bluuebunny/crossref_metadata_2025 huggingface dataset:
Analysis of two distinct B cell activation pathways mediated by a monoclonal T helper cell. II. T helper cell secretion of interleukin 4 selectively inhibits antigen-specific B cell activation by cognate, but not noncognate, interactions with T cells.
Authors: Asano Y , Nakayama T , Kubo M , Fujisawa I , Karasuyama H , Singer A , Hodes R J , Tada T
Published: December 2022

A single monoclonal T helper (Th) clone can activate B cells in two distinct pathways; a cognate pathway requiring a major histocompatibility complex (MHC)-restricted T-B cell interaction, and a noncognate pathway not requiring an MHC-restricted T-B cell interaction. The present study was undertaken to investigate whether Th cells mediating a given immune response provide further regulatory function to B cells other than helper function. It was demonstrated that conditions of high antigen concentration which activate a noncognate B cell activation pathway simultaneously inhibit IgG responses. The inhibition is shown to be mediated by the T cell factor interleukin 4, produced by activated cloned Th cells. The inhibitory effect of this factor is directed to B cells and is MHC-unrestricted, antigen-nonspecific, and IgG class-specific. In addition to being susceptible to the effects of augmenting cells and suppressor cells, cloned Th cell populations can therefore themselves function as regulatory cells to inhibit IgG responses when stimulated with high dose of specific antigen. These results indicate that Th cells function to regulate B cells both positively and negatively, depending upon the activation conditions.
Autoreactive B cells in normal humans. Autoantibody production upon lymphocyte stimulation with autoantigen-xenoantigen conjugates.
Authors: Logtenberg T , Melissen P M , Kroon A , Gmelig-Meyling F H , Ballieux R E
Published: December 2022

Mononuclear cells (MNC) from the blood of healthy individuals cannot be stimulated in vitro with the soluble autoantigen thyroglobulin (Tg). However, when Tg or pepsin fragments of Tg were coupled with a carrier protein, tetanus toxoid (TT), MNC from four healthy TT vaccinated individuals responded to the carrier-autoantigen conjugates by generating anti-Tg antibody forming cells (AFC), as shown in a spot enzyme-linked immunosorbent assay. Generation of anti-TT and anti-Tg AFC after stimulation with the conjugates required the donors to be boostered with TT. The autoantibodies were exclusively of the IgM class, in contrast to the carrier-specific anti-TT antibodies, which were predominantly of the IgG isotype. Activation of normal B cells to anti-Tg production was dependent on the presence of T cells in the cultures and required physical linkage of carrier and autoantigen: no anti-Tg AFC could be detected when MNC were stimulated with uncoupled combinations of Tg and TT. The autoreactive and the carrier-reactive B cells exhibited almost identical conjugate dose-response profiles, which suggest that they responded in a similar way to regulatory signals. These findings indicate that normal blood B cells are competent to respond to the autoantigen Tg in conjunction with signals originating from xeno-antigen-stimulated T cells.
Expression of high affinity receptors for murine interleukin 4 (BSF-1) on hemopoietic and nonhemopoietic cells.
Authors: Lowenthal J W , Castle B E , Christiansen J , Schreurs J , Rennick D , Arai N , Hoy P , Takebe Y , Howard M
Published: December 2022

In this report a method for the affinity purification and radiolabeling of recombinant mouse interleukin (IL)-4 is described. It is shown on the basis of several criteria that IL-4 retains full biologic activity after radioiodination and can therefore be used as a valid model for measuring the binding characteristics of native IL-4. By using Scatchard plot analysis of equilibrium binding data, it is demonstrated that 125I-IL-4 binds to a high affinity cell surface receptor which is expressed by both hemopoietic and nonhemopoietic cells. The dissociation constant for 125I-IL-4 (Kd = 20 to 60 pM) corresponds to the concentration of IL-4 which gives 50% biologic activity (i.e., 10 to 30 pM). Binding of 125I-IL-4 is rapid (t1/2 of 2 min), whereas dissociation occurs at a slow rate (t1/2 approximately 4 hr). The IL-4 receptor shows a high degree of specificity. Whereas unlabeled mouse IL-4 competed with mouse 125I-IL-4 in an equimolar fashion for binding to IL-4 receptors, several other lymphokines, including mouse IL-2, IL-3, interferon-gamma, granulocyte-macrophage colony-stimulating factor, and human IL-1, IL-2, and IL-4 were unable to inhibit, even at molar excesses of 400 to 800-fold. At 37 degrees C, 125I-IL-4 is rapidly internalized (approximately 200 molecules/cell/min) by HT-2 cells, with at least 85% of cell surface receptors being functional in this respect. Receptors for IL-4 were found to be expressed by subclasses of T and B cells, mast cells, macrophages, and by cells of the myeloid and erythroid lineages. This wide distribution of receptor expression closely matches the known spectrum of biologic activities of IL-4, including proliferation and/or differentiation of T and B cells, mast cells and granulocytes, and induction of macrophage antigen-presenting capacity. IL-4 receptors were also found on a variety of nonhemopoietic cells such as cloned stromal cell lines from the bone marrow, spleen, thymus, and brain, and on muscle, brain, melanoma, fibroblast, and liver cells. Indeed, only 5 of more than 90 cell types tested have undetectable numbers of IL-4 receptors. The biologic effects of IL-4 on nonhemopoietic cells have not yet been reported and await elucidation.
Up-regulation of interleukin 4 receptor expression on immature (Lyt-2-/L3T4-) thymocytes.
Authors: Lowenthal J W , Ransom J , Howard M , Zlotnik A
Published: December 2022

