bluuebunny/crossref_metadata_2025 huggingface dataset:
Binding and presentation of peptides derived from melanoma antigens MART-1 and glycoprotein-100 by HLA-A2 subtypes. Implications for peptide-based immunotherapy.
Authors: Rivoltini L , Loftus D J , Barracchini K , Arienti F , Mazzocchi A , Biddison W E , Salgaller M L , Appella E , Parmiani G , Marincola F M
Published: December 2022

Cellular immune responses to melanoma-associated Ags are the focus of ongoing studies aimed at developing immunotherapies for treatment of malignant melanoma. Melanoma predominantly affects Caucasians, a population in whom expression of HLA-A2 is prevalent. Among HLA-A2 subtypes, HLA-A*0201 is widely expressed, and HLA-A*0201-restricted, tumor-reactive CTL responses are well studied. We have observed in a group of melanoma patients an unexpectedly high frequency (approximately 20%) of non-HLA-A*0201 subtypes (*0202, *0204, and *0205), and little is known regarding antimelanoma response profiles in patients expressing such subtypes. We analyzed non-HLA-A*0201 peptide response profiles using HLA-A*0201-restricted epitopes from melanoma Ags MART-1/Melan A and glycoprotein 100. Most of these peptides bound to the majority of subtypes tested with 50% inhibitory concentrations less than 500 nM. Recognition of cells pulsed with different peptides (MART-1(27-35), G9(154), and G9(280) Flu M1(58-66)) and expressing different subtype molecules by HLA-A*0201-restricted CTL was limited to only a subset of non-HLA-A*0201 molecules, and the peptide/subtype complexes recognized varied among the effector populations tested. CTL responses elicited from PBL of patients and healthy donors expressing subtypes HLA-A*0202 and HLA-A*0205 suggested significant differences among HLA-A2 subtype function in the context of melanoma Ag presentation. These observations imply the necessity of subtyping patients considered for peptide-based protocols and highlight the need for further study of melanoma-directed cellular responses among patients expressing non-HLA-A*0201 subtypes.
Enhanced tumor outgrowth after peptide vaccination. Functional deletion of tumor-specific CTL induced by peptide vaccination can lead to the inability to reject tumors.
Authors: Toes R E , Blom R J , Offringa R , Kast W M , Melief C J
Published: December 2022

CTL can play an important role in the defense against tumors. Protective CTL-mediated immunity can be established in animal tumor models after vaccination with synthetic peptides representing CTL epitopes. We now report that immunization with synthetic peptides can also lead to CTL tolerance associated with the inability to reject tumors. B6 tumor cells transformed by the human adenovirus early region 1 (Ad5E1) present an Ad5E1A- and an Ad5E1B-encoded CTL epitope to the immune system. CTL clones directed against either of these epitopes are able to eradicate established Ad5E1-induced tumors, showing that these CTL epitopes are targets of CTL that can mediate tumor regression. Here, we show that protective immunity against Ad5E1-expressing tumor cells can be established by immunization with Ad5E1-transformed cells and with an adenovirus vector containing the Ad5E1 region. Protective immunity, in either case, is associated with specific CTL memory. To test whether vaccination with synthetic peptides leads to protection against Ad5E1-expressing tumor cells, we vaccinated mice s.c. with a low dose of the Ad5E1B peptide. This peptide was chosen because the CTL response against the Ad5E1B-encoded CTL epitope contributes most to the antitumor response in B6 mice after vaccination with Ad5E1-transformed cells. Ad5E1B peptide-vaccinated mice were not protected against the outgrowth of Ad5E1-expressing tumor cells, but instead were no longer able to reject a tumor inoculum that was rejected by nonvaccinated mice. Moreover, the protection induced by tumor cell vaccination against Ad5E1B-expressing tumors was gone when the Ad5E1B-encoded CTL epitope was injected a few days before tumor challenge. This is associated with peptide-induced tolerance of Ad5E1B-specific CTL activity. These findings are relevant for the design of therapeutic approaches against both malignancies and T cell-mediated autoimmune diseases.
Galectin-3 promotes adhesion of human neutrophils to laminin.
Authors: Kuwabara I , Liu F T
Published: December 2022

Galectin-3 is a member of a growing family of animal lectins composed of three domains, with the amino-terminal half consisting of a short segment followed by tandem repeats, and the carboxyl-terminal half representing the carbohydrate-recognition domain. Previously, we have shown that galectin-3 binds to the surface of human neutrophils and is capable of activating these cells. We have now studied the effect of exogenous galectin-3 on adhesion of human neutrophils to laminin-coated microtiter plates and found that this lectin promotes the adhesion in a dose-dependent manner. The effect was dependent on the lectin's carbohydrate-binding function, as well as its amino-terminal region. The galectin-3-induced adhesion was reduced significantly in the presence of EDTA, even though Ca2+ and Mg2+ are not required for the lectin binding, and the adhesion was significantly less at 4 degrees C, as compared with 37 degrees C. Galectin-3 also induced neutrophil adhesion to fibronectin, which is not recognized by the lectin, but much higher concentrations of the lectin were required, and the effect is completely dependent on Ca2+ and Mg2+. We conclude that galectin-3 induces neutrophil adhesion to laminin through a combination of two distinct mechanisms: 1) the lectin bridges neutrophils to laminin, in a carbohydrate-dependent and Ca2+-, Mg2+-independent manner, and 2) the lectin induces activation of neutrophils, in the presence of the divalent cations, resulting in the positive regulation of other cell adhesion molecules and enhanced adhesion to laminin. The results suggest that galectin-3 may play a role in the traversing of neutrophils through the basement membrane at inflammation sites.
Salicylates inhibit I kappa B-alpha phosphorylation, endothelial-leukocyte adhesion molecule expression, and neutrophil transmigration.
Authors: Pierce J W , Read M A , Ding H , Luscinskas F W , Collins T
Published: December 2022

