bluuebunny/crossref_metadata_2025_split huggingface dataset:
Induction of TCR-gamma delta+ cells from thymocytes stimulated by a fetal liver-derived hepatocyte clone.
Authors: Nanno M , Hata M , Shimada S , Doi H , Satomi S , Yagi H , Nakamura M , Sakata T , Suzuki R , Itoh T 
Published: January 2023

Abstract
We have previously reported that a fetal liver-derived hepatocyte clone, FHC-4D2, can support hematopoiesis in vitro. Here, we show that fetal thymocytes (FT) or adult thymocytes (AT) proliferate on the monolayer of FHC-4D2 cells in the presence of rIL-2. Fresh thymocytes contained few TCR-gamma delta+ cells (&lt; 4% for FT and &lt; 1% for AT); significant numbers of TCR-gamma delta+ cells were detected (2-11% for FT and 15-33% for AT) after the coculture with FHC-4D2 and rIL-2. Although FT-derived TCR-gamma delta+ cells predominantly used the V gamma 5 chain, the major population in AT-derived TCR-gamma delta+ cells used V gamma 1, V gamma 4, or V gamma 7 chains. Both FT- and AT-derived TCR-gamma delta+ cells killed FcR-bearing target cells when incubated with anti-TCR-gamma delta Ab. Half of FT-derived TCR-gamma delta+ cells were CD4-CD8 alpha+8 beta-; the rest were CD4-CD8 alpha-8 beta-. AT-derived TCR-gamma delta+ cells expressed neither CD4 nor CD8 molecules. Separation of thymocytes from FHC-4D2 cells with a membrane filter reduced the proliferative response by two- to threefold. Taken together, these results demonstrate that a fetal hepatocyte clone supports thymocytes to develop preferentially into TCR-gamma delta+ cells in cooperation with rIL-2 through cell-cell contact, that the repertoire and the phenotype of induced TCR-gamma delta+ cells are determined by the age of the mice, and that hepatocytes might thus play an active role in T lymphopoiesis in the fetal liver.
Role of the VLA-4 molecule in T cell costimulation. Identification of the tyrosine phosphorylation pattern induced by the ligation of VLA-4.
Authors: Sato T , Tachibana K , Nojima Y , D'Avirro N , Morimoto C 
Published: January 2023

Abstract
The very late activated Ag (VLA) molecules not only mediate T cell adhesions, but also provide costimulation in a TCR/CD3-dependent manner. However, little is known about the signals mediated by the ligation of VLA molecules. Previous work from our laboratory identified a 105-kDa protein that is predominantly phosphorylated on tyrosine residue upon engagement of VLA-4 in a human T lymphoblastic cell line, H9, and in peripheral T cells. In the present study, we have shown that the A and B epitope of VLA-4 plays a key role in VLA-4-mediated T cell costimulation. Moreover, we have demonstrated that the solid phase cross-linking of VLA-4 using Ab (against A and B) or the CS-1 region of fibronectin, stimulated tyrosine phosphorylation of 140-, 120-, 80- to 70-, 60- to 55-, 50-, and 45-kDa proteins in addition to the 105-kDa protein. In contrast, Ab ligation of the C epitope of VLA-4 mainly induced tyrosine phosphorylation of pp105, weakly induced other protein tyrosine phosphorylation, and additionally induced only minimal T cell costimulation. Using immunoblotting, we have identified some of the tyrosine-phosphorylated proteins to be phospholipase C gamma (pp140), pp125 focal adhesion kinase (pp120), paxillin (pp70 and pp50), p59fyn/p56lck (pp60-55), and mitogen-activated protein kinase (pp45). Since solid phase cross-linking of VLA-4 by B2 epitope-specific Ab induced T cell costimulation most strongly via the CD3 pathway, our results suggested that the above tyrosine-phosphorylated proteins may play an important role in VLA-4-mediated T cell costimulatory signaling events.
Intracellular transport of invariant chain-MHC class II complexes to the peptide-loading compartment.
Authors: Xu X , Song W , Cho H , Qiu Y , Pierce S K 
Published: January 2023