In this report, the effect of interleukin 4 (IL-4) on the growth and differentiation of Lyt-2-/L3T4-(2-4-) thymocytes was investigated. It was found that these thymocytes proliferated extensively when cultured in the presence of IL-4 + phorbol myristate acetate without apparent differentiation to Lyt-2+ or L3T4+ cells. We also demonstrated that 2-4- thymocytes constitutively express a high affinity (dissociation constant of 20 to 40 pM) receptor for IL-4. Freshly isolated 2-4- thymocytes expressed on average about 100 IL-4 receptors per cell, but the number of receptors increased approximately 8-fold within 3 days after activation by IL-4 + phorbol myristate acetate. These findings suggest that IL-4 may play an important role in T cell ontogeny by promoting self-renewal of stem cells within the thymus.
Effect of granulocyte-macrophage colony-stimulating factor and interleukin 3 on the v-src oncogene. Inhibition of tyrosine kinase activity in the absence of changes in gene expression.
Authors: Watson J D , Jenkins D R , Eszes M , Leung E
Published: December 2022

Three cloned murine interleukin 3 (IL-3)-dependent cell lines have been converted to interleukin 2 (IL-2) or granulocyte-macrophage colony-stimulating factor (GM-CSF) growth-dependent states. FD.C/1 32Dcl-23 and GM cells grown and maintained as IL-3-dependent cell lines, and cells grown with GM-CSF have been infected with a murine recombinant retrovirus containing the v-src oncogene, and grown as lymphokine-independent cell lines. There is a significant increase in tyrosine kinase activity in cells which become lymphokine-independent. FD.C/1 and 32Dcl-23 cells maintained as IL-2-dependent cells lines and infected with the same virus did not grow as IL-2-independent cells. The lymphokine-independent cells FD.C/1src, 32Dsrc, and GMsrc all expressed high levels of tyrosine kinase activity, ranging from 5- to 20-fold more than levels measured in virus-infected cell lines maintained as IL-2-dependent cells. The exposure of FD.C/1src and 32Dsrc cells to IL-3, and GMsrc cells to IL-3 or GM-CSF, resulted in significant decreases in tyrosine kinase activity. These changes were rapidly reversed by removal of IL-3 or GM-CSF from these cells. However, the synthesis of v-src-specific RNA was not affected by the presence of IL-3 or GM-CSF in these cell lines. The biochemical pathways activated by IL-3 or GM-CSF inhibit the activity of the tyrosine kinase encoded by the v-src oncogene without altering gene transcription.
Enhancement of antigen- and mitogen-induced human T lymphocyte proliferation by tumor necrosis factor-alpha.
Authors: Yokota S , Geppert T D , Lipsky P E
Published: December 2022

The capacity of human recombinant tumor necrosis factor-alpha (rTNF alpha) to modulate human T cell proliferation was examined. To examine the effect of rTNF alpha on the responding T cell directly, T cell activation was studied in the absence of viable accessory cells (AC). Highly purified AC-depleted peripheral blood T4 or T8 cells were stimulated with immobilized monoclonal antibodies to the cluster of differentiation (CD)3 molecular complex, an AC-independent stimulus. rTNF alpha augmented anti-CD3-stimulated T4 and T8 cell proliferation. The capacity of rTNF alpha to enhance T cell proliferation varied inversely with the density of immobilized anti-CD3 and the number of responding cells in each culture. The capacity of rTNF alpha to enhance antigen-induced T4 cell proliferation was also examined. Antigen-bearing paraformaldehyde-fixed antigen-presenting cells induced modest T4 cell proliferation when cultured in flat-bottomed wells; this response was enhanced by rTNF alpha. The results demonstrate that rTNF alpha has direct effects on T cells, facilitating their capacity to proliferate in response to mitogens and antigens. These data indicate that rTNF alpha may play an immunoregulatory role, enhancing the proliferation of T lymphocytes.
Identification of the DRw10 DR beta 1-chain allele as encoding a polymorphic class II major histocompatibility complex epitope otherwise restricted to DR beta 2 molecules of the DRw53 type.
Authors: Matsuyama T , Winchester R , Lee S , Shookster L , Nunez-Roldan A
Published: December 2022

Although the polymorphic human Ia epitope recognized by monoclonal antibody 109d6 typically is expressed by DRw53 beta 2 chains, the epitope was shown to be encoded by distinctive DR beta 1 chains of a DRw10 haplotype in three unrelated DR4-negative individuals with rheumatoid arthritis. No evidence of a DR beta 2 (DR beta 4) chain molecule was found to be encoded by this haplotype. Using two-dimensional gel analysis and partial radioactive N-terminal microsequencing, the DR and DQ products were characterized in the heterozygous members of a family in which the segregation of both varieties of DR beta chains specifying the 109d6 epitope was demonstrated. The expression of the epitope on the DR beta 2 chain, but not on the DR beta 1 chain, was abolished by preventing N-linked glycosylation, although in both molecules the epitope was not altered by neuraminidase digestion. The potential structural bases of the serologic cross reactions of DRw10 are discussed, as are the possible implications of the findings for the definition of susceptibility to rheumatoid arthritis.
Inhibition of cytotoxic T lymphocyte and natural killer cell-mediated lysis by O,S,S,-trimethyl phosphorodithioate is at an early postrecognition step.
Authors: Rodgers K E , Grayson M H , Ware C F
Published: December 2022

