bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immune responses of intact and embryonically enucleated frogs to self-lens antigens.
Authors: Rollins-Smith L A , Parsons S C , Cohen N 
Published: January 2023

Abstract
Embryonically enucleated frogs (Xenopus) will tolerate an isogeneic eye implanted during adult life although their immune system has never been previously exposed to eye-specific Ag. We hypothesized that such self-implants survive because they induce tolerance to the eye-specific Ag. We have developed evidence to support this hypothesis by studying the responses of embryonically enucleated or intact frogs, with or without eye implants, to self-lens proteins. After immunization with a low concentration of bovine lens proteins, spleen cells from all intact and all embryonically enucleated frogs displayed significant in vitro proliferation against the Ag. All animals in both groups of frogs also produced high titered xenoantibodies. After immunization with a comparable preparation and concentration of self-lens Ag, splenocytes from only some of the embryonically enucleated and intact frogs showed significant proliferation, and fewer of these frogs produced antibody. When the immunization protocol and Ag concentration were modified to evoke consistent anti-self-lens proliferative and antibody responses from enucleated frogs, intact frogs responded equally well. Because there were no significant differences in the magnitude of the responses, and the percent of enucleated and intact frogs responding did not differ, we conclude that there is little or no immunologic tolerance to self-lens Ag in intact frogs. When either embryonically enucleated or intact frogs were heterotopically implanted with isogeneic eyes and then immunized with self-lens Ag or foreign lens Ag using the optimal immunization protocol, the Ag-specific proliferative responses of their lymphocytes were significantly reduced after immunization with self-, but not foreign Ag. This argues that embryonically enucleated frogs can become tolerant of the organ-specific Ag of the lens, even in adult life.
Synergistic effect of murine cytomegalovirus on the induction of acute graft-vs-host disease involving MHC class I differences only. Analysis of in vitro T cell function.
Authors: Via C S , Shanley J D , Shearer G M 
Published: January 2023

Abstract
The development of acute graft-vs-host disease (GVHD) is a common outcome after the injection of fully MHC disparate parental T cells into unirradiated F1 mice. Murine cytomegalovirus (MCMV) infection has been previously shown to augment the development of acute GVHD in the parent-into-F1 (P----F1) model, such that 10-fold fewer parental cells are required. In the present study, we have investigated the effect of MCMV infection on the induction of non-lethal GVHD that occurs in P----F1 combinations involving MHC class I only or class II only differences. Using P----F1 combinations involving either an H-2K only difference or an H-2D only difference, MCMV infection of F1 mice 3 days before the injection of parental spleen cells led to a profound T cell immunodeficiency that strongly resembled that observed in acute GVHD. Further studies examining the H-2K disparate P----F1 combination, C57Bl/6---- (C57Bl/6xB6.C-H-2bm1) F1 and combined MCMV infection showed that the immunodeficiency is characterized by a profound loss of in vitro Th cell production of IL-2 and an intrinsic defect in T effector function as shown by an inability of rIL-2 to restore defective CTL responses. Additional experiments in these mice revealed the presence of suppressor cells as well as significant parent-anti-F1 CTL activity possibly accounting for the suppressor effect. This pattern of immunodeficiency was not seen after the administration of either MCMV or MHC class I disparate parental cells alone. MCMV infection did not detectably alter the immunodeficiency observed in a P----F1 combination involving a MHC class II difference only. These results indicate that MCMV infection can alter the pattern of GVHD in the setting of an MHC class I disparity, but not in the setting of class II disparity, such that it resembles acute GVHD. These results may have relevance to the human transplant setting where intercurrent CMV infection has been associated with an adverse clinical outcome.
Topology of receptor binding domains of mouse IFN-gamma.
Authors: Jarpe M A , Johnson H M 
Published: January 2023

