bluuebunny/crossref_metadata_2025 huggingface dataset:
Two distinct mechanisms account for the immune response (Ir) gene control of the T cell response to pigeon cytochrome c.
Authors: McElligott D L , Sorger S B , Matis L A , Hedrick S M
Published: December 2022

Previous experiments have demonstrated that the immune response of MHC congenic mice to pigeon cytochrome c is under Ir gene control. Expression of I-E-encoded gene products influences both the magnitude and fine specificity of the Th cell response to pigeon cytochrome c and phylogenetic derivatives. Results of those experiments implicate both determinant selection and repertoire selection as mechanisms of Ir gene control in this system. In this report we have compared the TCR expressed in pigeon cytochrome c-reactive Th cells from B10.A(I-Ek), B10.A(5R) (I-Eb), and B10.S(9R) (I-Es) mice. The B10.A(5R) strain is a low responder to pigeon cytochrome c, but in response to moth cytochrome c this strain produces T cells which respond to pigeon or moth cytochrome c on B10.A APC. These cells are phenotypically identical to the predominant clonal phenotype seen in the B10.A response to pigeon cytochrome c. In this report, we show that the B10.A and B10.A(5R) pigeon cytochrome c-reactive T cells express essentially identical T cell receptors. These results, coupled with recent studies reporting a relatively low affinity for I-Eb molecules by pigeon cytochrome c peptides compared with moth cytochrome c peptides, strongly argue that the immune response defect in the B10.A(5R) strain is due to a defect in Ag presentation (determinant selection). In contrast, B10.A and B10.S(9R) strains are high responders to pigeon cytochrome c. Both strains produce T cell clones which are capable of responding to cytochrome c presented by either B10.A or B10.S(9R) APC in vitro. We show that, even in T cells with this MHC restriction degeneracy, the TCR expressed in the two strains are different. Because the APC of both strains can clearly present the cytochrome c Ag, we conclude that the differential expression of the TCR in the responses is due to a T cell repertoire selection difference in the two strains. Thus, for the response to one Ag in three MHC congenic strains, there exists evidence that both determinant selection and repertoire selection can be mechanisms of Ir gene control of an immune response.
Characteristics of the IL-2 receptor expressed on large granular lymphocytes from patients with abnormally expanded large granular lymphocytes. Implication of a non-Tac IL-2-binding peptide.
Authors: Hori T , Uchiyama T , Onishi R , Kamio M , Umadome H , Tamori S , Motoi T , Kodaka T , Uchino H
Published: December 2022

Large granular lymphocytes (LGL) from four patients with abnormally expanded LGL in the peripheral blood were studied regarding their receptor for IL-2. LGL from none of the cases examined expressed Tac Ag, an Il-2R glycoprotein recognized by anti-Tac mAb. However, 125I-labeled IL-2 binding experiments demonstrated that 1400 to 2800/cell IL-2 binding sites with a single affinity (K: 0.46-1.4 nM) were expressed on LGL from the four patients. The affinity was not high but about 10-fold higher than that of the low affinity IL-2R expressed on activated normal T lymphocytes. Furthermore, LGL from the four patients proliferated in response to higher concentrations of IL-2 and these responses were not inhibited by an excess amount of anti-Tac antibody. 125I-Labeled IL-2 cross-linking studies performed in two cases revealed the predominant expression of an IL-2 binding molecule with an estimated Mr of 70,000 to 75,000. After the culture with IL-2 for 48 h, expression of a small amount of Tac Ag (p55) was induced on LGL in at least three cases. These data strongly suggested that the IL-2R expressed on LGL is functional and identical to the p70, a novel IL-2 binding peptide that has been recently identified and speculated to form the high affinity IL-2R in association with the p55.
The influence of IL-1 treatment on the reconstitution of the hemopoietic and immune systems after sublethal radiation.
Authors: Morrissey P , Charrier K , Bressler L , Alpert A
Published: December 2022

The influence of IL-1 administration on the recovery of the hemopoietic and immune systems from sublethal irradiation was assessed. Mice were irradiated (750 R) and injected twice daily with purified recombinant derived IL-1 beta (200 ng/injection). At various times after irradiation, the functional capacity of the hemopoietic and immune systems was determined. It was found that IL-1 therapy resulted in a significantly greater number of granulocyte-macrophage-CSF responsive colony-forming cells in the bone marrow of the irradiated mice on days 5 and 11 postirradiation but not at later times. In addition the radiation induced neutropenia recovered quicker in the IL-1-treated mice with significantly greater numbers of peripheral blood granulocytes being seen on days 15 and 20 after irradiation. The influence of IL-1 therapy on the recovery of the immune system was also assessed. Of note was the observation that mice receiving IL-1 therapy had chronically hypoplastic thymi. Although thymic cellularity increased with time after irradiation in the control mice, there was no such increase in the IL-1-treated mice. Similarly, the number of pre-B cells in the marrow of these mice was also diminished. Thus, in the IL-1-treated mice the regeneration of the peripheral immune function was retarded, characterized by a general lymphopenia and decreased splenic responses to mitogenic stimuli.
Functional heterogeneity among human inducer T cell clones.
Authors: Umetsu D T , Jabara H H , DeKruyff R H , Abbas A K , Abrams J S , Geha R S
Published: December 2022

