bluuebunny/crossref_metadata_2025_split huggingface dataset:
The binding subunit of pertussis toxin inhibits IL-1 induction of IL-2 and prostaglandin production.
Authors: O'Neill L A , Ikebe T , Sarsfield S J , Saklatvala J 
Published: January 2023

Abstract
The inhibitory effect of pertussis toxin on the action of IL-1 has been investigated. The toxin inhibited IL-1-induced production of IL-2 mRNA and protein in EL4 cells. The B oligomer of the toxin, which was shown to be devoid of ADP-ribosylating activity, proved as inhibitory as the holotoxin. The inhibition was therefore attributable to the binding subunit of the toxin and not to its ability to ADP-ribosylate G proteins. The toxin did not affect the IL-1R binding to its ligand, nor did it inhibit an early post-receptor event, the induction of the transcription factor NF kappa B. This implied that the toxin was not uncoupling IL-1R signaling. The toxin, or its B oligomer, inhibited PGE2 synthesis in human gingival fibroblasts stimulated by IL-1, but not by PMA. Assay of PG synthetic activity in the cells after addition of exogenous arachidonic acid suggested impairment by the toxin of induction of PG-synthesizing enzymes. IL-1 stimulation of IL-6 or collagenase production by fibroblasts was unaffected by pertussis toxin. The binding subunit of the toxin inhibits certain IL-1 responses by virtue of previously unrecognized actions on lymphoid and fibroblastic cells. It does not appear to block early signaling and the inhibition highly unlikely to involve inactivation of a G protein.
Human recombinant IL-3 is a growth factor for normal B cells.
Authors: Xia X , Li L , Choi Y S 
Published: January 2023

Abstract
IL-3 is a well known hemopoietic cell growth and differentiation factor. However, its functional role in normal B cell differentiation has not been established. We have investigated the effect of IL-3 on the growth and differentiation of human B cells. IL-3 enhanced the proliferation of Staphylococcus aureus Cowan 1 strain-stimulated B cells. The optimal time of IL-3 to stimulate B cell growth was on day 2 to day 3, suggesting that IL-3 was a B cell growth factor acting in the late stage. IL-3 synergized with IL-2 to enhance B cell proliferation and differentiation. Pretreatment of B cells with IL-3 for more than 3 days increased the expression of IL-2R on B cells. However, pretreatment of B cells with IL-2 did not alter the subsequent response to IL-3, suggesting that the synergy between IL-2 and IL-3 may be attributed to the up-regulation of IL-2 response by IL-3. In addition, pretreatment of B cells with IL-4 decreased subsequent response of B cells to IL-3 as well as IL-2, suggesting that IL-3- and IL-2-responding cells passed a similar way during the early stage of B cell activation. It appears that IL-3 and IL-6 mediate normal B cell differentiation via separate mechanisms. IL-3-induced B cell differentiation was mainly mediated by increasing cell growth, whereas IL-6 induced B cell differentiation without affecting proliferation.
Analysis of the effects of activation of the alternative pathway of complement on erythrocytes with an isolated deficiency of decay accelerating factor.
Authors: Holguin M H , Martin C B , Bernshaw N J , Parker C J 
Published: January 2023

Abstract
E from individuals with the Inab blood group phenotype have an isolated deficiency of decay accelerating factor (DAF, CD55). DAF is a glycosyl phosphatidylinositol anchored membrane protein that inhibits activation of both the classical and alternative pathways of complement. Deficiency of DAF from the E of paroxysmal nocturnal hemoglobinuria (PNH) is thought to contribute to their greater sensitivity to complement-mediated lysis. Unlike PNH E, however, Inab cells are not susceptible to acidified serum lysis, a process that is mediated through activation of the alternative pathway. This observation led us to hypothesize that membrane constituents other than DAF control susceptibility to acidified serum lysis. To investigate this hypothesis, Inab E were incubated in acidified serum, and hemolysis and C3 deposition (as a measure of alternative pathway activation) were quantitated. C3 deposition of Inab cells was approximately 20 times greater than normal, however, hemolysis was not observed. Inab E expressed a normal amount of membrane inhibitor of reactive lysis (MIRL, CD59), a glycosyl phosphatidylinositol anchored protein that is also deficient in PNH. When MIRL function was blocked with antibody, C3 deposition markedly increased, and 100% of the Inab cells hemolyzed in acidified serum. These studies demonstrate that susceptibility to acidified serum lysis is controlled primarily by MIRL, and that in addition to its regulatory affect on the membrane attack complex, MIRL also modulates the activity of the C3 convertase of the alternative pathway by a mechanism that remains to be determined.
The role of bactericidal/permeability-increasing protein as a natural inhibitor of bacterial endotoxin.
Authors: Marra M N , Wilde C G , Collins M S , Snable J L , Thornton M B , Scott R W 
Published: January 2023

