bluuebunny/crossref_metadata_2025_split huggingface dataset:
CD40 ligand is expressed and functional on activated neonatal T cells.
Authors: Splawski J B , Nishioka J , Nishioka Y , Lipsky P E 
Published: December 2022

Abstract
Deficient CD40 ligand (CD40L) expression by neonatal T cells has been proposed to explain the diminished Ig production by newborns. Therefore, we examined the expression and function of CD40L on activated neonatal CD4+ T cells isolated from cord blood. Anti-CD3 activation of neonatal T cells resulted in the expression of CD40L demonstrated with specific mAb or a soluble CD40.G1 construct. The level of expression was comparable to that of adult memory CD4+ T cells. In contrast, PMA and ionomycin induced only minimal CD40L expression by neonatal T cells, whereas adult memory T cells expressed CD40L comparably after stimulation with PMA and ionomycin or anti-CD3. The expression of CD40L was blocked by cyclosporine and prostaglandin E2 (PGE2). IL-2 IL-4 partially reversed the inhibition of CD40L expression by cyclosporine, and IL-2 reversed the inhibition by PGE2. CD40L expressed by neonatal T cells was functionally active, since neonatal T cell-dependent production of IgG4 and IgE was inhibited by a soluble CD40.G1 construct. Moreover, neonatal T cells supported the secretion of significantly more IgG, IgA, and IgE than CD40L-deficient hyper-IgM T cell clones. In addition, neonatal CD4+ T cells induced CD86 B7-2) expression by neonatal B cells that was blocked by anti-CD40L but not by control mAb. The results indicate that neonatal T cells activated through the TCR/CD3 complex express CD40L and use it to promote CD86 expression, Ig secretion and heavy chain isotype switching by neonatal B cells.
Molecular cloning and expression of cDNA encoding human macrophage C-type lectin. Its unique carbohydrate binding specificity for Tn antigen.
Authors: Suzuki N , Yamamoto K , Toyoshima S , Osawa T , Irimura T 
Published: December 2022

Abstract
A human macrophage calcium-dependent (C-type) lectin cDNA clone was obtained from a library derived from IL-2-treated peripheral blood monocytes. The cDNA cloning was based on the structural homology to hepatic asialoglycoprotein receptors. The nucleotide sequence of this cDNA clone was homologous to those of the galactose- and N-acetylgalactosamine-specific C-type macrophage lectins of rodents. In the putative carbohydrate recognition domain, deduced amino acid sequence revealed 60 and 63% homology to galactose- and N-acetylgalactosamine-specific C-type macrophage lectins of mice and rats, respectively. The cDNA clone was ligated into a mammalian expression vector and transfected into COS-1 cells. In the lysates of these cells, an MR 38,000 component, which bound to galactose-Sepharose, was identified after electrophoretic separation by its interaction with polyclonal antisera against synthetic polypeptides representing a portion of the carbohydrate recognition domain. The carbohydrate-binding specificity of the recombinant macrophage lectin was investigated by comparing elution profiles of various glycopeptides having defined carbohydrate structures from immobilized macrophage lectins. When N-terminal octapeptides from human glycophorin A that bore NeuAc alpha 2-3 Gal beta 1-3 (NeuAc alpha 2-6) GalNAc and its sequentially deglycosylated derivatives were compared, glycopeptides carrying three constitutive GalNAc-Ser/Thr (Tn Ag) strongly bound to the recombinant human macrophage lectin. This is the first study to demonstrate that human macrophage cell surface lectin recognizes Tn Ag, a well-known human carcinoma-associated epitope.
The role of NK cells during in vivo antigen-specific antibody responses.
Authors: Wilder J A , Koh C Y , Yuan D 
Published: December 2022

Abstract
Investigations into the role of NK cells in regulating Ab responses have yielded variable results, some suggesting that NK cells can down-regulate Ag-specific Ig production and others proposing an enhancing effect. These apparently inconsistent findings may stem partially from the specificity of reagents used in purifying cell populations and/or the nature of the in vitro systems used to study these events. We chose to investigate the ability of either resting or poly(I:C)-activated NK cells to alter an in vivo Ab response in mice given a T-independent (TNP-LPS) or T-dependent (TNP-keyhole limpet hemocyanin (KLH)) Ag. By using a more specific Ab, anti-NK-1.1, to deplete NK cells, we were able to clearly show that resting, endogenous NK cells do not affect either type of response, as measured by serum Ag-specific Ig levels quantitated by isotype-specific ELISA. In contrast, activation of NK cells by poly(I:C) increased Ag-specific IgC2a as well as IgG1 levels. Interestingly, only the effect on IgG2a production is reversible by depletion of NK cells.
Induction of microvariant-specific CTL lines reactive to a single amino acid mismatch in bulk cultures using a transfectant expressing a single HLA class I molecule.
Authors: Cereb N , Yang S Y 
Published: December 2022

