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2.
J Exp Med ; 194(3): 343-54, 2001 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-11489953

RESUMEN

The stimulation of interferon (IFN)-gamma by interleukin (IL)-12 has been shown to provide protection from intracellular pathogens such as Listeria monocytogenes. Tumor necrosis factor (TNF) is also a major player in the resolution of Listeria infections and is suggested to have more global effects than can be explained by the induction of IFN-gamma alone. Since IL-18 synergizes with IL-12 to induce IFN-gamma production by natural killer and T helper (Th)1 cells, we determined its role in responses to Listeria. IL-18 appeared to be even more potent than either IL-12 or IFN-gamma for protection against this pathogen and IL-18 enhanced bacterial clearance in the complete absence of IFN-gamma. Indeed IL-18 was comparable to TNF in its ability to resolve the infection and showed a lowered protective capacity in the absence of TNF. Moreover, IL-18 induced macrophages to secrete both TNF and nitric oxide after a Listeria infection. IL-18 was also essential for optimal IFN-gamma production by antigen-specific T cells. Therefore, IL-18 operates via its effects on both the innate immune response, including macrophages, as well as on Th1 cells, to protect against Listeria.


Asunto(s)
Interferón gamma/biosíntesis , Interleucina-18/fisiología , Listeria monocytogenes/inmunología , Animales , Anticuerpos Monoclonales/farmacología , Femenino , Memoria Inmunológica , Interleucina-12/fisiología , Interleucina-18/farmacología , Subunidad alfa del Receptor de Interleucina-18 , Listeria monocytogenes/patogenicidad , Listeriosis/etiología , Listeriosis/inmunología , Listeriosis/patología , Macrófagos/inmunología , Ratones , Ratones Endogámicos BALB C , Ratones SCID , Ratones Transgénicos , Pruebas de Neutralización , Receptores de Interleucina/inmunología , Receptores de Interleucina-18 , Proteínas Recombinantes/farmacología , Células TH1/inmunología , Factor de Necrosis Tumoral alfa/fisiología
3.
J Immunol ; 167(3): 1440-6, 2001 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-11466363

RESUMEN

IL-1 is of utmost importance in the host response to immunological challenges. We identified and functionally characterized two novel IL-1 ligands termed IL-1delta and IL-1epsilon. Northern blot analyses show that these IL-1s are highly abundant in embryonic tissue and tissues containing epithelial cells (i.e., skin, lung, and stomach). In extension, quantitative real-time PCR revealed that of human skin-derived cells, only keratinocytes but not fibroblasts, endothelial cells, or melanocytes express IL-1delta and epsilon. Levels of keratinocyte IL-1delta are approximately 10-fold higher than those of IL-1epsilon. In vitro stimulation of keratinocytes with IL-1beta/TNF-alpha significantly up-regulates the expression of IL-1epsilon mRNA, and to a lesser extent of IL-1delta mRNA. In NF-kappaB-luciferase reporter assays, we demonstrated that IL-1delta and epsilon proteins do not initiate a functional response via classical IL-1R pairs, which confer responsiveness to IL-1alpha and beta or IL-18. However, IL-1epsilon activates NF-kappaB through the orphan IL-1R-related protein 2 (IL-1Rrp2), whereas IL-1delta, which shows striking homology to IL-1 receptor antagonist, specifically and potently inhibits this IL-1epsilon response. In lesional psoriasis skin, characterized by chronic cutaneous inflammation, the mRNA expression of both IL-1 ligands as well as IL-1Rrp2 are increased relative to normal healthy skin. In total, IL-1delta and epsilon and IL-1Rrp2 may constitute an independent signaling system, analogous to IL-1alphabeta/receptor agonist and IL-1R1, that is present in epithelial barriers of our body and takes part in local inflammatory responses.