Abstract
Systemic release of endotoxin (LPS) after Gram-negative infection initiates a cascade of host cytokines that are thought to be the direct cause of shock, multisystem organ failure, and death. Endogenous LPS-binding proteins may play a role in regulating LPS toxicity in vivo. The human neutrophil granule protein bactericidal/permeability-increasing protein (BPI) shares sequence homology and immunocrossreactivity with an acute phase lipopolysaccharide binding protein (LBP) which has been shown to bind to LPS and accelerate LPS activation of neutrophils and macrophages. Although structurally similar, LBP and BPI are apparently functionally antagonistic. We previously showed that BPI inhibits LPS-mediated neutrophil activation in vitro. Here we demonstrate that BPI binds to LPS near the lipid A domain, and formation of the LPS-BPI complex abrogates detrimental host responses to LPS. For example, BPI blocks LPS-stimulated TNF release in vitro and in vivo, and LPS complexed to BPI is not pyrogenic in rabbits. Results demonstrating that BPI is released by stimulated human neutrophils further support the idea that BPI functions extracellularly in vivo to neutralize endotoxin. Taken together, these data argue that BPI neutralizes the toxic effects of LPS in vivo, and that BPI may represent a new therapeutic approach to the treatment of endotoxic shock.
Expression of platelet-derived growth factor-beta receptors on human fibroblasts. Regulation by recombinant platelet-derived growth factor-BB, IL-1, and tumor necrosis factor-alpha.
Authors: Tingström A , Reuterdahl C , Lindahl P , Heldin C H , Rubin K 
Published: January 2023

Abstract
Stimulation of human fibroblasts by platelet-derived growth factor (PDGF)-BB leads to a down-regulation of PDGF beta-receptors and a concomitant appearance of intracellular granular accumulations of receptors, as determined by stainings with the mAb PDGFR-B2. The granules contained both the ligand and PDGF beta-receptors, as revealed by double-immunofluorescence staining, and were formed in response to PDGF-BB but not in response to other cytokines tested. The formation of intracellular PDGF beta-receptor granules was dependent on PDGF-BB concentration and time of stimulation. The granular PDGF beta-receptor staining on cells treated with PDGF-BB for 1 h at 37 degrees C was used to investigate the effects of macrophage-derived cytokines on PDGF beta-receptor expression. The number of PDGF beta-receptor granules was found to be reduced in fibroblasts grown for 48 h in the presence of PDGF-BB, TNF-alpha, or IL-1; PDGF-AA under the same conditions had no effect. The reduction observed was paralleled by a decrease in cell surface expression of PDGF beta-receptors, measured as binding of 125I-PDGF-BB and of the PDGFR-B2 antibody. Furthermore, both TNF-alpha and IL-1 decreased the detergent-extractable pool of PDGF-beta receptors in the fibroblasts, as revealed by immunoblotting of detergent cell extracts. Finally, the decrease in PDGF beta-receptors after culturing of the cells in the presence of TNF-alpha and IL-1 was accompanied by a decreased incorporation of [3H]thymidine in response to PDGF-BB stimulation. In conclusion, our data suggest that certain macrophage-derived cytokines can modulate the expression of PDGF beta-receptors by cultured fibroblasts, which may contribute in part to their reduced responsiveness to PDGF.
Metabolic requirements for macrophage presentation of Listeria monocytogenes to immune CD8 cells.
Authors: Brown M L , Fields P E , Kurlander R J 
Published: January 2023