The expression of leukocyte adhesion molecules on endothelial cells is induced by TNF-alpha and other inflammatory cytokines. This induction of endothelial-leukocyte adhesion molecule-1, vascular cell adhesion molecule-1, and intercellular adhesion molecule-1 requires the transcription factor nuclear factor-kappa B (NF-kappa B). Recent work has suggested that some nonsteroidal anti-inflammatory agents, including sodium salicylate and aspirin, can inhibit NF-kappa B-dependent gene activation. We studied the effects of salicylates on expression of adhesion molecules in HUVECs. We found that sodium salicylate inhibited activation of NF-kappa B (p50/p65 and p65/p65) by preventing phosphorylation and subsequent degradation of the inhibitor 1 kappa B-alpha. Salicylate treatment had no effect on TNF-alpha-induced phosphorylation of the transcription factor ATF-2. Salicylate blocked the TNF-alpha-induced increase in mRNA levels of adhesion molecules and gave a dose-dependent inhibition of TNF-alpha-induced surface expression of vascular cell adhesion molecule-1, and intercellular adhesion molecule-1 with higher doses required to inhibit endothelial-leukocyte adhesion molecule-1 expression. Indomethacin, a nonsalicylate cyclooxygenase inhibitor, had no effect on surface expression of adhesion molecules, suggesting that the effects were not due to inhibition of cyclooxygenase. Treatment of endothelial cell monolayers with sodium salicylate inhibited transendothelial migration of neutrophils but had no significant effect on neutrophil adhesion under flow conditions. The clinical importance of high-dose salicylates in inflammation may be due, in part, to the ability to prevent expression of inducible adhesion molecules and recruitment of leukocytes.
Extracellular ATP activates mast cells via a mechanism that is different from the activation induced by the cross-linking of Fc receptors.
Authors: Sudo N , Tanaka K , Koga Y , Okumura Y , Kubo C , Nomoto K
Published: December 2022

In this study, the extracellular ATP (ATPo)-induced biochemical events were elucidated by comparing them with either the Fc epsilon RI- or Fc gamma R-induced events in the mouse mast cell line MC9. The omission of extracellular Ca2+ almost completely abolished the elevation of intracellular Ca2+ ([Ca2+]i) in the ATPo-stimulated cells, but only suppressed the second phase of the increase of [Ca2+]i in FcR-stimulated cells, thus suggesting that the ATPo-induced elevation of [Ca2+]i is totally dependent on the entry of extracellular Ca2+. Pretreatment with genistein, which inhibits protein kinases, especially protein tyrosine kinase, inhibited the FcR-triggered increase of [Ca2+]i, but not the ATPo-triggered one; however, such pretreatment did suppress both ATPo- and FcR-mediated beta-hexosaminidase release. An immunoblot analysis revealed that both ATPo and the cross-linking of FcRs led to tyrosine phosphorylation of 44- and 110-kDa proteins, which thus suggested that these tyrosine-phosphorylated proteins are involved in a modulation of the degranulation process following an elevation of [Ca2+]i. Pretreatment with PMA inhibited the FcR-induced [Ca2+]i increase, while not inhibiting the ATPo-induced one, thus suggesting that ATPo can mobilize [Ca2+]i even when protein kinase C (PKC) has already been activated. Pretreatment of calphostin C, a specific PKC inhibitor, had little effect on the ATPo-mediated beta-hexosaminidase secretion, thus indicating that the ATPo-induced degranulation is not mediated by PKC. Taken together, these results demonstrate that ATPo activates MC9 mast cells by a mechanism that is different from the activation induced by the cross-linking of FcRs.
Human lupus anti-spliceosome A protein autoantibodies bind contiguous surface structures and segregate into two sequential epitope binding patterns.
Authors: James J A , Harley J B
Published: December 2022

High levels of anti-spliceosomal autoantibodies are commonly found in systemic lupus erythematosus (lupus) sera. We have evaluated the binding of lupus autoantibodies to octapeptides of nuclear ribonucleoprotein (nRNP) A, identified patterns of binding that vary between sera, quantified the proportion of anti-nRNP that binds individual peptides, and related these data to the partial tertiary structure of nRNP A. Anti-nRNP A-positive lupus sera share binding to eight antigenic groups of octapeptides from nRNP A. The four shared antigenic sites in the known nRNP A tertiary structure are contiguous on its surface and include surface loops between beta sheets and/or alpha helices. Anti-peptide Abs account for a significant portion of the human autoimmune response to nRNP A. Lupus sera are also obviously divisible into two subsets by their binding to nRNP A-derived peptides. Eight of the thirteen anti-nRNP A sera tested bind most of the eight common antigenic regions of nRNP A. All five sera in the other subset bind to two and only two groups of nRNP A octapeptides. Of this subset, absorption experiments show that as much as 75% of the anti-nRNP found in a patient serum is bound to these two octapeptides from nRNP A. The 70K spliceosome protein contains similar peptides that are also bound by these sera (OR=13.5, p<0.001). Lupus autoantibodies bind to peptides of nRNP A in discernibly consistent patterns that identify serologic subsets and in a manner that provides useful insights into the autoimmunity and antigenic structure of the nRNP A spliceosomal protein.
Murine lupus in the absence of alpha beta T cells.
Authors: Peng S L , Madaio M P , Hughes D P , Crispe I N , Owen M J , Wen L , Hayday A C , Craft J
Published: December 2022