Asunto(s)
Interleucina-1/agonistas , Interleucina-1/fisiología , FN-kappa B/antagonistas & inhibidores , Proteínas/fisiología , Secuencia de Aminoácidos , Animales , Células Cultivadas , Embrión de Mamíferos , Células Epiteliales/inmunología , Células Epiteliales/metabolismo , Humanos , Proteína Antagonista del Receptor de Interleucina 1 , Interleucina-1/genética , Interleucina-1/inmunología , Interleucina-1/metabolismo , Subunidad alfa del Receptor de Interleucina-18 , Células Jurkat , Ligandos , Ratones , Datos de Secuencia Molecular , FN-kappa B/metabolismo , Especificidad de Órganos/genética , Especificidad de Órganos/inmunología , Psoriasis/inmunología , Psoriasis/patología , ARN Mensajero/biosíntesis , Receptores de Interleucina-1/antagonistas & inhibidores , Receptores de Interleucina-1/biosíntesis , Receptores de Interleucina-1/fisiología , Receptores de Interleucina-18 , Alineación de Secuencia , Sialoglicoproteínas/fisiología , Regulación hacia Arriba/inmunología
4.
J Immunol ; 167(1): 336-43, 2001 Jul 01.
Artículo en Inglés | MEDLINE | ID: mdl-11418668

RESUMEN

The sequence of a novel hemopoietic cytokine was discovered in a computational screen of genomic databases, and its homology to mouse thymic stromal lymphopoietin (TSLP) suggests that it is the human orthologue. Human TSLP is proposed to signal through a heterodimeric receptor complex that consists of a new member of the hemopoietin family termed human TSLP receptor and the IL-7R alpha-chain. Cells transfected with both receptor subunits proliferated in response to purified, recombinant human TSLP, with induced phosphorylation of Stat3 and Stat5. Human TSLPR and IL-7Ralpha are principally coexpressed on monocytes and dendritic cell populations and to a much lesser extent on various lymphoid cells. In accord, we find that human TSLP functions mainly on myeloid cells; it induces the release of T cell-attracting chemokines from monocytes and, in particular, enhances the maturation of CD11c(+) dendritic cells, as evidenced by the strong induction of the costimulatory molecules CD40 and CD80 and the enhanced capacity to elicit proliferation of naive T cells.


Asunto(s)
Citocinas/fisiología , Células Mieloides/metabolismo , Timo/fisiología , Secuencia de Aminoácidos , Animales , Línea Celular , Separación Celular , Células Cultivadas , Quimiocina CCL17 , Quimiocinas CC/biosíntesis , Biología Computacional , Citocinas/análisis , Citocinas/metabolismo , Células Dendríticas/inmunología , Células Dendríticas/metabolismo , Humanos , Integrina alfaXbeta2/biosíntesis , Interleucina-7/metabolismo , Interleucina-7/fisiología , Sustancias Macromoleculares , Ratones , Datos de Secuencia Molecular , Monocitos/metabolismo , Células Mieloides/inmunología , Receptores de Citocinas/análisis , Receptores de Citocinas/biosíntesis , Receptores de Interleucina-7/biosíntesis , Células del Estroma/fisiología , Timo/citología , Linfopoyetina del Estroma Tímico
5.
J Immunol ; 166(12): 7563-70, 2001 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-11390512

RESUMEN

p19, a molecule structurally related to IL-6, G-CSF, and the p35 subunit of IL-12, is a subunit of the recently discovered cytokine IL-23. Here we show that expression of p19 in multiple tissues of transgenic mice induced a striking phenotype characterized by runting, systemic inflammation, infertility, and death before 3 mo of age. Founder animals had infiltrates of lymphocytes and macrophages in skin, lung, liver, pancreas, and the digestive tract and were anemic. The serum concentrations of the proinflammatory cytokines TNF-alpha and IL-1 were elevated, and the number of circulating neutrophils was increased. In addition, ubiquitous expression of p19 resulted in constitutive expression of acute phase proteins in the liver. Surprisingly, liver-specific expression of p19 failed to reproduce any of these abnormalities, suggesting specific requirements for production of biologically active p19. Bone marrow transfer experiments showed that expression of p19 by hemopoietic cells alone recapitulated the phenotype induced by its widespread expression, pointing to hemopoietic cells as the source of biologically active p19. These findings indicate that p19 shares biological properties with IL-6, IL-12, and G-CSF and that cell-specific expression is required for its biological activity.


