bluuebunny/crossref_metadata_2025_split huggingface dataset:
Suppression of polyclonal antibody production in Trypanosoma cruzi-infected mice by treatment with anti-L3T4 antibodies.
Authors: Minoprio P , Eisen H , Joskowicz M , Pereira P , Coutinho A 
Published: December 2022

Abstract
Acute Trypanosoma cruzi infection of mice results in a very marked polyclonal activation of B and T lymphocytes, accompanied by high numbers of Ig-secreting PFC and lectin-dependent effector CTL. Treatment of mice with monoclonal anti-L3T4 antibodies from the time of infection (days 0, 4, and 8) completely suppresses the polyclonal PFC response and CTL generation. Treatment of nude mice with antibody does not alter the lipopolysaccharide-induced polyclonal PFC response, and it only modulates the isotypic profile of the PFC response to T. cruzi infection, without reducing its magnitude. Furthermore, antibody-treated, T. cruzi-infected euthymic mice do not develop the typical B cell blastogenic response, but show high numbers of activated Lyt-2+ lymphoblasts in the spleen. These results indicate that effector cell generation in T. cruzi-infected mice is predominantly helper T cell-dependent.
Cross-linking of T3 (CD3) with T4 (CD4) enhances the proliferation of resting T lymphocytes.
Authors: Anderson P , Blue M L , Morimoto C , Schlossman S F 
Published: December 2022

Abstract
Monoclonal antibodies reactive with defined T lymphocyte surface antigens were covalently coupled to protein A-Sepharose beads using the bifunctional imidoester, dimethyl pimelimidate. Sepharose-immobilized antibody reactive with T3 induced the proliferation of resting T lymphocytes in the presence of either recombinant interleukin 2 or phorbol myristate acetate. When monoclonal antibodies reactive with T3 and T4 were coupled to the same Sepharose bead (hereafter designated Sepharose (T3:T4)), proliferation was enhanced an average of three-fold. Similarly prepared Sepharose beads coupled to anti-T3 and anti-T8 also enhanced proliferation over that observed with anti-T3 alone. Sepharose (T3:T4) similarly increased the proliferation of T4+ lymphocytes and a T4+ clone but failed to enhance the proliferation of T8+ lymphocytes. The increased proliferation of T4+ lymphocytes resulted from a preferential activation of the T4+2H4- helper population over the T4+2H4+ suppressor-inducer population. The enhanced proliferation induced by Sepharose (T3:T4) could be completely inhibited by soluble anti-T4. These results suggest that perturbation of T3 may be a minimal signal for T cell activation and that the assembly of a multimeric complex including T3 and T4 may be required for optimal T cell activation.
Acquisition of non-MHC restricted cytotoxic function by IL 2 activated thymocytes with an "immature" antigenic phenotype.
Authors: Phillips J H , Lanier L L 
Published: December 2022

Abstract
Culture of human thymocytes in interleukin 2 (IL 2) results in the generation of cytotoxic T lymphocytes (CTL) that kill tumor cell targets without major histocompatibility complex (MHC) restriction. Thymic non-MHC restricted CTL expressed Leu-19 antigen, but were generated from thymic precursor cells that lacked expression of Leu-19. In contrast, short term culture in Il 2 of peripheral blood lymphocytes depleted of Leu-19+ lymphocytes did not result in the generation of cytotoxic activity. IL 2 was necessary and sufficient for the generation of cytotoxic thymocytes and induction of Leu-19 antigen expression. Thymic non-MHC restricted CTL were generated from precursor cells expressing CD1, an antigen present on the majority of thymocytes. Furthermore, cytotoxic activity was detected in IL 2 cultured thymocyte populations with an "immature" antigenic phenotype, i.e. CD1+ and CD4+, CD8+. Upon subsequent culture, thymic non-MHC restricted CTL lost expression of CD1, and developed an antigenic phenotype similar to peripheral blood non-MHC-restricted CTL, suggesting that peripheral non-MHC-restricted CTL may originate from these thymic precursors.
Recognition of EBV plasma membrane protein expressed on murine cells after gene transfer.
Authors: Reiss C S , Wang D , Ghosh D , Gaposchkin C , Kieff E 
Published: December 2022