Analysis of mouse CD4+ inducer T cells at the clonal level has established that a dichotomy among CD4+ T cell clones exists with regard to types of lymphokines secreted. Mouse T cell clones designated Th1 have been shown to secrete IL-2 and IFN-gamma, whereas T cell clones designated Th2 have been shown to produce IL-4 but not IL-2 or IFN-gamma. To determine if such a dichotomy in the helper inducer T cell subset occurred in man, we examined a panel of human CD4+ helper/inducer T cell clones for patterns of lymphokine secretion and for functional activity. We identified human T cell clones which secrete IL-4 but not IL-2 or IFN-gamma, and which appeared to correspond to murine Th2 clones. In marked contrast to murine IL-2 secreting Th1 clones which do not produce IL-4 or IFN-gamma, we observed that some human T cell clones secrete IL-2, and IFN-gamma as well as IL-4. Southern blot analysis indicated that these multi-lymphokine-secreting clones represented the progeny of a single T cell. IL-4 secretion did not always correlated with enhanced ability to induce Ig synthesis. Although one T cell clone which secreted IL-2, IL-4, and IFN-gamma could efficiently induce Ig synthesis, another expressed potent cytolytic and growth inhibitory activity for B cells, and was ineffective or inhibitory in inducing Ig synthesis. These results indicate that although the equivalent of murine Th2 type cells appears to be present in man, the simple division of T cells into a Th1 and Th2 dichotomy may not hold true for human T cells.
Generation and characterization of monoclonal antibodies specific for the human IFN-gamma receptor.
Authors: Sheehan K C , Calderon J , Schreiber R D
Published: December 2022

Purified preparations of the human IFN-gamma R derived from placental membranes were used to produce receptor-specific murine mAb. Supernatants from growth-positive wells were screened for their ability to block binding of 125I-IFN-gamma to human placental membranes. Ten inhibitory cultures were identified. Two of these (GIR-208 and GIR-301) abrogated all binding of radioligand to either intact placental membranes or soluble, purified IFN-gamma R. Three others (GIR-72, 76 and 94) showed moderate blocking activity (65, 59, and 49%, respectively) whereas the remaining five (GIR-57, 67, 83, 109, and 153) blocked binding to a low but significant extent (20 to 40%). Specificity experiments demonstrated that the antibodies reacted with the receptor and not the ligand (IFN-gamma). None of the antibodies reacted with IFN-gamma by ELISA. Moreover, GIR-208 and GIR-301, but not isotype-matched controls, identified the receptor by Western blot analysis. GIR-208 and GIR-301 also completely abrogated binding of 125I-IFN-gamma to either mononuclear phagocytes (U937) or human fibroblasts (WISH). Competition experiments revealed that GIR-208 and GIR-301 recognized similar epitopes on the IFN-gamma R and that these (or this) epitopes were identical to or linked to the ligand binding site of the receptor. In addition, both antibodies inhibited development of IFN-gamma-dependent anti-viral activity in WISH cells in a dose-dependent fashion. These data thus indicate that the IFN-gamma R expressed on human placental cells, mononuclear phagocytes, and fibroblasts are similar.
Anti-proliferative effect of IFN-gamma in immune regulation. I. IFN-gamma inhibits the proliferation of Th2 but not Th1 murine helper T lymphocyte clones.
Authors: Gajewski T F , Fitch F W
Published: December 2022

A biphasic dose-response curve was observed when the IL-1-dependent HTL clone D10 was exposed to IL-1 plus supernatants from some activated T cell clones but not others. The active component that inhibited proliferation at high concentrations of these supernatants appeared to be IFN-gamma based on the following findings: 1) the biphasic pattern of responsiveness correlated with the presence of IFN-gamma in the supernatants; 2) an anti-IFN-gamma mAb augmented the proliferation of D10 cells to these supernatants; 3) rIFN-gamma inhibited profoundly the response of D10 cells stimulated with rIL-1 plus supernatant from activated D10 cells or with rIL-1 plus rIL-4; 4) the response of D10 cells to rIL-1 plus rIL-2 also was inhibited by rIFN-gamma, although to a lesser extent. The proliferation of an additional Th2 clone stimulated with rIL-1 plus rIL-4 or rIL-2 also was inhibited by rIFN-gamma, implicating IFN-gamma as an inhibitory lymphokine for Th2 cells in general. rIFN-gamma did not affect the proliferation of two Th1 clones, nor did it affect the proliferation of an unconventional HTL clone which produces both IL-4 and IFN-gamma and proliferates in response to IL-2 or IL-4 in an IL-1-independent fashion. The proliferation of D10 cells stimulated by Ag or by immobilized anti-CD3 antibody also was blocked by rIFN-gamma, whereas IL-4 production in response to these stimuli was unaffected, indicating that proliferation and not general cell function was specifically inhibited. Collectively, these data implicate IFN-gamma as a suppressive factor for the proliferation of the subset of HTL designated Th2, and suggest that the relative amounts of the various lymphokines present during an immune response may direct which T cell types increase in number.
H-2-dependent binding of xenogeneic beta 2-microglobulin from culture media.
Authors: Kievits F , Boerenkamp W J , Ivanyi P
Published: December 2022

Sera of C57BL/6 mice contained lymphocytotoxic antibodies after injections with syngeneic lymphoblasts. The antibodies were directed against bovine beta 2-microglobulin, a component of the culture medium, and mimicked H-2-specific antibodies by a preferential recognition of target cells expressing certain H-2 Ag. This "polymorphic" reactivity pattern was due to a variable capacity of H-2 molecules associated with bovine beta 2-microglobulin.
The alpha-3 domain of class I MHC proteins influences cytotoxic T lymphocyte recognition of antigenic determinants located within the alpha-1 and alpha-2 domains.
Authors: Maziarz R T , Burakoff S J , Bluestone J A
Published: December 2022