Asunto(s)
Regulación del Desarrollo de la Expresión Génica/inmunología , Trastornos del Crecimiento/genética , Trastornos del Crecimiento/mortalidad , Infertilidad/genética , Infertilidad/mortalidad , Interleucinas/biosíntesis , Interleucinas/genética , Transgenes/inmunología , Proteínas de Fase Aguda/biosíntesis , Proteínas de Fase Aguda/genética , Anemia/sangre , Anemia/genética , Anemia/inmunología , Animales , Trasplante de Médula Ósea/inmunología , Trasplante de Médula Ósea/patología , Pollos , Citocinas/biosíntesis , Regulación hacia Abajo/genética , Regulación hacia Abajo/inmunología , Trastornos del Crecimiento/inmunología , Hematopoyesis Extramedular/genética , Hematopoyesis Extramedular/inmunología , Humanos , Infertilidad/inmunología , Inflamación/genética , Inflamación/inmunología , Inflamación/mortalidad , Factor I del Crecimiento Similar a la Insulina/metabolismo , Interleucina-23 , Subunidad p19 de la Interleucina-23 , Interleucina-6/biosíntesis , Recuento de Leucocitos , Hígado/metabolismo , Hígado/patología , Ratones , Ratones Endogámicos C57BL , Ratones Endogámicos DBA , Ratones Transgénicos , Neutrófilos/patología , Especificidad de Órganos/genética , Especificidad de Órganos/inmunología , Fenotipo , Conejos
6.
Proc Natl Acad Sci U S A ; 98(10): 5515-20, 2001 May 08.
Artículo en Inglés | MEDLINE | ID: mdl-11331761

RESUMEN

Melanoma inhibitory activity (MIA) is a 12-kDa protein that is secreted from both chondrocytes and malignant melanoma cells. MIA has been reported to have effects on cell growth and adhesion, and it may play a role in melanoma metastasis and cartilage development. We report the 1.4-A crystal structure of human MIA, which consists of an Src homology 3 (SH3)-like domain with N- and C-terminal extensions of about 20 aa. each. The N- and C-terminal extensions add additional structural elements to the SH3 domain, forming a previously undescribed fold. MIA is a representative of a recently identified family of proteins and is the first structure of a secreted protein with an SH3 subdomain. The structure also suggests a likely protein interaction site and suggests that, unlike conventional SH3 domains, MIA does not recognize polyproline helices.


Asunto(s)
Proteínas de Neoplasias/química , Secuencia de Aminoácidos , Proteínas de la Matriz Extracelular , Humanos , Modelos Moleculares , Datos de Secuencia Molecular , Conformación Proteica , Homología de Secuencia de Aminoácido
7.
Nature ; 409(6822): 836-8, 2001 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-11237003

RESUMEN

The outstanding problems facing immunology are whole system issues: curing allergic and autoimmune disease and developing vaccines to stimulate stronger immune responses against pathogenic organisms and cancer. We hope that the human genome sequence will reveal the molecular checks and balances that ensure both an effective immunogenic response against pathogenic microorganisms and a suitably tolerogenic response to self antigens and innocuous environmental antigens. Three synergistic approaches--sequence homology searches, messenger RNA expression profiling on microarrays, and mutagenesis in mice--provide the best opportunities to reveal, in the genome sequence, key proteins and pathways for targeting by new immunomodulatory treatments.


Asunto(s)
Genoma Humano , Inmunidad/genética , Animales , Antígenos CD/genética , Antígeno B7-1/genética , Antígeno B7-2 , Citocinas/genética , Bases de Datos Factuales , Expresión Génica , Proyecto Genoma Humano , Humanos , Internet , Glicoproteínas de Membrana/genética , Ratones , Homología de Secuencia , Factor de Necrosis Tumoral alfa/genética
8.
Immunity ; 13(5): 715-25, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11114383

RESUMEN

A novel sequence discovered in a computational screen appears distantly related to the p35 subunit of IL-12. This factor, which we term p19, shows no biological activity by itself; instead, it combines with the p40 subunit of IL-12 to form a novel, biologically active, composite cytokine, which we term IL-23. Activated dendritic cells secrete detectable levels of this complex. IL-23 binds to IL-12R beta 1 but fails to engage IL-12R beta 2; nonetheless, IL-23 activates Stat4 in PHA blast T cells. IL-23 induces strong proliferation of mouse memory (CD4(+)CD45Rb(low)) T cells, a unique activity of IL-23 as IL-12 has no effect on this cell population. Similar to IL-12, human IL-23 stimulates IFN-gamma production and proliferation in PHA blast T cells, as well as in CD45RO (memory) T cells.


