bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fas- and activation-induced apoptosis are reduced in human T cells preactivated in the presence of TGF-beta 1.
Authors: Cerwenka A , Kovar H , Majdic O , Holter W 
Published: January 2023

Abstract
The elimination of activated but not resting T cells involves apoptosis induced either by restimulation via the TCR/CD3 complex, CD2, or by signaling through the Fas Ag. The factors regulating the shift of an apoptosis-resistant to an apoptosis-sensitive phenotype and vice versa have not so far been clarified. Here we report that TGF-beta 1, when present during a PHA activation course, significantly increases viability of human T cells upon reculture in medium alone, following restimulation via CD2, CD3, or after triggering the Fas Ag. Using DNA gel electrophoresis and an in situ nick translation technique we further show that activation-induced and Fas-mediated apoptosis are reduced in T cells that were prestimulated with PHA plus TGF-beta 1, compared with control cells prestimulated with PHA alone. Moreover, when PHA-preactivated T cells are further expanded in IL-2, inclusion of TGF-beta 1 results in higher cell yields at any timepoint from day 30 to 75 of cell culture compared with control cultures without TGF-beta 1. However, no differences in Fas or bcl-2 protein expression are found between cells stimulated in the absence or presence of TGF-beta 1. Together, our data identify TGF-beta 1, when present during an activation course, as an important viability factor possibly of importance for the generation of effector and/or long-lived memory T cells.
B7-1 but not B7-2 efficiently costimulates CD8+ T lymphocytes in the P815 tumor system in vitro.
Authors: Gajewski T F 
Published: January 2023

Abstract
We recently have developed a method to generate primary P815-specific CTL in vitro from normal syngeneic splenocytes by employing transfection of B7-1 combined with exogenous IL-12 and IL-6. Surprisingly, when the homologous costimulator molecule B7-2 was substituted for B7-1 in this system, no specific CTL activity was obtained. Similarly, B7-1- but not B7-2-transfected P815 cells generated alloantigen-specific CTL activity from C57BL/6, accessory cell- and CD4(+)-depleted splenocytes, and costimulated proliferation of CD8+ lymphocytes in the presence of low doses of anti-CD3 mAb. In all systems, combined expression of both B7-1 and B7-2 costimulated as effectively as B7-1 alone, arguing against delivery of a dominant negative signal by B7-2. Proliferation of allogeneic, CD4(+)-depleted splenocytes in response to P815 cells, which relies on costimulation by normal accessory cells, was inhibited by anti-B7-1 but not anti-B7-2 mAbs. Finally, indirect evidence suggested a higher avidity of B7-1+ cells than B7-2+ cells for CTLA4. Thus, at least in the context of primary stimulation by irradiated P815 transfectants, B7-1 appears to be superior to B7-2 at costimulation of CD8+ T lymphocytes.
Reduction of early B lymphocyte precursors in transgenic mice overexpressing the murine heat-stable antigen.
Authors: Hough M R , Chappel M S , Sauvageau G , Takei F , Kay R , Humphries R K 
Published: January 2023

Abstract
To study the role of the murine heat-stable Ag (HSA) in lymphocyte maturation, we generated transgenic mice in which the HSA cDNA was under the transcriptional control of the TCR V beta promoter and Ig mu enhancer. The HSA transgene was expressed during all stages of B lymphocyte maturation. Expression was first detected in the earliest lymphoid-committed progenitors, which normally do not express HSA, and subsequently reached the highest levels in pro- and pre-B cells. In bone marrow, the number of IL-7-responsive clonogenic progenitors was &lt; 4% of normal, whereas the frequency of earlier B lymphocyte-restricted precursors, detectable as Whitlock-Witte culture-initiating cells, was normal. Pro- and pre-B cells detected by flow cytometry were reduced by approximately 50% relative to controls. Mature splenic B cells were also reduced but to a lesser extent than in marrow, and their response to LPS stimulation was impaired. Reconstitution of SCID and BALB/c-nu/nu mice with HSA transgenic marrow indicated that the perturbations in B lymphopoiesis were not caused by a defective marrow microenvironment or by abnormal T cells. Our previous studies showed elevated HSA expression throughout thymocyte development, which resulted in a profound depletion of CD4+CD8+ double-positive and single-positive thymocytes. Together, these results indicate that HSA levels can determine the capacity of early T and B lymphoid progenitors to proliferate and survive. Therefore, HSA could serve as an important regulator during the early stages of B and T lymphopoiesis.
Selective activation-induced apoptosis of peripheral T cells imposed by macrophages. A potential mechanism of antigen-specific peripheral lymphocyte deletion.
Authors: Munn D H , Pressey J , Beall A C , Hudes R , Alderson M R 
Published: January 2023