An interspecies class I MHC molecule, Kb1+2/A2 (in which the alpha-1 and alpha-2 domains of the H-2Kb molecule have been linked to the alpha-3, transmembrane and intracytoplasmic domains of the HLA-A2 molecule) has been expressed on both human and mouse target cells by gene transfer. Maintenance of serologic determinants has been demonstrated. However, decreased lysis by allospecific CTL populations of cell lines that expressed a hybrid interspecies class I molecule, Kb1+2/A2, as compared with lines that expressed the native Ag, H-2Kb, has been described. An analysis with a limited panel of H-2Kb allospecific clones demonstrated that not all H-2Kb-specific CTL can lyse cells that express Kb1+2/A2 Ag. This suggested that the reduction of lysis by CTL populations was due to the loss of specific alloreactive clones in the population. Each clone used in this study was then defined as having high or low affinity characteristics. No correlation between the affinity of the CTL and the ability to recognize the interspecies hybrid molecule could be shown. Rather, these data suggest that antigenic determinants that are located within the polymorphic domains, alpha-1 and alpha-2, may be conformationally influenced by the alpha-3 domain.
In vivo obtained antigen presented by germinal center B cells to T cells in vitro.
Authors: Kosco M H , Szakal A K , Tew J G
Published: December 2022

Shortly after secondary immunization germinal center (GC) B cells obtain antigen from follicular dendritic cells (FDC) in the form of immune complexes. This antigen appears to be degraded by the GC B cells and may be processed for presentation to T cells. The present study was undertaken to determine whether GC B cells can process and present antigen obtained from FDC in vivo to appropriate T cells in vitro. GC B cells were isolated from immune mice with the use of Percoll density separation followed by a panning procedure which utilizes the ability of the plant lectin, peanut agglutinin (PNA), to selectively bind to GC B cells. The enriched GC B cells were approximately 80% highly positive for PNA, 97% positive for Ia and surface IgM, but less than 0.01% positive for Thy-1.2 or esterase. In some experiments, this population was further purified to near 100% highly PNA-positive cells with the use of fluoresceinated PNA and a fluorescence-activated cell sorter. Cell sorting analysis indicated that the antigen (125I-labeled ovalbumin (OVA)) was restricted to the highly PNA-positive cell fraction. The capacity of these highly PNA-positive B cells to present antigen was assessed by monitoring interleukin 2 (IL-2) production by the OVA-specific T cell hybridoma, 3DO-54.8. GC B cells obtained from mice 3 wk or more after secondary immunization did not elicit IL-2 production in the absence of added OVA. However, GC B cells isolated as early as 1 day and for over 1 wk after a challenge with OVA, were able to stimulate high levels of IL-2 production, in the absence of adding OVA to the cell cultures. This response was maximal on day 5 and corresponded precisely with the kinetics of the ultrastructural studies which document the uptake of antigen by GC B cells in vivo. The FDC-derived antigen was remarkably immunogenic when compared with exogenous antigen. These findings demonstrated that antigen obtained in vivo by GC B cells could be processed and presented to T cells. In vivo, GC B cells may induce the T cell help needed for the germinal center reaction, generate B memory cells, and help induce the high titers of antibody associated with the secondary antibody response.
Regulation of T cell clone function via CD4 and CD8 molecules. Anti-CD4 can mediate two distinct inhibitory activities.
Authors: Blue M L , Hafler D A , Daley J F , Levine H , Craig K A , Breitmeyer J B , Schlossman S F
Published: December 2022

The functional effects resulting from CD4 and CD8 perturbation were analyzed by using a CD4+CD8+ clone and anti-CD4 and anti-CD8 monoclonal antibodies. Perturbation of CD8, but not CD4, by soluble antibody resulted in the inhibition of CD3-T cell receptor (CD3-Ti) triggering as determined by flow cytometric measurements of intracellular free Ca2+ concentrations. In addition, the CD3-T cell receptor-mediated cytotoxic function of the CD4+CD8+ clone was inhibited by anti-CD8, but not by anti-CD4. These results suggest that CD8, but not CD4, was functionally associated with CD3-Ti on the CD4+CD8+ clone. Although CD4 perturbation did not affect CD3-Ti-mediated activities, it resulted in the inhibition of the interleukin 2-dependent proliferation of this clone. Perturbation of CD8 did not affect the interleukin 2 dependent proliferation of the CD4+CD8+ clone. On the other hand, CD4 molecules of another CD4+CD8- clone unlike those of the CD4+CD8+ clone, were clearly linked to T cell receptor function. These results indicate that CD4 perturbation can result in two distinct regulatory activities; one involves the regulation of CD3-T cell receptor function, whereas the other is not directly associated with CD3-T cell antigen receptor function. The data are also consistent with the notion that CD4 and CD8 do not merely function as recognition and adhesion elements for accessory cell major histocompatibility complex molecules, but have a direct role in the regulation of T cell activation.
New differentiation antigens associated with the growth and maturation of B lymphocytes.
Authors: Suciu-Foca N , Cai J D , Gutiérrea C , Reed E , Morrison S , Pernis B , King D W
Published: December 2022

