bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Effect of Formalin on Botulinum Toxins A, B and C
Authors: Graham Robert , Thorp Frank 
Published: December 2022

Summary
The experimental evidence of the protective character of formolized botulinum toxoids A, B and C is demonstrable. Five-tenths per cent of formalin added to potent botulinum toxins A and B containing 10,000 guinea pig lethal doses per cubic centimeter detoxified the toxins at 37°C. in varying periods of time. Larger amounts of formalin seemed undesirable, while 0.3 per cent of formalin failed to kill the Cl. botulinum spores A and B, but did detoxify weak toxins containing 4000 guinea pig lethal doses per cubic centimeter and kill type C spores.
Potent toxoids protected a majority of guinea pigs, yet guinea pigs of 300 grams weight or slightly over more consistently withstood lethal amounts of unaltered toxin than pigs weighing less than 300 grams. In evaluating the antigenic value of botulinum toxoids in guinea pigs at least 3 of 4 pigs injected with appropriate doses of potent toxoid should survive lethal amounts of toxin. Three units administered subcutaneously to guinea pigs of 300 grams weight should also prove innocuous. Protective amounts of toxoid have been injected into fowls and horses without ill effects, suggesting that there is a desirable range of safety in this antigen in studying its immunizing value in the field.
The value of combined toxoids in one, two or three doses administered at weekly intervals against a single or a combined homologous toxin is suggested, but its effect in natural outbreaks of botulism in animals under farm conditions receiving contaminated rations remains to be established. The experimental evidence suggests that it may protect against lethal amounts of the toxin.
Alloantigen-Reactive Th1 Development in IL-12-Deficient Mice
Authors: Piccotti Joseph R. , Li Kewang , Chan Sherri Y. , Ferrante Jessica , Magram Jeanne , Eichwald Ernst J. , Bishop D. Keith 
Published: December 2022

AbstractIL-12p70, a 70- to 75-kDa heterodimer consisting of disulfide-bonded 35-kDa (p35) and 40-kDa (p40) subunits, enhances Th1 development primarily by its ability to induce IFN-γ production by NK and Th1 cells. Although homodimers of the p40 subunit of IL-12 are potent IL-12 receptor antagonists in some systems, we have reported that p40 homodimer may accentuate alloreactive CD8+ Th1 function. To test the role of endogenously produced p40 in alloimmunity, Th1 development was assessed in either IL-12 p35 knockout (p35−/−) mice, the cells of which are capable of secreting p40, or p40 knockout (p40−/−) mice. Compared with IL-12 wild-type controls, splenocytes obtained from both p35−/− and p40−/− mice produced markedly less IFN-γ after in vitro stimulation with Con A or alloantigens. Interestingly, in vivo-sensitized Th1 were detected in both p35−/− and p40−/− cardiac allograft recipients. However, in vivo Th1 development was enhanced in p35−/− recipients compared with p40−/− animals, suggesting that endogenous p40 produced in p35−/− mice may stimulate alloreactive Th1. Indeed, neutralizing endogenous p40 with anti-IL-12 p40 mAb reduced Th1 development in p35−/− allograft recipients to that seen in p40−/− mice. To determine whether Th1 development that occurred in the absence of IL-12p70 and p40 required IFN-γ, p40−/− allograft recipients were treated with anti-IFN-γ mAb. Neutralizing IFN-γ did not inhibit in vivo Th1 development in p40−/− recipients and resulted in a unique pathology of rejection characterized by vascular thromboses. Collectively, these data suggest that 1) endogenous p40 may substitute for IL-12p70 in alloantigen-specific Th1 sensitization in vivo and 2) in vivo alloreactive Th1 development may occur independent of IL-12 and IFN-γ, suggesting an alternate Th1-sensitizing pathway.
Migration of Lymphoid Cells from Vaginal Epithelium to Iliac Lymph Nodes in Relation to Vaginal Infection by Herpes Simplex Virus Type 2
Authors: King Nicholas J. C. , Parr Earl L. , Parr Margaret B. 
Published: December 2022