Abstract
IFN-gamma is an essential immunoregulatory lymphokine for a variety of immunologic functions including upregulation of MHC Ag. The elucidation of the structure, particularly the receptor binding domains, should further enhance our understanding of its mechanism of action, and provide a rational basis for modulation of its activity by alteration of its structure. A predicted model of murine IFN-gamma structure has been constructed based on data derived from our synthetic peptide studies, circular dichroism spectra, and predictive algorithms for secondary structure, surface accessibility, and tertiary structure, as well as predicted structural similarities to IL-2. Direct synthetic peptide competition studies using five overlapping peptides that encompassed the entire IFN-gamma sequence of 133 amino acids showed that only the N-terminus of IFN-gamma, IFN-gamma(1-39), blocked binding to receptor, suggesting that the N-terminus is directly involved in receptor binding. Rabbit antibodies to the N-terminal (IFN-gamma(1-39)) and C-terminal (IFN-gamma(95-133)) peptides neutralized IFN-gamma activity, whereas antibodies to the three peptides that spanned the internal region, sequence 36-107, were without effect. Thus, the antibody data support the involvement of the N-terminus as a receptor binding domain and also suggest that the C-terminus of the molecule is also a binding domain. Predictive algorithms assign six alpha-helices and five turns to the molecule and circular dichroism spectra of both intact human and murine IFN-gamma and synthetic peptides of murine IFN-gamma showed that the molecule is mainly alpha-helical in structure. Drawing mainly on the four alpha-helix bundle model, a common motif in globular proteins such as IFN-gamma and IL-2 (whose crystalline structure is known), we constructed a simple model of the tertiary structure of IFN-gamma that fits well with our synthetic peptide and circular dichroism data. The model consists of the four-alpha-helical bundle along with N- and C-terminal helices that are predicted to be closely associated and together form the receptor binding domains. The model presented should contribute to further understanding the molecular basis of IFN-gamma action and allow us to begin modulating the function of IFN-gamma through the design of agonists and antagonists.
The kinetics of gene expression and maturation of IL-1 alpha after induction with the surface coat of Trypanosoma brucei rhodesiense or lipopolysaccharide.
Authors: Mathias S , Perez R , Diffley P 
Published: January 2023

Abstract
The purpose of this study was threefold: to determine if the variant surface coat glycoprotein (VSG) of Trypanosoma brucei rhodesiense induces IL-1 alpha; to study the kinetics of IL-1 alpha transcription, maturation and secretion; and to compare VSG to LPS in its ability to induce IL-1 alpha. VSG was added to cultures of the P388D1 murine macrophage cell line. RNA was dotted onto nitrocellulose and hybridized with a murine IL-1 alpha cDNA probe. Maximal production of IL-1 alpha mRNA occurred in a dose- and time-dependent manner, peaking at 25 micrograms/ml VSG, within 2 h. Induction of IL-1 alpha was not due to contaminants because 1) absorption of VSG with a mAb abrogated IL-1 alpha mRNA synthesis, 2) the addition of polymyxin B did not affect mRNA levels, and 3) cellular IL-1 alpha was detectable in VSG-treated splenocytes from endotoxin nonresponder C3H/HeJ mice. Murine splenic macrophages also had enhanced levels of IL-1 alpha mRNA after administration of VSG in vivo or during an acute infection. Antiserum generated against the synthetic peptide SGDDSKYPV (amino acids 177-185 from the murine IL-1 alpha sequence) was used to measure the levels of the 33-, 22-, and 14-kDa proteins in cell lysates and medium of VSG-stimulated P388D1 cells. The 22-kDa protein was the predominant cellular form until secretion started. Secretion of the 14-kDa form began abruptly 6 to 8 h after the addition of VSG. By 12 h, the 33-kDa precursor was the major cytoplasmic form. In comparative analyses, LPS-stimulated P388D1 cells produced more transcript, generated peak levels of 22-kDa protein 3 h earlier, and began to secrete the 14-kDa molecule 5 h earlier. The rate of IL-1 alpha accumulation in the medium was linear between 6 and 24 h after LPS treatment, but began to drop by 8 h in VSG-treated cells. Functional (comitogenic) IL-1 activity was also detected in media from VSG-treated splenic macrophages and P388D1 cells. Activity peaked at 50 micrograms/ml and was lost if 0.2% IL-1 antisera were added to the cultures.
Syrian hamsters express diverse MHC class I gene products.
Authors: Watkins D I , Chen Z W , Hughes A L , Lagos A , Lewis A M , Shadduck J A , Letvin N L 
Published: January 2023

Abstract
MHC class I glycoproteins are highly diverse in most species. The Syrian hamster has long been thought to express monomorphic MHC class I molecules and thus be an exception to this rule. Here we show that Syrian hamsters express diverse MHC class I gene products. The nucleotide sequences of the alpha 1 and alpha-2 domains of classical Syrian hamster MHC class I molecules are highly variable and show evidence of having been under selective pressures at their Ag recognition sites. Interestingly, none of the Syrian hamster class I genes was closely related to their counterparts in the mouse. These observations suggest that Syrian hamsters in the wild may express diverse MHC class I molecules.
Regulation of Ig H chain gene transcription by IL-5.
Authors: Yuan D , Dang T , Sanderson C 
Published: January 2023