Asunto(s)
Citocinas/genética , Interleucina-12/genética , Interleucinas/genética , Secuencia de Aminoácidos , Animales , Linfocitos T CD4-Positivos/inmunología , Citocinas/inmunología , Bases de Datos Factuales , Humanos , Interleucina-12/inmunología , Interleucina-23 , Subunidad p19 de la Interleucina-23 , Interleucinas/inmunología , Ratones , Datos de Secuencia Molecular , Alineación de Secuencia , Análisis de Secuencia
9.
J Immunol ; 165(9): 4950-6, 2000 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-11046021

RESUMEN

IL-18 is critical in eliciting IFN-gamma production from Th1 cells both in vitro and in vivo. Th1 cells have been implicated in the pathogenesis of autoimmune disorders, making antagonists of IL-18 promising therapeutics. However, specificity and binding characteristics of IL-18R components have only been superficially explored. In this study, we show that IL-1R related protein 1 (IL-1Rrp1) and IL-1R accessory protein-like (IL-1RAcPL) confer responsiveness to IL-18 in a highly specific (no response to other IL-1 ligands) and unique manner (no functional pairing with other IL-1Rs and IL-1R-like molecules). Cotransfection with both receptor components resulted in expression of both low and high affinity binding sites for IL-18 (K:(d) of 11 and 0.4 nM, respectively). We prepared anti-IL-1RAcPL mAb TC30-28E3, which, in contrast to soluble R proteins, effectively inhibited the IL-18-induced activation of NF-kappaB. Quantitative PCR showed that Th1 but not Th2 cells are unique in that they coexpress IL-1Rrp1 and IL-1RAcPL. mAb TC30-28E3 inhibited IL-18-induced production of IFN-gamma by Th1 cells, being at least 10-fold more potent than anti-IL-18 ligand mAb. This study shows that IL-1RAcPL is highly specific to IL-18, is required for high affinity binding of IL-18, and that the anti-IL-1RAcPL mAb TC30-28E3 potently antagonizes IL-18 responses in vitro, providing a rationale for the use of anti-IL-1RAcPL Abs to inhibit Th1-mediated inflammatory pathologies.


Asunto(s)
Anticuerpos Monoclonales/farmacología , Interleucina-18/antagonistas & inhibidores , Interleucina-18/metabolismo , Proteínas/inmunología , Receptores de Interleucina-1/inmunología , Receptores de Interleucina/fisiología , Animales , Anticuerpos Monoclonales/metabolismo , Sitios de Unión de Anticuerpos , Línea Celular , Células Clonales , Humanos , Interferón gamma/antagonistas & inhibidores , Interferón gamma/biosíntesis , Proteína Accesoria del Receptor de Interleucina-1 , Subunidad alfa del Receptor de Interleucina-18 , Células Jurkat , Ligandos , Ratones , FN-kappa B/metabolismo , Unión Proteica/inmunología , Receptores de Interleucina/genética , Receptores de Interleucina/metabolismo , Receptores de Interleucina-18 , Células TH1/inmunología , Células TH1/metabolismo , Transfección
10.
Genomics ; 69(2): 252-62, 2000 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-11031108