Abstract
Th cells recognize peptide fragments of foreign Ags bound to MHC class II molecules. Upon synthesis in the endoplasmic reticulum, the alpha- and beta-chains of the class II molecules rapidly associate with invariant chains (li). The dissociation of li from class II molecules precedes binding of processed Ag and the formation of SDS-stable alpha beta dimers. We previously showed that functional, processed Ag-class II complexes are assembled in a dense lysosome-like compartment that contains stable class II molecules, but no li, referred to in this work as the peptide-loading compartment. We also identified a separate compartment that contains predominantly SDS-unstable li-class II complexes. Because we were unable to identify known organelle markers associated with this compartment, we refer to it as the X compartment. In this work, we provide results that indicate that the X compartment is composed of transport vesicles that move li-class II complexes to the peptide-loading compartment, where all events in the assembly of processed Ag-class II complexes occur.
Local release of IL-10 by transfected mouse mammary adenocarcinoma cells does not suppress but enhances antitumor reaction and elicits a strong cytotoxic lymphocyte and antibody-dependent immune memory.
Authors: Giovarelli M , Musiani P , Modesti A , Dellabona P , Casorati G , Allione A , Consalvo M , Cavallo F , di Pierro F , De Giovanni C 
Published: January 2023

Abstract
The cDNA coding for mouse IL-10 (mIL-10) was transduced into the parental cells of a spontaneous adenocarcinoma of BALB/c mice (TSA-pc), and clones secreting small, medium, and large quantities of IL-10 were selected. In vivo, both low and high producer clones do not display an enhanced ability to grow in H-2 and non-H-2 incompatible mice. Instead, the intensity of their rejection increases in function of the amount of mIL-10 released. After an initial growth period in syngeneic mice, high producer clones undergo complete rejection due to the combined action of CD8+ lymphocytes, NK cells, and neutrophils. After this rejection, mice are immune to a subsequent challenge with TSA-pc. This memory rests on a strong lytic activity of CD8+ CTL and granulocytes. Following the rejection, mice also develop anti-TSA Ab that guide the granulocytes in TSA-pc memory reaction. A direct comparison shows that although TSA clones engineered to release IL-2 activate CTL and no anti-TSA Ab, those engineered to release IL-4 activate a strong Ab response but not CTL. The kind of cytokine released by the tumors appears to determine the type of response. However, IL-10 high producer cells do not deviate the immune memory, neither toward a Th1 nor a Th2. Both the CTL activity and the Ab responses induced by IL-10 high producer cells are the strongest so far observed in the TSA system.
IL-13 down-regulates CD14 expression and TNF-alpha secretion in normal human monocytes.
Authors: Cosentino G , Soprana E , Thienes C P , Siccardi A G , Viale G , Vercelli D 
Published: January 2023

Abstract
CD14, a glycosylphosphatidylinositol (GPI)-linked protein expressed on monocytes and neutrophils, regulates monocyte-lymphocyte interactions and serves as the LPS receptor. We showed previously that IL-4 down-regulates the expression of human CD14 by acting at the transcriptional level. We now investigate whether CD14 expression could also be regulated by IL-13, another member of the chromosome 5 cytokine gene family. IL-13 dose-dependently inhibited CD14 expression on human monocytes. By contrast, expression of CD23 and CD11b was enhanced strongly. Down-regulation of CD14 involved neither shedding nor activation of endogenous GPI anchor-cleaving enzymes. Indeed, soluble CD14 was not increased in the supernatants of IL-13-stimulated monocytes, and expression of CD55/DAF, another GPI-linked protein, was unaffected by IL-13. CD14 transcript levels were reduced sixfold in IL-13-treated monocytes. These results suggest that IL-13 down-regulates membrane CD14 by suppressing CD14 RNA expression. IL-13-dependent down-regulation of CD14 resulted in the inhibition of CD14-mediated events. Indeed, CD14-mediated release of TNF-alpha was inhibited markedly (approximately 75%) in monocytes stimulated with LPS (100 ng/ml) after a 72-h preincubation with IL-13. However, IL-13 also directly inhibited monokine secretion, because it blocked PMA-induced, CD14-independent TNF-alpha release. Down-regulation of CD14 and TNF-alpha secretion may play a major role in the anti-inflammatory effects of IL-13 on LPS-stimulated monocytes.
Expression of CD25 defines peripheral blood mononuclear cells with productive versus latent HIV infection.
Authors: Borvak J , Chou C S , Bell K , Van Dyke G , Zola H , Ramilo O , Vitetta E S 
Published: January 2023