AbstractTo determine whether lymphocytes and Langerhans cells in vaginal epithelium are migratory, we stained mouse vaginal epithelium, including its lymphoid cells, by intraluminal administration of H33342, a fluorescent, vital dye. Stromal staining was superficial, and no free dye reached the iliac lymph nodes. The numbers and phenotypes of H33342-stained cells that migrated from the vagina to the iliac lymph nodes during the next 48 h were determined in four groups: normal mice, mice infected intravaginally with wild-type herpes simplex virus type 2 (HSV-2), mice that were immune to vaginal HSV-2 infection, and immune mice that received vaginal challenge with HSV-2. H33342-stained cells migrated from the vaginal epithelium to the iliac lymph nodes in all groups and were mainly Thy-1.2+ cells and B220+ cells. The number of migrating Thy-1.2+ cells was similar to the sum of CD4+ and CD8+ cells in all groups and was not significantly different from the number of CD44+ cells, suggesting that most of the migrating T cells were memory cells. B lymphocytes comprised 31, 32, 43, and 68% of the migrating cells in the four groups, respectively. We found no evidence that Langerhans cells or macrophages were migrating. Thus, most MHC class II+ cells in all groups were accounted for by B cells, and migrating cells did not express B7.1 or F4/80 or exhibit indented nuclei or dendritic processes. We suggest that the migrating T cells and B cells probably belonged to a pool of lymphocytes that recirculates from blood to tissues and back to the lymph nodes via their afferent lymphatics.
Cholera Toxin and Cholera Toxin B Subunit Induce IgA Switching Through the Action of TGF-β1
Authors: Kim Pyeung-Hyeun , Eckmann Lars , Lee Wha Jung , Han Wonkyo , Kagnoff Martin F. 
Published: December 2022

AbstractCholera toxin (CT) and its B subunit (CTB) are potent immunogens and adjuvants that, either alone or linked to protein Ags, can stimulate mucosal immune responses, modulate the induction of oral tolerance, and stimulate IgA isotype switching. The present studies addressed the mechanisms by which CT and CTB promote IgA switching. CT and rCTB, in the presence of IL-2, significantly increased IgA isotype switching at the clonal level in populations of purified and LPS-activated murine surface IgA− spleen B cells, as determined by ELISA, enzyme linked immunospot assays, and limiting dilution analysis. The IgA stimulatory effects of CT and CTB were independent of the A subunit of CT. CTB and CT did not increase the secretory rate of IgA-producing cells or the clonal burst size of IgA clones, and did inhibit B cell growth. Because TGF-β1 also inhibits B cell growth and promotes IgA switching, further studies tested whether the activity of CTB and CT on IgA isotype switching was mediated through TGF-β1. Anti-TGF-β Ab and soluble TGF-β1 type IIR inhibited CTB- and CT-stimulated IgA isotype switching. Furthermore, increased TGF-β1 mRNA levels and bioactive TGF-β1, within a range shown to induce IgA isotype switching, were detected in cultures of surface IgA− B cells stimulated with CT or CTB and IL-2. These data indicate that CTB- and CT-stimulated IgA isotype switching are mediated through TGF-β1. The finding that CTB up-regulates TGF-β1 activity has important implications for understanding the mechanisms by which CTB promotes both IgA mucosal immunity and oral tolerance.
Vascular Endothelial Growth Factor Affects Dendritic Cell Maturation Through the Inhibition of Nuclear Factor-κB Activation in Hemopoietic Progenitor Cells
Authors: Oyama Tsunehiro , Ran Sophia , Ishida Tadao , Nadaf Sorena , Kerr Lawrence , Carbone David P. , Gabrilovich Dmitry I. 
Published: December 2022

AbstractVascular endothelial growth factor (VEGF), produced by almost all tumor cells, affects the ability of hemopoietic progenitor cells (HPC) to differentiate into functional dendritic cells (DC) during the early stages of their maturation. In this study we demonstrate specific binding of VEGF to HPC. This binding was efficiently competed by placenta growth factor (PlGF), a ligand reportedly specific for the Flt-1 receptor. The number of binding sites for VEGF decreased during DC maturation in vitro associated with decreased levels of mRNA for Flt-1. VEGF significantly inhibited nuclear factor-κB (NF-κB)-dependent activation of reporter gene transcription during the first 24 h in culture. The presence of VEGF significantly decreased the specific DNA binding of NF-κB as early as 30 min after induction with TNF-α. This was followed on days 7 to 10 by decreases in the mRNA for RelB and c-Rel, two subunits of NF-κB. Blockade of NF-κB activity in HPC at early stages of differentiation with an adenovirus expressing a dominant IκB inhibitor of NF-κB reproduced the pattern of effects observed with VEGF. Thus, NF-κB plays an important role in maturation of HPCs to DC, and VEGF activation of the Flt-1 receptor is able to block the activation of NF-κB in this system. Blockade of NF-κB activation in HPCs by tumor-derived factors may therefore be a mechanism by which tumor cells can directly down-modulate the ability of the immune system to generate effective antitumor immune responses.
Functional Analysis by Site-Directed Mutagenesis of the Complex Polymorphism in Rat Transporter Associated with Antigen Processing
Authors: Deverson Edward V. , Leong Louise , Seelig Angela , Coadwell W. John , Tredgett Evelyn M. , Butcher Geoffrey W. , Howard Jonathan C. 
Published: December 2022