Abstract
Stimulation of B lymphocytes to high rate Ig secretion is accompanied by increased RNA polymerase initiation on the mu-delta gene complex as well as alterations in the sites of polymerase termination. Stimulation of Ig secretion by in vivo preactivated B lymphocytes with IL-5 seems to operate via a mechanism that only affects polymerase termination so that newly synthesized transcripts are preferentially processed to microS mRNA. The absence of increased polymerase initiation may account for previous observations indicating that IL-5 acts primarily as a terminal differentiation factor.
Regional and systemic distribution of anti-tumor x anti-CD3 heteroaggregate antibodies and cultured human peripheral blood lymphocytes in a human colon cancer xenograft.
Authors: Nelson H , Ramsey P S , Kerr L A , McKean D J , Donohue J H 
Published: January 2023

Abstract
Anti-tumor antibody (317G5) covalently coupled to an anti-CD3 antibody (OKT3) produces a heteroaggregate (HA) antibody that can target PBL to lyse tumor cells expressing the appropriate tumor Ag. The i.v. and i.p. distribution of radiolabeled HA antibody 317G5 x OKT3 and of radiolabeled cultured human PBL were studied in athymic nude mice bearing solid intraperitoneal tumor established from the human colon tumor line, LS174T. Mice were injected with 125I-labeled HA antibody, 125I-labeled anti-tumor mAb, or 111In-labeled PBL, and at designated timepoints tissues were harvested and measured for radioactivity. 125I-317G5 x OKT3 localized specifically to tumor sites. Tumor radioactivity levels (percent injected dose/gram) were lower with 125I-317G5 x OKT3 HA antibody than with 125I-317G5 anti-tumor mAb, but were similar to levels reported for other anti-tumor mAb. The major difference in radioactivity levels observed between i.v. and i.p. administration of 125I-317G5 x OKT3 was an increase in hepatic radioactivity after i.v. HA antibody administration. HA antibodies produced from F(ab')2 fragments, which exhibit decreased m. w. and decreased Fc receptor-mediated binding, demonstrated improved tumor:tissue ratios as compared to intact antibody HA. 125I-317G5 F(ab')2 x OKT3 F(ab')2 antibody levels were equivalent to intact HA antibody levels in tumor, but were lower than intact HA antibody levels in the blood, bowel, and liver. Tumor:bowel ratios (20:1 at 48 h) were highest when 317G5 F(ab')2 x OKT3 F(ab')2 was injected i.p. Autoradiography confirmed that anti-tumor x anti-CD3 HA antibodies localized specifically to intraperitoneal tumor; that i.p. administered HA antibodies penetrated tumor directly; and that i.v. administered HA antibodies distributed along tumor vasculature. Cultured human PBL distributed in moderate concentrations to intraperitoneal tumor when administered i.p., but not when administered i.v. The poor localization of i.v. injected PBL to tumor may reflect species disparity in homing receptors and/or endothelial ligands, a problem which may be overcome with a syngeneic model. These results suggest that regional therapy with HA antibodies and PBL may offer advantages over systemic therapy for initial clinical trials.
T cell responses specific for subregions of allogeneic MHC molecules.
Authors: Berkowitz N , Braunstein N S 
Published: January 2023

Abstract
The repertoire of C3H (H-2k) CD4+ T cells for I-Ab allopolymorphisms was analyzed by studying the responses of unprimed populations of T cells and of I-Ab-specific T cell clones for recombinant MHC molecules containing combinations of polymorphic subregions of the alpha- and beta-chains from the I-Ab and I-Ak molecules. In this system, polymorphisms in the predicted MHC alpha-helices were more potent than polymorphisms in the beta-strands in stimulating unprimed alloreactive T cells. Similarly, 75% of I-Ab-specific T cell clones responded to recombinants containing b polymorphisms in both the alpha- and beta-chains helices and tolerated the substitution of k polymorphisms in the beta-pleated sheet. Furthermore, 20% of the clones responded to a molecule containing allogeneic b residues in just the beta-chain helix. The results demonstrate that the T cell response to allogeneic MHC molecules consists largely of sets of T cells with overlapping specificities for subregions of the MHC molecule. In addition, they highlight the importance of the alpha-helices in these responses and a diminished role for polymorphisms in the beta-strands when, as in the present case, MHC structure and conformation is tolerant of beta-sheet substitutions. These results sharply contrast with observations made in the analysis of Ag-specific T cells and lead to the suggestion that a subset of alloreactive T cells are not peptide specific and can directly recognize MHC polymorphisms.
Increased surface expression of a newly identified 150-kDa dimer early after human T lymphocyte activation.
Authors: Bougeret C , Mansur I G , Dastot H , Schmid M , Mahouy G , Bensussan A , Boumsell L 
Published: January 2023