O,S,S,-Trimethyl phosphorodithioate (OSS-TMP), an organophosphate esterase inhibitor, has been shown to block the effector phase of the cytolytic reaction mediated by murine and human cytotoxic T lymphocytes (CTL) and human natural killer cells. The murine interleukin 2-dependent CTLL-1 (anti-Iad) clone was used to determine the phase of the cytolytic pathway inhibited by OSS-TMP. Pretreatment of the CTL or target cell with OSS-TMP was not effective at blocking lysis; however, inhibition of lysis was achieved if the reaction was carried out in the continuous presence of OSS-TMP (IC50 = 55 microM) or when CTL-target conjugates were performed and incubated with OSS-TMP (IC50 = 640 microM). Two structural analogues of OSS-TMP were unable to inhibit CTL-mediated lysis. In contrast to OSS-TMP, N-alpha-p-tosyl-L-lysine chloromethylketone required only a 5-min preincubation with the CTL to inhibit lysis. OSS-TMP did not block recognition-adhesion step(s) of the reaction since the ability to form conjugates was not impaired; however, the lytic efficiency of individual CTL-target pairs were blocked. OSS-TMP did not appear to be an inhibitor of the major granule-associated protease that cleaves the substrate, N-alpha-benzyloxycarbonyl-L-lysine thiobenzylester. Ca2+ pulse and kinetic experiments indicated that the OSS-TMP-sensitive site was at a pre-Ca2+-dependent phase but after recognition-adhesion. Human CTL and natural killer cell activity was also inhibited by OSS-TMP, suggesting the presence of a common site of action among these cytolytic systems. The results indicate that OSS-TMP may be a useful reagent in characterizing the early post-recognition events in the cytolytic pathway of CTL and natural killer effector cells.
The requirement for high intracellular cyclic adenosine monophosphate concentrations distinguishes two pathways of B cell activation induced with lymphokines and antibody to immunoglobulin.
Authors: Hoffmann M K
Published: December 2022

Mouse B lymphocytes proliferate when stimulated with anti-IgM and the lymphokines B cell-stimulating factor-1 (BSF-1) interleukin (IL)-4 and IL-1. We show herein that two anti-IgM-stimulated B cell responses can be distinguished by their sensitivity to cyclic adenosine monophosphate (cAMP). cAMP inhibits B cell proliferation facilitated by BSF-1 and enhances the B cell response facilitated by IL-1. IL-1 and BSF-1-dependent B cell responses are additive, suggesting that distinct B cell subpopulations are involved. BSF-1-reactive B cells are not inhibited by cAMP in the presence of IL-1. This suggests that IL-1 determines whether cAMP, which has elsewhere been shown to cause nuclear translocation of protein kinase C in resting B cells, inhibits or enhances B cell responses. Comparative studies suggest that the IgM response of spleen cells to red cell-bound antigen involves one of the two pathways described, namely the one that involves IL-1 and cAMP. BSF-1 has no noticeable effect on a Mishell-Dutton plaque-forming cell response. In view of literature on the facilitation by BSF-1 of the IgG response, we consider the possibility that IL-1 functions to stir B cells into an IgM response, whereas BSF-1 acts on B cells that are poised to become IgG producers.
Antigenic proteins of Mycobacterium leprae. Complete sequence of the gene for the 18-kDa protein.
Authors: Booth R J , Harris D P , Love J M , Watson J D
Published: December 2022

Recombinant clones expressing antigenic determinants of the 18-kDa protein antigen from Mycobacterium leprae recognized by the L5 monoclonal antibody were isolated from a lambda gt11 expression library and their nucleotide sequences determined. All clones expressed the M. leprae-specific determinant as part of a large fusion protein with Escherichia coli beta-galactosidase. The deduced amino acid sequence of the coding region indicated that all the lambda gt11 recombinant clones contained an incomplete M. leprae gene sequence representing the carboxy-terminal two-thirds (111 amino acids) of the 18-kDa gene and coding for a peptide of m.w. 12,432. Subsequent isolation and sequencing of a 3.2kb BamHI-PstI DNA fragment from a genomic M. leprae cosmid library permitted the deduction of the complete 148 amino acid sequence with a predicted m.w. of 16,607. A second open reading frame 560 bases downstream from the 18-kDa coding sequence was found to code for a putative protein of 137 amino acids (m.w. = 15,196). Neither this nor the 18-kDa amino acid sequence displayed any significant homologies with any proteins in the GENBANK, EMBL, or NBRF data bases. Crude lysates from recombinant lambda gt11 clones expressing part of the 18-kDa protein have been reported to stimulate the proliferation of some M. leprae-specific helper T cell clones. Thus, it is significant that the complete 18-kDa sequence contains five short peptides predicted to be possible helper T cell antigenic epitopes based on their propensity to form amphipathic helices. Although three of these occur within the 111 amino acid carboxy-terminal peptide expressed by lambda gt11 clones, the most highly amphipathic peptide is found in the amino-terminal region not present in the lambda gt11 recombinants.
Induction of immune tolerance during administration of monoclonal antibody to L3T4 does not depend on depletion of L3T4+ cells.
Authors: Carteron N L , Wofsy D , Seaman W E
Published: December 2022

Treatment of mice with mAb to L3T4 profoundly depletes T helper cells. This treatment inhibits humoral and cellular immunity, retards autoimmunity, and permits the induction of Ag-specific tolerance. Treatment of BALB/c mice with F(ab')2 anti-L3T4 inhibits humoral immunity without depleting L3T4+ cells, which is evidence that mAb to L3T4 may inhibit T helper cell function in vivo. In this report, we demonstrate that F(ab')2 anti-L3T4 also permits the induction of immune tolerance in a manner that is independent of T cell depletion. C57BL/6 mice were treated with 1 mg of F(ab')2 anti-L3T4 every other day for 18 days and from the onset were challenged weekly with the immunogen 2C7, a rat mAb to chicken ovalbumin. These mice failed to respond to 2C7 not only during the treatment period but also for at least 5 mo thereafter. This immune tolerance was Ag-specific; the mice rapidly produced antibodies to subsequent challenge with another Ag, human gamma-globulin. Unlike intact anti-L3T4, which immediately depletes L3T4+ cells by greater than 90%, F(ab')2 anti-L3T4 did not initially deplete cells and caused only a partial reduction by the end of the 18-day treatment. This partial reduction of L3T4+ cells did not contribute to the induction of tolerance because mice that were first challenged with 2C7 3 days after stopping the F(ab')2 anti-L3T4 treatment, when L3T4+ cells were lowest, had a normal Ir to 2C7. These findings demonstrate that mAb to L3T4 permits induction of Ag-specific immune tolerance by a mechanism independent of its ability to deplete L3T4+ cells. They also show that F(ab')2 anti-L3T4 treatment does not impair humoral immunity when immunization is initiated after treatment is stopped. Because L3T4 is homologous to CD4 in humans, our findings suggest that F(ab')2 anti-CD4 may offer significant advantages over the use of intact anti-CD4 as an immunosuppressive agent in humans.
Regulation of lymphocyte homing. I. Alterations in homing receptor expression and organ-specific high endothelial venule binding of lymphocytes upon activation.
Authors: Hamann A , Jablonski-Westrich D , Scholz K U , Duijvestijn A , Butcher E C , Thiele H G
Published: December 2022