Abstract
The transporter associated with Ag processing, TAP, is an endoplasmic reticulum resident heterodimeric member of the ATP-binding cassette transporter family. TAP transports short peptides from cytosol to the endoplasmic reticulum lumen for loading into recently synthesized class I MHC molecules. In the rat, two alleles of the TAP2 chain differ in their permissiveness to the transport of peptides with small hydrophobic, polar, or charged amino acids at the C terminus, and this correlates with differences between the peptide sets loaded into certain class I molecules in vivo. We have used segmental exchanges and site-directed mutagenesis to identify the residues in rat TAP2 responsible for differential transport between the two alleles of peptides terminating above all in the positively charged residue, arginine. Of the 25 residues by which the two functional TAP2 alleles differ, we have localized differential transport of peptides with a C-terminal arginine to two adjacent clusters of exchanges in the membrane domain involving a total of five amino acids. Each cluster, transferred by site-directed mutagenesis from the permissive to the restrictive sequence, can independently confer on TAP a partial ability to transport peptides with arginine at the C terminus. The results suggest that the permissive TAP2-A allele evolved in at least two steps, each partially permissive for peptides with charged C termini.
Variable Region Domain Exchange Influences the Functional Properties of IgG
Authors: Morrison Sherie L. , Porter Stephen B. , Trinh K. Ryan , Wims Letitia A. , Denham Jerrod , Oi Vernon T. 
Published: December 2022

Abstract
In the present study we have characterized a family of anti-dansyl Abs with the variable region of the heavy chain on human Cκ and the variable region of the light chain on different human γ constant regions (creating inside-out molecules). Although fully assembled molecules were secreted, this variable region exchange slowed the kinetics of Ab assembly. Although the variable region exchange does not lead to a detectable change in the microenvironment of the combining site, it did alter the kinetic parameters of binding to immobilized Ag, slowing both the on and off rates. When effector functions were evaluated, inside-out IgG1 and IgG3 were more effective in complement-mediated cytolysis than their wild-type counterparts. Variable region domain exchange may be one approach to obtaining Abs of identical specificity with altered binding characteristics.
Peptide Selection by an MHC H-2Kb Class I Molecule Devoid of the Central Anchor (“C”) Pocket
Authors: Molano Alberto , Erdjument-Bromage Hediye , Fremont Daved H. , Messaoudi Ilhem , Tempst Paul , Nikolić-Žugić Janko 
Published: December 2022

Abstract
The peptide-binding site of the murine MHC class I molecule H-2Kb contains a deep C pocket, that is critical for peptide binding, as it accepts the anchor phenylalanine or tyrosine residue located in the middle (position 5, P5F/Y) of H-2Kb binding peptides. H-2Kb predominantly binds octameric peptides. By both criteria, H-2Kb is unique among the known murine and human class I molecules, none of which have a deep C pocket or preferentially select octamers. We investigated the relative importance of the C pocket in peptide selection and binding by the MHC. An MHC class I H-2Kb variant, KbW9, predicted to contain no C pocket, was engineered by replacing valine at MHC9 with tryptophan. This mutation drastically altered the selection of peptides bound to KbW9. The KbW9 molecule predominantly, if not exclusively, bound nonamers. New peptide anchor residues substituted for the loss of the P5F/Y:C pocket interaction. P3P/Y, which plays an auxiliary role in binding to Kb, assumed the role of a primary anchor, and P5R was selected as a new primary anchor, most likely contacting the E pocket. These experiments demonstrate that the presence of a deep C pocket is responsible for the selection of octameric peptides as the preferred ligands for Kb and provide insight into the adaptation of peptides to a rearranged MHC groove.
Gene Structure, Promoter Characterization, and Basis for Alternative mRNA Splicing of the Human CD58 Gene
Authors: Wallich Reinhard , Brenner Christiane , Brand Yvonne , Roux Matthias , Reister Manuel , Meuer Stefan 
Published: December 2022