Abstract
The present studies were designed to further determine whether the CD25 marker could distinguish between cells productively and latently infected with HIV. This was accomplished by combining immunotoxin (IT)-mediated killing of CD25+ cells, highly sensitive indirect immunofluorescence to detect remaining CD25+ cells, and PCR-mediated amplification of proviral DNA in immunotoxin-treated vs untreated HIV-infected cells. Our results demonstrate that: 1) By direct immunofluorescence 3 to 8% of PBMCs are CD25+, whereas by indirect immunofluorescence 30% are CD25+. The increased number of CD25+ cells is due to their detection by the highly sensitive indirect immunofluorescence assay. Up to 60% of the CD25+ cells are CD4+ and 12% are CD8+. 2) Treatment of HIV-infected PBMCs with an anti-CD25 IT for 6 days eliminated both CD25high and CD25low cells and decreased the production of p24 by 99%. 3) Differences in the HIV proviral genome were detected in the unfractionated PBMCs vs PBMCs from which CD25+ cells had been eliminated by IT treatment. Hence, PBMCs containing both CD25+ and CD25- cells express all intermediate proviral species and full-length double-stranded proviral DNA. In contrast, CD25- quiescent cells contain predominantly intermediate species. These results confirm and extend our previous observations that expression of CD25 can distinguish latently infected cells from cells producing virus.
SLE-like autoantibodies and Sjögren's syndrome-like lymphoproliferation in TGF-beta knockout mice.
Authors: Dang H , Geiser A G , Letterio J J , Nakabayashi T , Kong L , Fernandes G , Talal N 
Published: January 2023

Abstract
Mice bearing the TGF-beta 1 null mutation (-/-) develop lymphoid infiltrates in the heart, lungs, salivary glands, and other organs similar to those seen in the pseudolymphoma of Sjögren's Syndrome. We studied sera from -/- mice and found elevated Ab levels to dsDNA, ssDNA, and Sm ribonucleoprotein. No Abs to SSA/Ro or SSB/La and no IgM rheumatoid factor were found. Serum autoantibodies were predominately IgG and were specific as shown by ELISA inhibition studies. Antinuclear Ab patterns on Western blots varied from one mouse to the next, indicating a random process responsible for the diversity. Wild-type and heterozygote mice had no autoantibodies. Ig glomerular deposits were found in -/- mice, indicating that these autoantibodies may be pathogenic. Treatment of -/- mice with dexamethasone or TGF-beta 1 failed to suppress autoantibody production. These mice represent an overlap combining the autoimmune serology of SLE with the tissue infiltrates of SS. Our results support the concept that TGF-beta 1 is an important naturally occurring immunosuppressive cytokine whose absence can lead to a systemic autoimmune disease.
Light chain contribution to specificity in anti-DNA antibodies.
Authors: Ibrahim S M , Weigert M , Basu C , Erikson J , Radic M Z 
Published: January 2023

