bluuebunny/crossref_metadata_2025_split huggingface dataset:
In vitro priming of tumor-reactive cytolytic T lymphocytes by combining IL-10 with B7-CD28 costimulation.
Authors: Yang G , Hellström K E , Mizuno M T , Chen L 
Published: December 2022

Abstract
Naive spleen cells from syngeneic mice generated tumor-reactive CTL following three cycles of in vitro culturing with IL-10 and cells from the P815 mouse mastocytoma that expressed the B7-1 or B7-2 costimulator. Unpurified as well as CD8-enriched naive splenocytes could be used for priming. The in vitro primed CTL were CD8+, and their recognition was MHC class I restricted. Both IL-10 and B7-transfected P815 cells were required for the priming. However, a combination of exogenous IL-10 and IL-2 in the presence of B7-negative wild-type P815 cells also induced tumor-reactive CTL. Injection of the neutralizing anti-IL-10 mAb JES-2A5 into mice reduced their ability to mount a primary CTL response after immunization with B7-1+ P815 cells, and inclusion of this mAb in the in vitro cultures inhibited a secondary CTL response. Adoptive transfer of the in vitro primed CTL had a therapeutic effect in mice with P815 established as an ascites tumor. Our results underscore an important role of IL-10 in the induction of a tumor-specific CTL response.
N-terminal and central regions of the human CD44 extracellular domain participate in cell surface hyaluronan binding.
Authors: Liao H X , Lee D M , Levesque M C , Haynes B F 
Published: December 2022

Abstract
CD44 molecules are cell surface receptors for hyaluronan (HA). To define regions of the extracellular domain of CD44 that are important for HA binding, we have studied the ability of HA-blocking CD44 mAbs to bind to CD44 from a variety of sources. Five CD44 mAbs (5F12, BRIC235, 3F12, BU-75, and HP2/9) of 21 studied were identified that at least partially blocked FITC-labeled HA (HA-FITC) binding to the standard form of CD44 (CD44S) in CD44-transfected Jurkat cells. Analysis of reactivity of HA-blocking CD44 mAbs defined three distinct epitopes. Lack of reactivity of mAb 5F12 with a CD44 fusion protein (CD44-Rg) containing an N-terminal truncation of 20 amino acids (aa), as well as reactivity of mAb 5F12 with an N-terminal CD44 synthetic peptide (CD44-9A), demonstrated that the N-terminal proximal region of CD44 (aa 1 to 20) was involved in mAb 5F12 binding. A mutant cell line, CEM-NKR, derived from the T-ALL cell line, CEM, did not bind mAb 5F12 nor bind HA, whereas wild-type CEM did bind mAb 5F12 and HA. Sequence analysis of wild-type CEM and CEM-NKR CD44 cDNA demonstrated a G to A point mutation at position 575 in the CD44 cDNA of CEM-NKR, resulting in an arginine to histidine mutation at aa position 154. Taken together, our studies demonstrated that there are three epitopes to which HA-blocking mAbs bind in the extracellular domain of CD44, and that the CD44 N-terminal proximal and central regions are two regions in the extracellular domain of CD44 that may interact and either mediate or regulate HA binding to cell surface CD44.
Cytotoxic T lymphocytes after oral immunization with attenuated vaccine strains of Salmonella typhi in humans.
Authors: Sztein M B , Tanner M K , Polotsky Y , Orenstein J M , Levine M M 
Published: December 2022

Abstract
Not only viruses, but certain parasites and bacteria as well, can elicit CTL involved in mediating protection. It has been surmised that CTL able to lyse Salmonella typhi-infected cells are likely to be important in protecting against S. typhi, an intracellular bacterial infection, but heretofore this has not been demonstrated. Consequently, the presence of CTL activity against S. typhi-infected cells was investigated in human volunteers immunized with attenuated vaccine strains of S. typhi. Oral immunization with S. typhi strain CVD 908 elicited circulating CTL effector cells capable of killing S. typhi-infected autologous EBV-transformed cells. CTL activity was observed after 6 to 8 days of in vitro expansion in the presence of S. typhi-infected autologous EBV-transformed cells. Maximum CTL activity was observed 29 days after immunization. Depletion of CD8+ T cells eliminated or markedly reduced the CTL activity, while depletion of CD4+ T cells did not affect CTL responses. CTL activity was blocked by mAbs to human class I MHC Ags, but not by mAbs to class II MHC Ags. This first demonstration that oral immunization of volunteers with attenuated S. typhi elicits CD8+ T cell, MHC class I-restricted, CTL responses raises the possibility that CTL activity might play a significant role in protection during typhoid fever. It also encourages the future use of such attenuated strains as liver vector vaccines to stimulate specific CTL against relevant foreign Ags.
Lipopolysaccharide stimulates the tyrosine phosphorylation of mitogen-activated protein kinases p44, p42, and p41 in vascular endothelial cells in a soluble CD14-dependent manner. Role of protein tyrosine phosphorylation in lipopolysaccharide-induced stimulation of endothelial cells.
Authors: Arditi M , Zhou J , Torres M , Durden D L , Stins M , Kim K S 
Published: December 2022

