bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anti-C5a receptor antibodies. Characterization of neutralizing antibodies specific for a peptide, C5aR-(9-29), derived from the predicted amino-terminal sequence of the human C5a receptor.
Authors: Morgan E L , Ember J A , Sanderson S D , Scholz W , Buchner R , Ye R D , Hugli T E 
Published: December 2022

Abstract
Results obtained indicate that a site-directed polyclonal antibody specific for a synthetic peptide based on the predicted amino-terminal sequence of human C5aR (anti-C5aR(9-29)) is capable of binding to both normal human and transfected cells bearing C5aR. Flow cytometric analysis of stable murine L cell transfectants (C5aR-neo), human neutrophils, and human monocytes indicated that these cells bound anti-C5aR(9-29) in a specific manner. Moreover, F(ab')2 fragments of anti-C5aR(9-29) specifically neutralized proinflammatory and immunoregulatory activities induced by natural human C5a. This antiserum was found to block, in a dose-dependent manner, 1) zymosan-induced neutrophil chemotaxis, 2) C5a-induced enzyme release from neutrophils, and 3) C5a-induced cytokine production (IL-6 and IL-8) from human monocytes in vitro. These results suggest that this site-directed polyclonal antiserum specifically interacts with the human C5aR molecule. To the best of our knowledge, none of the existing reports in the literature provided evidence for a site-directed antiserum to C5aR that was capable of specifically blocking C5a-mediated inflammatory/immunoregulatory activities in vitro. Studies conducted with anti-C5aR(9-29) indicated that this antiserum effectively blocked C5a-mediated cell activation but by itself did not activate either neutrophils or monocytes. Combined, these data suggest that this antiserum does not interact with the C5a "effector" site but sterically interferes with C5a binding to its receptor by interacting with the extracellular amino-terminal region of the receptor.
Immunotherapy with human monoclonal antibodies. Fragment A specificity of polyclonal and monoclonal antibodies is crucial for full protection against tetanus toxin.
Authors: Lang A B , Cryz S J , Schürch U , Ganss M T , Bruderer U 
Published: December 2022

Abstract
To investigate the feasibility of substituting human mAb (HmAb) for human polyclonal preparations in the treatment of infections, we employed anti-tetanus toxin (TT) as a model system. We established a large panel of hybridomas secreting anti-TT HmAb and compared their fine specificities and protectivity with those exhibited by tetanus immune globulin (TIG). Analysis of three different commercial TIG preparations indicated that the majority of anti-TT antibodies is directed against epitopes expressed by the A fragment, the L chain of TT. Absorption of TIG with purified A fragment completely abolished its protective capacity in mice. Absorption with C fragment, the carboxy-terminal portion of the H chain of TT, had no discernible effect, illustrating the crucial importance of anti-A fragment antibody. The vast majority of more than 100 generated TT-specific HmAb showed specificity for the A fragment. Six HmAb with significant neutralizing activity were identified and further characterized. Five of them recognized the A fragment, whereas one, ST12, bound to both the A fragment and the C fragment with equal affinity. ST12 by itself conferred long lasting protection against TT intoxication when singly administered, and the remainder mediated only a delayed death. ST12 conferred a protection of 13.2 IU/100 micrograms IgG. However, when individual HmAb were combined, synergistic effects were observed. Optimal potency (43 IU/100 micrograms IgG) was obtained with a combination of two HmAb. To obtain a 250-IU dose, only 0.7 mg of this mixture was required in contrast to 100 to 170 mg IgG for TIG.
Evidence for excessive Th2 CD4+ subset activity in vivo.
Authors: Field E H , Noelle R J , Rouse T , Goeken J , Waldschmidt T 
Published: December 2022

