bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vitro induction of a Haemophilus influenzae type b polysaccharide-specific antibody response in human peripheral blood lymphocytes of individuals recently vaccinated with an oligosaccharide-protein conjugate.
Authors: Peeters C C , Tenbergen-Meekes A M , Heijnen C J , Poolman J T , Zegers B J , Rijkers G T 
Published: December 2022

Abstract
In this paper an in vitro culture system for the induction of an antibody response to the Haemophilus influenzae type b polysaccharide (PRP) is described. Anti-PRP IgM and IgG antibody-secreting cells (ASC) and anti-diphtheria toxoid (DT) IgG ASC were detected in cultures of blood B and T cells derived from donors 4 to 6 wk after immunization with Haemophilus influenzae type b oligosaccharide-mutant diphtheria toxin (CRM197) conjugate (HbOC) and required in vitro restimulation with HbOC. When lymphocytes from HbOC-vaccinated donors were stimulated with PRP, anti-PRP IgM and IgG ASC could be detected in 50% offGe cases. Lymphocytes from PRP-vaccinated donors or non-vaccinated donors consistently failed to generate anti-PRP antibodies after in vitro stimulation with HbOC. Optimal in vitro responses were observed at concentrations of 0.06 to 0.6 micrograms/ml of Ag. At higher doses of Ag (6 micrograms/ml) anti-PRP and anti-DT antibody responses were suppressed. The in vitro generation of anti-PRP and anti-DT ASC, as detected by a spot-forming cell assay was shown to be T cell dependent, Ag dependent, and Ag specific. This culture system provides a model for the study of human B cell activation and immunoregulation by polysaccharide-protein conjugates and polysaccharides.
Immunologic control of C3 gene expression in tissue macrophages.
Authors: Goldman M B , Knovich M A , Goldman J N 
Published: December 2022

Abstract
Antigenic suppression of individual complement components can be induced when newborn animals or cells in tissue culture are treated for a period of time with antibody directed against that component. The initial exposure to antibody induces a network involving regulatory lymphocytes and soluble factors. Antigenic suppression has been accomplished either in vivo or in vitro with all three members of the evolutionarily related family C3, C4, and C5. In this report we have demonstrated that antigenic suppression is mainly the result of posttranscriptional regulation. After antibody treatment is terminated, during a period in which C3 protein is undetectable by sensitive assays, C3 mRNA is often briefly increased, after which it is modestly reduced. Therefore, the major mechanisms mediating immunologic control of C3 synthesis and secretion are not directly related to steady-state levels of C3 mRNA. The initially increased levels of C3 mRNA prove that there is no simple direct quantitative relationship between C3 mRNA and C3 synthesis and secretion. The later decreases in C3 mRNA levels are not sufficient to explain the quantitatively greater decreases in C3 synthesis. Therefore, the rate determining step in immune regulation of C3 production occurs after transcription. Regulation could be mediated by altered stability of C3 mRNA in the presence of antibody, formation of a defective primary transcript, defective processing of the transcript resulting in an abnormal mRNA, or a defective C3 translational apparatus. Although regulation is multifactorial, interference with translation is most likely to predominate.
Antiidiotypic vaccination against murine coronavirus infection.
Authors: Lamarre A , Lecomte J , Talbot P J 
Published: December 2022

Abstract
Rabbit polyclonal antiidiotypic antibodies were generated against a neutralizing mAb specific for a conformational epitope on the S glycoprotein of murine hepatitis virus, strain A59 (MHV-A59). These anti-Id were directed predominantly against an Id that was undetectable in rabbit and rat anti-MHV-A59 sera and weakly represented in syngeneic and allogeneic antiviral sera. However, some partial idiotypic sharing was observed between the Id-bearing antibody and a mAb with a similar antigenic site specificity. The anti-Id inhibited the virus-binding and neutralizing activities of the immunizing antibody, demonstrating that they recognize paratope-associated idiotopes. Mice immunized with affinity-purified anti-Id developed MHV-A59-specific antibodies that neutralized viral infectivity to high titers. Moreover, these animals survived an otherwise lethal challenge with viral murine hepatitis virus, unlike control mice immunized with normal rabbit Ig. These results indicate that at least a subpopulation of the polyclonal anti-Id could induce a protective immune response directed toward a biologically important MHV-A59 epitope, and demonstrate the feasibility of antiidiotypic vaccination against a coronavirus infection.
Uptake of lactoferrin by mononuclear phagocytes inhibits their ability to form hydroxyl radical and protects them from membrane autoperoxidation.
Authors: Britigan B E , Serody J S , Hayek M B , Charniga L M , Cohen M S 
Published: December 2022