Monoclonal antibodies (mAb) NDA3 and NDA4 were generated by hyperimmunizing mice with an alloreactive human T cell clone and fusing the splenocytes with the NS1 myeloma. Immunofluorescence studies indicated that these mAb react with activated, but not with resting T and B lymphocytes or with other types of cells. Immunoprecipitation studies with 125-I-labeled extracts from T and B cell lines demonstrated that the m.w. of the antigen recognized by mAb NDA3 is 36,000 and that of NDA4 is 46,000. Studies on the effect of mAb NDA3 and NDA4 on Epstein Barr Virus-transformed lymphoblastoid B cell lines (LBCL) demonstrated that these antibodies stimulate B cell proliferation and Ig synthesis. The level of expression of NDA3 and NDA4 on the membrane of LBCL is significantly augmented when cells are grown in the presence of recombinant human interferon-beta and gamma and is decreased in the presence of 12-O-tetradecanoyl-phorbol-13-acetate. These observations, in conjunction with the stimulatory effect of mAb NDA3 and NDA4 on the growth and differentiation of LBCL, suggest that these new differentiation antigens, NDA3 and NDA4, may serve as growth factor receptors.
Activation properties of T cell receptor-gamma delta hybridomas expressing diversity in both gamma- and delta-chains.
Authors: Marusić-Galesić S , Pardoll D M , Saito T , Leo O , Fowlkes B J , Coligan J , Germain R N , Schwartz R H , Kruisbeek A M
Published: December 2022

To elucidate the structure, diversity, and activation properties of the murine T3-associated gamma delta-receptor, examination was made of the gamma delta and T3 components, T cell receptor (TCR) gene transcription, activation properties, and lymphokine production in a panel of four cloned T cell hybridomas expressing a TCR-gamma delta. Biochemical analysis of the gamma and delta proteins expressed on these hybridomas reveals new gamma and delta species not observed in whole populations of dLy-1 Lyt-2-L3T4-thymocytes from which these hybridomas were derived. Thus, analysis of expression of the TCR-gamma delta complex at the clonal level indicates that both gamma and delta appear to be expressed as multiple distinct gene products within a homozygous inbred mouse strain. Northern blot analysis reveals that, whereas all gamma delta hybridomas had mature 1.5-kb TCR-alpha-chain and mature TCR-gamma-chain transcripts, none had mature 1.3-kb TCR-beta-chain transcripts, thus indicating that the type of TCR heterodimer expressed reflects of the state of TCR gene transcription in these hybridomas. Our results also reveal striking similarities between TCR-gamma delta and TCR-alpha beta cells with respect to their activation properties. First, all five of the T3 components associated with the gamma delta-complex are of the same size and have the same glycosylation patterns as those associated with alpha beta-heterodimers. Second, induction of function in these gamma delta cells (assayed by lymphokine production) can be achieved with a variety of stimuli known to elicit activation signals in alpha beta cells as well: direct receptor-engagement (i.e., through anti-Thy-1), and phorbol 12-myristate 13-acetate-plus-ionomycin-mediated. Collectively, these findings suggest that gamma delta T cells express a receptor of at least limited diversity and use T3-mediated activation pathways very similar to those employed by TCR-alpha beta-bearing T cells.
Suppression of experimental autoimmune encephalomyelitis by oral administration of myelin basic protein and its fragments.
Authors: Higgins P J , Weiner H L
Published: December 2022

We report that experimental autoimmune encephalomyelitis, a T cell-mediated autoimmune disease studied as a model for multiple sclerosis, can be suppressed in Lewis rats by the oral administration of myelin basic protein (MBP). Both the clinical and histopathologic manifestations of the disease were suppressed in a dose-dependent manner. In addition, proliferative responses to MBP and, to a lesser extent, serum levels of anti-MBP antibody were suppressed by feeding MBP. Suppression of clinical and histologic disease was observed whether animals were fed MBP before or after disease induction, although suppression was more complete when rats were fed before immunization. Disease was also suppressed by the oral administration of either encephalitogenic or nonencephalitogenic fragments and decapeptides of the MBP molecule, with more complete suppression observed when nonencephalitogenic fragments were fed, suggesting that suppressor determinants exist in the MBP molecule distinct from the encephalitogenic region. The oral administration of a non-disease-inducing portion of an autoantigen represents an antigen-specific method by which an experimental autoimmune disease can be immunoregulated.
Overlapping polypeptide induction in human fibroblasts in response to treatment with interferon-alpha, interferon-gamma, interleukin 1 alpha, interleukin 1 beta, and tumor necrosis factor.
Authors: Beresini M H , Lempert M J , Epstein L B
Published: December 2022

Cytokine-induced polypeptides were identified in whole cell lysates of human fibroblasts by computer-based analysis of two-dimensional gels with the use of the PDQuest System. Treatment with interferon-alpha (IFN-alpha) and interferon-gamma (IFN-gamma) enhanced the synthesis of 12 and 28 polypeptides, respectively. Exposure to interleukin 1 alpha (IL-1 alpha) or interleukin 1 beta (IL-1 beta) resulted in the increased synthesis of seven identical polypeptides. Treatment with tumor necrosis factor (TNF) at 100 U/ml led to enhanced expression of seven polypeptides, whereas exposure to TNF at 1000 U/ml increased the levels of these seven plus two additional polypeptides. The antiviral and antiproliferative effects of these cytokines in strain 153 fibroblasts were also assessed. Both IFN-alpha and IFN-gamma exhibited antiviral activity, whereas both IL-1 and TNF stimulated fibroblast growth. IFN-gamma was alone in inhibiting proliferation. Thus, although these cytokines exhibit low degrees of structural homology, they share some common functions, and a number of polypeptides were induced in common by two or more of these agents. The greatest similarities in polypeptide induction occur between IFN-alpha and IFN-gamma and between the IL-1s and TNF. However, polypeptides were also induced in common by IFN-alpha and TNF, IFN-gamma and IL-1, and IFN-gamma and TNF. These similarities in polypeptide induction may reflect the overlapping functions of these cytokines and may be indicative of common biochemical pathways in their mechanisms of action.
Lack of cross-reaction in antibody-dependent cellular cytotoxicity between human immunodeficiency virus (HIV) and HIV-related West African strains.
Authors: Ljunggren K , Chiodi F , Biberfeld G , Norrby E , Jondal M , Fenyö E M
Published: December 2022