Upon activation, lymphocytes display profound alterations in their in vivo migration behavior. In an attempt to understand some of the cellular mechanisms responsible for this altered behavior, in vitro stimulated lymphocytes have been analyzed for their expression of a putative homing receptor (HOR) (defined by mAb MEL-14) and for their ability to bind to specialized lymphoid organ high endothelial venules (HEV) in vitro. The results indicate that signals related to lymphocyte activation induce complex alterations in HOR expression and organ-specificity of HEV-binding: 1) submitogenic stimuli induce an increase in MEL-14 antigen expression. This applies to almost all lymphocytes in autologous cultures, for the fraction of cells in periodate, LPS- or Con A-treated cultures not fully activated and for cultures stimulated with suboptimal doses of Con A. 2) Full blast transformation is associated with a decrease or complete loss of MEL-14 antigen expression on the majority of blasts in all activating systems used, but a subset of up to 30 to 40% of fully activated cells may nonetheless express very high levels of the MEL-14 antigen. 3) Functional assays reveal that Con A and periodate stimulation lead to a selective, nearly complete suppression of the lymphocytes binding to HEV of Peyer's patches, even under conditions where overall binding to peripheral node HEV is increased. This indicates a differential regulation of the two respective receptors, with the mucosa system-specific HOR being more prone to down-regulation during in vitro activation by these mitogens.
Autoreactive T cells in mercury-induced autoimmunity. Ability to induce the autoimmune disease.
Authors: Pelletier L , Pasquier R , Rossert J , Vial M C , Mandet C , Druet P
Published: December 2022

It has been previously shown that autoreactive T cells appear during mercury-induced autoimmunity in Brown-Norway (BN) rats. In the present work, it is shown that: 1) T cells and T helper cells from HgCl2-injected BN rats are able to actively transfer autoimmunity in normal BN rats; the disease transferred is exacerbated when recipients are treated with the antisuppressor/cytotoxic T cell monoclonal antibody (OX8); 2) normal T cells preincubated with HgCl2 are also able to transfer the disease in OX8-treated but not in T cell-depleted rats; and 3) T cells from HgCl2-injected BN rats also transferred the disease in both normal and T cell depleted rats. It is concluded that: 1) autoreactive T cells, and presumably anti-Ia T cells are involved in the pathogenesis of mercury-induced autoimmunity; 2) these autoreactive T cells induce suppressor/cytotoxic T cells to proliferate in normal syngeneic recipients; the fact that this T cell subset did not proliferate in HgCl2-injected BN rats suggests that HgCl2 also affects T suppressor cells; and 3) mercury-induced autoimmunity could result from the additive effect of the emergence of autoreactive T cells and of a defect at the T suppressor level.
Effects of human recombinant tumor necrosis factor-alpha and interleukin 1 on the synthesis of glycosaminoglycan and DNA in cultured rat costal chondrocytes.
Authors: Ikebe T , Hirata M , Koga T
Published: December 2022

We examined effects of human rTNF alpha on the synthesis of glycosaminoglycan and DNA in cultured rat costal chondrocytes. The effects of human recombinant IL-1 alpha and IL-1 beta were also given attention. rTNF alpha, as well as rIL-1 alpha and rIL-1 beta, decreased the incorporation of [35S]sulfate into glycosaminoglycan to about 10% of the levels in the control. The half-maximal doses of rTNF alpha, rIL-1 alpha or rIL-1 beta required for the suppression of glycosaminoglycan synthesis (by rTNF alpha, rIL-1 alpha, and rIL-1 beta) were 2 ng/ml, 30 ng/ml, or 5 ng/ml, respectively. rTNF alpha stimulated incorporation of [3H]thymidine in the chondrocytes in a dose- and time-dependent manner. DNA synthesis was increased to about threefold over the control cultures in the presence of 1 microgram/ml rTNF alpha for 72 hr. The stimulatory effect of rTNF alpha on DNA synthesis was observed in both subconfluent and confluent cultures, whereas rIL-1 alpha and rIL-1 beta had no stimulatory activity on DNA synthesis. The addition of rTNF alpha to the cultures of chondrocytes stimulated DNA synthesis, even in medium containing no fetal calf serum. The fetal calf serum acted synergistically with rTNF alpha in increasing DNA synthesis. We propose that both TNF and IL-1 may be involved in inflammatory diseases of cartilage, and that TNF alpha, but not IL-1, may have some physiologic growth factor function for chondrocytes.
Novel receptor-mediated internalization of interleukin 2 in B cells.
Authors: Tanaka T , Saiki O , Doi S , Fuji M , Sugamura K , Hara H , Negoro S , Kishimoto S
Published: December 2022