Abstract
Human mononuclear phagocytes do not contain the iron-binding protein lactoferrin that we have previously demonstrated inhibits the potential for human neutrophils to generate hydroxyl radical in the presence of an exogenous iron catalyst of the Haber-Weiss reaction. Previous work by other investigators has suggested that mononuclear phagocytes (monocytes and monocyte-derived macrophages (MDM] have the capacity to bind exogenous lactoferrin via lactoferrin-specific membrane surface receptors. Accordingly, we examined the possibility that uptake of iron-free (apo) lactoferrin by human mononuclear phagocytes could play a role in limiting the potential for generation of hydroxyl radical during the monocyte/MDM respiratory burst. When monocytes or MDM were incubated in the presence of apo-lactoferrin, cell-associated lactoferrin increased in proportion to the concentration of lactoferrin provided. Similar results were obtained with iron-loaded (diferric) milk lactoferrin. Consistent with the in vivo importance of these findings, we found that lactoferrin was intimately associated with human alveolar macrophages obtained by bronchoalveolar lavage. The fucose polymer fucoidan inhibited lactoferrin uptake whereas exogenous transferrin or MDM exposure to IFN-gamma was without effect. Scatchard binding analysis confirmed the presence of a lactoferrin-specific receptor with a calculated kDa of 3.56 x 10(-6) M and 3.4 x 10(7) binding sites per cell. Subcellular fractionation studies indicated that twofold more of the lactoferrin which became cell-associated over the 1-h incubation time could be found in the cytoplasmic fraction compared to the plasma membrane-containing fraction, consistent with previous evidence by others for internalization of lactoferrin by mononuclear phagocytes. When lactoferrin-loaded monocytes/MDM were incubated in lactoferrin-free media, evidence for release of lactoferrin was obtained by SDS-PAGE and immunoblot analysis, suggesting the presence of a recyclable pool of cell-associated lactoferrin. To assess the impact of lactoferrin loading on monocyte/MDM hydroxyl radical formation, lactoferrin-loaded phagocytes were stimulated with PMA in the presence of catalytic iron. Hydroxyl radical generation by lactoferrin-loaded cells was decreased to about 50% of control cells. Similarly, monocytes that had been lactoferrin-loaded demonstrated a 28% decrease in autooxidation of their membrane when stimulated in the presence of catalytic iron. These data suggest that lactoferrin binding may play an important role in maintaining optimal mononuclear phagocyte function and protecting adjacent tissue from untoward phagocyte-associated hydroxyl radical generation.
Hierarchy of effects of the MHC and T cell receptor beta-chain genes in susceptibility to Theiler's murine encephalomyelitis virus-induced demyelinating disease.
Authors: Kappel C A , Dal Canto M C , Melvold R W , Kim B S 
Published: December 2022

Abstract
Intracerebral inoculation of susceptible mice with Theiler's murine encephalomyelitis virus induces a demyelinating disease that is similar to human multiple sclerosis. This murine model for human multiple sclerosis is apparently immune-mediated and the genes involved in the immune response influence the outcome of disease susceptibility as observed with human multiple sclerosis. These genes include the MHC and TCR genes. However, the functional relationships among these genes on the disease susceptibility has not yet been studied. In this study, we demonstrate that the effect of the H-2s genotype from susceptible SJL/J mice overrides the resistant effect of the BALB/c TCR beta-chain gene in CXJ recombinant-inbred and BALB.S congenic mice. These results strongly suggest the presence of a hierarchy of genes involved in the immune response in Theiler's murine encephalomyelitis virus-induced demyelinating disease.
Immunobiology of infection with recombinant vaccinia virus encoding murine IL-2. Mechanisms of rapid viral clearance in immunocompetent mice.
Authors: Karupiah G , Woodhams C E , Blanden R V , Ramshaw I A 
Published: December 2022