RESUMEN

The Interleukin-1 receptor (IL-1R) and Toll signaling pathways share the evolutionarily conserved Toll homology domain (THD), which is a critical component in the signaling cascade of the host defense responses to infection and inflammation. Our initial genomic database searches uncovered a novel THD signature sequence between DNA markers DXS87 and DXS366. The feasibility of subsequently applying a coordinated computational approach, including various exon-finding programs, homology-based searches, and receptor profile searches, in revealing the exons encoding this novel IL-1R family member is described. IL-1R9 shows restricted expression in fetal brain and is highly homologous to IL1RAPL (A. Carrie et al., 1999 Nat. Genet. 23: 25-31), which is reportedly involved in nonsyndromic X-linked mental retardation. These genes are scattered over separate genomic intervals in excess of 1.0 Mb and encode receptors with extended C-terminal tails. In our functional NF-kappaB reporter assays, IL1RAPL, IL-1R9, or versions lacking the extended C-terminal sequences failed in responding either to IL-1 directly or to IL-18 when various permutations of IL-18R ectodomain chimeras were fused to their cytoplasmic domains. Evolutionary sequence analyses reinforce our conclusion that these novel orphan receptors probably form a functionally distinct subset of the IL-1R superfamily.


Asunto(s)
Receptores de Interleucina-1/genética , Cromosoma X , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Clonación Molecular , Evolución Molecular , Humanos , Hibridación Fluorescente in Situ , Interleucina-1/metabolismo , Datos de Secuencia Molecular , FN-kappa B/metabolismo , Reacción en Cadena de la Polimerasa , Receptores de Interleucina-1/metabolismo , Receptores Tipo I de Interleucina-1 , Homología de Secuencia de Aminoácido , Transducción de Señal , Programas Informáticos
11.
J Biol Chem ; 275(44): 34442-50, 2000 Nov 03.
Artículo en Inglés | MEDLINE | ID: mdl-10946000

RESUMEN

Doublecortin (DCX) missense mutations are found in two clusters in patients with defective cortical neuronal migration. Although DCX can function as a microtubule-associated protein (MAP), the potential relationship between its MAP activity and neuronal migration is not understood. Here we show that the two clusters of patient mutations precisely define an internal tandem repeat. Each repeat alone binds tubulin, whereas neither repeat is sufficient for co-assembly with microtubules. The two tandem repeats are sufficient to mediate microtubule polymerization, and representative patient missense mutations lead to impaired polymerization both in vitro and in vivo as well as impaired microtubule stabilization. Furthermore, each repeat is predicted to have the secondary structure of a beta-grasp superfold motif, a motif not found in other MAPs. The patient mutations are predicted to disrupt the structure of the motif, suggesting that the motif may be critical for the DCX-tubulin interaction. These data provide both genetic and biochemical evidence that the interaction of DCX with microtubules is dependent upon this novel repeated tubulin-binding motif.


Asunto(s)
Proteínas Asociadas a Microtúbulos , Mutación Missense , Neuropéptidos/genética , Tubulina (Proteína)/metabolismo , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Sitios de Unión , Biopolímeros , Células COS , Movimiento Celular/genética , Cartilla de ADN , Proteínas de Dominio Doblecortina , Proteína Doblecortina , Humanos , Datos de Secuencia Molecular , Neuronas/citología , Neuropéptidos/química , Neuropéptidos/metabolismo , Pliegue de Proteína , Homología de Secuencia de Aminoácido , Secuencias Repetidas en Tándem
12.
J Biol Chem ; 274(32): 22729-38, 1999 Aug 06.
Artículo en Inglés | MEDLINE | ID: mdl-10428856