Abstract
Although distinct Th1 and Th2 CD4+ subsets are apparent in in vitro studies, controversy exists over whether these subsets occur functionally in vivo. We describe a patient whose presenting laboratory features of elevated IgG4 and IgE and eosinophilia suggested high levels of IL-4 and IL-5 and in vivo expansion of the CD4+ Th2 subset. Anti-CD3-activated patient PBL induced heightened levels of IgG4 and IgE from normal B cells, indicating that the patient's abnormal Ig isotypes were T cell driven. Stimulated PBL from the patient secreted more IL-4, compared with control PBL, but similar levels of IFN-gamma. Semiquantitative reverse polymerase chain reaction demonstrated that activated PBL from the patient produced higher IL-4 and IL-5, lower IL-2, and similar IFN-gamma mRNA levels, compared with controls. FACS analysis showed that the patient expressed an expanded population of CD4+Leu-8+CD45RA- cells, the memory-effector population, and RNA in situ hybridization confirmed that the CD4+Leu-8+CD45RA- population of the patient was enriched for IL-4-transcribing cells. Moreover, IL-4-transcribing cells outnumbered IFN-gamma-transcribing cells by 2:1 in the memory-effector CD4 population, confirming that Th2 cells exist in vivo within the expanded CD4+Leu-8+CD45RA- population. Taken together, these results provide evidence that Th2 cells exist in vivo and they suggest that the expanded Th2 population produces excessive cytokines that may contribute to the sinopulmonary pathology of the patient.
Where, when, and how to detect biased expression of disease-relevant V beta genes in rats with experimental autoimmune encephalomyelitis.
Authors: Offner H , Buenafe A C , Vainiene M , Celnik B , Weinberg A D , Gold D P , Hashim G , Vandenbark A A 
Published: December 2022

Abstract
The biased use of V beta 8.2 and V beta 6 in rats by encephalitogenic T cells specific for the S72-89 and S87-99 epitopes of guinea pig basic protein (Gp-BP) has allowed the use of anti-V beta antibodies and synthetic TCR peptides for treatment of experimental autoimmune encephalomyelitis (EAE). Striking V gene biases also occur in human autoimmune diseases, raising the question of to what degree these biases reflect potentially pathogenic T cells. To address this question, we evaluated the expression of the EAE-associated marker V beta 8.2 and V beta 6 molecules in the periphery, spinal cord (SC), and cerebrospinal fluid (CSF) during the course of EAE, in unselected, IL-2-expanded, and Gp-BP-restimulated populations. In CSF cells, there was a strong bias for the marker V beta before the onset of EAE, but this bias was not enhanced by IL-2, which skewed the CSF population to &gt; 80% CD8+ T cells. In SC, the marker V beta were expressed optimally during the onset of EAE, even in unselected cells, and this bias could be enhanced sequentially by IL-2 expansion and Gp-BP restimulation. During the recovery phase, however, the marker V beta 8.2 bias was obfuscated by the appearance of a heterogeneous V beta T cell population. Biased expression of the marker V genes was not detected in unselected or IL-2-expanded peripheral cells at any time during EAE. These data suggest that peripheral T cells bearing the disease-relevant V genes first appeared in CSF before disease onset and then migrated to SC beginning on the first day of clinical signs. During the recovery phase of the disease, these cells were diluted by an influx of T cells bearing other V beta genes, requiring restimulation with Gp-BP to observe the V beta 8.2 bias. These data have important implications for the interpretation of V beta gene biases that have been reported in human autoimmune diseases.
Immunosuppression mediated by an inhibitor of S-adenosyl-L-homocysteine hydrolase. Prevention and treatment of collagen-induced arthritis.
Authors: Wolos J A , Frondorf K A , Esser R E 
Published: December 2022