To investigate the possibility that non-alpha beta T cell-dependent mechanisms can induce systemic autoimmune disease, and to address the roles of alpha beta T cells in murine lupus, we analyzed lupus-prone MRL mice congenitally deficient in alpha beta T cells. Surprisingly, TCR-alpha-/- MRL mice developed several characteristics of human systemic lupus erythematosus, including hypergammaglobulinemia, autoantibodies against DNA and small nuclear ribonucleoproteins, and immune deposits in kidneys. These results, which contrast with past studies concluding that MRL autoimmunity requires CD4+ alpha beta T cells, demonstrate that non-alpha beta T cell-dependent mechanisms are capable of inducing lupus phenomena, and further suggest that MRL disease may consist of both alpha beta T cell-independent and alpha beta T cell-dependent mechanisms.
Complete TCR-delta rearrangements and partial (D-J) recombination of the TCR-beta locus in CD34+7+ precursors from human cord blood.
Authors: Ktorza S , Blanc C , Laurent C , Sarun S , Verpilleux M P , Debré P , Schmitt C
Published: December 2022

In the neonatal human thymus, early immature precursors co-express CD34 and CD7 cell surface Ags, and we have recently shown that its most primitive CD34+7+1- fraction includes TCR-beta-rearranging cells. Bone marrow and cord blood also contain a CD34+7+ population. Although this population is heterogeneous in terms of both phenotype and differentiation capacities, it may include T cell-committed thymus colonizing precursors (prothymocytes). Recently, it has been shown in the mouse that initiation of TCR-beta rearrangements is not restricted to early thymocytes. In the present study, we examined the TCR-beta and TCR-delta rearrangement and transcription status of cord blood CD34+7- and CD34+7+ subpopulations. RNA and DNA were isolated from these cell subsets purified by two consecutive rounds of fluorescence-activated cell sorting from CD3-depleted cord blood cells. Using D-J(beta) or V-J(beta) primer sets and genomic DNA PCR amplification, we showed that CD34+7+, but not CD34+7-, contained D-J(beta) rearrangements without concomitant V-D(beta) recombination. These partial TCR-beta rearrangements within CD34+7+ progenitors were also confirmed at the transcriptional level. Furthermore, whereas none of the CD34+ cord blood cell fraction expressed TCR-alpha transcripts, mature V(delta)1-C(delta) mRNA could be amplified from the CD34+7+ subset. The TdT gene was also transcriptionally active in CD34+7+ cells, thus confirming their lymphoid progenitor content. These data indicate that cord blood CD34+7+ cells, like CD34+7+1- neonatal thymocytes, can initiate TCR-beta gene recombination, reinforcing the idea that T cell commitment may occur before prothymocyte migration to the thymus.
Inactivation of the small GTP binding protein Rho induces multinucleate cell formation and apoptosis in murine T lymphoma EL4.
Authors: Moorman J P , Bobak D A , Hahn C S
Published: December 2022

The small G-protein Rho regulates the actin microfilament-dependent cytoskeleton. Exoenzyme C3 of Clostridium botulinum ADP-ribosylates Rho at Asn41, a modification that functionally inactivates Rho. Using a Sindbis virus-based transient gene expression system, we studied the role of Rho in murine EL4 T lymphoma cells. We generated a double subgenomic infectious Sindbis virus (dsSIN:C3) recombinant which expressed C3 in >95% of EL4 cells. This intracellular C3 resulted in modification and inactivation of virtually all endogenous Rho. dsSIN:C3 infection led to the formation of multinucleate cells, likely by inhibiting the actin microfilament-dependent step of cytokinesis. Intriguingly, in spite of the inhibition of cytokinesis, karyokinesis continued, with the result that cells containing a nuclear DNA content as high as 16N (eight nuclei) were observed. In addition, dsSIN:C3-mediated inactivation of Rho was a potent activator of apoptosis in EL4 cells. To discern whether the formation of multinucleate cells was responsible for the activation of apoptosis, 5-fluorouracil (5-FUra) was used to induce cell cycle arrest. As expected, EL4 cells treated with 5-FUra were prevented from forming multinucleate cells upon infection with dsSIN:C3. dsSIN:C3 infection, however, still caused marked apoptosis in 5-FUra-treated cells, indicating that this activation of apoptosis was independent of multinucleate cell formation.
Inhibition of constitutive serine phosphatase activity in T lymphoma cells results in phosphorylation of pp19/cofilin and induces apoptosis.
Authors: Samstag Y , Dreizler E M , Ambach A , Sczakiel G , Meuer S C
Published: December 2022

In untransformed T lymphocytes, pp19/cofilin, a cytoplasmic actin-binding protein, undergoes dephosphorylation and nuclear translocation in response to costimulation through accessory receptors (e.g., CD2), but not following TCR/CD3 triggering. In malignant T lymphoma cells, dephosphorylation and nuclear translocation of pp19/cofilin occur spontaneously through constitutive activation of a serine phosphatase. Blockade of these processes by the serine phosphatase inhibitor okadaic acid leads to apoptosis. Moreover, lowering the intracellular pp19/cofilin concentrations by antisense-cofilin transfection results in reduced cloning efficiencies. These findings provide support for the view that pp19/cofilin plays a critical role in the growth and survival of both untransformed and malignant T lymphocytes.
Expression of HLA-G in human mononuclear phagocytes and selective induction by IFN-gamma.
Authors: Yang Y , Chu W , Geraghty D E , Hunt J S
Published: December 2022