RESUMEN

We report the expression cloning of a novel leptin-binding protein of the immunoglobulin superfamily (OB-BP1) and a cross-hybridizing clone (OB-BP2) that is identical to a recently described sialic acid-binding I-type lectin called Siglec-5. Comparisons to other known Siglec family members (CD22, CD33, myelin-associated glycoprotein, and sialoadhesin) show that OB-BP1, OB-BP2/Siglec-5, and CD33/Siglec-3 constitute a unique related subgroup with a high level of overall amino acid identity: OB-BP1 versus Siglec-5 (59%), OB-BP1 versus CD33 (63%), and OB-BP2/Siglec-5 versus CD33 (56%). The cytoplasmic domains are not as highly conserved, but display novel motifs which are putative sites of tyrosine phosphorylation, including an immunoreceptor tyrosine kinase inhibitory motif and a motif found in SLAM and SLAM-like proteins. Human tissues showed high levels of OB-BP1 mRNA in placenta and moderate expression in spleen, peripheral blood leukocytes, and small intestine. OB-BP2/Siglec-5 mRNA was detected in peripheral blood leukocytes, lung, spleen, and placenta. A monoclonal antibody specific for OB-BP1 confirmed high expression in the cyto- and syncytiotrophoblasts of the placenta. Using this antibody on peripheral blood leukocytes showed an almost exclusive expression pattern on B cells. Recombinant forms of the extracellular domains of OB-BP1, OB-BP2/Siglec-5, and CD33/Siglec-3 were assayed for specific binding of leptin. While OB-BP1 exhibited tight binding (K(d) 91 nM), the other two showed weak binding with K(d) values in the 1-2 microM range. Studies with sialylated ligands indicated that OB-BP1 selectively bound Neu5Acalpha2-6GalNAcalpha (sialyl-Tn) allowing its formal designation as Siglec-6. The identification of OB-BP1/Siglec-6 as a Siglec family member, coupled with its restricted expression pattern, suggests that it may mediate cell-cell recognition events by interacting with sialylated glycoprotein ligands expressed on specific cell populations. We also propose a role for OB-BP1 in leptin physiology, as a molecular sink to regulate leptin serum levels.


Asunto(s)
Antígenos CD/metabolismo , Antígenos de Diferenciación Mielomonocítica/metabolismo , Inmunoglobulinas/genética , Lectinas , Familia de Multigenes , Ácido N-Acetilneuramínico/metabolismo , Proteínas/metabolismo , Secuencia de Aminoácidos , Antígenos CD/genética , Antígenos CD/aislamiento & purificación , Antígenos de Diferenciación Mielomonocítica/genética , Antígenos de Diferenciación Mielomonocítica/aislamiento & purificación , Clonación Molecular , ADN Complementario/genética , Evolución Molecular , Femenino , Expresión Génica , Humanos , Leptina , Ligandos , Datos de Secuencia Molecular , Placenta/química , Embarazo , Unión Proteica , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Lectina 3 Similar a Ig de Unión al Ácido Siálico , Distribución Tisular
13.
Biochemistry ; 38(5): 1402-14, 1999 Feb 02.
Artículo en Inglés | MEDLINE | ID: mdl-9931005

RESUMEN

Fractalkine, a novel CX3C chemokine, is unusual because of both its membrane-associated structure and its direct role in cell adhesion. We have solved the solution structure of the chemokine domain of fractalkine (residues 1-76) by heteronuclear NMR methods. The 20 lowest energy structures in the ensemble have an average backbone rmsd of 0.43 A, excluding the termini. In contrast to many other chemokines which form homodimers, fractalkine's chemokine module is monomeric. Comparison of the structure to CC and CXC chemokines reveals interesting differences which are likely to be relevant to receptor binding. These include a bulge formed by the CX3C motif, the relative orientation of the N-terminus and 30's loop (residues 30-38), and the conformation of the N-loop (residues 9-19). 15N backbone relaxation experiments indicate that these same regions of the protein are dynamic. We also titrated 15N-labeled protein with a peptide from the N-terminus of the receptor CX3CR1 and confirmed that this region of the receptor contacts the fractalkine chemokine domain. Interestingly, the binding site maps roughly to the regions of greatest flexibility and structural variability. Together, these data provide a first glimpse of how fractalkine interacts with its receptor and should help guide mutagenesis studies to further elucidate the molecular details of binding and signaling through CX3CR1.


Asunto(s)
Quimiocinas CX3C , Quimiocinas CXC/química , Proteínas de la Membrana/química , Fragmentos de Péptidos/química , Receptores de Quimiocina/química , Secuencia de Aminoácidos , Animales , Quimiocina CX3CL1 , Quimiocinas CXC/metabolismo , Simulación por Computador , Cristalografía por Rayos X , Humanos , Proteínas de la Membrana/metabolismo , Ratones , Modelos Moleculares , Datos de Secuencia Molecular , Resonancia Magnética Nuclear Biomolecular , Fragmentos de Péptidos/metabolismo , Conformación Proteica , Receptores CXCR3 , Receptores de Quimiocina/metabolismo , Soluciones , Termodinámica
14.
J Leukoc Biol ; 65(1): 87-93, 1999 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-9886250