Abstract
Alloreactivity against micromismatches in MHC class I molecules is difficult to measure. Here, we describe an in vitro model with which it is possible to examine alloreactivity against a single HLA class I allotype. The HLA class I- and class II-negative myelocytic leukemia cell line K562 was transfected with a genomic DNA clone carrying B*4403 to express a single allotype. CTL lines were generated from normal individuals carrying B*4402, B*4403, or unrelated HLA-B alleles by stimulation with B*4403- transfected K562. The bulk CTL lines generated from B*4402+ T cells against B*4403 that carry a single amino acid disparity at position 156 were specific for B*4403+ targets and did not react with targets carrying any other HLA allotype. However, the CTL lines generated from B44-negative individuals exhibited killing of the targets bearing not only B44, but also B44 CREG and a few other B alleles. Reverse transcriptase-PCR analysis of TCRs, expressed in the CTL clones uniquely specific for B*4403, showed that TCR V beta usage of alloreactive T cells directed against B*4403 was diverse but nonrandom and was affected by the HLA background of the responder. Thus, the K562-HLA transfectant system provides a useful in vitro tool to analyze alloreactivity against a single class I allele and to aid in the prediction of alloreactivity in unrelated marrow transplantation.
B cells from p50/NF-kappa B knockout mice have selective defects in proliferation, differentiation, germ-line CH transcription, and Ig class switching.
Authors: Snapper C M , Zelazowski P , Rosas F R , Kehry M R , Tian M , Baltimore D , Sha W C 
Published: December 2022

Abstract
To better understand the role of NF-kappaB in normal B cell physiology, we used a purified population of resting B cells from p50/NF-kappa B knockout (p50-/-) mice to determine their ability to proliferate, secrete Ig, express germ-line CHRNA, and undergo Ig isotype switching in vitro in response to a number of distinct stimuli. p50-/- B cells proliferated normally in response to dextran-anti-IgD Abs (alpha delta-dex) and membrane-bound, but not soluble, CD40 ligand (CD40), and they were virtually unresponsive to LPS when compared with control B cells. p50-/- B cells secreted markedly reduced Ig in response to alpha delta-dex or mCD40L in the presence of IL-4 + IL-5, despite their relatively normal proliferative rates, whereas normal Ig secretion was restored by the combination of alpha delta-dex and CD40L. p50-/- B cells expressed normal steady-state levels of germ-line CH gamma 1 and CH alpha RNA but markedly reduced germ-line CH gamma 3 and CH epsilon RNA upon appropriate stimulation. Although p50-/- B cells underwent substantial switching to IgG1, a marked reduction in the switch to IgG3 and IgE, as IgA, was observed. These data are the first to demonstrate key, independent roles for p50/NF-kappaB in normal B cell maturation to Ig secretion, germ-line CH gene activation, and Ig class switching, as well as mitogenesis, and provide a powerful and well-defined in vitro model system for studying the role of p50/NF-kappaB in a wide range of normal cellular functions.
Susceptibility to TNF in the presence of inhibitors of transcription or translation is dependent on the activity of cytosolic phospholipase A2 in human melanoma tumor cells.
Authors: Voelkel-Johnson C , Thorne T E , Laster S M 
Published: December 2022