Abstract
CD8+ cytotoxic T (Tc) lymphocytes mediate recovery from vaccinia virus (VV) infection. In mice, anti-VV Tc cells are detectable on or after day 3 after infection, and cytolytic activity peaks between days 5 and 6. A rVV encoding murine IL-2, VV-hemagglutinin (HA)-IL-2, was cleared more rapidly, compared with a control rVV, VV-HA-thymidine kinase (TK), from tissues of infected euthymic normal mice. The mechanism of VV-HA-IL-2 clearance was operative early in infection and correlated with an elevated NK cell response, before the induction of anti-VV Tc cell response. We have investigated the roles of NK cells, T cells, and IFN-gamma in the rapid clearance of VV-HA-IL-2, by using specific mAb. Depletion of NK cells with mAb significantly enhanced VV-HA-IL-2 but not VV-HA-TK titers 3 days after infection. NK cells alone could not account for rapid viral clearance, because VV-HA-IL-2 titers in NK cell-depleted mice were not comparable to VV-HA-TK titers. Treatment with a mAb to IFN-gamma completely abrogated the IL-2-induced mechanism(s) of VV-HA-IL-2 clearance, and titers of the IL-2-encoding virus were comparable to control virus titers. In addition, the elimination of CD4+ but not CD8+ T cells resulted in significant increases in VV-HA-IL-2 titers.
Activated T lymphocytes from mice infected by lymphocytic choriomeningitis virus display high affinity IL-2 receptors but do not proliferate in response to IL-2.
Authors: Saron M F , Colle J H , Dautry-Varsat A , Truffa-Bachi P 
Published: December 2022

Abstract
The i.v. injection of mice with lymphocytic choriomeningitis virus (LCMV) initiates a rapid and long lasting immunodepression which can be monitored in vivo or in vitro. Splenic T lymphocytes taken from mice infected for 7 days with LCMV are characterized by a low proliferative capacity in response to Con A stimulation in vitro. In an initial attempt to understand the molecular mechanisms regulating the general anergy induced by the viral infection, we have analyzed the transcription of IL-2 and of p55 IL-2R alpha gene, two genes involved in T cell proliferation. IL-2 gene transcripts were hardly detected after Con A activation of spleen cells from LCMV-infected mice. In contrast, the expression of the gene encoding IL-2R alpha chain was induced as in control noninfected cells. In addition, the expression of the p75 IL-2R beta chain was not modified. The transcripts of the IL-2R alpha and of the IL-2R beta genes were normally translated as high affinity. IL-2R were expressed on the membrane of T lymphocytes from LCMV-infected mice. Despite the finding that these receptors could also internalize IL-2, the exogenous addition of this growth factor did not induce cell proliferation, indicating that the virus-induced blockade is multifocal.
New human V beta genes and polymorphic variants.
Authors: Plaza A , Kono D H , Theofilopoulos A N 
Published: December 2022

Abstract
To extend the characterization of the human V beta gene repertoire, we utilized anchored or V beta-specific polymerase chain reaction to generate a large (approximately 200 clones) beta-chain library from the thymus of a single individual. Nine new V beta genes were identified, including single members for two new subfamilies (V beta 22 and 23), two new members of the V beta 5 subfamily, and one new member each for V beta 2, 6, 7, 9, and 12. Full-length sequences were also obtained for the published partial sequences of V beta 3, 5.3, 9.1, and 13.4, and additional nucleotides for V beta 7.1 and V beta 7.2. Based on consensus sequences from multiple clones, apparent allelic variants for six V beta genes (V beta 2.1, 5.3, 7.2, 8.2, 13.4, and 16) were also tentatively identified. Population and family studies for two of these (V beta 2.1 and 16) further confirmed that these V beta were alleles and not separate genes. Nonconservative substitutions in some of these alleles, as well as in previously identified alleles, are located at the hypervariable loops or the framework region. These findings indicate that V beta gene polymorphism appears to be significant in humans and might be the result of selective pressure imposed by conventional Ag (hypervariable loops) or superantigens (framework regions).
Effect of cytokines on switching to IgA and alpha germline transcripts in the B lymphoma I.29 mu. Transforming growth factor-beta activates transcription of the unrearranged C alpha gene.
Authors: Shockett P , Stavnezer J 
Published: December 2022