Abstract
The immune response to B lymphocytes infected with Epstein-Barr virus (EBV) prevents their overgrowth in normal humans. A murine model is now described for analyzing the T cell immune response to Epstein-Barr virus genes expressed in murine lymphoblasts by gene transfer. In mice, a 60,000 dalton virus-encoded protein characteristically found in the plasma membrane of latently infected human lymphocytes readily induces both proliferative and cytolytic T lymphocytes specific for both the EBV protein and murine major histocompatibility proteins. Longterm cultures of L3T4+ cells, some of which were cytolytic, were found to be restricted by H-2I-Ed and the latent membrane protein. Similarly, Lyt-2+ cells were cytolytic and were restricted by H-2Ld and the lymphocyte membrane protein gene product. The similarity in murine and human effector cell responses suggests that this is a useful experimental model, and the EBV latent infection membrane protein may be an important antigen in the immune restriction of growth transformed latently infected lymphocytes.
Autoreactivity accelerates the development of autoimmunity and lymphoproliferation in MRL/Mp-lpr/lpr mice.
Authors: Weston K M , Yeh E T , Sy M S 
Published: December 2022

Abstract
Lymph node T cells from autoimmune MRL/Mp-lpr/lpr mice, but not from congeneic MRL/Mp-+/+ mice, spontaneously proliferate and produce IL 2 when cultured in vitro for 5 to 7 days. This autologous activation depends critically on the length of in vitro culture and the initial culture density, indicating that cell to cell interaction may be essential. Phenotypic characterization of cultured cells suggests that both L3T4+ and Lyt-2+ T cells proliferate. However, only L3T4+ T cells produce IL 2. Mixing experiments reveal that the inability of freshly isolated lymph node cells from MRL/Mp-lpr/lpr mice to proliferate is not due to the presence of suppressor cells. Supernatant from 7-day cultures failed to induce freshly isolated cells to proliferate. Thus, the failure of freshly isolated cells to spontaneously proliferate and secrete IL 2 is not due to the inability of the cells to produce soluble mediators. Similar to the inactivation of normal T lymphocytes, in vitro addition of monoclonal anti-L3T4 or anti-IL 2 receptor antibody significantly inhibits the activation of these cultured lymphocytes. Spontaneous proliferation and IL 2 production can be blocked by the addition of monoclonal anti-I-Ak but not by monoclonal anti-I-Ad. Spontaneous proliferation and IL 2 production can be detected in young (4-wk-old) MRL/Mp-lpr/lpr mice at a time when their lymphocyte composition and physiology appear to be normal. More interestingly, spontaneous proliferation and IL 2 production cannot be detected in C57BL/6J mice bearing the lpr/lpr gene. These experiments support the notion that aberrant syngeneic autoreactivity may act as an accelerating factor in the pathogenesis of lymphoproliferation and autoimmunity in MRL/Mp-lpr/lpr mice.
Corticosteroid therapy suppresses spontaneous interleukin 2 release and spontaneous proliferation of lung T lymphocytes of patients with active pulmonary sarcoidosis.
Authors: Pinkston P , Saltini C , Müller-Quernheim J , Crystal R G 
Published: December 2022

Abstract
Active pulmonary sarcoidosis is characterized by the alveolar accumulation of activated helper T lymphocytes that are spontaneously releasing IL 2 and proliferating at an enhanced rate. In this regard, sarcoidosis represents a "model" human disorder to test in vivo the known in vitro action of corticosteroids on suppressing the activated IL 2 gene. Comparable groups of patients with active sarcoidosis were prospectively evaluated with no therapy or treated with corticosteroids. Over 3.2 +/- 0.4 mo, the untreated group had no significant change in spontaneous lung T cell release of IL 2 or spontaneous proliferation. In contrast, over the same period, the treated group had marked reduction of spontaneous lung T cell release of IL 2 and proliferation (p less than 0.01, all comparisons before therapy). Furthermore, Northern analysis of lung T cell RNA before therapy demonstrated IL 2 mRNA transcripts, whereas no IL 2 transcripts were observed during therapy. These observations are consistent with the concept that directly, or indirectly, corticosteroids are capable of suppressing the IL 2 gene in activated T lymphocytes in vivo.
Recombinant interferon-alpha, -beta, and -gamma enhance the proliferative response of human B cells.
Authors: Morikawa K , Kubagawa H , Suzuki T , Cooper M D 
Published: December 2022