Abstract
In this study, we have examined the relationship between the expression of the high molecular weight, cytosolic form of PLA2 (cPLA2) and ability of inhibitors of transcription or translation (ITT) to induce susceptibility to TNF. S Susceptibility to lysis was assayed by 51CR release, and the expression of cPLA2 was assayed by activity assay and by Western blot. The panel of cells that we examined included two murine cell lines, six human melanoma-derived cell lines, two samples of freshly explanted melanoma tumor tissue, and a culture of normal epidermal melanocytes. Our experiments revealed a near perfect correlation between the activity of cPLA2 per cell and susceptibility to TNF in the presence of either cycloheximide (CHI) or actinomycin D (r = 0.97). These results suggest that the activity of cPLA2 is both necessary and rate-limiting in this form of programmed cell death, conclusions that were confirmed in transfection experiments and in experiments with antisense oligonucleotides. Over-expression of cPLA2 in two melanoma-derived cell lines, WM793 and SK-MEL-131, led to enhanced susceptibility to TNF and CHI. Conversely, suppression of cPLA2 with antisense oligonucleotides dramatically decreased susceptibility to TNF and CHI in C3HA fibroblasts. These experiments also revealed a coupled, transformation-released change in the expression of cPLA2 and susceptibility to lysis. Normal melanocytes contained the lowest levels of cPLA2 and were completely resistant to sensitization with ITT. In contrast, all of the melanoma-derived cell lines and samples of melanoma tumor tissue we examined has higher levels of cPLA2 and could be killed, to some extent, by treatment with TNF and ITT.
Neuroinvasive properties of herpes simplex virus type 1 glycoprotein variants are controlled by the immune response.
Authors: Mitchell B M , Stevens J G 
Published: December 2022

Abstract
Neuroinvasiveness is a property central to the pathogenesis of herpes simplex virus (HSV) and most isolates demonstrate this property. Exceptions are HSV strains KOS and ANG, for which we have previously shown that the non-neuroinvasive phenotype is referable to single amino acid changes in glycoprotein D for ANG or glycoprotein B for KOS. Because glycoproteins B and D are immunologically significant, the possibility that the phenotype has an immunologic basis was examined. Nonimmunosuppressed mice could not be killed with any dose of these non-neuroinvasive viruses after footpad inoculation, but in cyclophosphamide-suppressed animals, the ratios of plaque-forming units to LD50 decreased by at least four orders of magnitude to levels comparable with that of ANG-path, a neuroinvasive derivative of ANG. KOS and ANG induced a more rapid circulating neutralizing Ab response than did ANG-path, and mice were protected when these agents were co-infected with the neuroinvasive strain. The noninvasive viruses engendered an enhanced mononuclear cell infiltrate in infected spinal ganglia which consisted of increased numbers of CD4+ and CD8+ T cells and an increased production and secretion of IgG. HSV-specific Ab-secreting cells were also observed. In addition, passive transfer of anti-HSV mouse serum protected immunosuppressed mice from lethal HSV challenge. Selective in vivo depletion of T lymphocytes increased the detectable levels of both KOS and ANG viruses in the spinal ganglia at 6 days postinfection, but it did not alter the ratios of plaque-forming units to LD50 or affect the HSV-induced increase in ganglionic IgG. Taken together, these data indicate that in these systems there is an immunologic basis for the control of HSV-1 neuroinvasiveness and that humoral, rather than cell-mediated immunity, is playing the major role.
IL-12 protects immunocompetent and immunodeficient neonatal mice against infection with Cryptosporidium parvum.
Authors: Urban J F , Fayer R , Chen S J , Gause W C , Gately M K , Finkelman F D 
Published: December 2022

Abstract
The protozoan parasite Cryptosporidium parvum (Cp) causes diarrhea that can be acutely severe in immunocompetent persons and can become chronic and life-threatening in immunocompromised individuals. Because studies in mice have implicated IFN-gamma in protection against this parasite, and IL-12 can induce IFN-gamma production, we examined the ability of IL-12 to prevent or cure Cp infection in neonatal BALB/c and SCID mice. Treatment of both immunocompetent and immunodeficient mice with IL-12 before experimental inoculation with Cp oocysts prevented or greatly reduced the severity of infection. Intestinal epithelial cell invasion and/or early intracellular development of Cp was inhibited by exogenous IL-12. The protective effect of IL-12 was completely blocked by anti-IFN-gamma mAb. Established infections were associated with elevated IFN-gamma gene expression and were not ameliorated by IL-12 treatment, even though such treatment further enhanced IFN-gamma gene expression. The severity of Cp infection was, however, exacerbated by treatment with anti-IL-12 Ab. These observations provide the first evidence that treatment with exogenous IL-12 can prevent Cp infection through an IFN-gamma-dependent, specific immune system-independent mechanism, and that endogenous IL-12 production has a role in limiting Cp infection.
IL-3 augments TCR-mediated responses of type 2 CD4 T cells.
Authors: Dan Y , Katakura Y , Ametani A , Kaminogawa S , Asano Y 
Published: December 2022