RESUMEN

In this study we describe the isolation and characterization of a new chicken (Gallus gallus) chemokine. This molecule belongs to the C or gamma-chemokine family and is related to the mouse and human lymphotactin (Lptn). Mouse and human Lptn are distinguished from alpha and beta chemokines by the absence of two cysteines (Cys 1 and 3) that form a disulfide bridge; the novel chicken chemokine shows the same cysteine pattern, but replaces a long carboxy-terminal tail found in the other Lptn proteins with a short extension rich in Arg residues. The 1-kb mRNA is mainly expressed in spleen, although weaker signals have been detected in liver and colon. It is interesting to note that the chicken chemokine seems to preferentially induce the migration of spleen B cells over T cells or B cells from the bursa of Fabricius.


Asunto(s)
Quimiocinas C/genética , Linfocinas/genética , Sialoglicoproteínas/genética , Secuencia de Aminoácidos , Animales , Linfocitos B/citología , Linfocitos B/efectos de los fármacos , Northern Blotting , Células COS/metabolismo , Bovinos , Quimiocinas C/aislamiento & purificación , Quimiocinas C/fisiología , Quimiotaxis de Leucocito , Pollos , ADN Complementario/genética , ADN Complementario/aislamiento & purificación , Perros , Haplorrinos , Humanos , Ratones , Datos de Secuencia Molecular , Filogenia , ARN Mensajero/metabolismo , Conejos , Ratas , Homología de Secuencia de Aminoácido , Bazo/metabolismo
15.
Genomics ; 47(2): 163-70, 1998 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-9479488

RESUMEN

We report here the identification and characterization of the mouse homologue of a human CX3C chemokine described by F. Bazan et al. (1997, Nature 385, 640-644). Termed fractalkine, this molecule constitutes a fourth or delta chemokine structural type that displays a novel CX3C sequence fingerprint. Distinct from the alpha, beta, or gamma chemokine families, the polypeptide chain of CX3C predicts a 373-amino-acid type I transmembrane glycoprotein with the chemokine domain resting on top of an extended mucin-like stalk. Comparison of the mouse and human protein chains shows a high degree of conservation in all the globular segments with the exception of the stalk portion. The striking identity of an amino acid stretch encompassing a putative juxtamembrane cleavage site suggests the evolutionary conservation of both membrane-bound and processed CX3C forms. Northern analysis reveals the presence of mouse CX3C mRNA in heart, brain, lung, kidney, skeletal muscle, and testis tissues. The mouse CX3C gene was further localized to the central region of chromosome 8 by interspecific backcross mapping; a related locus was detected on chromosome 11. The novel location of this gene from other chemokine gene clusters adds to the notion that CX3C is a fundamentally new class of chemokine.


Asunto(s)
Quimiocinas CX3C , Quimiocinas/química , Quimiocinas/genética , Proteínas de la Membrana/química , Proteínas de la Membrana/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Encéfalo/metabolismo , Quimiocina CX3CL1 , Quimiocinas/aislamiento & purificación , Mapeo Cromosómico , Clonación Molecular , Biología Computacional , ADN Complementario/aislamiento & purificación , Femenino , Humanos , Riñón/metabolismo , Pulmón/metabolismo , Masculino , Proteínas de la Membrana/aislamiento & purificación , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Músculo Esquelético/metabolismo , Miocardio/metabolismo , Especificidad de Órganos/genética , Testículo/metabolismo , Transcripción Genética
16.
Proc Natl Acad Sci U S A ; 95(2): 588-93, 1998 Jan 20.
Artículo en Inglés | MEDLINE | ID: mdl-9435236