Sera from individuals infected with human immunodeficiency virus (HIV) and HIV-related West African viruses can mediate high-titered, virus-specific antibody-dependent cellular cytotoxicity (ADCC) in all stages of infection. No cross-reactive ADCC can be detected between HIV and HIV-related West African strains LAV-2, HTLV-IV, and SBL-6669. Because these two groups of viruses have antigenically distinct envelope glycoproteins, ADCC-mediating antibodies are most likely directed against envelope antigens. For HIV-specific ADCC, this was further confirmed by using sera reacting with HIV envelope but negative for antibodies against viral core antigens.
Epitopes of an influenza viral peptide recognized by antibody at single amino acid resolution.
Authors: Schoofs P G , Geysen H M , Jackson D C , Brown L E , Tang X L , White D O
Published: December 2022

Antibodies raised against the synthetic peptide corresponding to the carboxy-terminal 24 amino acids (305-328) of the heavy chain of the hemagglutinin molecule of influenza virus A/X-31 (H3) bind this peptide at three antigenic sites. These sites were identified by assaying binding of polyclonal BALB/c mouse antipeptide sera to the complete set of all possible di-, tri, tetra-, penta-, hexa-, hepta-, and octapeptides homologous with the 24-residue sequence. Individual epitopes were defined and essential residues identified by testing the binding of monoclonal antibodies to sets of peptide analogues in which every one of the homologous residues was replaced in turn by each of the 19 alternative genetically coded amino acids. The immunodominant epitope was shown to be a linear sequence of five amino acids, 314LKLAT318. Replacement of any one of these residues with any other amino acid resulted in loss of antibody binding, indicating that all five are essential to the interaction and that they are probably contact residues. Another antigenic site contains at least two overlapping epitopes: polyclonal sera recognize predominantly an epitope or epitopes encompassed by the linear sequence 320MRNVPEKQT328, whereas the epitope defined by a particular monoclonal antibody comprises the seven amino acids 322NVPEKQT328, of which N322, E325, and Q327 were implicated as contact residues.
Analysis of the effect of a strain-specific alteration in the upstream octamer region on transcription of a mouse V kappa Ser light chain gene.
Authors: Goldrick M M , Gottlieb P D
Published: December 2022

Previous studies had shown that several phenotypic markers expressed by several strains of mice (C58, AKR, PL, RF) involve a light chain group, called V kappa Ser, encoded by a single germ-line gene (Igk-VSera). Most other inbred strains (e.g., BALB/c) contain an allele (Igk-VSerb) which differs from Igk-VSera both in coding regions and in an upstream octamer region known to be important for transcription. Since no evidence for expression of the Igk-VSerb gene product has been observed, experiments were undertaken to determine whether the alteration in the regulatory octamer region of BALB/c might have rendered it defective for transcription. The upstream octamer-containing region of a cloned functional V kappa Ser gene expressed by the C.C58 myeloma M75 was replaced by the corresponding region from BALB/c or deleted entirely. Constructs were transfected into J558L cells and quantity of transcription and site of transcription initiation were compared. Results suggest that the BALB/c octamer (CTTTGCGT), which differs at two of eight nucleotides from the consensus octamer sequence (ATTTGCAT), is fully functional in transcription initiation. This is consistent with results of S1 nuclease protection experiments which indicate the presence of small amounts of correctly initiated V kappa Ser-related RNA in BALB/c spleen.
Afferent and efferent cellular interactions in natural resistance directed against MHC class I deficient tumor grafts.
Authors: Ljunggren H G , Ohlén C , Höglund P , Yamasaki T , Klein G , Kärre K
Published: December 2022

H-2-deficient variants, selected from the murine lymphoma RBL-5, were recently shown to be less tumorigenic in syngeneic mice compared with the corresponding H-2-positive wild-type cell line. The present study focused on the detailed cellular interactions leading to the specific rejection of H-2-deficient cells in vivo. In vivo experiments with mixed tumor inocula, measuring either tumor outgrowth or rapid elimination, showed that the presence of H-2-positive lymphoma cells did not suppress the rejection of H-2-deficient cells. Conversely, H-2-deficient cells did not activate a rejection of H-2-positive cells. H-2-deficient cells were selectively eliminated even when they were present in a 10-fold excess compared with the H-2-positive lymphoma cells in the same inoculum. In vitro, H-2-deficient cells were more sensitive to killing by spleen cells from mice treated with interferon or natural killer-inducing agents. The presence of cold H-2-deficient cells did not activate the killing of H-2-positive cells, and H-2-positive cells did not inhibit killing of H-2-deficient cells. Such mixing experiments revealed a more efficient cold target inhibition by the H-2-deficient cells, although no difference was seen between these and the H-2-positive wild-type cells in target binding assays. When Thy-1.2+, nylon wool adherent or phagocytic populations were removed from normal spleen effectors, the difference in spontaneous cell-mediated cytotoxicity between the H-2-deficient and the H-2-positive cells persisted. This result was also obtained when spleen cell effectors from nude mice or asialo GM1+ effectors, positively enriched by fluorescence-activated cell sorter, were used. The results show that the selectivity in the rejection of H-2-deficient cells was not determined in the afferent arm alone. The present data fit with a previously proposed model where natural killer cells would bind equally well to both major histocompatibility complex class I negative and class I positive target cells, but only the latter would be able to present a postbinding inhibitory signal allowing them to escape killing which results in outgrowth in vivo and poor cold target competition in vitro.
Characterization and growth factor requirements of SJL lymphomas. I. Development of a B cell growth factor-dependent in vitro cell line, cRCS-X.
Authors: Lasky J L , Ponzio N M , Thorbecke G J
Published: December 2022