Novel IL-2-binding molecules (p70 and p75) mediating internalization and degradation of IL-2 were examined by employing a human B lymphoblastoid line, SKW6-4 cells. High concentrations of IL-2 induced IgM secretion in these cells through a receptor distinct from Tac antigen. The acid-wash technique revealed that more than 60% of 125I-labeled IL-2 bound to the cells became acid-unremovable in the first 30 min of incubation at 37 degrees C and degradation products of 125I-IL-2 increased after 30 min of incubation. Treatment of the cells with NaN3 buffer inhibited the appearance of acid-unremovable 125I-IL-2, suggesting that acid-unremovable 125I-IL-2 was not due to fluid-phase pinocytosis but due to internalization. Loss of labeled bands by incubation of cells with 125I-IL-2 at 37 degrees C before affinity cross-linking demonstrated that 125I-IL-2 was internalized via novel IL-2-binding molecules. These results suggest that novel IL-2-binding molecules are responsible for internalization and may mediate signal transduction in B cells in the absence of Tac antigen.
Mapping of HLA epitopes recognized by H-2-restricted cytotoxic T lymphocytes specific for HLA using recombinant genes and synthetic peptides.
Authors: Pala P , Corradin G , Strachan T , Sodoyer R , Jordan B R , Cerottini J C , Maryanski J L
Published: December 2022

Immunization of DBA/2 (H-2d) mice with syngeneic P815 tumor cell transfectants that express HLA class I genes elicits CTL that recognize HLA in the context of H-2Kd molecules. Anti-HLA-CW3 CTL cross-react to a variable extent on the related alleles A3 and A24. Using a panel of target cells expressing native or recombinant HLA genes, we could map the epitope recognized by a CTL clone specific for CW3 to the second external (alpha 2) domain of CW3. Moreover, the epitope recognized by this clone could be mimicked by incubating P815 (HLA negative) target cells with a synthetic peptide corresponding to the C-terminal 12 amino acids of the CW3 alpha 2 domain (residues 171 to 182). Other independent anti-CW3 CTL clones with different fine specificities recognized the same CW3 peptide. In contrast, CTL clones specific for HLA-A24 or HLA-A3 that did not lyse P815-CW3 transfectants did not recognize this peptide. The CW3 peptide could be recognized on other tumor cell targets that were also of H-2d origin, but not on those of H-2b or H-2k origin. The requirement for the expression of H-2Kd by the target cells was directly demonstrated using L cell Kd transfectants. Our results suggest that the CTL response of DBA/2 mice immunized with P815-CW3 transfectants is predominantly Kd restricted and focused on epitopes contained within the 12 C-terminal amino acids of the alpha 2 domain.
The B cell-associated CD37 antigen (gp40-52). Structure and subcellular expression of an extensively glycosylated glycoprotein.
Authors: Schwartz-Albiez R , Dörken B , Hofmann W , Moldenhauer G
Published: December 2022

The human B lymphocyte-associated CD37 antigen (gp40-52) has been characterized by the monoclonal antibody HD28. The CD37 antigen is strongly expressed on surface immunoglobulin positive B lymphocytes and weakly on a subpopulation of T lymphocytes and myeloid cells. The total molecular mass of the antigen ranges from approximately 40 to 52 kDa in B cell-derived leukemias and malignant lymphomas as well as in normal and anti-mu/B cell growth factor-activated tonsillar B cells. The polydisperse nature of the electrophoretic pattern of the CD37 antigen was found to be due to a microheterogeneity in its carbohydrate moiety. Biochemical analysis showed that the CD37 antigen derived from B cell-lines BJAB and LICR-LON-HMy2 consists of a single chain protein core of approximately 25 kDa to which two N-linked, complex carbohydrate antennae of various length are bound. The glycosylation of the molecule comprises about 50% of the total molecular mass. The molecule does not contain O-linked carbohydrate chains. In contrast, the non-Hodgkin's lymphoma cell line, OCI.LY1, which is growth-dependent on human serum, carries a CD37 antigen with an additional carbohydrate chain resulting in a total molecular mass of approximately 40 to 64 kDa. At the electron microscopy level, this cell surface-expressed antigen was found to be associated with intracellular vesicles. The subcellular distribution of the CD37 antigen may reflect a function of this antigen both at the cell surface and in the cytoplasm. We found that, both due to its peculiar biochemical structure and its ultrastructural distribution, the CD37 antigen closely resembles the 46-kDa species of the mannose 6-phosphate receptor. The implications of this possible congruence for the function of the CD37 antigen are discussed.
Proliferation and production of IL-2 and B cell stimulatory factor 1/IL-4 in early fetal thymocytes by activation through Thy-1 and CD3.
Authors: Tentori L , Pardoll D M , Zuñiga J C , Hu-Li J , Paul W E , Bluestone J A , Kruisbeek A M
Published: December 2022

To examine which cell surface molecules can operate as transducers of activation signals to early fetal thymocytes, we analyzed the ability of mAb to CD3 and Thy-1 to induce fetal thymocyte activation. Both proliferation and lymphokine secretion were used as measures of activation. We show that anti-CD3 antibodies induce activation of fetal thymocytes as early as day 13 of fetal thymus development, 2 days before CD3 can be detected by flow cytometry. In addition, an alternative activation signal can be delivered to fetal thymocytes through the Thy-1 molecule as early as it is expressed, i.e., day 13. Both CD3- and Thy-1-mediated activation of day 15 fetal thymocytes results in expansion of cells expressing a CD3-gamma delta receptor complex; no CD3-alpha beta receptor complex could be detected. IL-2 production induced by CD3- and Thy-1-induced activation of fetal thymocytes is evident at the 13th day of gestation. Finally, an additional lymphokine B cell stimulatory factor-1 (BSF-1)/IL-4 (so far known only to be produced by mature CD3- cells), is also produced by fetal thymocytes. The results demonstrate that at least two cell surface molecules, Thy-1 and CD3, can function as pathways of activation in fetal thymocytes, and that at least two lymphokines, IL-2 and BSF-1/IL-4, are produced upon activation. These findings may well reflect a role for the early appearance of CD3- cells in thymus ontogeny.
Antigen-specific inhibition of immune interferon production by suppressor cells of autoimmune encephalomyelitis.
Authors: McDonald A H , Swanborg R H
Published: December 2022

