bluuebunny/crossref_metadata_2025_split huggingface dataset:
IL-4-dependent up-regulation of IL-4 receptor expression in murine T and B cells.
Authors: Renz H , Domenico J , Gelfand E W 
Published: December 2022

Abstract
This study examined mRNA levels and cell surface expression of IL-4 receptor (IL-4R) in murine T and B cells after incubation with IL-4. Northern blot analysis of mRNA levels of T cells isolated from mesenteric lymph nodes and spleen revealed that IL-4 induced a transient augmentation of IL-4R mRNA in a dose-dependent manner. Maximal levels of mRNA were detected as early as 5 h after initiation of culture. These data were complemented by studies examining the cell surface expression of IL-4R using an anti-IL-4R mAb. Resting T and B lymphocytes express IL-4R (T greater than B) and incubation of these cells with exogenous IL-4 increased IL-4R expression to a maximum after 24 h. This effect was abolished after addition of anti-IL-4 antibody. Continuous incubation of T cells in the presence of high concentrations of IL-4 resulted in a down-regulation of IL-4R expression. Addition of the protein synthesis inhibitor cycloheximide blocked the induced increases in IL-4R expression, indicating the requirement for de novo protein synthesis. Both the levels of mRNA and cell surface expression of IL-4R were not affected by addition of exogenous IL-2, and IL-4 regulation of IL-4R expression was not influenced by the immunosuppressive drug cyclosporin A. These data demonstrate that in T and B cells, IL-4 induces a transient up-regulation of IL-4 mRNA levels that is subsequently reflected in increased numbers of IL-4R displayed on the cell surface. This regulation of IL-4R expression by IL-4 provides an important mechanism for amplification of IL-4-dependent activation pathways.
Splenic macrophage function in early syphilitic infection is complex. Stimulation versus down-regulation.
Authors: Tomai M A , Fitzgerald T J 
Published: December 2022

Abstract
Macrophages are important regulatory cells that can both stimulate and down-regulate various immune functions. During syphilitic infection, these cells phagocytize, kill, and lyse Treponema pallidum. They also modulate early T cell activation by decreasing IL-2 production through secretion of PG. This report focuses on additional complexities of macrophage regulation. Non-adherent splenic cells were stimulated with Con A to induce IFN-gamma synthesis. High levels were detected in preparations from normal rabbits and much lower levels in preparations from infected rabbits. The organisms also readily stimulated IL-1 synthesis by adherent spleen preparations from normal but not from infected rabbits. When indomethacin was added to these latter preparations, this IL-1 defect was reversed, implicating PG in this down-regulation. Spleen cells were obtained from normal rabbits and from rabbits infected testicularly for 9 to 12 days. Infection elevated basal levels of class II Ia Ag on adherent cells. In addition, macrophage Ia expression was increased during 4 days of in vitro incubation with treponemes. Non-adherent spleen cells from infected animals inhibited two different macrophage functions. First, culture filtrates obtained after 48 h of incubation contained a soluble factor that subsequently decreased LPS-induced IL-1 synthesis. Second, when macrophages were co-incubated with non-adherent cells, treponemal stimulation of macrophage Ia expression was inhibited; this inhibition was reversed by indomethacin implicating prostaglandins in this down-regulation. In further experiments an exogenous source of IFN-gamma was incubated with adherent cells from infected rabbits. This stimulated macrophage function as shown by increased IL-1 synthesis and Ia expression and decreased PGE2 secretion. Results are discussed in terms of the complexities of immunoregulation by macrophages during syphilitic infection.
Characterization of an immunoreactive 93-kDa core protein of Borrelia burgdorferi with a human IgG monoclonal antibody.
Authors: Volkman D J , Luft B J , Gorevic P D , Schultz J , Padovano L 
Published: December 2022