Abstract
Though ingested Ag are readily degraded into peptides within endocytic vesicles, APC usually cannot present these fragments to CD8 cells. Despite this generalization, some exceptions have been noted. For example, murine macrophage targets readily process heat-killed Listeria monocytogenes (HKLM) into a form recognizable by immune CD8 CTL. Using an assay of Listeria-specific, CD8-mediated cytotoxicity to quantitate Ag presentation by C57Bl/6 macrophage targets, we have examined some of the cellular requirements for this form of Ag processing. To assess whether the physical form of the Ag is an important determinant of processing, we compared the ability of macrophages to present intact HKLM, fractionated L. monocytogenes (LM) membranes, and octyl-beta-d-thioglucopyranoside-solubilized extracts of LM membranes. Macrophages presented each Ag form in a similar manner indicating that processing is not critically dependent on the presence of intact bacteria or even on the introduction of Ag in a particulate form. To gain insight into the metabolic requirements for Ag processing, we examined the effects of several inhibitors. As might be expected, listerial Ag presentation was blocked by brefeldin, a known inhibitor of the endogenous pathway of Ag processing. LM Ag presentation, however, was also blocked by inhibitors of endosomal acidification (chloroquine, ammonium chloride, and monensin) and by the acid protease inhibitor pepstatin A, suggesting that endocytic processing may play an essential role in CD8 recognition of this Ag. To formally establish that this pattern of exogenous Ag processing requires the presence of a class I MHC product, we demonstrated that beta-2 microglobulin-deficient macrophages, which lack class I MHC product expression, cannot present HKLM to CD8 cells. However, we could not block Ag presentation by incubating macrophages with monoclonal anti-H-2K or H-2D antibodies, suggesting that LM Ag presentation may be mediated by some other class I MHC product. Additional characterization of this pathway of Ag presentation is warranted in view of its possible role in initiating CD8-mediated immunity against microbial Ag.
Adenosine acts as an endogenous modulator of IL-2-dependent proliferation of cytotoxic T lymphocytes.
Authors: Antonysamy M A , Moticka E J , Ramkumar V 
Published: January 2023

Abstract
CTLL-2 cells are a clone of CTL that are dependent on IL-2 for proliferation. In addition to various cytokine receptors, we observed that these cells express three subtypes of adenosine receptors (ARs). In an initial attempt to delineate the functions of these receptors in CTLL-2 cells, we tested their role in proliferation. Elimination of endogenous adenosine with adenosine deaminase (ADA) markedly suppressed IL-2-dependent proliferation of these cells. This proliferative response was restored by addition of R-phenylisopropyladenosine (R-PIA), a non-hydrolyzable adenosine analogue. The stimulatory response to R-PIA was attenuated following blockade of ARs by 0.5 mM theophylline and 10 microM BW-A1433, but not by blockade of the A1AR with 100 nM xanthine amine congener. The rank order of potency of adenosine analogues in proliferation assays was R-PIA &gt; or = N-ethylcarboxamide adenosine &gt; S-PIA &gt; PAPA-APEC (a substituted ethylamino-5'-N-ethylcarboxamidoadenosine). These data suggest a potential role of the A3AR in the proliferative response. R-PIA stimulates production of 1,4,5-inositol trisphosphate in CTLL-2 cells, suggesting a role of the phospholipase C signaling pathway in the proliferative response. A23187 (100 nM) and phorbol 12,13 dibutyrate (10 nM), but not 4 alpha-phorbol (10 nM), were able to restore IL-2-dependent CTLL-2 proliferation in the presence of ADA. Furthermore, inhibition of protein kinase C by staurosporine (10 nM) and of phospholipase C by tricyclodecan-9-yl-xanthogenate (D609) blocked R-PIA-mediated cell proliferation. These data demonstrate an obligatory role of adenosine in IL-2-dependent proliferation of CTLL-2 cells and support the involvement of an AR-stimulated phospholipase C signaling pathway in this process.
T cell recognition of the immunodominant Sendai virus NP324-332/Kb epitope is focused on the center of the peptide.
Authors: Cole G A , Hogg T L , Woodland D L 
Published: January 2023

Abstract
The CTL response to Sendai virus in C57BL/6 mice is directed almost exclusively to a single H-2Kb-restricted epitope derived from the virus nucleoprotein, NP324-332 (FAPGNYPAL). We have previously shown that the repertoire of T cells elicited by this epitope following primary Sendai virus infection is very diverse. The current experiments were undertaken to determine how a diverse array of TCR are able to interact with a single class I epitope. Crystallographic analysis of NP324-332 bound to Kb has shown that the side chains of peptide residues F1, G4, N5, and A8 protrude toward the solvent and are potentially available for recognition by the TCR. Notably, the N5 residue protrudes prominently from the peptide-binding site due to its localization on a bulge in the center of NP324-332. To determine the importance of these residues for T cell recognition, we analyzed the response of a large panel of hybridomas to NP324-332 analogues substituted at these four positions. The data suggested that there is dominant recognition of the central G4 and N5 residues at the center of the peptide. However, individual hybridomas exhibited distinct patterns of fine specificity for residues F1 and A8, in that they were dependent on one, both, or neither of these residues for recognition of NP324-332. These data are consistent with a critical role for the G4 and N5 residues in governing NP324-332/Kb recognition by T cells and may have implications for T cell recognition of class-I restricted epitopes in general.
Paradoxical IgA immunity in CD4-deficient mice. Lack of cholera toxin-specific protective immunity despite normal gut mucosal IgA differentiation.
Authors: Hörnquist C E , Ekman L , Grdic K D , Schön K , Lycke N Y 
Published: January 2023