Previous work from this laboratory has revealed that spleen and/or lymph node cells from Lewis rats, that have recovered from an acute episode of experimental autoimmune encephalomyelitis (EAE), suppress the development of EAE when injected into syngeneic recipients subsequently challenged with myelin basic protein (MBP) in CFA. In an effort to understand the mechanism of this suppression, we measured the production of immune IFN-gamma, which may be required for the induction of an immune response, by EAE effector T cells (which transfer disease) and EAE suppressor cells when cultured in vitro with MBP. We now report that EAE effector T cells produce IFN-gamma when cultured in vitro with MBP. In contrast, spleen cells from recovered rats (which manifest suppressor activity in vivo) do not produce IFN-gamma. Moreover, in cell mixing experiments, these suppressor spleen cells inhibited the production of IFN-gamma by EAE effector cells. This inhibition was not eliminated by the removal of macrophages nor by the inhibition of PG synthesis by indomethacin. Furthermore, the inhibition was shown to be Ag-specific and mediated by nylon-adherent, radiation-sensitive splenic T cells. The findings suggest that suppressor cells regulate EAE by inhibiting IFN-gamma production by effector cells. This inhibition may result in the down-regulation of IFN-gamma-induced expression of class II major histocompatibility Ag on cells of the central nervous system, thus reducing the presentation of tissue-specific Ag (i.e., MBP) to autoreactive lymphocytes.
Lack of an obligate role for IFN-gamma in the primary in vitro mixed lymphocyte response.
Authors: Bucy R P , Hanto D W , Berens E , Schreiber R D
Published: December 2022

We have investigated the relative importance of two lymphokines, IL-2 and IFN-gamma, in the primary murine MLR. Three separate lines of evidence indicate that IL-2 and not IFN-gamma is the relevant lymphokine for both proliferation and activation of CTL in these cultures. No obligate role for IFN-gamma was found. First, CTL activation in the presence of high dose cyclosporin A was partially reconstituted with IL-2, although no detectable IFN-gamma was produced in such cultures. In addition, IFN-gamma could not reconstitute cyclosporin-inhibited cultures. Second, inclusion of a high concentration of several distinct anti-IFN-gamma antibodies failed to inhibit MLR cultures. Third, CTL activation by stimulator cells inactivated by UV irradiation was reconstituted by IL-2, but not by IFN-gamma. These data do not support an autocrine role of IFN-gamma in CTL activation and confirm the importance of IL-2 in the primary murine MLR.
Molecular properties and regulation of mRNA expression for murine T cell-replacing factor/IL-5.
Authors: Tominaga A , Matsumoto M , Harada N , Takahashi T , Kikuchi Y , Takatsu K
Published: December 2022

We previously cloned cDNA for a T cell-replacing factor (TRF) that has been defined as a T cell-derived lymphokine that acts on activated B cells as a B cell growth and differentiation factor. Based on the diverse activities of rTRF on different target cells, we proposed that TRF be called IL-5. In this study, the molecular characteristics of TRF/IL-5 prepared by rDNA technology and TRF/IL-5 mRNA expression in various T cell lines and normal T cells have been studied. Specific immunoassay showed that rTRF/IL-5, which is transiently translated in vitro by rabbit reticulocyte lysate, has an apparent m.w. of 14,000. By contrast, active forms of rTRF/IL-5 translated in Xenopus oocytes has an apparent m.w. of 45,000 to 50,000 in the nonreducing condition and migrates to the m.w. of 25,000 to 30,000 under the reducing condition, indicating that active form of rTRF/IL-5 consists of dimer forms. The rTRF/IL-5 does not show detectable levels of IL-2, IL-3, and B-cell stimulatory factor 1 (IL-4) activities. Northern blot hybridization of poly (A)+ RNA from constitutively TRF-producing B151K12 T cell hybridoma revealed a single 1.7-kb band hybridizing to the cloned murine TRF/IL-5 cDNA. The expression of TRF/IL-5 mRNA in B151K12 was augmented by the stimulation with PMA plus calcium ionophore. In contrast, neither thymoma BW5147 nor IL-2-producing T cell hybridoma A55, both of which produced an undetectable level of TRF, expressed detectable levels of TRF/IL-5 mRNA. Stimulation of EL 4 and D9 cells with PMA and Con A, respectively, induced an increase in the levels of TRF/IL-5 mRNA expression accompanied by TRF/IL-5 production, whereas both cell lines did not show significant gene expression in the absence of the stimulation. In spleen cells from Mycobacterium tuberculosis-primed mice, significant expression of TRF/IL-5 mRNA was detected only when the cells were stimulated with relevant Ag, PPD. Normal spleen cells stimulated with Con A showed a significant, but approximately four-fold less expression of TRF/IL-5 mRNA. Molecular and functional properties of TRF/IL-5 will be discussed.
Electrostatic properties of cryoimmunoglobulins.
Authors: Lawson E Q , Brandau D T , Trautman P A , Middaugh C R
Published: December 2022

