of their tighter association with the receptor should prove useful in isolation of the receptor.
Detection and characterization of idiotype-specific enhancing cells generated in mice immunized with idiotype.
Authors: Inada T , Yamamoto H , Bitoh S , Fujimoto S , Hamaoka T
Published: December 2022

Cellular interaction between MOPC-104E (M104E) cross-reactive idiotypic (CRI) antibody-producing B lymphocytes and lymphocytes generated by immunization with the relevant idiotype, M104E, was investigated. Adoptive transfer of M104E idiotype-primed and normal spleen cells into 600R x-irradiated syngeneic recipient mice resulted in striking enhancement of the M104E-CRI positive antibody response upon simultaneous immunization of recipients with dextran B1355S. The enhancement was not attributable to a simple additive effect but was due to synergistic cooperation between the two lymphocyte populations. This synergistic enhancement of the anti-idiotype immune cells producing CRI antibody was specific for MOPC-104E CRI, and was reproducible in an in vitro culture system. Because of the cellular characteristics of the enhancing cells, they were assumed to be B lymphocytes specific for the corresponding idiotype, since the activity was not abrogated by treatment with anti-Thy-1, anti-Lyt-1, anti-Lyt-2, or anti-brain-associated theta antisera plus complement, but was eliminated by means of a planning method using a rabbit-anti-mouse immunoglobulin-coated or idiotype-coated dish. The mechanisms of interaction between the CRI-positive B cells and anti-idiotypic B cells in response to the thymus-independent antigen dextran B1355S are discussed.
Immune response to the p-azobenzenearsonate (ABA)-GAT conjugate: role of I region genes in the selective activation of ABA-specific or GAT-specific T helper cells.
Authors: Seman M , Regnier D , Hermier B , Dubert J M
Published: December 2022

Immunization of GAT non-responders with ABA-GAT leads to the activation of ABA-specific T cells. These hapten specific T cells are Lyt-1+2- helper cells capable of inducing anti-ABA antibody responses in vivo or B cell activation in vitro. However, their activation does not modify the GAT non-responder phenotype. Immunization of GAT responder mice with ABA-GAT activates GAT-specific T cells, which can help anti-ABA and anti-GAT antibody responses. Since the responder and non-responder strains used in these experiments differ only in the alleles present in the I region, the results suggest that the selective activation of hapten- or carrier-specific T cells is controlled by I region genes. Yet sensitization of the two strains with ABA-KLH or ABA-Tyr induces KLH-specific or ABA-specific T cells, respectively. This provides further evidence that the use of an immunogenic carrier prevents the expression of the hapten-specific T cell clones present in the repertoire of both responder and non-responder animals. Macrophages from responder animals pulsed with ABA-GAT can present ABA and GAT determinants to T cells. Thus, the absence of ABA-specific T cells in responders primed with ABA-GAT and their presence in GAT non-responders reflects a competition between hapten- and carrier-specific T cells and not an epitope selection by macrophages. We discuss the significance of the results in terms of Ir genes determining the self-plus-antigen-specific T cell repertoire rather than controlling antigen presentation by macrophages.
The human HLA-DR antigens are encoded by multiple beta-chain loci.
Authors: Hurley C K , Nunez G , Winchester R , Finn O J , Levy R , Capra J D
Published: December 2022

Monoclonal antibodies have been used to isolate and characterize human HLA-DR antigens from human B cell lines. Using sequential immunodepletion experiments, several subsets of DR antigens have been identified. Partial amino-terminal amino acid sequencing has identified these subsets as DR molecules with sequences homologous to the murine I-E alloantigens. In addition, sequence data provide evidence for primary structural differences in the DR beta-chains of two of the subsets. These results provide primary structural evidence for the presence of multiple DR beta-chain loci.
H2 antihistamines augment antigen-induced histamine release from human basophils in vitro.
Authors: Tung R , Kagey-Sobotka A , Plaut M , Lichtenstein L M
Published: December 2022

H2 antihistamines, including cimetidine, burimamide, metiamide, and tiotidine, consistently augmented antigen-induced histamine release from human basophils in vitro when control histamine release was less than 20% of total. This effect was specific to the H2-receptor blocking activity of these drugs: equivalent degrees of receptor blockade by four different H2 antihistamines resulted in equipotent enhancement; H1-receptor antagonists did not alter histamine release; and aminoguanidine and amodiaquine, agents that inhibit histamine metabolism but do not block H2 receptors, did not enhance histamine release. Cimetidine did not enhance release when present a) when basophils were "activated" but did not release histamine ("first stage"), or b) when basophils were no longer susceptible to histamine inhibition ("second stage"). Thus, H2 antagonists enhanced histamine release by blocking the capacity of released histamine to act on H2 receptors to inhibit release. Because it is likely that only small percentages of histamine are released in vivo, it is possible that H2 antihistamines amplify the inflammatory process by blocking the inhibitory effects of the released histamine.
Effects of taxol on human neutrophils.
Authors: Roberts R L , Nath J , Friedman M M , Gallin J I
Published: December 2022

Taxol, a plant alkaloid, promotes and stabilizes microtubule assembly in cells and cellfree systems. In the present study, the effects of taxol on various functional, morphologic, and biochemical phenomena in human peripheral blood PMN (Hypaque-Ficoll) were examined. Taxol (10(-7) M) inhibited PMN chemotaxis stimulated by N-formyl-methionyl-leucyl-phenylalanine (f-met-leu-phe) or endotoxin-activated serum by more than 60%. The inhibition was not readily reversed by washing, and taxol itself was not a chemoattractant, nor is it a secretagogue. Spontaneous nondirected migration, cell spreading on a glass surface, and orientation of cell organelles in response to a chemoattractant gradient were also inhibited by taxol. Taxol (10(-5) M) decreased killing of Staphylococcus aureus, but did not alter phagocytosis of heat-killed Candida or hexose monophosphate shunt activity in resting or stimulated PMN. Ultrastructural studies showed that PMN incubated in f-met-leu-phe, taxol, or both had increased (p less than 0.001) numbers of centrosome-associated microtubules, and the microtubules of cells incubated in taxol with or without f-met-leu-phe were organized into bundles. Taxol (10(-5) M) markedly inhibited post-translational tyrosinolation of alpha-chains of tubulin in both resting and f-met-leu-phe-stimulated PMN. The data indicate that taxol inhibits PMN locomotion and bacterial killing, supporting a role for microtubules in these processes. The ultrastructural and biochemical data also support the view that taxol mediates its effects on PMN by its effect on microtubules.