Abstract
Vascular endothelial cell (EC) injury or activation by LPS plays a critical role in the pathogenesis of Gram-negative meningitis and endotoxic shock. EC do not express membrane CD14, but respond to LPS in a soluble CD14-dependent manner. The signal transduction mechanisms involved in LPS-induced EC responses are largely unknown. We used bovine and human brain microvessel EC (BBMEC, and HBMEC) to study LPS-induced protein tyrosine phosphorylation. LPS rapidly induced the tyrosine phosphorylation of several proteins in BBMEC and HBMEC, which was detectable by 5 to 15 min, reached a maximum by 30 min, and declined by 60 to 90 min. The increase in tyrosine phosphorylation was apparent following stimulation with LPS at 0.1 ng/ml and was dose dependent up to 100 ng/ml. Similar changes in tyrosine phosphorylation were induced by smooth and rough LPS as well as lipid A, but not by the inactive lipid A analogue, Rhodopseudomonas sphaeroides diphosphoryl lipid A. Pretreatment of EC with the tyrosine kinase inhibitor, herbimycin A, inhibited LPS-stimulated protein tyrosine phosphorylation and LPS-mediated lactic dehydrogenase release from BBMEC and IL-6 release from HBMEC in a dose-dependent manner. Three proteins with apparent m.w. of 44, 42, and 41 kDa were predominant among the LPS-induced tyrosine phosphoproteins, and they were identified as mitogen-activated protein kinase isoforms ERK1, ERK2, and p38, respectively. LPS-induced protein tyrosine phosphorylation in HBMEC and BBMEC was soluble CD14 dependent, since pretreatment of these cells with anti-hCD14 mAb inhibited the LPS-induced tyrosine phosphorylation of p44, p42, and p41. Additionally, LPS induced a mobility shift in p44 and p42 mitogen-activated protein kinase isozymes, which was inhibited by herbimycin A pretreatment of the EC. These findings demonstrate for the first time that increased protein tyrosine phosphorylation and activation of mitogen-activated protein kinases occur rapidly after LPS stimulation of EC in the presence of soluble CD14. Our data also suggest that a herbimycin-sensitive step, presumably a tyrosine kinase, is involved in mediating LPS-induced human EC activation and IL-6 secretion.
Genetic analysis of experimental allergic encephalomyelitis in mice.
Authors: Baker D , Rosenwasser O A , O'Neill J K , Turk J L 
Published: December 2022

Abstract
Experimental allergic encephalomyelitis (EAE) is an autoimmune disease of the central nervous system that exhibits many pathologic similarities with multiple sclerosis. While products of the MHC are known to control the development of EAE, it is clear that non-MHC products also influence susceptibility. The chromosomal locations of these were investigated in selective crosses between MHC class II-compatible, EAE-susceptible Biozzi ABH, and low responder nonobese diabetic (NOD) mice. The disease was dominant and highly influenced by gender in the backcross one (BC1) generation. Female mice were significantly more susceptible than male mice. Segregation of disease frequency of female animals in this cross suggested that EAE was controlled by a major locus. Although microsatellite-based exclusion mapping indicated that a number of regions on chromosomes 5, 6, 7, 8, 9, 10, 11, 12, 13, and 18 showed evidence of linkage (p &lt; 0.05) compared with expected random distributions of alleles, disease susceptibility was most strongly linked (p &lt; 0.001) to chromosome 7. However, by selectively analyzing animals that were either severely affected or almost normal, additional susceptibility loci were mapped on chromosomes 18 and 11 that were linked (p &lt; 0.001) to resistance and the development of severe disease, respectively. The data indicate a major locus on chromosome 7, affecting initiation and severity of EAE that is probably modified by several other unlinked loci. These localizations may provide candidate loci for the analysis of human autoimmune-demyelinating disease.
Cytokine patterns during progression to AIDS in children with perinatal HIV infection.
Authors: Hyjek E , Lischner H W , Hyslop T , Bartkowiak J , Kubin M , Trinchieri G , Kozbor D 
Published: December 2022