Inhibition of the cryoprecipitation of cryoimmunoglobulins by neutral salts suggests that intermolecular electrostatic (charge-charge) interactions are responsible for their abnormal solution properties. To test this hypothesis, H+ titration curves and isoelectric points were measured for two monoclonal IgG cryoglobulins (Ger and Muk) and compared with four normal (cold soluble) monoclonal IgG. The cryoglobulin Ger manifested values outside the range encountered for the other proteins. The partitioning of the IgG proteins was also examined in aqueous polyethylene glycol-dextran two-phase systems in the presence of both positive and negative salt-induced electrostatic potentials across the phase interface. Both cryoglobulins were found to behave as if they were more negatively charged than the noncryoglobulins. The experiments support the hypothesis that the differences in solubility behavior of monoclonal cryoglobulin and noncryoglobulin proteins are caused by differences in the electrostatic properties of the proteins.
The immune response toward beta-adrenergic ligands and their receptors. VIII. Extensive diversity of VH and VL genes encoding anti-alprenolol antibodies.
Authors: Nahmias C , Strosberg A D , Emorine L J
Published: December 2022

The V region genes (VH and VL) used in the immune response of BALB/c mice to alprenolol, a synthetic beta-adrenergic ligand, were examined by Southern blot and nucleotide sequence analyses. Fourteen anti-alprenolol hybridomas utilize 10 different combinations of six Vk, one V lambda, eight VH, three JK, one J lambda, and three JH genes. In addition to the combinatorial association, somatic mutations and junctional variation of assembled genes further contribute to diversity of the anti-alprenolol response. Although differing both in length and structure, the five H-chain third complementarity-determining region analyzed contain several acidic residues. Neither V gene utilization, nor H-chain third complementarity-determining-region structure can be simply correlated with affinity of the antibodies for the ligand. The anti-alprenolol V genes were compared with the corresponding sequences of unrelated antibodies. Antibody 37A4 shares a VH gene with anti-(Glu60Ala30Tyr10)n random terpolymer and anti-nitrophenyl antibodies, and a Vk gene with two anti-oxazolone antibodies. Antibodies 14C3 and 17C1 use the same germ-line VH and Vk genes as do anti-anti-idiotypic antibodies of the (Glu60Ala30Tyr10) system. These data demonstrate the genetic diversity of the antibody response to alprenolol, and illustrate the extensive flexibility of the immune system.
Molecular cloning of the murine homologue of CD2. Homology of the molecule to its human counterpart T11.
Authors: Yagita H , Okumura K , Nakauchi H
Published: December 2022

In order to characterize the mouse homologue of the CD2 molecule, which has not yet been identified by immunologic means, cDNA clones putatively encoding mouse CD2 have been isolated by cross-hybridization with a cDNA probe for rat CD2. The predicted amino acid sequence of the putative mouse CD2 protein is consistent with that of a transmembrane glycoprotein, i.e., it consists of an N-terminal region of 186 amino acids bearing six potential N-glycosylation sites, a hydrophobic transmembrane segment of 25 residues, and a large cytoplasmic region of 116 amino acids rich in proline and basic residues. Comparison with the human and rat CD2 sequences clearly indicated the predicted mouse protein to be the mouse equivalent. Striking evolutionary conservations between mouse, rat, and human CD2 were found in their cytoplasmic region, suggesting a functional consequence of that segment for the physiologic role of CD2, such as signal transduction. RNA blot hybridization analysis demonstrated the expression of CD2 in T lymphocytes and in the NK cell lineage in mice. These data strongly suggest that the putative mouse CD2 molecule may perform some biologic functions in mouse T lymphocytes and NK cells as documented in humans.
B lymphoblastoid cell lines with rearranged T cell receptor beta-chain genes retain conventional B cell surface antigen and Ig expression.
Authors: Robinson M A , Kindt T J
Published: December 2022

Transformation of peripheral blood lymphocytes by co-incubation with EBV produces B lymphoblastoid cell lines, but rearrangement of TCR beta-chain genes was observed in three different cell lines derived from two individuals. Because rearrangement of TCR genes in B lymphocytes is considered a rare event, these B lymphoblastoid cell lines with rearranged TCR beta-genes were examined in detail to determine whether there were any additional characteristics to distinguish them from B lymphoblastoid cell lines with germ-line TCR beta-genes. All B lymphoblastoid cell lines contained rearranged Ig H and kappa L chain genes, secreted Ig, and expressed B and not T cell surface markers. Cell lines with rearranged TCR beta-genes had rearranged both IgH genes and had rearranged and subsequently deleted both kappa C region genes. Furthermore all three B lymphoblastoid cell lines with rearranged TCR beta-genes produced small amounts of Ig with lambda-L chains. Although the cellular mechanisms maintaining lineage-specific rearrangement events remain unknown, extensive Ig gene rearrangement and inefficient Ig production by B cells may be indicators of a cellular status where normally stringent lineage-specific control elements fail to function efficiently.
Antigen-induced suppression of the proliferative response of T cell clones.
Authors: Suzuki G , Kawase Y , Koyasu S , Yahara I , Kobayashi Y , Schwartz R H
Published: December 2022

Proliferation of Ag-specific T cell clones can be inhibited by the addition of high concentrations of Ag at the beginning of culture. Under these conditions the cells produce lymphokines and express high affinity IL-2R but fail to divide, even after the addition of exogenous IL-2. This state results from restimulation of the cells with Ag-Ia molecule complexes approximately 20 h after initiation of culture. It can be prevented by addition of either an anti-Ia or an anti-L3T4 mAb at that time, but not by cyclosporin A, and mimicked in cultures containing low concentrations of antigen by addition at that time of high Ag concentrations or normal stimulatory concentrations of Con A. These observations suggest that restimulation of activated T cell clones 20 h after their initial stimulation prevents them from dividing.
A colostral protein that induces the growth and differentiation of resting B lymphocytes.
Authors: Julius M H , Janusz M , Lisowski J
Published: December 2022