Abstract
We studied mice expressing one of two H chain transgenes. Both transgenes expressed the same 3H9 anti-DNA VDJ, but differed in their constant domains. The IgM transgene efficiently induced tolerance and selected for a subset of endogenous L chains that prevented dsDNA binding. In contrast, the IgG2b secreted-only H chain allowed expression of a broad range of L chains, most of which yielded anti-dsDNA Ab. To deduce the features of L chains that affect DNA binding, we derived hybridomas from LPS-stimulated splenic B cells from the two transgene lines and compared the V kappa sequences of Ab they secreted. Identification of L chains with related sequences but different binding to ssDNA, dsDNA, and cardiolipin allowed us to pinpoint L chain residues that correlate with enhanced or reduced binding. Arginines at the junction of V kappa 1 or V kappa 8 regions and J kappa 1, and arginines or asparagines in CDR1 or CDR2 enhanced DNA binding. Negatively charged residues at the same positions were found to interfere with binding. Thus, we predict that appropriate amino acids at these positions may form contacts with DNA. The likely locations of contact residues in the combining site were evaluated by inspection of previously determined Ab structures. Our results indicate that L chains in anti-DNA Ab are able to modulate DNA binding and contribute contact sites for additional determinants on a complex autoantigen.
flk2/flt3 ligand is a potent cofactor for the growth of primitive B cell progenitors.
Authors: Hunte B E , Hudak S , Campbell D , Xu Y , Rennick D 
Published: January 2023

Abstract
We have investigated the role of flk2/flt3 ligand (FL) in B cell lymphopoiesis. The ability of FL to stimulate the growth of immature B cells was assessed using distinct populations: CD43lowB220+ pre-B cells, CD43+B220+ pro-B cells, and CD43+B220low progenitors. FL failed to affect the growth of the pro-B or pre-B cells whether used alone or in combination with stem cell factor (SCF) or IL-7. In striking contrast, FL was a potent cofactor for the CD43+B220low progenitor cells, interacting with either IL-7 and/or SCF to stimulate their growth. The combination of FL with IL-7 plus SCF stimulated maximum expansion of these cells, albeit, less than that stimulated in stromal cell cultures. When the CD43+B220low progenitors were divided based on expression of heat stable Ag (CD24) into a CD24- and a CD24+ subset, the FL-responsive cells were contained only within the CD24- subset. FL interacted with SCF or with IL-7 to stimulate their growth resulting in a 20- and 50-fold increase in cellularity, respectively. Since the CD24- subset was the most immature of the B cell populations studied, our data suggest that FL costimulates the expansion of very primitive B cell progenitors.
Regulation of the catalytic subunit (p34PSK-J3/cdk4) for the major D-type cyclin in mature B lymphocytes.
Authors: Tanguay D A , Chiles T C 
Published: January 2023

Abstract
We examined the expression of the cyclin-dependent kinase 4, p34PSK-J3/cdk4 protein, in small dense, activated, and proliferating primary B lymphocytes. A small steady state level of cdk4 synthesis was detected in resting B cells. Stimulation of resting B cells with mitogenic amounts of F(ab')2 fragments of goat anti-mouse IgM (anti-Ig) resulted in increased synthesis of cdk4 protein during the mid to late G1 phase of the cell cycle; LPS or the combination of phorbol ester and calcium ionophore also elevated cdk4 levels. Resting B cells that we rendered competent by treatment with IL 4 or low doses of anti-Ig or, alternatively, were activated by phorbol ester or ionomycin alone also exhibited heightened cdk4 protein levels. Subsequent analysis of potential cdk4 regulatory subunit D-type cyclins revealed that cyclin D2, not cyclin D1 or D3, is expressed in primary mature B lymphocytes. The induction of cyclin D2 synthesis in response to mitogenic anti-Ig paralleled cdk4 expression; however, IL-4 or low dose anti-Ig alone did not increase the rate of de novo cyclin D2 synthesis above that of resting B cells. The significance of the lack of cyclin D2 regulation by competence-inducing growth factors was demonstrated, in that only mitogenic factors that stimulated DNA synthesis 1) led to the formation of stable cyclin D2/cdk4 holoenzyme complexes during G1 phase progression, and 2) afforded the isolation of anti-cyclin D2 or anti-cdk4 immunoprecipitates that phosphorylated retinoblastoma. These findings suggest a role for these proteins during the mid to late G1 phase progression and possibly the G1/S phase transition in primary mature B lymphocytes.
Rhinovirus enters but does not replicate inside monocytes and airway macrophages.
Authors: Gern J E , Dick E C , Lee W M , Murray S , Meyer K , Handzel Z T , Busse W W 
Published: January 2023