Abstract
Lymphocyte activation induces or increases the expression of several surface structures, some of which are directly involved in cell growth such as receptors for IL-2 or transferrin. In order to identify new structures characteristic of activated lymphocytes, we developed a series of mAb against functionally defined human T cell clones. In the present study we report the isolation of a mAb termed BB18 recognizing, at the cell surface, a novel 150-kDa glycoprotein dimer whose expression on T lymphocytes increases readily after their activation with various stimuli including lectins. In contrast, in the presence of PMA, cell-surface expression of this 150-kDa structure is down-regulated even earlier than CD3 molecules. Biochemical studies as well as phenotypic analysis revealed that this structure is different from all previously identified molecules on the lymphocyte cell surface. Furthermore, functional studies showed that triggering this disulfide-linked dimer through BB18 epitope in the presence of submitogenic concentrations of PMA induced strong lymphocyte proliferation. This proliferative response require E+ cells and accessory cells, and this even after immobilization of BB18 mAb.
Characterization of a novel rat thymocyte costimulating antigen by the monoclonal antibody 1.3.
Authors: Bristol L A , Finch L , Romm E V , Takács L 
Published: January 2023

Abstract
To define membrane-associated molecules that impart signals for the activation and expansion of double negative (DN) cells, mAb were raised against in vitro-cultured rat DN cells. One such mAb, 1.3, stimulated proliferation of DN cells along with submitogenic concentrations of PMA and IL-2 without affecting the mobilization of Ca2+. The 1.3 mAb precipitated a heterodimeric protein from DN cells and kidney (130/110 kDa). Although the tissue distribution and biochemical characteristics of the 1.3 determinant resemble the neutral aminopeptidase (AP-N) first described as the thymocyte activating molecule in the mouse, other data are contradictory; AP-N message was not detected in mRNA from 1.3 positive cells and the AP-N gene was absent in the genomic DNA from rat DN hybridomas expressing high levels of 1.3 Ag. In addition, the 1.3 mAb did not affect AP-N enzyme activity suggesting that 1.3 mAb does not function through this enzyme to transduce signals for proliferation. Thus, the 1.3 mAb defines a new and important thymocyte costimulating Ag.
In vitro maximum binding of antigenic peptides to murine MHC class II molecules does not always take place at the acidic pH of the in vivo endosomal compartment.
Authors: Nag B , Passmore D , Deshpande S V , Clark B R 
Published: January 2023

Abstract
Presentation of Ag to the T cell requires binding of specific peptide fragments of the Ag to MHC II molecules. The ability of a peptide to bind to MHC class II appears to be pH dependent. Recent reports indicate that the binding of peptide to MHC class II molecules takes place primarily within an endosomal compartment of the cell at around pH 5. In this study, we have explored the in vitro pH dependence of peptide binding to different haplotypes of murine MHC class II molecules. The binding of peptides to MHC II was analyzed and quantitated by silica gel TLC, using radiolabeled peptides. The MBP peptide fragments, MBP(1-14)A4 and MBP(88-101)Y88, bound maximally at pH 8 to IAk and IAs, respectively. The binding of PLP peptide fragment, PLP(138-151)Y138, to IAs was maximal at around neutral pH. The maximum binding of an OVA peptide fragment, OVA(323-340)Y340, to IAd, was found to occur at pH 6. Results presented in this report thus suggest that the in vitro maximum binding of peptide is pH dependent and does not always occur at pH 5. The optimum pH range for maximum binding may depend on the nature and net charge of the peptide and its interaction with MHC class II molecules.
Studies of CD4- CD8- alpha beta bone marrow T cells with suppressor activity.
Authors: Palathumpat V , Dejbakhsh-Jones S , Holm B , Wang H , Liang O , Strober S 
Published: January 2023