Abstract
Recombinant interferons (IFN-alpha, -beta, and -gamma) were examined for their effects on B cell activation. Relatively small IgM+ B cells from human blood samples were isolated by fluorescence-activated cell sorting and were used as target cells. Although the interferons themselves were nonmitogenic, each enhanced the proliferative response induced by a mitogenic anti-mu monoclonal antibody, with IFN-beta usually showing the greatest enhancement and IFN-gamma the least. Pretreatment with the interferons primed resting B cells to undergo enhanced DNA synthesis in response to the anti-mu antibody DA4. Conversely, anti-mu pretreatment, followed by IFN treatment, did not induce B cells to enter the S phase. Time-course analysis revealed that IFN could augment the anti-mu response even when added as late as the final 24 hr of a 3-day culture interval. Combinations of IFN-gamma plus IFN-alpha or -beta were synergistic in the anti-mu response, whereas the IFN-alpha plus IFN-beta combination was not. The data suggest that interferons produced by both lymphocytes (IFN-gamma) and nonlymphoid inflammatory cells (IFN-alpha and -beta) can enhance B cell growth via different mechanisms.
Role of the macrophage-derived hybridoma growth factor in the in vitro and in vivo proliferation of newly formed B cell hybridomas.
Authors: Bazin R , Lemieux R 
Published: December 2022

Abstract
It has been shown recently that monocyte-macrophage cells produce a growth factor (HGF) active on newly formed B cell hybridomas. We have studied the effect of HGF on the proliferation of an HGF-sensitive clone of B cell hybridoma. Results obtained showed that the murine P388D1 cell-derived HGF has a m.w. of 29,000 and an isoelectric point (pI) of 6.2 whereas the human monocyte-derived HGF has a m.w. of 34,000 and a pI of 4.9. The HGF activity was not mediated by interleukin 1 because the two activities could be completely separated by gel filtration. Results obtained in in vivo experiments showed that HGF-sensitive cells are tumorigenic in mice. The finding that the HGF biochemical parameters (m.w. and pI) are similar to the ones of a recently described plasmacytoma growth factor suggests that HGF and the plasmacytoma growth factor are similar and that the HGF sensitivity of SP 2/O myeloma cells is reactivated after fusion with normal B lymphocytes.
C3a(C3adesArg) induces production and release of interleukin 1 by cultured human monocytes.
Authors: Haeffner-Cavaillon N , Cavaillon J M , Laude M , Kazatchkine M D 
Published: December 2022

Abstract
Purified human C3a(C3adesArg) induced dose-dependent generation of intracellular IL 1 activity and release of IL 1 in cultures of human mononuclear adherent cells in serum-free conditions. Concentrations of C3a(C3adesArg) of 10(-8) M and 6 hr of culture were sufficient to induce production of cell-associated IL 1, as detected in monocyte lysates. Ten- to 100-fold higher concentrations of C3a(C3adesArg) and 24 hr of culture were required for induction of IL 1 release. Release of IL 1 induced by suboptimal amounts of C3a(C3adesArg) was greatly enhanced by the addition of indomethacin to the culture medium. Contamination with C5a of the C3a(C3adesArg) preparation did not account for C3a(C3adesArg)-induced IL 1 production. Induction of IL 1 activity by C3a(C3adesArg) was not due to contaminating LPS, as indicated by the following observations: the amount of contaminating LPS in C3a(C3adesArg) was below that which could induce IL 1 release from human monocytes in serum-free conditions; induction of IL 1 by C3a(C3adesArg) was not suppressed by polymyxin B; kinetics of IL 1 production and release in the presence of C3a(C3adesArg) differed from those observed in the presence of LPS; and sialated gangliosides, which inhibit IL 1 release induced by LPS, had no effect on the induction of IL 1 by C3a(C3adesArg). The C3a(C3adesArg) preparation used in this study mostly contained the desArg derivative, suggesting that, in contrast with the requirement for an intact C-terminal arginyl residue for the spasmogenic activity of C3a, both C3a and its C3adesArg derivative may interact with receptors on human monocytes. By inducing IL 1 production and release, C3a(C3adesArg) may contribute to the generation of the inflammatory process and the regulation of the immune response.
Serologically defined V region subgroups of human lambda light chains.
Authors: Solomon A , Weiss D T 
Published: December 2022