In situ hybridization studies have shown that at early but not late stages of gestation, human placental stromal cells, many of which are macrophages (Hofbauer cells), contain HLA-G message. In this study, the HLA-G protein was identified in the macrophage-like stromal cells by immunohistochemistry using the anti-HLA-G mAb, 87G. Expression of the HLA-G gene was then analyzed in macrophage cell lines (U937, HL-60, THP-1) and blood monocytes. HLA-G mRNA identified by using reverse transcriptase PCR was consistent with production of a transcript containing intron 4, which codes for a soluble form of HLA-G. Low levels of HLA-G mRNA were identified in mononuclear phagocytes by Northern blot hybridization, and little if any HLA-G Ag was detectable. By contrast, essentially all of the cells displayed high levels of HLA-B/C H chains detected by the mAb, 4E, and B2m. Treatment of macrophage cell lines and monocytes with IFN-gamma increased steady-state levels of HLA-G mRNA, stimulated higher levels of cell surface and intracellular HLA-G Ag in a dose-dependent manner, and increased the proportions of HLA-G relative to HLA-B/C. INF-alpha and IFN-beta enhanced steady-state levels of HLA-G mRNA and in some lines modestly increased the numbers of weakly positive cells but were poor inducers of cell-surface and intracellular HLA-G and did not increase HLA-G relative to HLA-B/C. Thus, mononuclear phagocytes express low levels of HLA-G mRNA and protein, and IFN-gamma selectively enhances expression of this HLA class Ib gene relative to HLA class Ia, which could influence the repertoire of peptides presented during embryogenesis as well as during inflammatory situations in adults. Soluble HLA-G might influence both fetal and maternal immune responses.
Characterization and subcellular localization of target membrane soluble NSF attachment protein receptors (t-SNAREs) in macrophages. Syntaxins 2, 3, and 4 are present on phagosomal membranes.
Authors: Hackam D J , Rotstein O D , Bennett M K , Klip A , Grinstein S , Manolson M F
Published: December 2022

Phagosomes formed during ingestion of microorganisms by leukocytes undergo a rapid maturation, generating an acidic, microbicidal organelle. Maturation requires interactions with intracellular vesicles that dock and fuse preferentially with the phagosomal membrane. The basis of specificity of vesiculo-phagosomal interaction has not been elucidated. By contrast, the molecular basis of vesicular fusion in other systems is better understood. At neural synapses, vesicular docking and fusion to the plasma membrane are mediated by a protein complex including syntaxin 1. We explored whether macrophages contain syntaxins, and whether selective fusion of vesicles with the phagosome results from the accumulation of syntaxins in the phagosomal membrane. Isoform-specific Abs were utilized to demonstrate utilized to demonstrate that syntaxins 2, 3, and 4, but not syntaxin 1, are present in murine and human macrophages. Biochemical characterization demonstrated the presence of these syntaxins on microsomes, where they are integral membrane proteins. Subcellular localization using confocal immunofluorescence microscopy demonstrated that syntaxins 3 and 4 are present on the plasma membrane as well as on intracellular vesicles. Importantly, phagosomes isolated by fractionation were shown by immunoblotting to contain syntaxins 2, 3, and 4, suggesting that they may participate in phagosomal maturation. The density of the syntaxins on the phagosomal membrane was found to be comparable with that on the surface membrane. This suggests that preferential fusion of vesicles with the phagosomal membrane is not the result of segregation of the syntaxins to this organelle. Instead, local generation of second messengers in the vicinity of the phagosomal membrane may trigger focal fusion.
Stimulation of macrophages and neutrophils by complexes of lipopolysaccharide and soluble CD14.
Authors: Hailman E , Vasselon T , Kelley M , Busse L A , Hu M C , Lichenstein H S , Detmers P A , Wright S D
Published: December 2022

Sensitive responses of monocytes, macrophages, and neutrophils to bacterial LPS require membrane-bound CD14 (mCD14) and a plasma protein called LPS-binding protein (LBP). Cells lacking mCD14 respond to complexes of LPS and soluble CD14 (sCD14); these responses do not require LBP. To determine whether LBP is necessary for responses of mCD14-bearing cells to LPS, we measured responses of macrophages and neutrophils to complexes of LPS and sCD14 formed in the absence of LBP. We found that the amount of LPS needed to induce adhesive responses of neutrophils or cytokine production by macrophages was the same whether LPS was added with LBP or as LPS-sCD14 complexes, and was >100-fold less than when LPS was added alone. This result supports the view that LBP transfers LPS to CD14, but is not directly involved in responses of CD14-bearing cells to LPS. Responses of neutrophils to LPS-sCD14 complexes could be inhibited partially by blocking mCD14, suggesting that LPS may move rapidly from sCD14 to mCD14. Additionally, we found that responses of neutrophils to LBP and smooth LPS were made 30 to 100 times more sensitive when sCD14 was added. Our findings show that LBP is not necessary for the activation of CD14-bearing cells with LPS, and suggest that LPS-sCD14 complexes are an important intermediate in the inflammatory responses of leukocytes to LPS.
Calreticulin binds hYRNA and the 52-kDa polypeptide component of the Ro/SS-A ribonucleoprotein autoantigen.
Authors: Cheng S T , Nguyen T Q , Yang Y S , Capra J D , Sontheimer R D
Published: December 2022

Calreticulin (CR) is a multifunctional, calcium-binding protein that has recently been shown to bind to and promote the replication of the rubella virus genome in mammalian cells. While CR is now widely recognized as a new human autoantigen, the relationship between CR and the Ro/SS-A ribonucleo-protein (RNP) autoantigen has been somewhat controversial. In this work, we demonstrate that unphosphorylated human rCR binds specifically and distinctly to in vitro transcribed forms of hYRNA, the RNA backbone of the Ro/SS-A RNP particle. This interaction appears to be mediated by binding through the N- and C-terminal domains of CR, but not by the central proline-rich domain. Furthermore, our studies indicate that CR can facilitate the binding of the 60-kDa polypeptide component of the Ro/SS-A RNP (Ro60) to hYRNA. In addition, CR and the 52-kDa Ro/SS-A polypeptide (Ro52) appear to be capable of interacting through direct protein-protein binding. These studies confirm that CR is an hYRNA-binding protein, and provide for the first time a molecular mechanism by which Ro52 can be linked physically to hYRNA. Through these molecular interactions and its known functional role as a chaperone, it is suggested that CR plays a supportive role in the formation of the Ro/SS-A RNP complex. The capacity of CR to interact with RNA viruses such as rubella provides an additional argument for an infectious trigger for autoantibody production against self RNP particles such as Ro/SS-A.
Selection of antigenic and immunogenic mimics of hepatitis C virus using sera from patients.
Authors: Prezzi C , Nuzzo M , Meola A , Delmastro P , Galfrè G , Cortese R , Nicosia A , Monaci P
Published: December 2022