Abstract
The self-reactive T cells that escape clonal deletion in the thymus must be suppressed by the less well characterized process of peripheral tolerance. In this study, we show that monocyte-derived macrophages (M phi) undergoing terminal differentiation in the presence of macrophage CSF (M-CSF) acquire the ability to selectively induce apoptosis of T cells in an activation-specific fashion. Lymphocytes were stimulated via the TCR using anti-CD3 cross-linking, staphylococcal superantigen, or allogeneic mixed-leukocyte cultures. T cells activated while in contact with M-CSF-derived M phi exited the resting G0 state and re-entered the cell cycle, but experienced a sustained arrest near the first G1/S transition, followed by progressive apoptosis. In contrast, lymphocytes that were not stimulated remained viable, and could later activate normally when removed from contact with M phi. Functionally, exposure of T cells to alloantigens presented by M-CSF-derived M phi resulted in a selective depletion of the alloresponsive T cell population, while preserving reactivity to other mitogens and to alloantigens from different donors. The ability of M phi to impose activation-induced apoptosis on lymphocytes was regulated developmentally, being absent in fresh monocytes, progressively acquired during differentiation in M-CSF, and abrogated if monocytes were exposed to IFN-gamma before differentiation. We speculate that this novel interaction may help to selectively delete autoreactive T cells that respond to self Ags presented by noninflammatory tissue M phi.
Ubiquitin-like moiety of the monoclonal nonspecific suppressor factor beta is responsible for its activity.
Authors: Nakamura M , Xavier R M , Tanigawa Y 
Published: January 2023

Abstract
Monoclonal nonspecific suppressor factor (MNSF), a lymphokine produced by murine T cell hybridoma, possesses pleiotrophic Ag-nonspecific suppressive functions. Most recently, a cDNA clone encoding MNSF beta (a subunit of MNSF) was isolated and characterized. The MNSF beta cDNA encodes a 14.5-kDa fusion protein with MNSF-like activity consisting of an 8-kDa ubiquitin-like segment (ubi-L) and the ribosomal protein S30 (6.5 kDa). To determine whether ubi-L itself has biologic activity, cDNA encoding the ubi-L region was expressed in bacteria and the recombinant product was tested for the activity. Ubi-L showed MNSF-like biologic activity without any cytotoxic action. Interestingly, the addition of ubiquitin to the assay inhibited ubi-L-induced suppression. IFN-gamma, which is known to enhance the expression of MNSF receptor, induced splenocytes to secrete ubi-L by increasing mRNA. Ubi-L has species-specific action and the ability to selectively inhibit the B cell proliferative response stimulated by soluble but not by Sepharose-bound anti-Ig Ab. In addition, okadaic acid, a serine/threonine phosphatase 1 and 2A inhibitor, showed a synergistic inhibitory action with ubi-L, indicative of the possible involvement of phosphatase(s) in the regulation of ubi-L action.
Quantitative analysis of the expression of the HLA-DRB genes at the transcriptional level by competitive polymerase chain reaction.
Authors: Vincent R , Louis P , Gongora C , Papa I , Clot J , Eliaou J F 
Published: January 2023