Reticulum cell sarcomas (RCS) of SJL mice are completely dependent on host cells for their growth and therefore fail to grow in vitro. RCS cells induce marked proliferation in SJL Ly-1+2- T cells accompanied by lymphokine production. In an attempt to fully understand the host-tumor cell interaction, an RCS cell line, cRCS-X, was established in vitro from a transplantable tumor by the addition, every 3 wk, of gamma-irradiated syngeneic lymph node (LN) cells to the culture. cRCS-X maintains all of the characteristics of the parent tumor, RCS-X, including cell surface phenotype (Ks and I-As positive, Ds negative and B cell marker 14.8 positive), ability to stimulate host T cells, and ability to grow in nonirradiated but not in gamma-irradiated SJL mice. The growth factor requirements of cRCS-X were examined. It was found that human BCGF can replace gamma-irradiated LN cells in the maintenance of long term in vitro growth of cRCS-X. cRCS-X cells respond to human B cell growth factor (BCGF) or to recombinant murine interleukin (IL)-5 in a short term proliferation assay [( 3H]thymidine incorporation) in a dose-dependent manner in the presence and absence of fetal calf serum. BCGF also promotes colony formation in soft agar by cRCS-X cells. Although both IL-1 and interferon-gamma can synergize with BCGF in the induction of cRCS-X proliferation, these lymphokines, as well as IL-2, IL-3, granulocyte-macrophage colony-stimulating factor, and IL-4 have no effect on cRCS-X growth when added alone. In addition, it was shown that SJL LN cells produce both IL-4 and BCGF II activities as assayed on murine B cells, after stimulation with gamma-irradiated cRCS-X cells. In light of these results it is postulated that IL-5, [corrected] produced by syngeneic T cells [corrected] after stimulation with RCS, is essential for RCS growth, both in vitro and in vivo.
Asialo-GM1-positive T killer cells are generated in F1 mice injected with parental spleen cells.
Authors: Knobloch C , Dennert G
Published: December 2022

(C57BL/6 x DBA/2)F1 mice transplanted with parental C57BL/6 spleen cells become splenic chimeras, show donor antihost cytotoxic T cell activity, and lose their T cell-mediated, humoral, and natural immunity. Injection of anti-asialo-GM1 (ASGM1) into transplanted mice strongly suppresses splenic cytotoxic activity and causes a significant reduction of spleen cells expressing ASGM1, Thy-1, and Lyt-2. In vitro treatment of spleen cells from transplanted mice with antibody and complement shows that the cytotoxic effector cells are ASGM1+, Thy-1+, Lyt-2+, L3T4-, NK1.1-, and H-2d-, hence of donor origin. The cytotoxic effector cells are specific for H-2d targets and lack NK activity. In an attempt to explore whether in vivo elimination of the cytotoxic effector cells has any influence on splenic chimerism or humoral immunity, F1 mice injected with parental splenocytes were treated with anti-ASGM 1. Results show that this treatment eliminates a substantial proportion of cytotoxic effector cells but has no effect on splenic chimerism or restoration of humoral immunity. It therefore appears that cytotoxic effector cells are not primarily responsible for induction of chimerism or suppression of humoral immunity. In support of this injection of parental spleen cells with the nu/nu mutation induces killer cells in F1 mice but fails to induce splenic chimerism or immunosuppression. In contrast, injection of parental spleen cells with the bg/bg mutation generates both splenic chimerism and suppression of humoral immunity although their ability to generate cytotoxic effector cells in F1 hosts is seriously impaired and comparable to the cytotoxic potential of C57BL/6 nu/nu cells. It is concluded that the ASGM1 + cytotoxic T cells are not primarily responsible for splenic chimerism and suppression of humoral immunity and that the two effects are likely caused by parental cells with a different phenotype and function.
Functional properties of human B cell subpopulations defined by monoclonal antibodies HB4 and FMC7.
Authors: Bloem A C , Chand M A , Dollekamp I , Rijkers G T
Published: December 2022

Human B cell subpopulations can be distinguished by the expression of B cell-associated antigens. mAb directed against these structures allow the isolation and subsequent functional analysis of such subsets. Blood B cells from healthy individuals were separated on basis of the expression of the antigens recognized by the mAb HB4 and FMC7. The B cells present in the thus obtained populations were analyzed for their ability to secrete IgM and IgG after stimulation in vitro with polyclonal B cell activators (PWM, Staphylococcus aureus Cowan I), antigens (tetanus toxoid, type 4 pneumococcal polysaccharides), and soluble B cell differentiation factors. The results suggest that B cells capable of Ig and anti-tetanus toxoid or anti-type 4 pneumococcal polysaccharide antibody production after in vitro culture are localized in a relative small B cell subpopulation carrying the FMC7 determinant but lacking HB4. This holds true for both the IgM- and IgG-secreting B cells. These data further suggest that the majority of B cells found in the blood and which can be characterized as being surface IgM+/IgD+ HB4+ are immature cells unable to respond to differentiation-inducing signals.
Expression of a 33-kDa antigen Tm 1 on lymphocyte surface after modulation of cell surface antigens by IgM monoclonal antibody.
Authors: Hara T , Jung L K , Fu S M
Published: December 2022