Abstract
Patterns of cytokine expression were analyzed in polyclonal and antigenic responses in children with perinatal HIV infection. Responses of PBL to PMA and A23187 calcium ionophore studied in patients in different stages of HIV infection revealed reduced levels of IL-2 in HIV-infected children beginning before 6 mo of age, and age-dependent increases in expression of IL-4, IL-10, and IFN-gamma. The levels of IL-4, IL-10, and IFN-gamma expression did not differ significantly between HIV-infected and age-matched uninfected children of HIV-seropositive mothers, except for a small reduction in HIV-infected children in late stages of infection. Responses to PHA, HLA alloantigens, HIV envelope peptides T1 and P18, and tetanus toxoid were studied in PBMC derived from asymptomatic and mildly symptomatic HIV-infected children. IL-2, IFN-gamma, IL-4, and IL-5 expression was detected in PHA-stimulated PBMC from all analyzed patients. HIV-infected children who failed to respond to HLA alloantigens, tetanus toxoid, or the envelope peptides had lower numbers of CD4+ cells and expressed, on PHA stimulation, higher levels of IL-4 and IL-5 and lower levels of IL-2 and IFN-gamma than patients who responded to the antigenic stimulation. Results of these analyses suggest that cytokine expression in HIV-infected children depends on the character of the stimuli as well as the phenotype of PBMC, and indicate possible prevalence of Th2 Ag-specific responses during the progression of HIV-induced immunodeficiency.
Both a precursor and a mature population of dendritic cells can bind HIV. However, only the mature population that expresses CD80 can pass infection to unstimulated CD4+ T cells.
Authors: Weissman D , Li Y , Orenstein J M , Fauci A S 
Published: December 2022

Abstract
Dendritic cells (DC) are the principle APC involved in primary immune responses; their major function is to obtain Ag in tissues, migrate to lymphoid organs, and activate T cells. DC are also the first immune cells to arrive at sites of inflammation on mucous membranes, the major site of sexual transmission of HIV. We have demonstrated previously that three populations of cells that can develop a dendritic morphology are present in peripheral blood. Two of these populations can express CD83, a marker of DC, and appear to be at different stages of maturation: 1) a precursor population and 2) a mature immunostimulatory DC. Precursor-derived DC express high levels of CD86 (B7-2) and HLA-DR but no CD80 (B7-1), whereas mature DC have high levels of expression of all three markers. Mature DC in peripheral blood bind HIV to their surface and induce infection when added to autologous CD4+ T cells in the absence of added stimuli, such as mitogens. These mature DC, when isolated directly from peripheral blood, appear to be conjugated to T cells, and these conjugates are infected easily and productively with HIV. These findings suggest a role for DC in early HIV infection in which they bind virus and interact with T cells locally or after migrating to a lymphoid organ, thus establishing a productive infection. Furthermore, they likely play a role in the propagation of HIV infection by activating T cells in the presence of HIV, which leads to viral replication and immune cell destruction.
The Ig-related killer cell inhibitory receptor binds zinc and requires zinc for recognition of HLA-C on target cells.
Authors: Rajagopalan S , Winter C C , Wagtmann N , Long E O 
Published: December 2022