Abstract
Using normal and CD4 gene-targeted (CD4-/-) mice, we asked whether mucosal immune responses and IgA B cell differentiation require the presence of CD4+ T helper cells. We found that CD4-/- mice had numerous B cell germinal centers in Peyer's patches and other gut-associated lymphoid tissues. Membrane IgA+ B cells were found to co-localize to germinal center areas and CD4-CD8- double negative CD3+ T cells had replaced CD4+ T cells in the follicular areas of the Peyer's patches. CD4-/- mice had normal levels of IgA-producing cells in gut-associated lymphoid tissues, and gut lavage contained unaltered levels of total IgA. However, despite T cell help for IgA B cell differentiation, CD4-/- mice did not respond with Ag-specific intestinal IgA following oral immunization with the powerful mucosal immunogen cholera toxin (CT). By contrast, these mice demonstrated serum alpha-CT IgG following oral immunization, suggesting that double negative CD3+ T cells provided some help for systemic immune responses after oral immunization. Perorally immunized CD4-/- mice were completely unprotected against CT-induced diarrhea while both normal and CD8-/- mice were well protected and also demonstrated high levels of gut mucosal alpha-CT IgA. After reconstitution of the CD4-/- mice by adoptive transfer of naive mesenteric lymph node CD4+ T cells, the mice acquired the ability to respond with specific mucosal immune responses following oral immunization and also developed resistance against CT-induced diarrhea. Thus, paradoxically, although IgA B cell differentiation appears to proceed normally in CD4-/- mice, specific gut mucosal immune responses are grossly impaired in the absence of CD4+ T cells.
Purification to homogeneity of a novel human B cell differentiation factor.
Authors: De Kuang Y , Cidon M , Mayer L 
Published: January 2023

Abstract
By immunization with a partially purified form of a novel human B cell differentiation factor, 446-BCDF, we generated a series of mAbs that inhibit the functional activity of this cytokine (induction of Ig secretion by Staphylococcus aureus Cowan I strain organisms-activated B cells). Two mAbs, 929 and 204, were shown to be specific for 446-BCDF in that they failed to inhibit B cell differentiation in response to other known cytokines (IL-2, IL-6) or mitogens (PWM). More importantly, passage of crude 446-BCDF over a mAb 929-Sepharose 4B column resulted in the depletion of 446-BCDF activity, which could be recovered after elution with 0.1 M glycine, pH 2.8. Finally, TCA precipitation of column-eluted fractions was run on SDS-PAGE. Two bands corresponding to the previously described m.w. range of 446-BCDF were detected in the eluate, but not in the effluent column fractions. Furthermore, protein eluted from these bands resolved with nondenaturing gels also demonstrated 446-BCDF activity. Thus, together these data further support the existence of a novel human B cell differentiation factor that has been purified to homogeneity.
Histamine-induced secretion of lymphocyte chemoattractant factor from CD8+ T cells is independent of transcription and translation. Evidence for constitutive protein synthesis and storage.
Authors: Laberge S , Cruikshank W W , Kornfeld H , Center D M 
Published: January 2023

Abstract
We have reported previously that histamine induces the release of the CD4+ cell-specific lymphocyte chemoattractant factor (LCF) into the culture supernatants of CD8+ cells between 1 and 4 h following stimulation. To determine the mechanism of histamine-induced secretion of LCF, we evaluated the effects of inhibitors of gene transcription and translation on LCF production, and determined the effects of histamine stimulation on LCF mRNA induction and stability. The histamine-induced secretion of LCF from CD8+ cells was not associated with de novo synthesis of protein, nor did histamine have an effect on the induction or stability of LCF mRNA. Biologically active LCF was found in cell lysates of unstimulated CD8+ but not CD4+ T cells; however, LCF mRNA was detected at similar levels in both cell types. The only detectable lymphocyte chemoattractant present in unstimulated cells was LCF, and histamine induced the secretion of LCF, but no other lymphocyte chemoattractant activities, within 4 h. These studies demonstrate that histamine can act as a secretagogue for the protein LCF, which is constitutively synthesized and present in a biologically active form in CD8+ T cells. The rapid appearance of LCF induced by histamine may represent a mechanism for recruitment and activation for CD4+ cells in diseases such as asthma.
IFN-gamma and IL-4 regulate the growth and differentiation of CD8+ T cells into subpopulations with distinct cytokine profiles.
Authors: Noble A , Macary P A , Kemeny D M 
Published: January 2023