Abstract
A subset of type 2, but not type 1, CD4 T cell clones expresses IL-3R and can be stimulated by IL-3. Expression of IL-3R on these type 2 T cell clones is induced by TCR stimulation, and subsequent stimulation by IL-3 augmented the proliferation of and IL-4 production by these cells. This augmented response is inhibited by anti-IL-4 mAb, suggesting the involvement of IL-4 in this response. In place of TCR stimulation, treatment of these type 2 CD4 T cell clones with PMA rendered them responsive to further stimulation of proliferation by IL-3, indicating the cooperation between the IL-3R-elicited signals and PKC-mediated signals in stimulating proliferation. Although the augmentation of the TCR-mediated proliferative response by IL-3 was mainly due to the increased production of IL-4, we also demonstrated the presence of IL-4-independent mechanism mediating the response to IL-3. In situ, we found that splenic T cells could be induced to respond to Il-3 by TCR stimulation. Thus, IL-3 can stimulate a specific population of T cells and influence the immune response.
Mast cell tryptase is a mitogen for epithelial cells. Stimulation of IL-8 production and intercellular adhesion molecule-1 expression.
Authors: Cairns J A , Walls A F 
Published: December 2022

Abstract
Tryptase, a protease unique to the mast cell secretory granule, is released in substantial quantities into the respiratory tract of patients with inflammatory disease of the airways. We have investigated the potential of tryptase to act as a mitogen for bronchial epithelial cells and to stimulate release of IL-8 and expression of ICAM-1. Tryptase was isolated from extracts of human lung tissue using ammonium sulphate precipitation, octyl agarose, and heparin agarose chromatography. Purified tryptase stimulated DNA synthesis in the human epithelial cell line H292, as measured by [3H] thymidine incorporation. Maximal growth was observed after 24 h using 25 mU/ml of tryptase (where 1 micron is defined as that which can hydrolyze 1 mumol of the peptide substrate N-alpha-benzoyl-DL-arginine p-nitroanilide hydrochloride per minute at 25 degrees C), a concentration that is likely to be achieved in vivo. Inhibitors of tryptase activity, including leupeptin and benzamidine hydrochloride, significantly decreased tryptase-induced stimulation of DNA synthesis, indicating the requirement for an active catalytic site. Tryptase stimulated a catalytic site-dependent release of IL-8 from epithelial cells after 24 h, and this was associated with up-regulation of ICAM-1 expression, as revealed by FACS analysis. Tryptase may play a critical role in epithelial repair and in the recruitment of granulocytes following mast cell activation.
Urokinase-type plasminogen activator receptor reversibly dissociates from complement receptor type 3 (alpha M beta 2' CD11b/CD18) during neutrophil polarization.
Authors: Kindzelskii A L , Laska Z O , Todd R F , Petty H R 
Published: December 2022

Abstract
Previous studies have shown that the leukocyte integrin CR3 (CD11b/CD18) is physically associated with the urokinase-type plasminogen activator receptor (uPAR;CD87), a glycosyl-phosphatidylinositol (GPI)-linked protein, in resting neutrophil membranes. We now show that uPAR-to-CR3 interactions are reversible, correlating with cell shape. Neutrophils were first labeled with fluorescein conjugates of anti-CR3 F(ab')2 fragments followed by capping using a second-step F(ab')2 directed against murine F(ab')2s. Cells were then probed using rhodamine-conjugated anti-uPAR F(ab')2s. Although uPAR co-caps with CR3 on resting cells, uPAR was found to dissociate or "uncap" coincident with spontaneous cell polarization for migration. CR3 caps transformed into uropods while uPAR accumulated at lamellipodia of polarized cells. Capping was unnecessary for the observed distribution of CR3 and uPAR since the anti-CR3 and anti-uPAR F(ab')2s traffic to the uropod and lamellipodium, respectively, during polarization of uncapped cells. These receptors reassociate when cells return to a spherical morphology. In contrast to uPAR, Fc gamma RIIIB did not dissociate from CR3 caps during cell polarization. Resonance energy transfer (RET) microscopy was used to image the spatial distribution of RET and to follow the kinetics of association and dissociation. Initial levels of RET dramatically fell during cell polarization, but did not change on cells fixed with paraformaldehyde. Receptor reassociation was a biphasic process with initial reassociation about the perimeter of a cap, followed by a plateau and a slower rise in RET within a cap. We suggest that cells regulate receptor-receptor associations depending upon their physiologic activities.
Cholera toxin increases IL-6 synthesis and decreases TNF-alpha production by rat peritoneal mast cells.
Authors: Leal-Berumen I , Snider D P , Barajas-Lopez C , Marshall J S 
Published: December 2022