Abstract
In addition to polymorphism of the peptide-binding site, the density of the MHC class II molecules expressed on the membrane of APC could well play a significant role in the MHC-peptide-TCR interaction during the immune response. We therefore investigated the regulation of the expression of the HLA-DRB genes at the transcriptional level. A competitive PCR approach was used to estimate the quantities of the HLA-DRB transcripts in peripheral blood B cells. When comparing the amounts of steady-state mRNAs among the different DRB1 alleles, the DRB1 transcripts in the DR52 haplotype group were found to be 2.5 to 3.5 times more abundant than the DRB1*01 transcripts, 1.5 to 2 times more abundant than the DRB1*04 transcripts, and 7 times more abundant than the DRB1*08 transcripts. Within the DR52 haplotype group, the DRB1 and DRB3 transcripts had the same abundance. Taken together, these results are in good agreement with the previously reported transcriptional activities of the DRB promoters except for DRB1*04, thus suggesting a differential post-transcriptional regulation among the DRB1 mRNAs.
Pregnancy impairs resistance of C57BL/6 mice to Leishmania major infection and causes decreased antigen-specific IFN-gamma response and increased production of T helper 2 cytokines.
Authors: Krishnan L , Guilbert L J , Russell A S , Wegmann T G , Mosmann T R , Belosevic M 
Published: January 2023

Abstract
Resolution of cutaneous leishmaniasis in infected mice is associated with a polarized Th1 immune response by the host, whereas maternal immune responses during pregnancy appear to be biased toward humoral (Th2) and away from cell-mediated (Th1) responses. The objective of this study was to evaluate whether the putative Th2 bias in pregnant C57BL/6 mice would impair their normal ability to mount a curative Th1 response against Leishmania major infection. Pregnant C57BL/6 mice developed larger cutaneous lesions that showed no signs of resolution up to 70 days after infection. The infection appeared to be contained but not cured, as the footpad lesion remained stable, neither decreasing (as in normal C57BL/6 mice) nor showing uncontrolled expansion leading to death (as in susceptible mouse strains such as BALB/c). The number of parasites harvested from the footpads of pregnant mice was markedly higher than controls throughout the course of infection. The increased severity of infection in pregnant mice was accompanied by reduced IFN-gamma and increased IL-4, IL-5, and IL-10 production by spleen and popliteal lymph node cells stimulated in vitro with Leishmania Ags. Furthermore, IgG1 was elevated in the serum of pregnant mice as opposed to an increase of IgG2a in infected but nonpregnant controls. These observations support the existence of a bias toward Th2 cytokine expression during pregnancy and suggest that these cytokines effectively down-regulate the course of a normal Th1 response against a parasite infection in the periphery.
Cellular detachment and deformation induce IL-8 gene expression in human bronchial epithelial cells.
Authors: Shibata Y , Nakamura H , Kato S , Tomoike H 
Published: January 2023

Abstract
Neutrophil elastase (NE) is known to be one of the most potent proteases capable of deforming and detaching human bronchial epithelial cells (BECs) and inducing IL-8 gene expression. However, mechanisms of NE-induced IL-8 gene expression are unclear, especially with respect to how they relate to cellular detachment. To elucidate these mechanisms, effects of cell detachment and deformation following mechanical injury or pharmacologic stimuli on IL-8 gene expression were examined by Northern analyses. When BET-1A cells from a human bronchial epithelial cell line were incubated with NE (100 nM), trypsin (0.5 mg/ml), EGTA (7 mM), or EDTA (0.7 mM) to induce deformation and detachment, IL-8 mRNA transcript levels were up-regulated, as demonstrated in a case of mechanical detachment from the culture plate using a cell scraper. This IL-8 gene expression was inhibited by pretreatment with 5 microM taxol, a microtubule-stabilizing agent. Colchicine or vinblastine, microtubule-disrupting agents, induced IL-8 gene expression, which was also inhibited by taxol treatment. These data suggest that structural changes, including deformation of the cytoskeleton, especially microtubules, may contribute to IL-8 gene expression in human BECs. Since detachment and cellular deformation of BECs caused by proteases have been observed frequently in a variety of inflammatory airway diseases, our findings provide evidence that detached or deformed BECs potentially enhance production of inflammatory mediators in the pathogenesis of airway inflammation.
Deficient CD4+ T cell proliferation in the class 1 MHC-restricted 2C TCR-transgenic mouse.
Authors: Chen F L , Kung J T 
Published: January 2023