Abstract
The 60-kDa lymphocyte function-associated Ag-3 (LFA-3/CD58), a highly glycosylated adhesion molecule that serves as ligand for the T cell-restricted glycoprotein CD2, is encoded by a gene at the human chromosome locus 1p13. We have elucidated the exon-intron organization of the entire human CD58 gene, including ∼2.5 kilobases (kb) of 5′-flanking DNA. Four overlapping genomic clones, spanning ∼65 kb, contained the entire ∼1-kb coding sequence of CD58 and consisted of six separate exons, which varied from 72 to 294 bp in size. At least two different CD58 mRNA precursors can be generated from the human gene as a result of alternative choice of one of the two acceptor splice sites located within exon 5. DNA sequence analysis of about 2.5 kb of 5′-flanking sequence of the CD58 gene indicated the absence of a CAAT box. However, potential binding sites for the transcriptional activators AP-2, GATA, PU.1, and Sp-1 are present. Two consensus TATAA elements, located ∼2.4 kb upstream of the transcriptional start site, have been identified. The 2.5-kb CD58 promoter sequence displayed functional activity in transient transfection assays in the hepatocellular carcinoma cell line HepG2. Comparing the response of CD58 promoter-driven luciferase plasmids to several cytokines and other agents suggests that the CD58 promoter is regulated by up-regulatory, enhancer-like and down-regulatory, silencer-like elements. Further analysis of this region should allow researchers to gain insight into the molecular mechanisms by which this gene is regulated, e.g., during inflammatory responses.
Oligoclonality of Vδ1 and Vδ2 Cells in Human Peripheral Blood Mononuclear Cells: TCR Selection Is Not Altered by Stimulation with Gram-Negative Bacteria
Authors: Shen Jian , Andrews David M. , Pandolfi Franco , Boyle Lenora A. , Kersten Catalina M. , Blatman Robert N. , Kurnick James T. 
Published: December 2022

AbstractDespite the enormous potential repertoire of γδ T cells, there are several observations which suggest that the expressed γδ repertoire in the periphery of normal individuals is often quite restricted. To assess selective expansions among γδ T cells from both adult and newborn blood samples, PBMC from 12 normal adults and cord blood from 15 normal newborns were analyzed for TCRDV1 and TCRDV2 junctional diversity by CDR3 size spectratyping and single-strand conformational polymorphism. Although TCRBV usage showed extensive heterogeneity in adults and newborns, both populations often showed CDR3 region restriction for TCRDV1 and TCRDV2. Analysis of the CDR3 spectratype patterns of newborn twins suggested that clonal selection for TCRDV is independent of genetic background. The possible role of Gram-negative bacteria in driving selective responsiveness of γδ T cells in PBMCs from adults was examined by in vitro stimulation with Escherichia coli and Pseudomonas aeruginosa. Donors whose TCRDV repertoire was highly clonal in the unstimulated blood cells showed the same predominant clones among the bacteria-stimulated cultures. In individuals whose γδ T cells were less restricted, in vitro stimulation did not select for clonality; rather, the TCRDV repertoires were similar before and after bacterial stimulation. Together, these data indicate that γδ T cells are often clonally restricted in adults as well as in newborns and suggest that the prominent stimulatory activity of Gram-negative bacteria does not by itself account for the restriction or diversity of the γδ T cell repertoire.
Androstenediol Antagonizes Herpes Simplex Virus Type 1-Induced Encephalitis Through the Augmentation of Type I IFN Production
Authors: Daigle Jennifer , Carr Daniel J. J. 
Published: December 2022

Abstract
Dehydroepiandrosterone and androstenediol (AED) have previously been found to protect mice from viral-induced encephalitis resulting in an increased survival rate of the animals. These hormones have been shown to antagonize corticosteroids, which have immunosuppressive effects in vivo and in vitro, suggesting the antiviral effect of DHEA and AED may be linked to the anticorticosteroid action. The present study was undertaken to address the immune response to herpes simplex virus type 1 (HSV-1) during the acute ocular infection with and without AED treatment focusing on the early immune events in the eye and trigeminal ganglion. AED treatment was found to significantly improve the survival of HSV-1-infected mice in a dose-dependent fashion. While AED did not antagonize the elevated serum corticosterone levels following acute infection, AED enhanced the expression of IFN-α mRNA and decreased the expression of HSV-1-infected cell polypeptide 27 mRNA in the trigeminal ganglion during the acute (day 6 postinfection) infection of mice, as determined by reverse transcription-PCR. However, there was no change in the viral load from the eye or trigeminal ganglion when comparing the AED-treated with the vehicle-treated mice. Neutralization Abs to IFN-α, -β, or -α/β, but not control Ab, blocked the protective effect following AED exposure, confirming the involvement of type I IFN in the enhancement of survival in AED-treated mice. Collectively, these results identify innate immunity as a key component in augmenting the survival of HSV-1-infected mice following AED treatment.
Cutting Edge: Dichotomous Effects of β-Chemokines on HIV Replication in Monocytes and Monocyte-Derived Macrophages
Authors: Kelly Mark D. , Naif Hassan M. , Adams Susan L. , Cunningham Anthony L. , Lloyd Andrew R. 
Published: December 2022