Abstract
The availability of numerous antisera prepared against lambda-type Bence Jones proteins and lambda chains of known amino acid sequence has led to the differentiation and classification of human lambda light chains into one of five V lambda subgroups. The five serologically defined subgroups, V lambda I, V lambda II, V lambda III, V lambda IV, and V lambda VI, correspond to the chemical classification that is based on sequence homologies in the first framework region (FR1). Proteins designated by sequence as lambda V react with specific anti-lambda II antisera and are thus included in the V lambda II subgroup classification. The isotypic nature of the five V lambda subgroups was evidenced through analyses of lambda-type light chains that were isolated from the IgG of normal individuals. Based on analyses of 116 Bence Jones proteins, the frequency of distribution of the lambda I, lambda II/V, lambda III, lambda IV, and lambda VI proteins in the normal lambda chain population is estimated to be 27%, 37%, 23%, 3%, and 10%, respectively. This distribution of V lambda subgroups was comparable to that found among 82 monoclonal Ig lambda proteins. Considerable V lambda intragroup antigenic heterogeneity was also apparent. At least two sub-subgroups were identified among each of the five major V lambda subgroups, implying the existence of multiple genes in the human V lambda genome. The V lambda classification of 54 Ig lambda proteins obtained from patients with primary or multiple myeloma-associated amyloidosis substantiated the preferential association of lambda VI light chains with amyloidosis AL and the predominance of the normally rare V lambda VI subgroup in this disease.
Biosynthesis and glycosylation of p150,95 and related leukocyte adhesion proteins.
Authors: Miller L J , Springer T A 
Published: December 2022

Abstract
The p150,95 cell surface protein is a member of a family of heterodimeric leukocyte adhesion proteins that have homologous alpha subunits, each noncovalently associated with a common beta subunit. In this report we have metabolically labeled the U937 cell line at various timepoints during its phorbol myristic acetate-induced maturation to examine the kinetics of synthesis of these proteins during monocytic differentiation, and their maturation and glycosylation. The p150,95 alpha subunit was immunoprecipitated with p150,95-specific monoclonal antibody (MAb), or an antiserum to the denatured, purified alpha X subunit. The glycosylation and polypeptide chain length of the p150,95, Mac-1, and lymphocyte function associated antigen (LFA-1) alpha and beta subunits were compared by immunoprecipitation with subunit specific MAb and antisera, and by digestion with Endo H and N-glycanase. The p150,95 alpha subunit is synthesized as a precursor of 146,000 Mr, has five to six N-linked oligosaccharides, and has a polypeptide chain backbone of 132,000 Mr. Over 50% of the carbohydrate on the mature alpha subunit of 150,000 Mr was sensitive to Endo H digestion. The p150,95 alpha and beta precursors can associate before maturation into the mature form. Conversion to the mature form was accompanied by loss of reactivity with the antiserum to the denatured alpha X subunit, suggesting a change in conformation. Mac-1 and LFA-1 alpha subunits have precursors of 160,000 Mr and 165,000 Mr, respectively, and contain N-linked carbohydrates. The polypeptide chain length for the Mac-1 alpha subunit is 137,000 Mr, and for LFA-1 is 149,000 Mr. Only 14% of the oligosaccharide on the mature LFA-1 alpha subunit was sensitive to Endo H, suggesting that unlike p150,95, most is converted to the complex type. The differences noted in the Mr of the three homologous alpha subunits are therefore due to differences in both polypeptide chain length and carbohydrate processing during biosynthesis.
T cell antigen receptor triggered exocytosis in cytotoxic T lymphocytes is inhibited by soluble, but not immobilized monoclonal antibodies to Lyt-2 antigen.
Authors: Takayama H , Trenn G , Kruisbeek A , Kanagawa O , Sitkovsky M V 
Published: December 2022

Abstract
The effect of monoclonal antibodies (mAb) to surface antigens on the T cell antigen receptor (TcR)-triggered exocytosis of intracellular granules in cytotoxic T lymphocytes (CTL) was studied. Soluble anti-LFA-1, anti-TcR, and anti-Lyt-2 mAb inhibited both CTL-inflicted 51Cr-release from the target cell (TC) and TC-stimulated exocytosis of granules from cloned CTL. Soluble anti-TcR and anti-Lyt-2 mAb but not soluble anti-LFA-1 mAb inhibited exocytosis, which was triggered by solid-phase anti-TcR mAb. Immobilized anti-Lyt-2 did not inhibit secretion triggered by immobilized anti-TcR mAb; immobilized anti-LFA-1 mAb had an modest inhibiting effect. Inhibition of exocytosis by soluble anti-Lyt-2 mAb was greater when stimulating anti-TcR mAb were immobilized at a lower density on a plastic surface. When the requirement for TcR cross-linking was bypassed by synergistic action of phorbol ester and ionophore A23187, no inhibition of exocytosis by soluble anti-Lyt-2 mAb was detected. The obtained data point to steric hindrance as the most likely explanation of the inhibition of TcR-triggered CTL activation by anti-Lyt-2 mAb.
The role of macrophages in anti-idiotypic antibody and T suppressor factor induction of timothy grass pollen antigen B-specific T suppressor cells.
Authors: Malley A , Bradley L M , Shiigi S M 
Published: December 2022