Abstract
Lyme borreliosis is an infectious disease caused by the tick-borne spirochete Borrelia burgdorferi, which carries the potential for chronic infection. Ag on the etiologic Borrelia are currently being defined structurally and their ability to elicit immune responses delineated. EBV can be used to immortalize human B. burgdorferi-specific B cells from infected donors and generate antibodies against antigenic epitopes encountered in natural infection. A human mAb secreting EBV-transformed B cell line, D7, has been developed that is specific for a 93-kDa B. burgdorferi protein and has been used to characterize this potentially important Ag. D7 produces an IgG3 antibody that detects the 93-kDa Ag as well as smaller fragments at 46 kDa and lower molecular mass. The antibody detects similar epitopes on all B. burgdorferi isolates tested and on a Borrelia hermsii protein with molecular mass greater than 100 kDa but binds poorly to Treponema species. In contrast, polyclonal sera from Lyme disease patients show little binding to the homologous Ag in B. hermsii. Structurally, the 93-kDa protein is associated with the flagellum and may be firmly anchored in the protoplasmic cylinder. It is not solubilized by nonionic detergent treatment of the whole Borrelia. Antibodies against a comparable m.w. protein are present in sera from patients with both early and late infection. Thus, antibodies against this Ag are a sensitive and specific marker of Borrelia infection. This Ag is likely of structural importance and may represent a target of host defenses.
The E alpha promoter: a linker-scanning analysis.
Authors: Viville S , Jongeneel V , Koch W , Mantovani R , Benoist C , Mathis D 
Published: December 2022

Abstract
To accurately delineate the DNA sequence elements involved in the transcriptional regulation of the murine MHC class II gene E alpha, we have constructed a set of "linker-scanning" mutants of the E alpha promoter region. These were made by the gapped heteroduplex technique and result in a set of 10-bp replacement mutations, covering the -206 to -6 stretch of the promoter. The effect of these mutations on transcriptional activity was evaluated in several systems, either by transfection into cultured cells or by in vitro transcription. The data points to the now classical X and Y boxes as the most important control elements, either for constitutive expression in B lymphoma cells, or for IFN-gamma-inducible expression in macrophages. Motifs upstream of the X box also play a role, but are somewhat less critical. Overall, we find no marked difference between regulatory strategies in B lymphomas or activated macrophages.
CD4+ T cell clones specific for the human p97 melanoma-associated antigen can eradicate pulmonary metastases from a murine tumor expressing the p97 antigen.
Authors: Kahn M , Sugawara H , McGowan P , Okuno K , Nagoya S , Hellström K E , Hellström I , Greenberg P 
Published: December 2022

Abstract
p97 is a human tumor-associated Ag present on most melanoma cells that represents a possible target for immunologic attack. To evaluate the capacity of T cells reactive with this protein to promote elimination of melanoma cells expressing p97, a murine model was developed by transfecting a C3H/HeN melanoma with the p97 cDNA, generating p97-specific CD4+ T cells by in vivo immunization of C3H/HeN mice with a vaccinia/p97 recombinant virus followed by in vitro cloning with soluble p97 protein, and determining whether these CD4+ T cells could mediate rejection of pulmonary metastases. Characterization of the T cell clones demonstrated the presence of both I-Ak and I-Ek-restricted clones, although the majority of clones recognized p97 in the context of I-Ek. Analysis of clonal specificity using truncated p97 proteins revealed that at least three epitopes were immunogenic, and further studies with overlapping 15-amino acid peptides from a region of the p97 molecule defined by these truncated proteins identified an immunodominant epitope responsible for the majority of the I-Ek response. The T cell clones were not capable of directly recognizing the p97-expressing melanoma cells but responded to the tumor if syngeneic APC were present to process the tumor-derived p97 Ag. The therapeutic efficacy of these CD4+ T cell clones was evaluated in an adoptive therapy model in which mice bearing metastatic pulmonary lesions were treated by i.v. administration of the p97-specific cells. Despite the inability of the CD4+ clones to directly respond to or lyse the tumor cells, the clones were effective in promoting tumor eradication. In vitro studies demonstrated that this may have reflected secretion of lymphokines that activated macrophages to lyse the tumor. The results suggest that noncytolytic p97-specific CD4+ T cell clones can be effective in therapy of pulmonary melanoma metastases. Moreover, if human T cells reactive with the p97 protein could be generated, the expression of this tumor-associated Ag in melanoma cells might be adequate for such T cells to mediate a therapeutic antitumor response.
Effect of a new monoclonal antibody, TA-2, that inhibits lymphocyte adherence to cytokine stimulated endothelium in the rat.
Authors: Issekutz T B , Wykretowicz A 
Published: December 2022