The mAb Tm 1 was obtained from a fusion of SP2/O tumor cells with spleen cells from CF1 mouse immunized with T cells modulated by an IgM anti-CD3 mAb.mAb Tm 1 reacted with IgM anti-CD3 modulated T cells (66.6%) but not with unmodulated T cells (4.4%). Tm 1 was not expressed on T cells modulated with either IgG2a or IgG1 anti-CD3 mAb. Immunoprecipitation from 125I-labeled CD3-modulated T cells showed that Tm 1 Ag is a single polypeptide of 33 kDa under reducing and nonreducing conditions. Kinetic studies revealed that Tm 1 was detectable on T cells 10 min after incubation and maximally expressed after 4 h of incubation with IgM anti-CD3 mAb. CD3 expression was markedly modulated by this anti-CD3 mAb after the same period of incubation. Studies with cycloheximide revealed that Tm 1 expression on T cells does not require new protein synthesis. Tm 1 expression persisted long after CD3-reexpression 24 h later. Tm 1 was present on a small fraction of circulating T cells, B cells, and monocytes and absent from granulocytes, platelets, E, and thymocytes. Tm 1 was not expressed on T cells after various activation stimuli but was expressed on B cells upon activation. Additional studies indicate that IgM mAb against other T cell differentiation Ag and IgM mAb against B cell Ag also lead to the expression of Tm 1 on these cells. Thus, modulation of surface Ag by IgM mAb externalizes this cytoplasmic Ag. However, one exception has been noted. Purified mAb Tm 1 was not mitogenic and was unable to block either the T cell proliferation induced by 12-O-tetradecanoyl phorbol-13-acetate plus anti-CD3 mAb and other T cell stimuli, or the B cell proliferation induced by B cell mitogens. The role of Tm 1 on lymphocyte function remains to be determined.
Purification and partial sequence of rabbit polymorphonuclear leukocyte-derived lymphocyte proliferation potentiating factor resembling IL-1 beta.
Authors: Goto F , Goto K , Ohkawara S , Kitamura M , Mori S , Takahashi H , Sengoku Y , Yoshinaga M
Published: December 2022

A rabbit polymorphonuclear leukocytes (PMN)-derived lymphocyte proliferation-potentiating factor (PMN factor) was finally purified to homogeneity. PMN factor was released from early inflammatory peritoneal exudate cells (98% of PMN) stimulated with kaolin under roller bottle culture conditions. PMN factor was purified by large sequential scale steps, using membrane-type ion exchangers and gel filtration, followed in this order by HPLC steps with cationic ion exchangers and a hydroxylapatite column. Homogeneity was manifested based on the criteria of a single m.w. 18, 500 band on silver-stained polyacrylamide gel, a superimposable activity on a UV absorbance peak in analytic HPLC gel filtration, and detection of a single amino-terminal sequence. The homogeneous PMN factor had an isoelectric value of 7.2 and an activity of 1.9 x 10(7) U/mg in the thymocyte comitogenic assay. PMN factor stimulated one-half of the maximal response of thymocyte proliferation at 2.8 x 10(-12) M. Because of similarities in the physicochemical properties, specific activity, and amino-terminal sequence between rabbit PMN factor and human IL-1 beta, this PMN factor is therefore considered to be a rabbit IL-1 beta.
Both B151-T cell replacing factor 1 and IL-5 regulate Ig secretion and IL-2 receptor expression on a cloned B lymphoma line.
Authors: Nakanishi K , Yoshimoto T , Katoh Y , Ono S , Matsui K , Hiroishi K , Noma T , Honjo T , Takatsu K , Higashino K
Published: December 2022

In the present study, we have demonstrated that both B151-T cell-replacing factor 1 and rIL-5 are responsible for the activity to partially induce CL-3 cells into IgM-synthesizing cells and also to synergize with IL-2 to augment IL-2R expression on and IgM synthesis in CL-3 cells. These actions of rIL-5 on a homogeneous cloned line (BCL1-CL-3 cells) allow us to identify and characterize the two alternated B cell developmental pathways. One is an IL-2-independent, IL-5-driven differentiation pathway without preceding up-regulated IL-2R expression, and the other is an IL-5 plus IL-2-dependent augmented differentiation pathway with preceding up-regulated IL-2R expression. We have also demonstrated the functional difference of two distinct B cell growth-promoting factors, B cell-stimulating factor 1 (rIL-4) and rIL-5. CL-3 cells are equally stimulated to grow by rIL-4 and rIL-5, whereas only rIL-5 can render CL-3 cells responsive to rIL-2, indicating that these two lymphokines affect B cells in a strikingly different manner.
Monoclonal antipeptide antibodies recognize IL-3 and neutralize its bioactivity in vivo.
Authors: Ziltener H J , Clark-Lewis I , Fazekas de St Groth B , Orban P C , Hood L E , Kent S B , Schrader J W
Published: December 2022