Abstract
The potent irreversible inhibitor of S-adenosyl-L-homocysteine hydrolase (Z)-5'-fluoro-4',5'-didehydro-5'-deoxyadenosine (MDL 28,842) was examined for its effect on the development and treatment of collagen-induced arthritis in mice. We have previously shown that MDL 28,842 inhibits T cell activation without affecting B cell activation. Animals were dosed with MDL 28,842 at 5, 2.5, or 1 mg/kg/day p.o. in water beginning 1 day before immunization with chick type II collagen (CII) and continuing through day 51 postimmunization. None of the animals treated with MDL 28,842 at 5 or 2.5 mg/kg/day developed arthritis compared with 87.5% of the controls. Animals treated with 1 mg/kg MDL 28,842 had a delay in the development of the disease and a decreased incidence of arthritis (55%) during the course of treatment. After the treatment was discontinued, 40% of the mice in the 5-mg/kg treatment group, 60% of the mice who had previously received 2.5 mg/kg MDL 28,842, and 27% of the mice in the 1-mg/kg treatment group remained free of any signs of arthritis. Treatment with MDL 28,842 also lowered serum anti-CII IgG levels. In addition, T cells taken from animals immunized with CII and treated with 2.5-mg/kg/day MDL 28,842 had a lower proliferative response to denatured CII in vitro than controls. Therapeutically, MDL 28,842 was administered to animals at 2.5 mg/kg/day p.o., beginning at the first clinical signs of arthritis and continuing for 4 wk. Over the course of treatment, there was significantly less clinical disease in animals given MDL 28,842. In addition, at the end of treatment, hind paws were removed from the animals and examined radiographically and histologically for joint pathology. Animals treated with MDL 28,842 had significantly fewer bone lesions than control animals. These results suggest that inhibitors of S-adenosyl-L-homocysteine hydrolase may be effective anti-arthritic agents.
Migration of natural killer cells across endothelial cell monolayers.
Authors: Bianchi G , Sironi M , Ghibaudi E , Selvaggini C , Elices M , Allavena P , Mantovani A 
Published: December 2022

Abstract
Under certain conditions, NK cells accumulate rapidly at extrahematic sites. In an effort to define the mechanisms underlying recruitment of NK cells in tissues, we investigated their ability to migrate across endothelial cell (EC) monolayers. A considerable proportion of NK cells adhered to EC and about 30 to 40% of the adherent NK cells migrated across EC. NK cells were two to three times more efficient than resting unseparated T cells but were considerably less efficient than monocytes. Exposure of NK cells to IL-2 or of EC to IL-1, TNF, or IFN-gamma augmented transendothelial migration. mAb directed against CD18 and CD11a inhibited binding and migration of NK cells across resting or IL-1-activated EC, whereas anti-CD11b and c mAb did not. Thus, the LFA-1 pathway is a crucial determinant of the adhesive and migratory interactions of NK cells with vascular endothelium. Using IL-1-activated EC, We found that anti-VLA-4 and anti-VCAM-1 mAb, utilized in concert with anti-CD18, significantly reduced adhesion and transmigration. The CS-1 peptide of fibronectin had no effect on binding and migration but, when used in concert with anti-CD18 and anti-VCAM-1 (but not anti-VLA-4), caused a small, but significant, increase in inhibition. The capacity to bind and migrate across endothelial monolayers underlies the recruitment of NK cells in tissues under certain physiologic and pathologic conditions.
Differential induction of VCAM-1 on human iliac venous and arterial endothelial cells and its role in adhesion.
Authors: Hauser I A , Johnson D R , Madri J A 
Published: December 2022