Abstract
Members of the Ig superfamily are predominantly receptors that mediate interactions between cells or provide signals to cells when binding specific ligands. Here we describe an Ig-related receptor that requires zinc for its function. Killer cell inhibitory receptors (KIR) belonging to the Ig superfamily mediate inhibition of NK cells upon recognition of HLA-C molecules on target cells. An abundance of histidine residues in the first extracellular domain of KIR, including the signature zinc binding motif HEXXH, suggested that this receptor may bind zinc. Two distinct KIR molecules that mediate recognition of HLA-Cw4 and -Cw8, respectively, bound specifically to zinc affinity columns. Furthermore, addition of the zinc chelator 1,10-phenanthroline during chromium release assays reversed the inhibition of killing by NK clones specific for HLA-Cw4 or HLA-Cw8, demonstrating that zinc is necessary for the inhibitory function of KIR. Such functionally relevant zinc binding has not been described for other members of the Ig superfamily and may represent a novel regulatory mechanism for Ag receptor-ligand interactions.
Divergent induction of apoptosis and IL-8 secretion in HT-29 cells in response to TNF-alpha and ligation of Fas antigen.
Authors: Abreu-Martin M T , Vidrich A , Lynch D H , Targan S R 
Published: December 2022

Abstract
Colonic epithelial cell injury is the common manifestation of inflammatory diseases of the bowel. One form of epithelial injury is apoptosis. In our study, we investigated the mechanism leading to apoptosis in HT-29 cells in response to TNF-alpha and ligation of Fas Ag. HT-29 displayed a dual response to TNF-alpha and Fas Ag ligation: in combination with IFN-gamma, HT-29 cells underwent apoptosis, whereas independently, these factors stimulated secretion of IL-8. We used this model of immune-mediated epithelial cell injury to elucidate the signals leading to apoptosis in response to TNF-alpha and Fas Ag ligation compared with the signals leading to induction of IL-8 secretion. The model was further used to distinguish signaling differences between TNF-alpha receptors and the Fas Ag in this cell line. The experiments presented here demonstrate that Fas Ag ligation alone led to production of IL-8 by colonic epithelial cells and represented another function mediated by Fas Ag in addition to apoptosis. This study shows that the pathways leading to cell death and IL-8 production in response to Fas Ag ligation and TNF-alpha were similar with regard to their requirements for new gene expression, protein synthesis, and protein kinase activity. Specifically, new gene expression and protein synthesis were not necessary for TNF-alpha- and Fas Ag-mediated apoptosis, but were necessary for TNF-alpha- and Fas Ag-mediated IL-8 secretion. Tyrosine protein kinase phosphorylation was necessary to signal secretion of IL-8 in response to both agonists but it was not necessary for apoptosis. In spite of the similarities between these two agonists, the kinetics of apoptosis via Fas Ag were significantly more rapid than through the TNF-alpha receptor and serve to distinguish these two signals.
A nonlethal conditioning approach to achieve durable multilineage mixed chimerism and tolerance across major, minor, and hematopoietic histocompatibility barriers.
Authors: Colson Y L , Wren S M , Schuchert M J , Patrene K D , Johnson P C , Boggs S S , Ildstad S T 
Published: December 2022

Abstract
Reconstitution of lethally irradiated mice with a mixture of syngeneic and allogeneic (A+B--&gt;A) bone marrow results in multilineage mixed allogeneic chimerism, donor-specific transplantation tolerance, superior immunocompetence and resistance to graft-vs-host disease. However, the morbidity and mortality associated with lethal irradiation would be a major limitation to the clinical application of chimerism to induce tolerance for solid organ grafts or treat other nonmalignant hematologic diseases. We report here that durable multilineage mixed allogeneic chimerism and donor-specific transplantation tolerance for skin and primarily vascularized allografts can be achieved across multiple histocompatibility barriers using a nonmyeloablative radiation-based approach. The percentage of B10 mouse recipients that engrafted directly correlated with the degree of disparity between donor and recipient and the dose of total body irradiation administered. Although the occurrence of engraftment following conditioning with doses of total body irradiation of &gt; or = 600 cGy was similar for animals receiving bone marrow disparate at MHC or MHC, minor and hematopoietic (Hh-1) loci (67% vs 78%), the level of donor chimerism was significantly less when multiple histocompatibility barriers were present (94.6 +/- 3.8% vs 37.5 +/- 12.5%). Treatment of the recipient with cyclophosphamide 2 days following allogeneic bone marrow transplantation reduced the dose of radiation sufficient for reliable engraftment to only 500 cGy of total body irradiation, regardless of MHC and Hh-1 disparity. Donor chimerism was stable and present in all lineages, with production of lymphoid (T and B cell), NK, and myeloid (erythrocyte, platelet, granulocyte, and macrophage) cells. Mixed chimeras exhibited donor-specific tolerance in vitro, as assessed by mixed lymphocyte culture (MLR) and cytotoxicity (CML) assays, and in vivo to skin and primarily vascularized cardiac allografts. The observation that engraftment and tolerance can be achieved across multiple histocompatibility barriers using nonmyeloablative recipient conditioning may allow allogeneic bone marrow transplantation to be applied to nonmalignant disease states in which lethal conditioning cannot be justified, including the induction of donor-specific tolerance for solid organ transplantation and the treatment of hemoglobinopathies and enzyme deficiency states.
Peptide-induced anergy in allergen-specific human Th2 cells results in lack of cytokine production and B cell help for IgE synthesis. Reversal by IL-2, not by IL-4 or IL-13.
Authors: Fasler S , Aversa G , Terr A , Thestrup-Pedersen K , de Vries J E , Yssel H 
Published: December 2022