Abstract
Potential interactions between rhinovirus (RV) and both the airway macrophage and its precursor cell, the blood monocyte, were investigated in terms of direct binding, intracellular replication, cell survival, and cytokine production. When HeLa cell suspensions are inoculated with RV as a positive control, virus titer increases by 100-fold in the first 24 h, confirming intracellular replication. In contrast, RV titer in monocyte and macrophage suspensions steadily decreased. Despite a lack of productive RV replication, cell-associated RV RNA was detectable using a biotin-labeled cDNA probe as early as 6 h after inoculation. Direct binding of RV16 to macrophages was confirmed using radiolabeled virus, although preincubation with anti-ICAM-1 mAb did not block this interaction. Synthesis of RV RNA, as indicated by [3H]uridine incorporation in actinomycin D-treated cells, was detected in HeLa cells but not macrophages, suggesting that the viral RNA detected inside macrophages was from input virus and was not newly synthesized. RV inoculation did not adversely affect monocyte or macrophage viability. Finally, RV caused macrophage activation, as indicated by the induction of TNF-alpha secretion. These in vitro findings suggest that macrophages interact with major group RV in vivo, and raise the possibility that there is a second cellular receptor for these viruses. Furthermore, macrophages do not serve as permissive host cells during in vivo RV infection, but instead may be active participants in anti-RV immunity and RV-induced airway inflammation.
Effects of Mycoplasma fermentans on the myelomonocytic lineage. Different molecular entities with cytokine-inducing and cytocidal potential.
Authors: Rawadi G , Roman-Roman S , Castedo M , Dutilleul V , Susin S , Marchetti P , Geuskens M , Kroemer G 
Published: January 2023

Abstract
Mycoplasma fermentans is a mycoplasma species that has been accused of serving as a cofactor of AIDS development. Here, we show that M. fermentans affects the function of human monocytes and myelomonocytic cell lines on at least two different levels. Heat-inactivated mycoplasma particles induce inflammatory cytokines such as IL-1, IL-6, and TNF in monocytes, as well as in THP-1 cells. Moreover, M. fermentans induces IL-10 (but not IL-12) in freshly isolated human monocytes. The cytokine-inducing effect is mediated by lipid-associated molecules. In addition, we have detected a novel biologic activity that resides in the nonlipid-associated protein fraction of M. fermentans (approximate molecular mass: 15 to 30 kDa) and that has a cytocidal effect on nondifferentiated myelomonocytic cell lines (U937 cells, HL-60 cells), as well as on actinomycin-D-sensitized monocytes. Death is accompanied by oligonucleosomal DNA fragmentation and loss of chromosomal DNA. U937 and HL-60 cells fail to produce cytokines and rather undergo cell death in response to heat-inactivated M. fermentans, provided that they are kept in a relatively undifferentiated stage. Whereas the cytokine-inducing activity is a general feature of many mycoplasma species, it appears that only a restricted panel of mycoplasma species exert a cell death-inducing activity. In addition to M. fermentans strains, Mycoplasma penetrans, another hypothetical cofactor of AIDS, possess a cytocidal activity. This does not apply to other mycoplasma species, including pathogenic ones such as Mycoplasma pneumoniae and Ureaplasma urealyticum. The cell death-inducing effect of M. fermentans is not mediated by cytokines and obeys different principles than TNF-alpha-mediated apoptosis. Thus, in contrast to TNF-alpha-induced death, it is not accompanied by a decrease in the mitochondrial transmembrane potential and is not inhibited by preincubation with the antioxidant drug N-acetylcysteine. In synthesis, it appears that certain AIDS-associated mycoplasma species perturb the function and/or generation of cells from the myelomonocytic lineage via several distinct pathways.
Structural requirements for mucosal vascular addressin binding to its lymphocyte receptor alpha 4 beta 7. Common themes among integrin-Ig family interactions.
Authors: Briskin M J , Rott L , Butcher E C 
Published: January 2023