Abstract
The predominant T cell subset in the bone marrow of specific pathogen-free C57BL/Ka and BALB/c mice expressed the alpha beta+ TCR CD4- CD8- surface phenotype. Purified C57BL/Ka alpha beta+ TCR CD4- CD8- marrow cells obtained by cell sorting suppressed the MLR of C57BL/Ka responder and BALB/c stimulator spleen cells. Although the percentage of typical T cells in the spleen was markedly reduced in adult nude mice or normal neonatal mice as compared to the normal adult, the percentage of alpha beta+ TCR CD4- CD8- cells in the spleen and marrow was not. The percentage of "self-reactive" V beta 5+ T cells in the BALB/c spleen was markedly reduced as compared to that in the C57BL/Ka spleen. However, the percentages in the bone marrow were similar. The results indicate that the predominant subset of marrow T cells in these pathogen-free mice differ with regard to surface marker phenotype, function, dependence on the adult thymus, and deletion of certain self-reactive V beta receptors as compared to typical spleen T cells. The marrow T cells appear to develop directly from marrow precursors without rearranged beta chain genes during a 48 hour in vitro culture.
A lipoyl synthetic octadecapeptide of dihydrolipoamide acetyltransferase specifically recognized by anti-M2 autoantibodies in primary biliary cirrhosis.
Authors: Tuaillon N , Andre C , Briand J P , Penner E , Muller S 
Published: January 2023

Abstract
Close to 95% of patients with established clinical, biochemical and histologic features of primary biliary cirrhosis (PBC) possess antimitochondrial M2 antibodies reacting with the E2 component, dihydrolipoamide acetyltransferase, of the pyruvate dehydrogenase complex. We examined the ability of synthetic peptides of E2 to be recognized in ELISA by sera from patients with PBC and autoimmune-related disorders. Sera from 14 PBC M2+ patients, 1 PBC M2- patient, 5 non-PBC M2+ patients, and 6 patients with chronic active hepatitis were studied. Among the seven E2 synthetic peptides tested (namely peptides 87-119, 167-184, 169-202, 267-302, 456-477, 498-513 and 530-543), only peptide 167-184 used as OVA conjugate and prepared with lipoic acid (LA) located on lysine 173 (natural inner lipoyl-binding site) was recognized in direct ELISA by PBC M2+ sera. The conjugated peptide 167-184 LA was not recognized in direct ELISA by non-PBC M2+ sera or by sera from patients with chronic active hepatitis. The free peptide 167-184 LA inhibited the ELISA reaction of PBC antibodies to PDH and totally abolished the typical immunofluorescence reaction of PBC sera on rat kidney, stomach and liver, or human HEp-2 cell substrates. No inhibition of ELISA or immunofluorescence reaction was found with the other E2 fragments including peptide 167-184 without LA. Our results show that the lipoyl moiety forms an integral part of a dominant conformational epitope recognized by PBC sera. Inasmuch as the peptide 167-184 LA was not recognized by non-PBC sera in direct ELISA, it could be used as a valuable probe for PBC diagnosis.
The melanoma growth stimulatory activity receptor consists of two proteins. Ligand binding results in enhanced tyrosine phosphorylation.
Authors: Cheng Q C , Han J H , Thomas H G , Balentien E , Richmond A 
Published: January 2023

Abstract
The human melanoma growth-stimulatory activities (MGSA alpha, beta, gamma/GRO) are products of immediate early genes coding for cytokines that exhibit sequence similarity to platelet factor-4 and beta-thromboglobulin. MGSA/GRO alpha has been demonstrated to partially complete for binding to the approximately 58-kDa neutrophil receptor for another beta-thromboglobulin-related chemotactic protein, IL-8. We demonstrate that when [125I]MGSA/GRO alpha was cross-linked to receptors/binding proteins from human placenta, there were two major [125I]MGSA cross-linked bands of approximately 64,000 and approximately 84,000 Mr. Because [125I]MGSA exists primarily in monomer and dimer forms at the concentrations used here, it is not clear whether the receptor/binding proteins represented by the cross-linked bands are approximately 50,000 and approximately 70,000 or approximately 58,000 and approximately 78,000 Mr. Ligand binding to the receptor proteins is associated with enhanced tyrosine phosphorylation of a number of substrates, including proteins in the same Mr range as the MGSA/GRO receptor/binding proteins.