Abstract
A comparative study of immune function and marker expression of CD4+ T cells from MHC class 1-restricted 2C TCR-transgenic (2C+) and control transgene-negative littermate (2C-) mice was performed. While 2C+CD4+ T cells resembled memory T cells on the basis of CD44highCD45RBlow expression, the majority of 2C-CD4+ T cells were of the CD44lowCD45RBhigh naive phenotype. Slightly lower levels of TCR-beta and CD3 were found on 2C+CD4+ T cell than 2C-CD4+ T cells. Vigorous proliferation by 2C-CD4+ T cells was observed upon stimulation with 1) anti-CD3 mAb presented through the FcR of macrophages; 2) immobilized (plate-bound) anti-CD3 + anti-CD28 mAbs; and 3) PMA + ionomycin. In marked contrast, all three mitogenic stimuli stimulated highly deficient proliferative responses by 2C+CD4+ T cells. However, significant IL-2 production was detected both in anti-CD3 and in PMA + ionomycin-stimulated cultures of 2C+CD4+ T cells. While intracellular calcium in 2C-CD4+ T cells rapidly increased following anti-CD3 addition, no such increase was observed for similarly stimulated 2C+CD4+ T cells. Anti-CD28, PMA, and coculture with 2C-CD4+ T cells each failed to significantly correct the deficient 2C+CD4+ T cells proliferation as induced by anti-CD3. In addition, IL-2, IL-4, and IL-7 supplements also failed to reverse the deficient proliferation of 2C+CD4+ T cells despite expression of IL-2R component alpha-, beta-chains and the gamma-chain common also to IL-4R and IL-7R. Thymus CD4+8- T cells from the 2C-transgenic mouse were similarly deficient in proliferation as spleen CD4+ T cells. A small subpopulation of CD4+ T cell from the 2C-transgenic mouse expressed the transgenic TCR alpha:beta heterodimer as detected by the 1B2 anti-2C clonotypic mAb; both 1B2+ and 1B2- subpopulations proliferated poorly in response to anti-CD3 and to PMA + ionomycin. These results raise the possibility that TCR engagement with MHC class 1 molecules during early intrathymic development can result in the emergence of CD4+ T cells characterized by unusual marker expression and function.
Evidence for the expression of HLAA-C class I mRNA and protein by human first trimester trophoblast.
Authors: King A , Boocock C , Sharkey A M , Gardner L , Beretta A , Siccardi A G , Loke Y W 
Published: January 2023

Abstract
In this study, evidence is provided that normal human first trimester extravillous trophoblast expresses class I HLA-C molecules in addition to HLA-G. cDNA from highly purified trophoblast cells obtained by flow cytometric sorting was amplified by reverse-transcriptase PCR using HLA locus-specific primers. The identity of the product was confirmed by Southern blotting and hybridization by a second HLA-C-specific oligonucleotide. HLA-C mRNA was clearly demonstrated in all trophoblast samples as well as in JEG-3 and BeWo choriocarcinoma cells. JAR choriocarcinoma cells did not express HLA-C. The presence of HLA-C protein in extravillous trophoblast was investigated using a panel of Abs: L31 is specific for heavy chains of all HLA-C alleles; Q1/28 reacts with all HLA class I products except HLA-G; HC-10 has preferential reactivity with HLA-B and HLA-C heavy chains. We performed 35S metabolic and 125I surface labeling of normal first trimester trophoblast and found abundant HLA-C intracellularly together with low levels of expression of both the beta 2m-associated forms and free heavy chains on the surface. Flow cytometric analysis of normal trophoblast confirmed the expression of a class I HLA molecule distinct from HLA-G by positive reactivity with Q1/28. Immunohistologic studies of first trimester placenta and the implantation site clearly showed expression of HLA-C in all extravillous trophoblast populations. Our results demonstrate the presence of two HLA class I molecules, HLA-G and HLA-C, on the surface of extravillous trophoblast. These results have implications in understanding how maternal uterine lymphocytes, notably the abundant NK-like cells, might recognize the implanting placenta.
Identification of MECL-1 (LMP-10) as the third IFN-gamma-inducible proteasome subunit.
Authors: Nandi D , Jiang H , Monaco J J 
Published: January 2023