Using sera from hepatitis C virus (HCV)-infected patients and noninfected subjects to screen random peptide libraries displayed on phage, we selected peptides specifically reacting with sera from infected patients. These phage- borne peptides were shown to mimic distinct HCV determinants. They detected in all cases the presence of anti-HCV Abs in a large panel of patients' sera, thus demonstrating the high sensitivity of the selected peptides as diagnostic markers. In addition, this diagnostic approach allowed a detailed characterization of the individual humoral response to viral infection. Phage-displayed HCV mimics were substitutes for the authentic HCV epitopes in inducing a strong specific response against HCV when used as immunogens in mice. These results support the search for HCV mimics with the potential to elicit a protective immune response as leads for the development of a mimotope-based vaccine against viral infection.
Anti-psoriatic drug anthralin activates transcription factor NF-kappa B in murine keratinocytes.
Authors: Schmidt K N , Podda M , Packer L , Baeuerle P A
Published: December 2022

Anthralin is one of the most effective and safest therapeutic agents for the treatment of psoriasis, a skin disease characterized by epidermal hyperproliferation and hyperkeratosis. The drug induces and inflammatory response in the skin involving the expression of cytokine and cell adhesion molecule genes that is thought to be essential for its therapeutic efficacy. Reactive oxygen intermediates (ROIs) generated in vivo during the auto-oxidation of anthralin were discussed as mediators of the inflammatory response, but it is not yet understood how this is translated into novel inflammatory gene expression. In this study, we show that at little as 10 microM anthralin can activate a prototypic form of transcription factor NF-(kappa)B, a central transcriptional regulator of inflammatory and immune responses. Two different lines of evidence show that ROIs, in particular H2O2, are second messengers for the anthralin-induced NF-(kappa)B activation. Firstly, the activation could be inhibited by the structurally unrelated antioxidants N-acetyl-L-cysteine and pyrrolidinedithiocarbamate. Secondly, keratinocytes stably overexpressing catalase showed a significant reduction of NF-(kappa)B activation, while stable overexpression of Cu/Zn-superoxide dismutase augmented the anthralin effect. Our data suggest that ROI-induced NF-(kappa)B plays a role in the anti-psoriatic activity of the drug anthralin.
Collagen-induced arthritis in CD4- or CD8-deficient mice: CD8+ T cells play a role in initiation and regulate recovery phase of collagen-induced arthritis.
Authors: Tada Y , Ho A , Koh D R , Mak T W
Published: December 2022

Collagen-induced arthritis (CIA) is an experimental autoimmune disease induced by immunization with collagen type II (CII). We studied CIA in CD4- or CD8-deficient DBA/1 mice to further define the roles of CD4+ and CD8+ T cells in the disease. CD4-deficient mice developed severe arthritis, and no differences in incidence, clinical course, and severity were observed between CD4 -/- and CD4 +/- mice. Proliferative responses of lymph node T cells to CII was, however, reduced in CD4 -/- mice, and inflamed joints revealed relative accumulation of CD4-CD8-TCR(alpha)(beta)+ cells. A CII-specific T cell line generated from CD4-deficient mice responded to CII in a MHC-restricted fashion and had a CD4-CD8-TCR(alpha)(beta)+ phenotype. Disease incidence in CD8 -/- mice was significantly decreased compared with CD8 +/- mice, even though the severity of arthritis in arthritic mice was not different. These results suggests a role for CD8+ T cells in initiating CIA. Interestingly, CD8-deficient mice were more susceptible to a second induction of arthritis after remission of initial disease, pointing towards an immunoregulatory role for CD8+ T cells. CD8-deficient mice did not, however, show any defect in oral tolerance induction using CII. Taken together, our findings demonstrate that CD4-CD8-TCR(alpha)(beta) cells can trigger systemic arthritis in CD4-deficient mice and that CD8+ T cells can play dual and opposing roles, important both in initiation of CIA and in providing resistance to reinduction of CIA after recovery from initial disease.
Lipopolysaccharide up-regulates platelet-derived growth factor (PDGF) alpha-receptor expression in rat lung myofibroblasts and enhances response to all PDGF isoforms.
Authors: Coin P G , Lindroos P M , Bird G S , Osornio-Vargas A R , Roggli V L , Bonner J C
Published: December 2022

Differential expression of PDGF receptor alpha and beta subunits controls the response of mesenchymal cells to the three PDGF isoforms (AA, AB, and BB). Cultured rat lung myofibroblasts (RLMF) possess abundant PDGF receptor-beta (PDGF-Rbeta) and little PDGF receptor-alpha (PDGF-Ralpha). Here we show that LPS up-regulates expression of PDGF-Ralpha and increases the sensitivity of RLMF to all three PDGF isoforms. Treatment of RLMF for 4 to 48 h with LPS enhanced PDGF-Ralpha surface expression and mRNA 5- to 10-fold but caused no change in expression of PDGF-Rbeta. Both RNA and protein synthesis were necessary for up-regulation of PDGF-Ralpha, and the increase in PDGF-Ralpha mRNA was most likely regulated at the transcriptional level. PDGF-Ralpha up-regulation was not mediated by the IL-1R system and was independent of LPS-binding proteins in serum. Highly confluent cultures of RLMF responded more strongly to LPS than did subconfluent cultures. LPS treatment enhanced the mitogenic and chemotactic responses of RLMF to all PDGF isoforms at least threefold. We postulate that signal transduction by PDGF-receptor alphabeta heterodimers was important in the enhanced responses to PDGF-AB and -BB. We propose that regulation of PDGF-Ralpha is a critical event in the genesis of pulmonary fibroproliferative diseases.
Morphine-induced conformational changes in human monocytes, granulocytes, and endothelial cells and in invertebrate immunocytes and microglia are mediated by nitric oxide.
Authors: Magazine H I , Liu Y , Bilfinger T V , Fricchione G L , Stefano G B
Published: December 2022