Abstract
H chain isotype switch recombination is preceded by the appearance of RNA initiating 5' of the specific switch region that will undergo recombination. In an effort to understand the potential function of germline transcripts in switch recombination and whether the regulation of germline transcripts correlates with the regulation of switching, we are studying this process in the murine B lymphoma cell line I.29 mu, which switches, after treatment with bacterial LPS, primarily to IgA and less frequently to IgE. Levels of alpha germline transcripts initiating upstream of alpha switch (S alpha) sequences are elevated in clones of this line that switch well, compared with clones that switch less frequently. Transforming growth factor-beta (TGF-beta) has been shown to increase alpha germline transcripts and switching to IgA expression in LPS-stimulated murine splenic B cells. We now demonstrate that TGF-beta increases LPS-induced switching to IgA by 10-fold at optimal doses and increases the level of alpha germline transcripts 5- to 9-fold in I.29 mu cells. Nuclear run-on analysis shows that this increase is at the level of transcription. Thus, TGF-beta appears to direct switching to IgA by inducing transcription from the unrearranged S alpha-C alpha DNA segment. Germline alpha RNA is quite stable in I.29 mu cells, having a half-life of about 5 h, and we find no evidence for further stabilization in the presence of TGF-beta. Levels of epsilon germline transcripts are decreased by TGF-beta treatment. IL-4, which modestly increases switching in I.29 mu cells, slightly increases transcription of alpha germline RNA. IFN-gamma, which reduces switching to IgA in these cells, also reduces the level of alpha germline transcripts. IFN-gamma also reduces the level of epsilon germline transcripts induced by IL-4. Our results support the hypothesis that the regulation of transcription of particular switch sequences by cytokines regulates the specificity of recombination. We also present evidence that IL-4 may provide other signals, distinct from transcriptional targeting, that increase LPS-induced switching to IgA.
Abnormal thymocyte development and production of autoreactive T cells in T cell receptor transgenic autoimmune mice.
Authors: Zhou T , Bluethmann H , Eldridge J , Brockhaus M , Berry K , Mountz J D 
Published: December 2022

Abstract
Development of a C57BL/6-+/+ TCR transgenic mouse containing the rearranged TCR alpha- and beta-chain specific for the Db + HY male Ag results in production of a nearly monoclonal population of early thymocytes expressing the Db + HY reactive TCR. These thymocytes are autoreactive in H-2Db male mice and undergo clonal deletion and down-regulation of CD8. To study the effect of the lpr gene on development of autoreactive T cells, these transgenic mice were backcrossed with C57BL/6-lpr/lpr mice. T cell populations in the thymus and spleen were analyzed by three-color flow cytometry for expression of CD4, CD8, and TCR. The thymus of TCR transgenic H-2b/b lpr/lpr male mice had an increase in percent and absolute number of CD8dull thymocytes compared to TCR transgenic H-2b/b +/+ male mice. However, there was not a complete defect in clonal deletion, because clonal deletion and down-regulation of CD8 was apparent in both +/+ and lpr/lpr H-2Db HY+ male mice compared to H-2Db HY- female mice. The phenotype of splenic T cells was almost identical in TCR transgenic +/+ and lpr/lpr males with about 50% CD4-CD8- T cells and 50% CD8+ T cells. However, there was a dramatic increase in the SMLR proliferative response of splenic T cells from TCR transgenic lpr/lpr males compared to TCR transgenic +/+ males. To determine the specificity of this response, spleen cells from TCR transgenic lpr/lpr and +/+ mice were cultured with irradiated H-2b/b and H-2k/k male and female spleen cells. T cells from TCR transgenic C57BL/6-lpr/lpr male mice had an increased proliferative response to H-2b/b male spleen cells compared to T cells from TCR transgenic C57BL/6(-)+/+ male mice, but both lpr/lpr and +/+ mice had a minimal response to irradiated H-2b/b female or H-2k/k male or female stimulator cells. The splenic T cells from TCR transgenic lpr/lpr mice also had an increased specific cytotoxic activity against H-2b/b male target cells compared to TCR transgenic +/+ mice. These results demonstrate that there is a defect in negative selection of self-reactive T cells in the thymus of lpr/lpr mice and a defect in induction or maintenance of clonal anergy of self-reactive T cells in the periphery of lpr/lpr mice.
Tumor necrosis factor production in HIV-seropositive subjects. Relationship with lung opportunistic infections and HIV expression in alveolar macrophages.
Authors: Israël-Biet D , Cadranel J , Beldjord K , Andrieu J M , Jeffrey A , Even P 
Published: December 2022