Abstract
Cultures of normal spleen cells with anti-idiotypic antibody (anti-Id) or antigen B (AgB)-specific T suppressor factor (Tsf1) in mini-Marbrook chambers for 4 days at 37 degrees C lead to the in vitro induction of AgB-specific T suppressor (TS) cells. These TS cells significantly suppress a secondary AgB-specific IgE response, but they do not affect a secondary AgB-specific IgG response. Depletion of both B cells and macrophages from normal spleen cells by panning on anti-Ig-coated petri dishes provides an enriched T cell population. These enriched T cells when cultured with anti-Id or Tsf1 in mini-Marbrook chambers do not produce AgB-specific TS cells, and mice treated with cells harvested from the mini-Marbrook chambers have normal secondary AgB-specific IgG and IgE responses. The addition of as few as 1000 bone marrow-derived macrophages (BMDM) to cultures of the enriched T cells with anti-Id, or Tsf1 restores the ability of these cultures to produce significant levels of AgB-specific TS cells. Further studies reveal that the macrophage population must be histocompatible and express a cell surface I-J antigen. Attempts to pulse BMDM with anti-Id or Tsf1 at 4 degrees C and to culture in mini-Marbrook chambers 10(3) pulsed BMDM with enriched T cells were unsuccessful in producing AgB-specific TS cells. However, pulsing BMDM with anti-Id or Tsf1 at 37 degrees C, and adding 10(3) of these pulsed BMDM to enriched T cells in culture led to the formation of significant levels of AgB-specific TS cells.
Protein kinase C activation blocks anti-IgM-mediated signaling BAL17 B lymphoma cells.
Authors: Mizuguchi J , Ji Y Y , Nakabayaschi H , Huang K P , Beaven M A , Chused T , Paul W E 
Published: December 2022

Abstract
Short term pretreatment of the B lymphoma, BAL17, with phorbol 12-myristate, 13-acetate (PMA) blocks elevation in inositol trisphosphate (InsP3) and increases in intracellular free calcium concentration ([Ca2+]i) in response to anti-IgM. The inhibition of enhanced InsP3 level is detected at 30 sec after the addition of anti-IgM, the earliest point measured, and is reversed by 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride, an inhibitor of protein kinase C (PKC). The blockade of increased [Ca2+]i by PMA is also observed at the earliest time examined (15 sec), is reversed by 1-(5-isoquinoline-sulfonyl)-2-methylpiperazine dihydrochloride, and is mimicked by dioctanoylglycerol, a physiologic activator of PKC. The enhanced production of inositol phosphates in response to NaF is also blocked in BAL17 cells pretreated with PMA. Extended treatment of BAL17 cells with PMA depletes cellular PKC. Such pretreatment with PMA enhances rather than inhibits increased InsP3 levels in response to anti-IgM and leads to more sustained elevations in [Ca2+]i than in normal BAL17 cells. These results lead us to conclude that PMA-blockade of the response of B cells to anti-IgM represents a disruption of the transmembrane signaling process (desensitization of the signaling pathway) as a result of a PKC-mediated phosphorylation event.
Isotype switching in human B lymphocyte malignancies occurs by DNA deletion: evidence for nonspecific switch recombination.
Authors: Borzillo G V , Cooper M D , Kubagawa H , Landay A , Burrows P D 
Published: December 2022

Abstract
The mechanism and specificity of isotype switching operative in human B lymphocytes was investigated by a determination of immunophenotype and immunoglobulin heavy and light chain gene status in a panel of human Ig-, IgM, IgG, and IgA B cell malignancies. Regardless of specific tumor type or switched immunophenotype, isotype switching was accompanied by the rearrangement of the expressed CH gene downstream of VDJH, with concomitant deletion of upstream CH genes in all cases. On the allelically excluded chromosome, 25% of the IgG or IgA tumors have retained C mu, and 75% have deleted C mu. The 5' recombination breakpoints for both productive and excluded alleles lie within or near S mu, 3' of the enhancer. No correlation between the extent of allelically excluded CH deletions and the isotype produced by the tumor was observed. Excluded chromosome deletion endpoints were found 5', equal to, or 3' of productive chromosome deletion endpoints. Furthermore, we have identified at least one IgM+ tumor that has undergone abortive CH gene deletions and have observed several unanticipated switch region deletions and potential translocations. The data suggest that isotype switching in human B cells occurs by a nonsubclass- and nonclass-specific switch recombinase.