We evaluated the contribution of nitric oxide (NO) to morphine-induced rounding of spontaneously activated (mobile) ameboid human monocytes, granulocytes, or arterial endothelial cells and invertebrate immunocytes and microglia. Morphine induced significant rounding and inactivation of ameboid cells within 20 min except for arterial endothelial cells, which became rounded 24 h after morphine exposure. The effects of morphine on cell conformation were blocked in the presence of N-nitro-L-arginine, a nitric oxide synthase inhibitor. Treatment of cells with the NO donor, sodium nitroprusside, induced cell rounding similar to that observed following morphine exposure, suggesting that NO release may mediate morphine-induced changes in cell conformation. The contribution of NO release to morphine-induced cell rounding was determined by direct evaluation of NO concentration in real-time using a NO-specific amperometric probe. Significant increases in NO concentration were observed 2 min after morphine stimulation, whereas morphine-induced NO release was markedly impaired by pretreatment with N-nitro-L-arginine or the opiate alkaloid antagonist, naloxone. In contrast, opioid peptides failed to induce NO release, consistent with our previous observations that demonstrated the failure of opioid peptides to promote cell rounding. Taken together, these data suggest that morphine-induced NO release may be mediated by activation of the opiate alkaloid-selective, opioid peptide-insensitive micro3 receptor, and that functional coupling of morphine to NO production has been conserved during evolution and may modulate cellular activation.
Activation of a p38 mitogen-activated protein kinase in human neutrophils by lipopolysaccharide.
Authors: Nick J A , Avdi N J , Gerwins P , Johnson G L , Worthen G S
Published: December 2022

Stimulation of human neutrophils by LPS is central to the pathogenesis of sepsis and the adult respiratory distress syndrome. The intracellular signaling pathway that results in cellular responses following LPS stimulation in neutrophils is unknown. We report that exposure of neutrophils to LPS results in the phosphorylation and activation of a p38 mitogen-activated protein (MAP) kinase, occurring in a concentration-dependent manner, with maximum response at 20 to 25 min. Partial purification of a p38 MAP kinase by ion exchange chromatography established it as distinct from the p42/p44 (extracellular signal-regulated kinases (ERK-1 and ERK-2) MAP kinases). Activation of the p38 MAP kinase by LPS in human neutrophils occurs via CD14, a proposed LPS receptor, and requires the presence of plasma containing the LPS-binding protein. This intracellular signaling pathway is independent of protein kinase C and does not involve Raf, MAP/ERK kinase kinase-1, MAP/ERK kinase-1, or MAP/ERK kinase-2 and does not result in the activation of the p42/p44 ERK MAP kinases or the c-jun N-terminal kinases.
Inhibition by CTLA4Ig of experimental allergic encephalomyelitis.
Authors: Arima T , Rehman A , Hickey W F , Flye M W
Published: December 2022

B7-1 and B7-2 are well characterized costimulatory ligands on Ag presentation cells for the CD28 and CTLA4 receptors on T cells. The fusion protein CTLA4Ig can block this interaction and prevent specific T cell activation. The development of fatal CD4+ T cell-mediated experimental allergic encephalomyelitis (EAE) in susceptible female Lewis rats was optimized by immunization with 20 mg of guinea pig spinal cord homogenate in CFA on day 0 with three doses of 1 microgram pertussis toxin given i.v. on days 0, 3, and 7. This immunization regimen uniformly resulted in the development of severe clinical neurologic signs of EAE with 100% mortality by day 17 postimmunization. Treatment with 0.5 mg/dose of rhCTLA4-Ig on days - 2, 0, 3, 6, 9, 12, 15 and 18 significantly decreased the incidence, delayed the onset, and reduced the severity of clinical EAE (p = 0.0002 vs control by the Mann-Whitney U test) enough to completely prevent fatal EAE, whereas treatment with control human IgG had no effect. Histologically, perivascular neutrophilic infiltrates were also dramatically decreased in the spinal cords of animals treated with CTLA4 but not in those treated with control human IgG. The proliferative response to encephalitogenic Ags (guinea pig myelin basic protein and proteolipid protein) by lymph node cells from animals immunized with guinea pig spinal cord 10 days before was also significantly suppressed in vitro by CTLA4Ig (1 microg/ml). However, the protective effect of CTLA4Ig could be completely prevented by the daily i.p. administration, from day 0 to 10, of exogenous human rIL-2 (180,000 IU). These results indicate a critical requirement of the costimulatory B7/CD28 pathway early in the development of CD4+ T cell-mediated EAE in the rat.
beta2-microglobulin dependence of the lupus-like autoimmune syndrome of MRL-lpr mice.
Authors: Christianson G J , Blankenburg R L , Duffy T M , Panka D , Roths J B , Marshak-Rothstein A , Roopenian D C
Published: December 2022