Abstract
We show that six proteasome-associated proteins are induced by IFN-gamma, corresponding to three proteasome beta-type subunits and their precursors: the MHC-linked subunits (LMP-2 and LMP-7) and LMP-10. Concurrently, incorporation of LMP-9, LMP-17, and LMP-19 into proteasomes is reduced. LMP-10 appears to be the product of a previously cloned proteasome subunit gene, MECL-1. MECL-1 transcription is increased in the presence of IFN-gamma, whereas the transcription of two other proteasome genes, Lmp-15 and Lmp-3, is not affected. The three IFN-gamma-inducible subunits and their constitutively expressed counterparts contain most or all of the catalytic sites of the proteasome. Independent assortment of LMP-2, LMP-7, and LMP-10 into different proteasome complexes may thus generate up to 36 unique proteasome subsets. This may increase the repertoire of potentially antigenic peptides for presentation by MHC class I.
Bacterial superantigen-induced human lymphocyte responses are nitric oxide dependent and mediated by IL-12 and IFN-gamma.
Authors: Sriskandan S , Evans T J , Cohen J 
Published: January 2023

Abstract
Bacterial superantigens cause marked proliferation of T cells and release of lymphokines. Nitric oxide, derived from the conversion of L-arginine to L-citrulline, inhibits this activation in murine cells. We have now investigated the roles of IL-12, IFN-gamma, lymphotoxin-alpha, and nitric oxide during superantigen-induced human lymphocyte activation. Lymphocyte activation was determined by measurement of proliferative responses and lymphokine release. Both toxic shock syndrome toxin-1 from Staphylococcus aureus and recombinant streptococcal pyrogenic exotoxin A induced proliferation and production of IFN-gamma, lymphotoxin-alpha, and IL-12 by human mononuclear cells in a time-dependent fashion. The release of IFN-gamma was abrogated by a neutralizing Ab to IL-12, but lymphocyte proliferative responses were unaffected. A neutralizing Ab to IFN-gamma prevented the release of lymphotoxin-alpha, but did not affect proliferation. The neutralization of lymphotoxin-alpha using two different Abs did not affect IFN-gamma release or proliferation. In contrast to previous findings in mice, the arginine analogue, NG-monomethyl-L-arginine, significantly inhibited both proliferation and lymphokine release by superantigen-stimulated human cells. Thus, the release of lymphotoxin-alpha by lymphocytes following superantigen stimulation is dependent upon the presence of IFN-gamma; the IFN-gamma response is in turn under the control of IL-12. There is no evidence that nitric oxide plays an inhibitory role during superantigen-mediated human lymphocyte activation. Indeed, arginine is a prerequisite for such activation.
Effects of granulocyte-macrophage colony-stimulating factor on eicosanoid production by mononuclear phagocytes.
Authors: Brock T G , McNish R W , Coffey M J , Ojo T C , Phare S M , Peters-Golden M 
Published: January 2023