We describe the first protein of mammalian origin that induces the growth and differentiation of resting B lymphocytes. A proline-rich protein has been isolated from sheep colostrum. A purified proline-rich protein preparation (PRPP) induced resting mouse B cells into and supported their progression through the cell cycle at frequencies comparable with those seen for LPS. Differentiation of resting B cells to plaque formation was also supported as efficiently by PRPP as it was by LPS. However, PRPP was distinct from LPS in that it supported the growth and differentiation of resting B cells derived from either C3H/Tif or C3H/HeJ mice. Splenocytes from neonatal mice responded robustly to PRPP with the growth and differentiation of contained B cells to plaque formation. Unlike LPS, PRPP did not induce detectable Ig isotype switching.
A monoclonal antibody (NKI-L16) directed against a unique epitope on the alpha-chain of human leukocyte function-associated antigen 1 induces homotypic cell-cell interactions.
Authors: Keizer G D , Visser W , Vliem M , Figdor C G
Published: December 2022

In the present study a unique antibody (NKI-L16) reacting with the alpha-chain of the human leukocyte function-associated Ag-1 (LFA-1) is described, which stimulates homotypic cell-cell interactions in a manner very similar to 12-O-tetradecanoyl-phorbol-13-acetate (TPA), in contrast to other anti-LFA-1 mAb which inhibit cell aggregation. The induction of aggregate formation of EBV-transformed B cells (JY) and CTL clones by TPA or NKI-L16 is not accompanied by an increase in the expression of LFA-1. Nevertheless, this cluster formation is LFA-1 dependent, inasmuch as anti-LFA-1 antibodies, other than NKI-L16, completely abrogate aggregation. Simultaneous addition of NKI-L16 and TPA did not result in a further increase of the speed of cluster formation, suggesting that a similar pathway is activated. Immunoprecipitation and enzyme digestion studies revealed that NKI-L16 recognizes a unique epitope on the alpha-chain of LFA-1, most likely situated close to the transmembrane segment of the molecule. It is hypothesized that NKI-L16 or TPA can cause the LFA-1 molecule to convert from an inactive to an active configuration, thereby permitting binding of LFA-1 to its natural ligand.
Cytofluorometric analyses of human T cell CD2/CD4 inter-molecular interactions.
Authors: Bueso-Ramos C E , Donahoe R M , Nicholson J K , Madden J J , Falek A
Published: December 2022

Incubation of human T lymphocytes with saturating concentrations of combinations of certain anti-CD2 and -CD4 mAb results in reciprocal down-regulation of the cell surface density expression of the respective CD molecules. Such reciprocal down-regulation occurs at 0 degrees C in the presence of sodium azide and appears selective for CD2 and CD4 molecules because mAb identifying various other CD T cell surface molecules (anti-Leu2a, -OK-CLL, -W6/32, -beta 2-microglobulin, -4B4) do not modulate CD2 or CD4 R density, and because anti-CD2 mAb (anti-OKT11 and -D66 clone-1) do not alter CD8 R density (anti-OKT8, -Leu2a) and vice versa. Down-regulation of CD2 by mAb specific to CD4 is epitope-specific but does not vary on the basis of the antibody isotype used. The anti-CD4 mAb, Leu3a, was the strongest CD2 down-regulator examined followed by OKT4F. mAb specific to other CD4 epitopes (B, C, D, and E) caused only slight down-regulation of CD2 expression whereas anti-OKT4 and -OKT4A mAb had no significant regulatory effect. Also, mAb specific to the 9.6 (anti-OKT11) and D66 (anti-D66 clone 1) epitopes of the CD2 molecule down-regulated CD4 density detectable with Leu3a, OKT4, and OKT4A anti-CD4 mAb. Down-regulation of CD2 by anti-CD4 mAb also occurred with the transformed T cell line, KE-37, which demonstrates that such effects can occur without mononuclear phagocytic accessory cells. From these data it can be concluded that important T cell immunoregulatory signals may be transmitted intramembranally between CD2 and CD4 glycoproteins.
Intrathymic differentiation and tolerance induction of lymphokine-secreting Lyt-2+ T helper cells.
Authors: Mizuochi T , Singer A
Published: December 2022

The present study has assessed thymic influence on the differentiation and recognition specificity of developing Lyt-2+ lymphokine-secreting T cells, and compared it with those of developing Lyt-2+ CTL. It was demonstrated that development of Lyt-2+ lymphokine-secreting Th cells requires an intrathymic differentiation step, and that peripheral Lyt-2+ lymphokine-secreting Th cells, unlike peripheral Lyt-2+ CTL, are profoundly tolerant to intrathymically expressed alloantigens. These data are interpreted as demonstrating that functionally distinct Lyt-2+ T cell populations are heterogeneous in their requirements for differentiation and/or activation.
Expression of IgG Fc receptors in myeloid leukemic cell lines. Effect of colony-stimulating factors and cytokines.
Authors: Liesveld J L , Abboud C N , Looney R J , Ryan D H , Brennan J K
Published: December 2022

Three classes of FcR have been defined on human myeloid cells by their reactivity with mAb; FcRI (mAb 32); FcRII (mAb IV3); and FcRIII (mAb 3G8). We have quantitated the expression of each FcR on human myeloid leukemia cells and cell lines (KG-1, HL-60, U937, and K562). Detailed analysis of FcR surface expression is provided for the U937 cell line after exposure to CSF and cytokines. Increased expression of FcRI and FcRII occurred at 72 h in cells exposed to GCT or Mo cell line-conditioned medium as well as to medium from PHA-treated mononuclear cells. The augmentation of FcRII required protein synthesis and was diminished by a neutralizing antibody to granulocyte-macrophage CSF. We also show that fractions containing natural granulocyte CSF or granulocyte-macrophage CSF as well as r-granulocyte and r-granulocyte-macrophage CSF are capable of inducing FcRII on these cells, whereas other cytokines such as IL-1 and IL-2, TNF-alpha, INF-gamma and macrophages CSF failed to do so.