Abstract
An important event in the migration of lymphocytes out of the blood is their adherence to endothelial cells (EC). In inflammatory sites cytokines activate EC and promote lymphocyte EC adherence and migration. Small peritoneal exudate lymphocytes (sPEL) preferentially migrate from the blood to cutaneous delayed-type hypersensitivity reactions and to sites injected with IFN-gamma, IFN-alpha/beta, and TNF-alpha, rather than to peripheral lymph nodes. The basis of this migration is sPEL adherence to cytokine-activated EC. To study this adhesion mAb to rat sPEL were screened for inhibition of sPEL adherence to IFN-gamma-stimulated EC. One mAb, TA-2, inhibited IFN-gamma-stimulated adherence to EC by 60%. This antibody had no effect on the baseline adherence of sPEL to unstimulated EC. Treatment of sPEL, but not EC, with TA-2-inhibited adhesion. TA-2 also inhibited adhesion to EC activated with mIL-1 alpha, TNF-alpha, and LPS, and the adhesion of spleen T cells to activated EC. The TA-2 Ag was expressed on virtually all lymph node, spleen, and sPEL lymphocytes but sPEL expressed two to three times higher levels than lymph node lymphocytes, and the highest levels were found on CD4+ and CD45R- memory T cells. TA-2 immunoprecipitated a group of four polypeptides with molecular mass of 150, 130, 83, and 66 kDa. Finally, TA-2 inhibited sPEL adhesion to TNF-alpha and IL-1 stimulated human umbilical vein EC to the same extent as an anti-human VCAM-1 mAb, and combinations of TA-2 and anti-VCAM-1 were not different from treatment with either antibody alone. Thus, TA-2 appears to recognize rat VLA-4 based on immunoprecipitation, immunofluorescence, and lymphocyte EC studies. VLA-4 mediates the adhesion of rat lymphocytes to rat microvascular EC stimulated with IFN-gamma, mIL-1 alpha, TNF-alpha, and LPS. VLA-4 is important in the increased adhesion of sPEL to EC and the enhanced sPEL migration to inflammation may in part be explained by increased expression of VLA-4 on these cells.
Manganese superoxide dismutase is induced by IFN-gamma in multiple cell types. Synergistic induction by IFN-gamma and tumor necrosis factor or IL-1.
Authors: Harris C A , Derbin K S , Hunte-McDonough B , Krauss M R , Chen K T , Smith D M , Epstein L B 
Published: December 2022

Abstract
We have previously characterized more than 20 proteins induced by the immunoregulatory lymphokine IFN-gamma in human fibroblasts by their m.w. and isoelectric points determined in two-dimensional gels. Some of these proteins are induced uniquely by IFN-gamma, whereas others are also induced by IFN-alpha, TNF, or IL-1. Recent technologic advances have allowed us to begin to rapidly identify proteins induced by IFN-gamma and other cytokines by sequencing the induced proteins from blots of preparative two-dimensional gels of total cell lysates. In this study, we show that the approximately 21 kDa, isoelectric point greater than 7 protein induced by IFN-gamma is manganese superoxide dismutase (Mn-SOD), a mitochondrial protective enzyme encoded by a nuclear gene. Mn-SOD is induced by IFN-gamma and also by TNF in all four human cell lines examined: HS153 fibroblasts, ACHN renal carcinoma, A549 lung carcinoma, and A375 melanoma. Induction of Mn-SOD mRNA is a primary, rapid, and dose-dependent response to IFN-gamma. In ACHN renal carcinoma cells, Mn-SOD mRNA and protein are induced synergistically by IFN-gamma in combination with either TNF or IL-1, and the induced protein is enzymatically active. IFN-gamma and TNF together induce Mn-SOD mRNA by more than 100-fold relative to its level in untreated ACHN cells. The induction of Mn-SOD by IFN-gamma and its synergistic induction by IFN-gamma in combination with TNF and IL-1 should protect healthy cells from the toxicity of O2- during an immune response, and may provide a mechanism for selective killing of infected cells.
CD4+ Leu-8+ T cell supernatant activity that inhibits Ig production.
Authors: Kanof M E , Strober W , Kwan W C , O'Connell N A , James S P 
Published: December 2022