Abstract
Mast cells have been traditionally associated with an acute allergic response. However, their role in regulating chronic inflammatory processes must also be considered in view of evidence that mast cells synthesize and release a number of cytokines. In this study, we have examined the effect of cholera toxin (CT) on peritoneal mast cell IL-6 and TNF-alpha production. Highly purified, freshly isolated, rat peritoneal mast cells from Brown Norway rats were cultured in the presence of CT or its B subunit (CTB) alone or in combination with anti-IgE or bacterial LPS. Histamine release was measured after 10 min; IL-16 and TNF-alpha production was assessed in supernatants after 18 h. We found that CT or CTB alone did not affect histamine release; however, mast cell IL-6 production was significantly enhanced by CT but not by CTB. In contrast, constitutive production of TNF-alpha was inhibited by CT. The effects of CT were similar to our previous observations of the actions of prostaglandin E2 on mast cells. We also examined the effects of CT in combination with other mast cell activating agents. CT had no significant effect on anti-IgE-induced histamine release. An additive effect on IL-6 production was observed in the context of LPS. Forskolin, an agent known to increase intracellular cAMP levels, also induced a significant increase in IL-6 production, whereas TNF-alpha production was decreased. These data have important implications for our understanding of the regulation of mast cell cytokine production and the effects of CT on local cytokine production.
Dehydroepiandrosterone modulation of lipopolysaccharide-stimulated monocyte cytotoxicity.
Authors: McLachlan J A , Serkin C D , Bakouche O 
Published: December 2022

Abstract
Dehydroepiandrosterone (DHEA), the predominant androgen secreted by the adrenal cortex, can be converted to both potent androgens and estrogens. In addition to its role as a precursor for other steroid hormones, DHEA has been proposed to play an important role in immunity. This study has investigated DHEA modulation of LPS-induced monocyte cytotoxicity. Cytotoxicity markers assessed include tumor cell killing, IL-1 secretion, reactive oxygen intermediate release, nitric oxide synthetase activity as measured by the release of reactive nitrogen intermediates, complement receptor-1 cell surface protein, and TNF-alpha protein presence. Monocytes stimulated with LPS concentrations of 1.0 micrograms/ml displayed the above cytotoxic markers, whereas monocytes stimulated with DHEA alone or with LPS at a lower concentration of 0.2 ng/ml did not. However, when used simultaneously, DHEA and LPS 0.2 ng/ml displayed a synergistic effect on monocyte cytotoxicity against cancerous cell lines, IL-1 secretion, reactive nitrogen intermediate release, complement receptor-1 cell-surface protein, and TNF-alpha protein to levels comparable with levels obtained using LPS 1.0 microgram/ml. Finally, Scatchard plot analysis demonstrated the presence of a DHEA receptor in monocytes, suggesting that DHEA effects on LPS-stimulated monocytes are mediated through a receptor-dependent process.
In vivo response of mature T cells to Mlsa antigens. Long-term progeny of dividing cells include cells with a naive phenotype.
Authors: Hayden K A , Tough D F , Webb S R 
Published: December 2022

Abstract
To characterize T cells surviving elimination following strong in vivo responses, bromodeoxyuridine (BrdU) was used to mark the V beta 6+ CD4+ T cells proliferating after exposure to MLsa superantigens. Though a portion of the surviving V beta 6+ cells failed to label with BrdU, many were BrdU+, indicating that some proliferating cells escape elimination. Both the portion of V beta 6+ cells responding to MLs Ag in vivo and the number of responding cells that escaped elimination were influenced by the MHC haplotype; weaker responses correlated with enhanced survival of BrdU+ V beta 6+ cells. As expected, some of these cells expressed cell surface markers generally associated with an activated/memory phenotype. Significantly, however, a large proportion of BrdU+ V beta 6+ cells were phenotypically indistinguishable from naive cells.