Abstract
The induction of anergy in T cells is believed to be the result of triggering of the TCR in the absence of adequate costimulation mediated through the interaction of CD28 and its ligands, CD80 and CD86. Here, we demonstrate that stimulation of human group I allergen in Dermatophagoides pteronyssinus extract (Der p 1)-specific CD4+ Th2-like T cell clones with Der p 1-derived peptides in the absence of professional APC results in a state of nonresponsiveness. The induction of anergy occurred despite the expression of high levels of CD28, CD80, and CD86 on the surface of the T cell clones and was not prevented by the addition of anti-CD28 mAb. The anergic, Der p 1-specific, Th2 cells failed to mobilize calcium from intracellular stores, to proliferate, and to produce IL-2, IL-4, IL-13, GM-CSF, and TNF-alpha following optimal stimulation with Der p 1-derived peptide and autologous APC. However, they mobilized intracellular calcium following stimulation with Ca(2+)-ionophore and produced all of the above cytokines, including IFN-gamma, when stimulated with phorbol ester and Ca2+ ionophore. These results indicate that the anergic T cell clones are capable of responding to signals circumventing the TCR/CD3 complex activation pathway. In contrast to T cell clones optimally activated with peptide and APC, anergic T cells failed to induce IgG4 and IgE synthesis when cocultured with B cells, even in the presence of exogenous IL-4 or IL-13. Anergic T cells expressed normal levels of CD40L, suggesting that their inability to help in Ig production by B cells is due to conditions other than a lack of expression of this molecule. Finally, exogenous IL-2 restored the helper function of anergic Th2 T cells for IgE production by B cells, which was greatly enhanced by the addition of IL-4 or IL-13. These data suggest that induction of anergy in allergen-specific Th2 T cells by allergen-derived peptides may play an important role in the successful desensitization of allergic patients.
Removal of the majority of epidermal Langerhans cells by topical or systemic steroid application enhances the effector phase of murine contact hypersensitivity.
Authors: Grabbe S , Steinbrink K , Steinert M , Luger T A , Schwarz T 
Published: December 2022

Abstract
Whereas epidermal Langerhans cells (LC) are thought to be the principal APCs for initiation of contact hypersensitivity (CHS) responses, their role as APC in the effector phase of CHS is still unclear. It is currently thought that LC elicit the CHS response by presenting Ag to trafficking Ag-specific T cells within the skin. To test this hypothesis, we removed the majority of resident LC at the site of CHS challenge by topical application of various steroid creams to one ear in BALB/c mice (&gt; 85% LC depletion). Either 2 days before or 4 days after steroid treatment of the ear, mice were sensitized on the abdomen with the hapten trinitrophenyl and challenged 10 days later at the steroid-pretreated ear. At that time point, direct anti-inflammatory effects of the steroid were no longer present. Surprisingly, CHS responses were markedly stronger at the sites of prior steroid application when compared with vehicle-treated controls, indicating that depletion of most of the resident LC not only fails to impair, but enhances, the expression of CHS significantly. UV irradiation or application of croton oil at the challenge site, as well as systemic steroid application, all of which are alternative methods of diminishing the number of epidermal LC, also significantly up-regulated CHS. In contrast, irritant dermatitis and sensitization or elicitation of CHS in steroid-treated mice at distant sites, as well as delayed-type hypersensitivity responses against the same hapten, were unaffected by topical steroid pretreatment. In conclusion, our data suggest that resident LC are not the relevant APC in the effector phase of CHS and that they may even provide down-regulatory, rather than stimulatory, signals during elicitation of CHS.