MRL-lpr/lpr mice develop a distinctive immunologic disease characterized by accumulation of unusually large numbers of T cells in the peripheral lymphoid organs. Most of the accumulating T cells express an alpha beta-TCR but are peculiar in that they express neither CD4 nor CD8 co-ligands. Concurrent with lymphoaccumulation of such double negative (DN) T cells, MRL-lpr/lpr mice develop a lethal systemic lupus erythematosus-like autoimmune syndrome. This study focuses on the role of MHC class I molecules in this latter pathologic process. Highly backcrossed class I molecule-deficient MRL and MRL-lpr mice carrying a functionally defective allele of the gene beta 2-microglobulin (B2m) were produced. Class I deficient MRL-lpr/lpr mice demonstrated a substantial reduction in DN T cells, confirming other reports indicating that most DN T cells arise from progenitors positively selected on MHC class I molecules. Significantly, class I-deficient MRL-lpr/lpr mice also demonstrated a diminution of every autoimmune disease indicator analyzed including hypergammaglobulinemia; autoantibodies including anti-DNA, anti-Smith antigen, and rheumatoid factor; and glomerulonephritis. The results indicate that class I-dependent T cells are crucial not only for the development of DN T cells, but for multiple features of the MRL-lpr/lpr systemic lupus erythematosus syndrome. Moreover, the pattern of hypergammaglobulinemia suggests that the requirement for MHC class I proteins is restricted temporally to later stages of the disease.
Exploitation of the Vbeta8.2 T cell receptor in protection against experimental autoimmune encephalomyelitis using a live vaccinia virus vector.
Authors: Chunduru S K , Sutherland R M , Stewart G A , Doms R W , Paterson Y
Published: December 2022

This study takes advantage of the predominant usage of Vbeta8.2 by the TCRs of encephalitogenic T cells specific for myelin basic protein. Vaccinia virus recombinants expressing Vbeta8.2 (VVbeta8.2) 8.2) and Vbeta3 (VVbeta 3) proteins were constructed, and their abilities to confer protection against experimental autoimmune encephalomyelitis (EAE) induction in H-2u mice were examined. Mice immunized with VVbeta8.2 developed very mild EAE by comparison with mice that were vaccinated with VVbeta3, which developed severe clinical symptoms. This reduction in EAE correlated with a diminished T cell proliferative response to myelin basic protein in the mice that received VVbeta8.2 compared with that in mice receiving VVbeta3.
Enhanced expression of IL-12 associated with Th1 cytokine profiles in active pulmonary sarcoidosis.
Authors: Moller D R , Forman J D , Liu M C , Noble P W , Greenlee B M , Vyas P , Holden D A , Forrester J M , Lazarus A , Wysocka M , Trinchieri G , Karp C
Published: December 2022

Sarcoidosis is a multisystem granulomatous disease of unknown etiology characterized by the expansion of activated oligoclonal CD4+ T cells and macrophages at sites of disease. To investigate the immunopathogenesis of sarcoidosis, we analyzed patterns of cytokine expression in bronchoalveolar lavage cells and fluid from patients with pulmonary sarcoidosis and idiopathic pulmonary fibrosis and from normal volunteers. We found dominant type 1 cytokine expression, with elevated mRNA and protein levels of IFN-gamma, but not IL-4, in sarcoid lung cells and fluid compared with those in normal samples. To define immunoregulatory mechanisms important to this type 1 response, we analyzed the expression of IL-12 and IL-10 in lung cells and fluid. Using semiquantitative PCR, we found significantly higher mRNA expression of the regulated IL-12 p40 subunit, but not IL-10, in sarcoid compared with normal lung cells. Consistent with these observations, strikingly elevated levels of p40 protein were found in sarcoid compared with normal bronchoalveolar lavage fluid. Unstimulated and Staphylococcus aureus-stimulated sarcoid alveolar macrophages produced greater amounts of IL-12 than normal alveolar macrophages when cultured in vitro. We hypothesize that sarcoidosis is a Th1-mediated disease driven by chronic, dysregulated production of IL-12 at sites of disease.
Restriction of the TCR repertoire inhibits the development of memory T cells and prevents autoimmunity in lpr mice.
Authors: Perkins D L , Listman J A , Marshak-Rothstein A , Kozlow W , Kelley V R , Finn P W , Rimm I J
Published: December 2022

The lpr mutation, a disruption of the fas gene, induces spontaneous autoimmunity characterized by high titers of autoantibodies, lymphadenopathy, autoreactive T cells, and early mortality. The mechanism of autoimmunity, however, remains unknown. The driving force for disease could result from the T cell recognition of autoantigen or, alternatively, an intrinsic T cell defect that promotes autoreactivity. We investigated the role of antigen-TCR interaction in the pathogenesis of lpr autoimmunity by transferring the DO-11.10 TCR beta-chain transgene (Vbeta8.2-Dbeta1.1-Jbeta1.1) to the MRL-lpr/lpr background producing the MRL-lprbeta strain. Our results show that the MRL-lpr beta transgenic strain has increased survival, lower titers of autoantibodies, and decreased lymphadenopathy compared with nontransgenic littermates. These beneficial effects were associated with decreased expansion of CD4+ T cells expressing memory phenotypes (CD44+, CD45RB-, and LECAM-) in the transgenic compared with nontransgenic strains. A role for impaired recognition of autoantigen by T cells expressing the TCR transgene was suggested by comparing the phenotypes of Vbeta8.2+ (transgene+) vs Vbeta8.2- (transgene-) CD4+ T cells within the transgenic mice. These experiments show that Vbeta8.2- T cells, which express endogenously rearranged TCR, are the major contributors to the expansion of memory T cells in the transgenic mice. In contrast, T cells with memory phenotypes expand similarly in both the Vbeta8.2+ and Vbeta8.2- subsets of nontransgenic mice. Based on these results, we hypothesize that TCR recognition of autoantigen is a major contributor to autoimmunity in lpr mice and that T cells expressing a memory phenotype are perpetrators of this process.
MEK1 and the extracellular signal-regulated kinases are required for the stimulation of IL-2 gene transcription in T cells.
Authors: Whitehurst C E , Geppert T D
Published: December 2022