Abstract
The subpopulation of CD4+ T cells that expresses the Leu-8 peripheral lymph node homing receptor suppresses PWM-stimulated Ig synthesis. To determine the mechanism of this suppression, the immunoregulatory activity of culture supernatants obtained from peripheral blood CD4+ Leu-8+ T cells cultured with anti-CD3 mAb and PMA (Leu-8+ supernatant) was determined. Leu-8+ supernatant suppressed PWM-stimulated Ig synthesis in cultures containing non-T cells and CD4+ Leu-8- T cells. In contrast, the supernatant from CD4+ Leu-8- T cells did not suppress Ig synthesis. The inhibitory activity of CD4+ Leu-8+ T cell supernatants could not be accounted for by a deficiency or excess of IL-2, IL-4, IFN-gamma, IL-6, or PGE2. In studies examining the effect of CD4+ Leu-8+ supernatant on T cells, the supernatant did not alter either mitogen-induced proliferation or the helper function of CD4+ Leu-8- T cells. In studies examining the effect of CD4+ Leu-8+ supernatant on B cells, the supernatant inhibited Staphylococcus aureus Cowan I strain-induced B cell Ig secretion but not B cell proliferation. The suppressor activity of Leu-8+ supernatant was eliminated by protease treatment and was eluted by HPLC in two main peaks, with molecular sizes of 44 and 12 kDa. In summary, these studies indicate that supernatants from activated CD4+ Leu-8+ T cells directly suppress B cell Ig production.
CD45 is not involved in the processing of spatial information required for chemotaxis.
Authors: Gatewood B , Joe J , Zigmond S H 
Published: December 2022

Abstract
To examine the possible role of CD45 (a cell surface tyrosine phosphatase) in processing spatial information leading to the orientation of neutrophils in a gradient of chemoattractant, we used antibodies to cap CD45. If the phosphatase activity of CD45 was processing spatial information coming from occupied receptors and leading to the directional cell response, sequestering CD45 in one region of the cell surface should lead to a decreased ability of the cells to orient in a gradient of chemoattractant. CD45 was capped by sequential addition of KC56, a mAb against CD45, and a rabbit anti-mouse antiserum. Cells with capped CD45 were able to orient toward N-formylnorleucylleucylphenylalanine and C5a at levels similar to those achieved by cells processed simultaneously but without capping CD45. This indicates that the spatial arrangement of CD45 is not critical for the ability of cells to orient in a gradient of chemoattractant.
Vaccination with the major secretory protein of Legionella induces humoral and cell-mediated immune responses and protective immunity across different serogroups of Legionella pneumophila and different species of Legionella.
Authors: Blander S J , Horwitz M A 
Published: December 2022

Abstract
In a previous study, we demonstrated that immunization of guinea pigs with the major secretory protein (MSP) of Legionella pneumophila, serogroup 1 induced humoral and cell-mediated immune responses to MSP and protective immunity against lethal aerosol challenge with this serogroup of L. pneumophila. Although serogroup 1 L. pneumophila cause most cases of Legionnaires' disease, other serogroups of L. pneumophila and species of Legionella cause many cases. In this study, we have examined if immunization with MSP induces humoral and cell-mediated immune responses and protective immunity across different serogroups of L. pneumophila and species of Legionella. By immunoblot analysis, MSP from L. pneumophila serogroup 1 (Lp1 MSP), L. pneumophila serogroup 6 (Lp6 MSP), and Legionella bozemanii (Lb MSP) shared common epitopes recognized by guinea pig anti-Lp1 MSP antiserum. These MSP molecules, however, were not identical as they had different apparent m.w. Immunization of guinea pigs with MSP induced strong cell-mediated immune responses across the different serogroups and species, as indicated by splenic lymphocyte proliferation and cutaneous delayed-type hypersensitivity in response to both homologous and heterologous MSP. Immunization with MSP induced strong protective immunity across two serogroups of L. pneumophila; overall, 9 survived aerosol challenge with L. pneumophila serogroup 1 compared to 0 of 12 (0%) sham-immunized control animals (p = 3 x 10(-4), Cochran-Mantel-Haenzel chi 2 statistic for pooled data). Immunization with MSP also induced protective immunity across species of Legionella but protection was species-specific. Whereas immunization with Lb MSP induced protective immunity against L. pneumophila, neither immunization with Lp1 MSP nor immunization with Lb MSP induced protective immunity against L. bozemanii, which produces MSP. Not surprisingly, immunization with MSP did not induce protective immunity against MSP-negative Legionella micdadei. In the case of both L. bozemanii and L. micdadei, immunization with a sublethal dose did confer protective immunity to aerosol challenge indicating that these species do contain immunoprotective components. This study demonstrates that immunization with MSP induces humoral and cell-mediated immune responses across different serogroups of L. pneumophila and species of Legionella, but that the capacity of MSP immunization to induce protective immunity is species-specific. Nevertheless, an MSP vaccine has the potential to induce protective immunity against the great majority of cases of Legionnaires' disease.
Sequence and immunogenicity of the 70-kDa heat shock protein of Mycobacterium leprae.
Authors: McKenzie K R , Adams E , Britton W J , Garsia R J , Basten A 
Published: December 2022