Abstract
Venous and arterial large vessel endothelial cells (EC) were compared for their constitutive and TNF-alpha-induced expression of the cell-surface adhesion molecules ICAM-1 and -2, VCAM-1 and ELAM-1 by FACS analysis. Human iliac venous and arterial EC (HIVEC and HIAEC) constitutively express ICAM-1 and ICAM-2. TNF-alpha increases the expression of ICAM-1, but not ICAM-2, and induces the expression of ELAM-1 on both EC types. However, TNF-alpha induces VCAM-1 cell-surface expression and mRNA only in venous, but not in arterial EC. We next investigated the function of these adhesion molecules and their ligands, LFA-1, very late activation Ag (WLA-L) and sialylated Lewis x glycoprotein (sLe(x)), in adhesion assays with the monocyte-like cell line U937. Untreated U937 cells do not adhere to untreated HIVEC or HIAEC and adhesion is much lower to TNF-alpha-treated arterial than to TNF-alpha-treated venous EC. In adhesion-inhibition assays we demonstrate that U937 cell adhesion to TNF-alpha-treated HIVEC is mediated by VCAM-1/VLA-4 and ELAM-1/sLe(x) interaction, whereas the lower adhesion to TNF-alpha-treated HIAEC is only mediated by ELAM-1/sLe(x) interaction. U937 cells treated with the phorbol ester PMA for 3 days adhere to both HIVEC and HIAEC; this adhesion is mediated by LFA-1 interaction with ICAM-1 and/or -2. Adhesion of PMA-treated U937 cells is increased by TNF-alpha treatment of EC. This increased adhesion is mediated in part by the TNF-alpha-induced VCAM-1 expression on venous EC. Therefore, the cell-surface adhesion molecule VCAM-1 is differentially induced on these two EC types and the differential expression is functionally important in U937 cell adhesion.
Alloantigen presentation by individual clones of mouse splenic macrophages. Selective expression of IL-1 alpha in response to CD8+ T cell-derived IFN-gamma defines the alloantigen-presenting phenotype.
Authors: McCormack J M , Askew D , Walker W S 
Published: December 2022

Abstract
Approximately one-third of mouse splenic macrophage (M theta) progenitors yield progeny that constitutively present MHC class I alloantigen to naive T cells, a response that is restricted to CD8+ T cells and is elicited in a CD4+ Th cell-independent manner. In addition, both the alloantigen-presenting (alloAP+) and nonpresenting (alloAP-) M theta subsets constitutively express similar levels of MHC class I molecules, and their alloAP phenotypes are unaffected by IFN-gamma, which enhances the expression of both class I and II MHC molecules. We therefore postulated the restricted expression of costimulator molecules to account for the alloAP+ phenotype. Using cytokine-specific antibodies, recombinant mouse cytokines, and polymerase chain reaction analyses (to detect specific cytokine mRNA transcripts), we identified the putative costimulators as IL-1 alpha, IL-6, and TNF-alpha. TNF-alpha transcripts were present in both the alloAP+ and alloAP- M theta subsets, but IL-1 alpha and IL-6 were not constitutively expressed by the alloAP+ subset of M theta; rather, they were induced by IFN-gamma, which was released from naive CD8+ T cells only during coculture with alloAP+ M theta. Although IFN-gamma induced IL-6 gene transcription in both alloAP+ and alloAP- M theta subsets, it induced IL-1 alpha transcripts only in the alloAP+ subset. Finally, CD8+ T cells exposed to alloAP- M theta were unresponsive when subsequently cultured with alloAP+ M theta. We conclude that the ability of some M theta to elicit IFN-gamma from CD8+ T cells and to respond to this cytokine by producing IL-1 alpha defines the alloAP phenotype of the cell population, and that alloAP- M theta induce a state of alloantigen-specific tolerance in naive CD8+ T cells.
Polymorphism in the mouse Tap-1 gene. Association with abnormal CD8+ T cell development in the nonobese nondiabetic mouse.
Authors: Pearce R B , Trigler L , Svaasand E K , Peterson C M 
Published: December 2022