AbstractThe role of β-chemokines in the pathogenesis of HIV disease remains undefined. Given the potent capacities of these proteins to attract mononuclear cells to inflammatory sites, such as lymph nodes of patients with HIV disease, the effects of exposure of monocytes and monocyte-derived macrophages to β-chemokines before HIV infection were compared with their effects when added either simultaneously with or after HIV infection. In this system, HIV replication was substantially increased in cells that had been exposed to β-chemokines before HIV infection. These effects were pertussis toxin sensitive. By contrast, HIV replication was inhibited in cells that had been exposed to β-chemokines either simultaneously with or after HIV infection. These effects were not pertussis toxin sensitive. In view of this potent capacity of β-chemokines to stimulate HIV replication, treatment approaches for HIV disease based on the apparent inhibitory activity of these proteins on viral replication should be undertaken with caution.
Discoordinate Surface Expression of IFN-γ-Induced HLA Class II Proteins in Nonprofessional Antigen-Presenting Cells with Absence of DM and Class II Colocalization
Authors: Muczynski Kimberly A. , Anderson Susan K. , Pious Donald 
Published: December 2022

AbstractWe compared HLA class II expression in a human melanoma line (a nonprofessional APC), induced by IFN-γ or by stable transfection with CIITA, with constitutive class II expression in an EBV-transformed B lymphoblastoid cell line (a professional APC) from the same donor. IFN-γ-induced and CIITA-transfected melanoma cells expressed DR, DP, and DQ at levels similar to those expressed by the professional APC; however, DP and DQ proteins and DM-dependent DR epitopes were delayed in appearing on the cell surface when induced by IFN-γ. The delay in cell surface expression of some IFN-γ-induced class II epitopes was observed even though Northern blots demonstrated class II and DM genes to be coordinately transcribed and their mRNA levels to be equivalent to that in B lymphoblastoid cells. Confocal microscopy suggests that discoordinate cell surface expression of class II results from different intracellular trafficking for IFN-γ-induced class II proteins in the melanoma line compared with that in professional APCs. Specifically, although DR and DM proteins were present 2 days after IFN-γ induction, colocalization of DR and DM proteins intracellularly was not apparent in cells at any time after induction. Failure of DR and DM proteins to colocalize suggests that IFN-γ-induced cells lack an intracellular MIIC-like compartment. The absence of a compartment containing DR and DM to facilitate interaction between the two proteins may account for the delayed surface expression of class II epitopes whose formation requires both class II and DM.
In Vivo IL-4 Responses to Anti-IgD Antibody Are MHC Class II Dependent and β2-Microglobulin Independent and Develop Normally in the Absence of IL-4 Priming of T Cells
Authors: Morris Suzanne C. , Coffman Robert L. , Finkelman Fred D. 
Published: December 2022

AbstractA crucial role for CD1-responsive, MHC class II-unrestricted T cells in the generation of T cell IL-4 responses is suggested by the: 1) requirement for IL-4 to prime in vitro IL-4 responses by naive CD4+ T cells; 2) ability of TCR cross-linking to induce CD1-responsive T cells, but not conventional naive T cells, to produce IL-4; 3) failure of anti-IgD Ab to induce an IL-4-dependent IgE response in β2-microglobulin-deficient mice, which lack CD1; and 4) reported ability of MHC class II-deficient mice to make IgE responses to anti-IgD Ab. In contrast, the Ag specificity of cytokine and Ab responses in anti-IgD-injected mice and the normal IgE responses made by anti-IgD-treated CD1-deficient mice are difficult to reconcile with this view. We now find that the failure of β2-microglobulin-deficient mice to make an IgE response to anti-IgD Ab is caused by their rapid degradation of anti-IgD; sustained anti-IgD treatment induces them to make relatively normal IL-4 and IgE responses. Furthermore, in our study, MHC class II-deficient mice make little or no IL-4 or IgE responses to anti-IgD Ab and β2-microglobulin-deficient mice make large in vivo IL-4 responses to anti-CD3 mAb. Finally, although IL-4 priming of T cells for IL-4 production is Stat6 dependent, Stat6-deficient mice make normal IL-4 responses to anti-IgD. Thus, CD1-responsive T cells and other β2-microglobulin-dependent T cells are not required to prime conventional CD4+ T cells to make IL-4 responses to anti-IgD in vivo; in fact, the large IL-4 response made in this system does not require IL-4 priming.