Abstract
In this study, we have investigated the effects of IL-4 and IFN-gamma on the growth and differentiation of CD8+ T cells in vitro. Rat splenic CD8+ T cells expressed higher levels of IL-4, IL-5, IL-10, and IFN-gamma mRNA, as measured by reverse-transcription PCR, than CD4+ T cells from the same source, whereas CD4+ T cells expressed more IL-2 and IL-6 mRNA. CD8+ T cells were cultured for 6 days with PMA, ionomycin, and IL-2, and their ability to proliferate, to express mRNA for IL-2, IL-4, IL-5, IL-6, IL-10, and IFN-gamma, and to secrete IFN-gamma and IL-2 was determined. IL-4 could act as a growth factor for CD8+ T cells during primary stimulation, but inhibited proliferation of the restimulated 6-day-cultured CD8+ T cells. The highest levels of mRNA for IL-2 and IL-6 were detected in control cultures in which little mRNA for IL-4, IL-5, or IL-10 was detected. Addition of IL-4 to the primary cultures reduced the capacity of the restimulated cells to express mRNA for IL-2, and for IL-6, but enhanced expression of mRNA for IL-4 and IL-5. Addition of IFN-gamma to the cultures, alone or in conjunction with IL-4, or addition of IFN-gamma-specific neutralizing Ab, had little effect. However, in conjunction with IL-4, anti-IFN-gamma enhanced expression of mRNA for IFN-gamma, and for IL-10. These results indicate that IL-4 and IFN-gamma regulate the differentiation of CD8+ T cells and the growth of cytotoxic and other types of CD8+ T cells, and suggest pathways through which CD8+ T cells may interact with other immune cells.
Characteristics of the influenza virus-specific CD8+ T cell response in mice homozygous for disruption of the H-2lAb gene.
Authors: Tripp R A , Sarawar S R , Doherty P C 
Published: January 2023

Abstract
The development of influenza virus-specific CD8+ cytotoxic T lymphocyte precursors (CTLp) is diminished in H-2b mice that are homozygous (-/-) for disruption of the H-2lAb gene. Virus clearance was not obviously delayed when compared with the congenic H-2lAb (+/+) controls, and evidence of CTL activity was apparent for inflammatory cells recovered from the respiratory tract in both cases. However, the virus-specific CTLp that are normally present in the regional lymph nodes and in the infected lung were evidently being consumed at the peak of the host response to give the terminally differentiated CTL effectors. Even so, any exhaustion of the CTLp pool was apparently transitory with this localized infection as, though the frequencies were consistently lower than those found for the (+/+) controls, CTLp could be detected reproducibly in both lymph nodes and spleen through 14 mo after infection. Analysis of cytokine profiles during the acute response showed a substantial defect in the (-/-) mice, indicating that cytokine production is largely dependent on the influenza-specific CD4+ set.
Relationships between intermediate TCR cells and NK1.1+ T cells in various immune organs. NK1.1+ T cells are present within a population of intermediate TCR cells.
Authors: Watanabe H , Miyaji C , Kawachi Y , Iiai T , Ohtsuka K , Iwanage T , Takahashi-Iwanaga H , Abo T 
Published: January 2023

Abstract
Experiments to date have revealed a population of T cells that carry intermediate (int) levels of TCR (or CD3) and express IL-2R beta-chain (IL-2R beta) in mouse liver. Such int TCR cells also reside in other immune organs, although in low numbers. On the other hand, NK1.1+ T cells with int TCR do reside in the thymus and other peripheral organs. To determine the relationship of two types of cells, we characterized int CD3 cells and NK1.1+ T cells throughout the organs in terms of the phenotype, V beta repertoire, and morphology. Although both IL-2R beta+ T cells and NK1.1+ T cells are classified as int CD3 cells, NK1.1+ T cells are present within int CD3 cells. The majority of int CD3 cells in the liver and thymus were NK1.1+, whereas the minority of such cells in the spleen, lymph nodes, and bone marrow were NK1.1+. Among int CD3 cells, double-negative (DN) CD4-8- cells and/or CD4+ were abundant in NK1.1+ subset, whereas CD8+ cells were generally abundant in NK1.1- subset. Self-reactive V beta+ clones estimated by the M1s system were distributed to both NK1.1+ and NK1.1- subsets. High CD3 cells in the thymus and other organs contained neither DN cells nor forbidden clones. Int CD3 cells had the morphology of granular or agranular lymphocytes carrying perforin. Among int CD3 cells, NK1.1+ subset had a higher level of perforin-positive cells than NK1.1- subset. These results clearly demonstrate the relationship between int TCR cells and NK1.1+ T cells in various organs.