Abstract
Tap-1 and Tap-2 genes code for a heterodimeric peptide transporter required for the normal maturation and surface expression of class I molecules. Polymorphic variants of these MHC encoded genes occur in rats and humans. After failing to amplify a 3' polymerase chain reaction (PCR) product from thymic and splenic cDNA of the nonobese nondiabetic (NON) strain, we considered it possible that Tap-1 polymorphism was present, since cDNA from CBA/J, C57BL/6, BALB/c, and NOD (nonobese diabetic) mice all yielded Tap-1 3' products. Overlapping PCR fragments spanning the highly conserved ATP-binding cassette (ABC) were generated for purposes of restriction endonuclease analysis, studies of IFN-gamma regulation, and sequencing. To avoid amplifying other members of the transporter family, we used a gel-purified 1670-bp Tap-1 PCR "long product" as template for nested PCR. Sequencing revealed three polymorphic alleles. The most divergent was for the NON strain and involved two non-conserved amino acid substitutions (Arg--&gt;Cys397 and Leu--&gt;Arg491) and three silent mutations. NON mice show an abnormal pattern of class I (Kb) expression and a sizeable reduction in the percentage of CD8+ cells in the blood and thymus. In F2 segregants, the low CD8 phenotype mapped to the MHC. Tap-1 genes of NON and C57BL/6 mice were equally sensitive to up-regulation by IFN-gamma. We conclude that the mouse Tap-1 transporter gene, like the Tap-2 of the rat and the Tap-1 and Tap-2 of the human, is polymorphic. The extensive variation and specific codon changes of Tap-1 in the NON mouse raise the possibility that this gene is the MHC locus responsible for altering the intrathymic development of CD8+ T cells.
Impairment and delay of neutralizing antiviral antibody responses by virus-specific cytotoxic T cells.
Authors: Battegay M , Moskophidis D , Waldner H , Bründler M A , Fung-Leung W P , Mak T W , Hengartner H , Zinkernagel R M 
Published: December 2022

Abstract
After infection with some viruses that tend to persist, neutralizing antibodies are generated rather late, i.e., after 1 to 3 mo. This has been observed for HIV, Hepatitis B infection in man, or after infection with lymphocytic choriomeningitis virus (LCMV) in mice. In contrast, nonneutralizing antibodies to LCMV are generated by day 7 and reach high titers by day 10. This study attempts to evaluate reasons for late and low titered neutralizing antibody responses. After a primary infection with low doses (10(2) plaque forming units) of the poorly cytopathic LCMV-WE, neutralizing antibodies were rarely produced at detectable levels before days 60 to 120. In vivo depletion of CD8+ CTL led to a marked enhancement and acceleration of kinetics of the neutralizing antibody response. In contrast, nonneutralizing antibodies, including those specific for LCMV-GP carrying the neutralizing determinant, were detectable very early, i.e., 4 to 7 days after infection, with maximum titers usually by day 10 irrespective of the presence or absence of CTL. Mice completely lacking CD8+ T cells because of deletion by homologous recombination (CD8-/-) also exhibited neutralizing antibodies early by day 10 to 20, and by day 120 reached very high titers. The neurotropic isolate LCMV-ARMSTRONG induced low but significant titers of neutralizing antibodies relatively early (i.e., by days 7 to 10), whereas the lympho-viscerotrope mutant virus LCMV-ARMSTRONG Cl-13 did not. Early and effective CTL responses causing immunopathology (and immunosuppression) correlated with the absence of neutralizing antibodies. The discrepancy between the CTL-dependent inhibition of neutralizing versus unimpaired anti-GP ELISA responses cannot be explained by different Ag doses alone. Additionally, it may reflect different kinetics of the responses, whereby the later neutralizing responses possibly requiring IgG affinity maturation may be more susceptible to general immunosuppression; also B cells expressing neutralizing receptors, but not those with antibodies binding GP (or NP), may be actively infected, therefore they present viral peptides on class I MHC Ag and may become targets for anti-LCMV-specific CTL.
Role of acyl residues in polyclonal murine B cell activation by acylpoly(1,3)galactosides from Klebsiella pneumoniae.
Authors: Hmama Z , Lina G , Normier G , Binz H , Revillard J P 
Published: December 2022