Abstract
Granulocyte-macrophage CSF (GM-CSF) primes granulocytes for leukotriene (LT) synthesis. Here, we examined the effects of GM-CSF on arachidonic acid (AA) metabolism in rat alveolar macrophages (AM), peritoneal macrophages, and human peripheral blood monocytes. Pretreatment of AMs with GM-CSF for 24 h significantly increased the synthesis of immunoreactive LTB4 upon subsequent stimulation with calcium ionophore. Enhanced LT synthesis required a minimum of 6 h of GM-CSF pretreatment, suggesting that protein synthesis was required for enhanced LT production; indeed, cycloheximide completely abolished the GM-CSF effect on LT synthesis. HPLC analysis confirmed that GM-CSF primed AMs for enhanced generation of LTB4, as well as the 5-lipoxygenase products LTC, and 5-HETE. Moreover, parallel increases in other AA metabolites and free AA were observed following GM-CSF pretreatment. The enhanced production of all AA metabolites indicated that GM-CSF up-regulated AA release. Consistent with this, whole cell lysates from GM-CSF-treated AMs demonstrated increased phospholipase A2 (PLA2) activity. The increased activity was resistant to DTT, indicating the involvement of a PLA2 other than the 14-kDa PLA2s. By immunoblot analysis, GM-CSF treatment caused an increase in the 85-kDa PLA2 protein comparable to the observed increase in PLA2 activity. Unlike AMs, neither peritoneal macrophages nor peripheral blood monocytes showed increased eicosanoid generation or increased expression of the 85-kDa PLA2 protein following GM-CSF pretreatment. These results indicate that GM-CSF increases the capacity of AMs, but not peritoneal macrophages or peripheral blood monocytes, to generate eicosanoids. This effect results from increased PLA2 activity, due at least in part to increased levels of the 85-kDa PLA2 protein.
TNF-alpha stimulates monocyte adhesion to glomerular mesangial cells. The role of intercellular adhesion molecule-1 gene expression and protein kinases.
Authors: Pai R , Bassa B , Kirschenbaum M A , Kamanna V S 
Published: January 2023

Abstract
TNF-alpha has been implicated in glomerular cell activation to produce adhesion molecules and monocyte chemoattractants associated with glomerular monocyte infiltration. This study examined the regulatory role of protein kinases and cAMP on TNF-alpha-induced intercellular adhesion molecules-1 (ICAM-1) expression and monocyte adhesion to mesangial cells. Activation of mesangial cells with TNF-alpha induced ICAM-1 mRNA and protein expression. Mesangial cells preincubated with phorbol 12-myristate 13-acetate (PMA), a protein kinase C (PKC) activator, stimulated both the gene and protein expression of ICAM-1. Mesangial cell PKC depletion abolished ICAM-1 mRNA message, while activation with TNF-alpha did not inhibit ICAM-1 transcripts. Preincubation of mesangial cells with calphostin C did not affect TNF-alpha-induced mesangial cell ICAM-1 message, while it blocked PMA-induced ICAM-1 mRNA expression. Protein tyrosine kinase (PTK) inhibitors blocked TNF-alpha-mediated mesangial cell ICAM-1 transcripts. cAMP-generating substances (e.g., pertussis toxin, isoproterenol, or dibutyryl cAMP) did not induce mesangial cell ICAM-1 gene expression. However, incubation of mesangial cells with TNF-alpha and dibutyrl cAMP blocked TNF-alpha-induced ICAM-1 message. Finally, preincubation of mesangial cells with TNF-alpha increased monocyte adhesion that could be blocked by anti-ICAM-1. Parallel to ICAM-1 gene expression data, TNF-alpha-induced monocyte-mesangial cell adhesion was inhibited by PTK inhibitors, but was not regulated through either PKC or intracellular cAMP-associated pathways. These results suggest that increased ICAM-1 expression by TNF-alpha activation of mesangial cells is one of the major pathways involved in monocyte adhesion to the mesangium, a phenomenon presumably regulated by signal-transduction pathways dependent on PTK, but not PKC or cAMP.