Abstract
The mucosal vascular addressin, MAdCAM-1, is an Ig family adhesion receptor preferentially expressed by venular endothelial cells at sites of lymphocyte extravasation in mucosal lymphoid tissues and lamina propria. MAdCAM-1 binds the lymphocyte homing receptor for Peyer's patches, the integrin alpha 4 beta 7. We describe a point mutation within the first Ig domain of MAdCAM-1 that abolishes activation-independent alpha 4 beta 7 binding. This point mutation resides within an eight-amino acid motif with homology to sequences important for the integrin binding ability of the related vascular Ig family members, ICAM-1 and VCAM-1. To understand the contributions of the individual MAdCAM-1 domains, chimeric exchanges with the beta 1 integrin ligand, ICAM-1, were made. The two N-terminal domains of MAdCAM-1 are sufficient to confer alpha 4 beta 7 binding comparable to that of native MAdCAM-1. A chimera containing only the N-terminal Ig domain (domain 1) of MAdCAM-1 can also bind (to a lesser extent) alpha 4 beta 7, but only after integrin (to a lesser extent) alpha 4 beta 7, but only after integrin activation. Conversely, the first domain of ICAM-1 appears sufficient to bind activated LFA-1. These data suggest that the first domain of MAdCAM-1 is sufficient for interaction with alpha 4 beta 7, but that sequences within the second domain support this interaction, either by providing additional contact points for integrin binding or by contributing to the conformation or presentation of the N-terminal domain. The second domain of MAdCAM-1 can also support activation-dependent LFA-1 binding to domain 1 of ICAM-1. The findings parallel studies of VCAM-1 binding to alpha 4 beta 1 and suggest that structural differences exist between vascular Ig-like ligands for alpha 4 vs beta 2 integrins.
Induction and regulation of IL-15 expression in murine macrophages.
Authors: Doherty T M , Seder R A , Sher A 
Published: January 2023

Abstract
IL-15 is a recently described cytokine which resembles IL-2 in its biologic activities, stimulating T cell and NK cell proliferation and activation as well as enhancing B cell expansion and Ab production. Unlike IL-2, IL-15 is not produced by lymphocytes, but instead (at least among cells of the immune system) appears to be synthesized primarily by monocyte/macrophages. We have examined the induction of IL-15 in murine macrophages (by semiquantitative reverse transcriptase-PCR and bioassay) in response to a variety of different macrophage-activating stimuli and compared the regulation of IL-15 production to that of IL-12 and TNF-alpha. Optimal induction of IL-15, in each of the macrophages populations tested, was found to require both priming (IFN-gamma) and triggering (LPS, mycobacteria, or Toxoplasma gondii) stimuli. When compared with IL-12 mRNA synthesis by the same macrophages, IL-15.mRNA production was more resistant to inhibition by the down-regulatory cytokines IL-14, IL-13, and TGF-beta. Moreover, IL-10, which is inhibitory for most other monokines, increased levels of IL-15 mRNA found after stimulation. These data establish IL-15 as a product of the macrophage/monocyte lineage, which is up-regulated on activation. IL-15 could thus play an important role in the initiation of immune responses by microbial agents.