Abstract
We have evaluated the TNF production by alveolar macrophages (AM) in 43 HIV-infected subjects in relation with 1) their clinical and biologic status; 2) the presence of lung opportunistic infections (OI); and 3) the expression of HIV by AM. This production was assessed in a standard chromium release test, using monocytic U937 cells as targets. The spontaneous TNF production by AM from patients without lung OI was higher than that from seronegative controls (p less than 0.02). This production by AM was similar to that of blood monocytes, suggesting that it was not related, in these subjects, to any particular lung status. The extent of TNF release by AM was correlated to the presence of a lymphocytic alveolitis (p less than 0.05), and not to the patients' clinical presentation nor to their CD4 cell count. Finally, AM from these subjects could be normally stimulated in vitro by IFN-gamma. On the other hand, it appeared that the spontaneous TNF release by AM shown in vitro to express HIV (p24+ AM) was significantly higher than that by their p24- counterparts (p less than 0.05) and by controls (p less than 0.01). In addition, contrasting with the marked increase of TNF release by p24- AM after their stimulation with IFN-gamma (p less than 0.001), p24+ AM appeared to be refractory to any stimulation by IFN, arguing for their activation in vivo. Finally, the spontaneous TNF release by AM was significantly increased during lung OI, compared with controls (p less than 0.01) as well as with AIDS patients without OI (p less than 0.01). In addition, the production of TNF by AM in these subjects was higher than that by the corresponding blood monocytes (p less than 0.02), suggesting a compartmentalization of this response within the lungs. In conclusion, it appears that the TNF production by AM of seropositive patients is highly related to the presence of lung OI as well as to the expression of HIV by these cells. In the context of the up-regulation of HIV expression induced by TNF in vitro, our data could suggest that the in vivo release of TNF by AM could participate in viral dissemination. Moreover, we hypothesize that the generation of activated AM refractory to any further stimulation could in turn lead to the development of additional pulmonary infections.
Platelet-activating factor produces shock, in vivo complement activation, and tissue injury in mice.
Authors: Sun X M , Hsueh W 
Published: December 2022

Abstract
We previously showed that TNF and endotoxin (LPS) synergize to activate the complement system and produce shock and bowel injury in normal mice. However, C5-deficient mice were protected from these adverse effects. In this study, we show that in mice, platelet-activating factor (PAF) antagonist prevents TNF- and LPS-induced complement activation, bowel injury, and death, indicating that PAF mediates the actions of TNF and LPS. We then examined the role of the complement system in PAF-induced shock and tissue injury. We found that 1) PAF (3 micrograms/kg) induces shock, hemoconcentration, bowel necrosis, and death in normal mice, whereas C5-deficient mice are protected from these effects. (Protection was abrogated when the dose of PAF was raised to 5 micrograms/kg.) Furthermore, when C5-deficient mice were reconstituted with normal serum, they also developed shock, bowel injury, and death in response to PAF. Thus, C5 is required for PAF to induce injury. 2) PAF activates the complement system in vivo, but not in vitro. The mechanism of complement activation by PAF is unclear. Inasmuch as PAF stimulates neutrophils to release protease that may activate the complement system, we examined the effect of neutrophil depletion on PAF-induced injury and complement activation. We found that neutrophil depletion fails to prevent PAF-induced complement activation, although PAF-induced lethality is much reduced. We conclude that PAF causes complement activation, and acts in synergy with active complement fragments to produce shock and tissue injury. Neutrophils probably do not play the pivotal role in PAF-induced complement activation.
IL-10: a novel cytotoxic T cell differentiation factor.
Authors: Chen W F , Zlotnik A 
Published: December 2022

Abstract
A previous report concluded that a new cytokine, designated IL-10, is a growth cofactor for thymocytes, spleen, and lymph node cells. In this report, we have focused on the effects of IL-10 on CD8+ spleen T cells. We first observed that IL-10 enhances the growth of CD8+ T cells to IL-2. We then investigated the effect of murine rIL-10 on the induction of murine effector CTL from CTL precursors (CTL-p) using both bulk and filler cell-free limiting-dilution cultures. IL-10 alone could not induce Con A-activated FACS-sorted CD8+ T cells either to proliferate or to generate effector CTL. In combination with IL-2, however, IL-10 augmented the cytolytic activity of effector CTL generated from Con A-activated spleen CD8+ T cells in bulk cultures incubated for 5 days. In limiting-dilution cultures (using solid-phase anti-CD3 mAb as stimulus), IL-10, in combination with IL-2, substantially increased the CTL-p frequency and augmented the cytolytic activity per clone expanded from one CD8+ T cell when compared with cells cultured in IL-2 alone. Kinetic studies showed that IL-10 is required at both early and late culture stages for optimal generation of effector CTL. The potentiating effects of IL-10 on CTL function were neutralized by an anti-IL-10 mAb. These results indicate that IL-10 has direct effects on mature T cells, and suggest that IL-10 also functions as a cytotoxic T cell differentiation factor, which promotes a higher number of IL-2-activated CTL-p to proliferate and differentiate into effector CTL. In contrast, IL-10 did not enhance significantly the lymphokine-activated killer cell activity of IL-2-grown CD8+ cytotoxic T cells.