Abstract
Several components of Klebsiella pneumoniae including a membrane proteoglycan (Kp-MPG) were reported to activate macrophages and to induce T-independent polyclonal activation of mouse B cells. Chemically defined derivatives of Kp-MPG were prepared and characterized, enabling us to approach the molecular substructures involved in the binding to lymphocytes and the activation of B cells. Five derivatives were characterized: (i) an acylpoly(1,3)galactoside containing ester-linked fatty acids (EFA-APG) which was obtained by mild alkaline hydrolysis, (ii) a polymer of EFA-APG (APG pol1), (iii) a preparation obtained by drastic alkaline hydrolysis and delipidation which removed the esterified fatty acids (APG), (iv) a polymer of the latter compound (APG pol2), and (v) an APG preparation submitted to mild acid hydrolysis which removed all fatty acids but left the galactose chain of APG (GC-APG) intact. The derivatives were studied for their capacity to bind to and to activate mouse splenocytes. Binding was investigated on BALB/c and C3H/HeJ splenocytes by indirect immunofluorescence using biotinylated F(ab')2 of anti-Kp-MPG antibodies and the streptavidin-phycoerythrin amplification system in flow cytometry and by competition of unlabeled APG with biotinylated APG. Activation was studied by measuring (i) [3H]thymidine incorporation into spleen cells from BALB/c, C3H/HeJ, nude (nu+/nu+) mouse strains, and purified B cells of BALB/c; (ii) immunoglobulin secretion in culture supernatants; and (iii) blastogenesis. The results demonstrate a specific uptake of EFA-APG and APG by T cells as well as by B cells and exclude a contribution of the polygalactose part of the APG molecule (GC-APG) to the binding to spleen lymphocytes. Unlike LPS from the same strain of K. pneumoniae, APG pol1 stimulated B cell activation in the LPS-resistant C3H/HeJ strain as well as in BALB/c mice. The compounds did not activate T cells and were T-independent B cell activators, stimulating nu+/nu+ spleen cells and inducing primarily IgM and IgG3 synthesis. Polymers were more potent activators than monomers and removal of ester-linked fatty acids completely abrogated B cell-activating properties. The monomer APG antagonized B cell activation by Kp-MPG, LPS from K. pneumoniae, and APG pol1. The data indicate that within the EFA-APG molecule, distinct substructures are required for binding and for triggering B cell response.
Trypanosoma cruzi acidic ribosomal P protein gene family. Novel P proteins encoding unusual cross-reactive epitopes.
Authors: Skeiky Y A , Benson D R , Guderian J A , Sleath P R , Parsons M , Reed S G 
Published: December 2022

Abstract
We have cloned and characterized cDNA molecules that encode members of the acidic ribosomal protein family (TcP proteins) from the protozoan parasite Trypanosoma cruzi. These proteins have been shown to be antigenic in individuals with T. cruzi infection. Unlike other known eukaryotic cells, T. cruzi possesses at least four types of P protein genes TcP0, TcP1, TcP2a, and TcP2b, each of which is present in multiple copies in the genome. These genes are present on at least three different chromosomes. Although the abundance of TcP0, TcP2a, and TcP2b transcripts do not appear to vary among the parasite life-cycle stages, TcP1 is predominantly expressed in the epimastigote (insect) stage. TcP0 has a C-terminal heptapeptide sequence that is similar to those of archaebacterial acidic (P-like) proteins, but the TcP1/P2 proteins terminate with a shared sequence characteristic of the P proteins of higher eukaryotes. The serine residues or other potential phosphorylation sites typically found within the highly charged C-terminal acidic domain are absent in T. cruzi P proteins. Using synthetic peptides, we demonstrated that approximately 80% of T. cruzi-infected individuals produce two distinct but cross-reactive anti-P antibody specificities directed against the C-termini of TcP0 and TcP1/P2. We also expressed the full length (non-fusion) recombinant human P0 and demonstrated that the T. cruzi anti-P antibodies cross-react with the C-terminal residues of human P-proteins. Conversely, human anti-P protein antibodies in sera from patients with SLE cross-react with the C-terminal epitope of T. cruzi TcP1/P2 proteins. The cross-reactivity of anti-TcP antibodies with human P proteins suggests that, through antigenic conservation, TcP proteins may contribute to the development of autoreactive antibodies in Chagas' disease patients.