Mixtures of synthetic peptides corresponding to segments of murine IL-3 or synthetic IL-3 were used to raise murine mAb. Several mAb able to recognize synthetic IL-3 were obtained, two of which exhibited significant cross-reactivity with native IL-3 as shown by precipitation of biosynthetically 35S-labeled IL-3 and their effectiveness as affinity reagents for the purification of IL-3 from conditioned medium. The amino acid sequence recognized by the two mAb was determined by using synthetic peptide segments of IL-3. In both cases binding of the mAb to synthetic IL-3 was inhibited best with a hexapeptide corresponding to the amino acid residues 130-135 of IL-3, although the mAb differed in other characteristics. Neither mAb neutralized IL-3 bioactivity in vitro. However, we observed that in vivo administration of one mAb abrogated the increase in splenic mast cells and their precursors that normally occurred in mice bearing a s.c. IL-3-producing tumor, WEHI-3B.
Nonimmune binding of Ig to Clostridium perfringens. Preferential binding of IgM and aggregated IgG.
Authors: Lindahl G , Kronvall G
Published: December 2022

In an attempt to find a bacterial IgM receptor, a large number of bacterial strains of different species were screened for the ability to bind human IgM. Certain strains of the anaerobic bacterium Clostridium perfringens were found to bind a major fraction of polyclonal IgM. One bacterial strain showed a particularly high binding capacity and was studied in more detail. This strain is also able to bind a minor fraction of polyclonal IgA and IgG. Inhibition experiments indicate that the different Ig classes bind to one and the same R structure. The ability of the strain to bind polyclonal Ig is correlated to the number of subunits in the Ig. This correlation can most simply be explained by increasing avidity with increasing number of subunits. In agreement with this hypotheses, experiments with aggregated IgG show that binding ability increases with aggregate size. Experiments with Ig fragments indicate that the binding structure in Ig is located in the F(ab')2 region. The ability of this bacterial strain to bind a majority of IgM molecules as well as aggregated IgG is potentially useful in immunologic work and represents a new type of Ig binding to bacteria.
Cytolysis of tumor necrosis factor (TNF)-resistant tumor targets. Differential cytotoxicity of monocytes activated by the interferons, IL-2, and TNF.
Authors: Philip R
Published: December 2022

Herein we demonstrate that IFN-alpha, IFN-gamma, and IL-2 can induce human peripheral blood monocyte-mediated lysis of tumor cells that are resistant to both the direct effects of TNF and to monocytes activated by TNF. Monocytes activated by TNF kill only TNF-sensitive tumor targets, whereas those activated by IFN and IL-2 can lyse both TNF-sensitive and TNF-resistant tumor targets. Monocyte cytotoxicity against TNF-sensitive lines induced by the IFN, IL-2, or TNF can be completely abrogated by the addition of anti-TNF antibodies. In contrast, anti-TNF antibodies have no effect on IFN- or IL-2-induced monocyte cytotoxicity against TNF resistant targets, confirming non-TNF-mediated lysis induced by lymphokine-activated monocytes. Neither induction of TNF receptors by IFN-gamma nor inhibition of RNA synthesis by actinomycin D increased the susceptibility of TNF-resistant tumor targets to TNF-mediated monocyte cytotoxicity. Thus, non-TNF-mediated modes of monocyte cytotoxicity are induced by IFN and IL-2, but not by TNF, indicating that different cytotoxic mechanisms are responsible for the lysis of TNF-sensitive and TNF-resistant tumor cells. In addition, these findings also suggest that TNF-sensitive lines are susceptible only to TNF-mediated killing and apparently insensitive to non-TNF-mediated monocyte cytotoxicity.
Synergistic effect of colony-stimulating factors and IL-2 on prothymocyte proliferation linked to the maturation of macrophage/dendritic cells within L3T4-Lyt-2-Ia-Mac- cells.
Authors: Papiernik M , Lepault F , Pontoux C
Published: December 2022

Bone marrow-derived precursors colonize the thymus, where they constitute the minor L3T4-Lyt2- subset which can give rise to all thymocyte subpopulations. We show in the present paper that L3T4-Lyt2- population depleted of Ia+, Mac-1+ cells contain pluripotent hemopoietic stem cells (CFU-S) and granulocyte-macrophage colony-forming cells (GM-CFC). Addition of GM-CSF to the culture medium leads to the production of adherent and nonadherent cells of the macrophage-monocyte lineage. L3T4-Lyt2- cells poorly respond to IL-2 in vitro, but the addition of either rIL-3 or rGM-CSF allows the IL-2 response of L3T4-Lyt2- cells. This response is at least partly mediated by maturation of double-negative cells for L3T4 and Lyt-2 Ag into cells able to produce IL-1.
Up-regulation of c-fos expression is a component of the mIg signal transduction mechanism but is not indicative of competence for proliferation.
Authors: Monroe J G
Published: December 2022

Control of entry into and progression through the early phases of cell cycle in B lymphocytes is poorly understood at the molecular level. Products of the c-fos proto-oncogene have been implicated in regulation of G0 to G1 cell cycle phase transition and cell proliferation in other systems. In view of these observations, the relationship between signals generated through receptor Ig which alter the B cells position in cell cycle and relative level of c-fos expression was investigated. Not unexpectantly, anti-Ig under conditions which promote G0-G1 and G1-S phase transition was observed to selectively up-regulate expression of c-fos. More interestingly, however, anti-Ig-induced cross-linking of surface Ig on the WEHI-231 B lymphoma also caused rapid and transient up-regulation of c-fos mRNA levels although it was associated with inhibition of proliferation of these cells. These results are important because they show that 1) c-fos expression is inducible in both normal and transformed B lymphocytes as a consequence of signals generated through receptor Ig, and 2) up-regulation of c-fos expression is not positively linked to B cell proliferation but rather appears to be a component of the surface Ig signal transduction mechanism. Finally, studies utilizing phorbol diesters suggest that pathways leading through protein kinase C are involved in both the growth inhibition and c-fos expression WEHI-231 following membrane-associated Ig cross-linking.