Abstract
The gene encoding the Mycobacterium leprae 70-kDa heat shock protein has been isolated from a cosmid library using a fragment of the clone JKL2. Southern blot analysis of a positive clone identified a 4.4-kb fragment containing the entire coding region of the gene plus 2.4 kb upstream. Sequencing revealed the gene to encode a 621-amino acid protein, bearing 56% identity with the Escherichia coli dnaK gene product and 47% and 46% identity with the human and Caenorhabditis elegans hsp70, respectively. Comparison with the C-terminal 203 amino acids of the Mycobacterium tuberculosis 71-kDa Ag yielded 70% identity. Recombinant M. leprae p70 was produced in E. coli as a fusion protein (rp70f) with a portion of the schistosomal glutathione-S-transferase, using the expression vector, pGEX-2T. Cleavage with thrombin resulted in the release of a 70.0-kDa protein (rp70c) from the glutathione-S-transferase. Examination of the proteins by immunoblotting demonstrated that anti-M. leprae mAb, L7, and sera from lepromatous leprosy patients bound to both the cleaved and fusion proteins. We compared the T cell reactivity of the M. leprae recombinant proteins with that of mAb affinity-purified bacille Calmette-Guerin (BCG) 70-kDa Ag using proliferation assays. PBMC of BCG vaccinees responded to both M. leprae cleaved and fusion p70, though more subjects responded to the rp70c (18 of 20) than to rp70f (13 of 20). Responses were generally higher to rp70c than to rp70f, however all responses to the M. leprae recombinant proteins were lower than to mAb affinity-purified BCG p70. Thus, the M. leprae 70-kDa heat shock protein elicits T and B cell responses in subjects exposed to mycobacteria, despite its homology with the human hsp70.
Clonal anergy is induced in vitro by T cell receptor occupancy in the absence of proliferation.
Authors: DeSilva D R , Urdahl K B , Jenkins M K 
Published: December 2022

Abstract
Murine Th1 clones that receive signals through their TCR in the absence of APC-derived co-stimulatory signals do not produce IL-2 and instead become anergic, i.e., they are subsequently unable to produce IL-2 in response to Ag and normal APC. The critical cellular event required to prevent the induction of this anergic state appears to be T cell proliferation. Anergy was induced when T cell clones were stimulated under conditions where both TCR occupancy and costimulatory signals were provided but where proliferation in response to the IL-2 produced was prevented. Once induced, anergy could be reversed if the T cells were allowed to undergo multiple rounds of cell division. These results show that anergy is induced as a consequence of TCR occupancy in the absence of cell division; this can be achieved either by limiting IL-2 production because of deficient provision of co-stimulatory signals or by preventing response to IL-2.
Priming of influenza virus-specific cytotoxic T lymphocytes vivo by short synthetic peptides.
Authors: Gao X M , Zheng B , Liew F Y , Brett S , Tite J 
Published: December 2022

Abstract
Influenza virus-specific CTL were primed in vivo by immunization with short synthetic peptides representing major CTL epitopes from the nucleoprotein of type A influenza virus. The resultant CTL after in vitro boosting of primed spleen cells recognized both virus-infected and peptide-pulsed target cells. The requirement of CD4+ T cell activation was investigated in several ways. First the addition of helper epitopes to the CTL epitope did not enhance CTL generation, suggesting that helper activity was either not limiting or not required. However, in vivo depletion of CD4+ T cells completely inhibited the generation of CTL by peptide immunization. The inclusion of anti-CD4 in the in vitro restimulation with peptide also prevented the generation of CTL, whereas in vitro reactivation of virus immune spleen cells with peptide was not inhibited by anti-CD4. Thus there appears to be heterogeneity in the requirement of CD4+ T cell proliferation in CTL generation. One possibility is that virus infected cells can stimulate higher affinity T cells that are less helper T cell dependent.