TCR engagement stimulates the activation of the protein kinase Raf-1. Active Raf-1 phosphorylates and activates the mitogen-activated protein (MAP) kinase/extracellular signal-regulated kinase kinase 1 (MEK1), which in turn phosphorylates and activates the MAP kinases/extracellular signal regulated kinases, ERK1 and ERK2. Raf-1 activity promotes IL-2 production in activated T lymphocytes. Therefore, we sought to determine whether MEK1 and ERK activities also stimulate IL-2 gene transcription. Expression of constitutively active Raf-1 or MEK1 in Jurkat T cells enhanced the stimulation of IL-2 promoter-driven transcription stimulated by a calcium ionophore and PMA, and together with a calcium ionophore the expression of each protein was sufficient to stimulate NF-AT activity. Expression of MEK1-interfering mutants inhibited the stimulation of IL-2 promoter-driven transcription and blocked the ability of constitutively active Ras and Raf-1 to costimulate NF-AT activity with a calcium ionophore. Expression of the MAP kinase-specific phosphatase, MKP-1, which blocks ERK activation, inhibited IL-2 promoter and NF-AT-driven transcription stimulated by a calcium ionophore and PMA, and in addition, MKP-1 neutralized the transcriptional enhancement caused by active Raf-1 and MEK1 expression. We conclude that the MAP kinase signal transduction pathway consisting of Raf-1, MEK1, and ERK1 and ERK2 functions in the stimulation IL-2 gene transcription in activated T lymphocytes.
Deletional mapping of fifteen mouse VH gene families reveals a common organization for three Igh haplotypes.
Authors: Mainville C A , Sheehan K M , Klaman L D , Giorgetti C A , Press J L , Brodeur P H
Published: December 2022

In addition to the content of germ-line variable gene segments, the organization of V genes has been implicated in the development of the Ab repertoire. We have searched the expressed VH genes of BALB/c mice for additional VH gene families and utilized deletion mapping to explore the extent of VH gene family interspersion. We have identified and characterized one new VH gene family (VH15) and extended our previous studies of the Igha and Ighb haplotypes to include a third haplotype (Ighj) using a newly developed panel of pre-B cell lines (CXCB cell lines). We conclude that the Igha, Ighb, and Ighj haplotypes have a similar Igh-V locus structure. A refined deletional map for 15 VH gene families and an individual member of the VHSM7 family (H10) has been constructed based on the deletion profiles of 72 rearranged heavy chain loci. These results demonstrate previously unrecognized examples of interspersion among members of the VHS107, VH10, and VHSM7 families.
Molecular cloning and characterization of murine IL-12 genes.
Authors: Yoshimoto T , Kojima K , Funakoshi T , Endo Y , Fujita T , Nariuchi H
Published: December 2022

IL-12 is a heterodimeric cytokine composed of two covalently linked chains, p40 and p35. p40 expression appears to be restricted to monocytes/macrophages and B cells and is highly regulated, while p35 is more ubiquitously and constitutively expressed. To investigate the mechanism involved in the regulation of IL-12 expression, we molecularly cloned and characterized the murine p40 and p35 genes. The p40 gene spans over 14 kb, consists of eight exons and seven introns, and was shown to be localized on chromosome 11A5-B2 by fluorescence in situ hybridization. A single major transcription initiation site was detected by primer extension analysis, and a TATA box was found at approximately 30 bp upstream from the transcription initiation site. The 5' flanking region preceding the transcription initiation site induced the enhanced expression of a promoterless reporter gene after LPS stimulation when transfected into a macrophage-like cell line. In contrast, the p35 gene spans over 8 kb and consists of seven exons and six introns on chromosome 6C, and multiple transcription initiation sites were detected. The 5' flanking region lacks canonical TATA and CAAT boxes at the appropriate position, but, instead, contains GC-rich sequences and constitutively mediated promoter activity when placed upstream of a promoterless reporter gene and transfected into a B cell lymphoma cell line. Thus, the characteristics of promoter regions of p40 and p35 genes are quite different, and this would account for the different regulations of p40 and p35 expression.
Serum amyloid A binds specific extracellular matrix glycoproteins and induces the adhesion of resting CD4+ T cells.
Authors: Preciado-Patt L , Hershkoviz R , Fridkin M , Lider O
Published: December 2022

Serum amyloid A (SAA), a prototypic acute phase protein reactant, exists naturally in the serum of healthy individuals. However, the levels of SAA in serum and its presence in sites of inflammation increase during certain chronic diseases associated with a local elevation of cytokine concentrations. Although the chemical structure of SAA is defined, its putative immunologic role(s) is still obscure. Nevertheless, it has been shown that 1) SAA acts as a chemoattractant and regulator of the migration of monocytes, polymorphonuclear cells, and T lymphocytes through endothelial cell monolayers; and 2) SAA and its proteolytically degraded N-terminal amyloid A fragment contain an extracellular matrix (ECM)-related cell adhesion epitopes. Herein, we examined whether SAA can associate with specific ECM moieties, and whether immobilized SAA-ECM complexes affect T lymphocyte adhesion. Radiolabeled human rSAA ([125I]rSAA) interacted avidly (Kd = 10(-9) M) and transiently with intact ECM, laminin, and vitronectin, but not with fibronectin or collagen type II. The binding of [125I]rSAA to ECM and laminin was inhibited by unlabeled rSAA and by the AA fragment, but not by the C-terminal portion of SAA (amino acid residues 2-82 and 77-104, respectively). Upon interactions with SAA or amyloid A, immobilized ECM, laminin, and vitronectin induced the adhesion of resting human CD4+ T cells in an apparently beta 1-integrin-mediated manner. Thus, the ECM appears to serve as a temporary anchorage site for SAA and amyloid A, and these ECM-complexed molecules seem to be involved in regulating the recruitment and accumulation of immunocytes in extravascular inflammatory compartments.