RESUMEN

The discovery of sequence homology between the cytoplasmic domains of Drosophila Toll and human interleukin 1 receptors has sown the conviction that both molecules trigger related signaling pathways tied to the nuclear translocation of Rel-type transcription factors. This conserved signaling scheme governs an evolutionarily ancient immune response in both insects and vertebrates. We report the molecular cloning of a class of putative human receptors with a protein architecture that is similar to Drosophila Toll in both intra- and extracellular segments. Five human Toll-like receptors--named TLRs 1-5--are probably the direct homologs of the fly molecule and, as such, could constitute an important and unrecognized component of innate immunity in humans. Intriguingly, the evolutionary retention of TLRs in vertebrates may indicate another role--akin to Toll in the dorsoventralization of the Drosophila embryo--as regulators of early morphogenetic patterning. Multiple tissue mRNA blots indicate markedly different patterns of expression for the human TLRs. By using fluorescence in situ hybridization and sequence-tagged site database analyses, we also show that the cognate Tlr genes reside on chromosomes 4 (TLRs 1, 2, and 3), 9 (TLR4), and 1 (TLR5). Structure prediction of the aligned Toll-homology domains from varied insect and human TLRs, vertebrate interleukin 1 receptors and MyD88 factors, and plant disease-resistance proteins recognizes a parallel beta/alpha fold with an acidic active site; a similar structure notably recurs in a class of response regulators broadly involved in transducing sensory information in bacteria.


Asunto(s)
Proteínas de Drosophila , Drosophila/genética , Proteínas de Insectos/genética , Glicoproteínas de Membrana/genética , Receptores de Superficie Celular/genética , Secuencia de Aminoácidos , Animales , Clonación Molecular , Secuencia Conservada , ADN Complementario/análisis , ADN Complementario/genética , Humanos , Datos de Secuencia Molecular , Homología de Secuencia de Aminoácido , Receptor Toll-Like 4 , Receptor Toll-Like 5 , Receptores Toll-Like
17.
Eur J Immunol ; 27(11): 2787-92, 1997 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9394800

RESUMEN

Interferon-gamma inducing factor (IGIF) is a recently identified cytokine which stimulates the production of interferon-gamma (IFN-gamma) by T cells and enhances natural killer (NK) cell cytolytic activity. Protein fold recognition, structure prediction and comparative modeling have revealed that IGIF is a member of the interleukin (IL)-1 cytokine family and has prompted the designation IL-1 gamma. Here we report functional similarities between members of the IL-1 family by comparing the effects of IL-1 alpha, IL-1 beta and IGIF on NK cell production of IFN-gamma. All three IL-1 types enhanced NK cell production of IFN-gamma when induced by IL-2 or IL-12, although at high concentrations (> 10 ng/ml), IGIF was five- to tenfold more potent than IL-1 alpha or IL-1 beta. This effect correlated with enhanced levels of mRNA for IFN-gamma when NK cells were stimulated with IGIF plus IL-12. In contrast to IL-12 and IL-2, the ability of IGIF to stimulate NK cell production of IFN-gamma was not increased by IL-1 alpha or IL-1 beta. The ability of IGIF to enhance IFN-gamma production was independent of the type I and type II IL-1 receptors or the IL-1R accessory protein. Together, these results identify IGIF as a potent stimulator of NK cell production of IFN-gamma and demonstrate that the effect of IGIF on NK cell production of IFN-gamma is similar to that of IL-1 alpha and IL-1 beta but distinct from that of IL-12.


Asunto(s)
Citocinas/farmacología , Inductores de Interferón/farmacología , Interferón gamma/biosíntesis , Interleucina-1/farmacología , Células Asesinas Naturales/efectos de los fármacos , Células Asesinas Naturales/metabolismo , Adyuvantes Inmunológicos/farmacología , Animales , Citocinas/antagonistas & inhibidores , Femenino , Interferón gamma/efectos de los fármacos , Proteína Antagonista del Receptor de Interleucina 1 , Interleucina-1/antagonistas & inhibidores , Interleucina-1/fisiología , Proteína Accesoria del Receptor de Interleucina-1 , Interleucina-18 , Células Asesinas Naturales/inmunología , Ratones , Ratones Endogámicos C57BL , Ratones SCID , Proteínas/fisiología , Receptores de Interleucina-1/fisiología , Sialoglicoproteínas/fisiología
18.
Genomics ; 45(2): 332-9, 1997 Oct 15.
Artículo en Inglés | MEDLINE | ID: mdl-9344657

RESUMEN

The myeloid differentiation (MyD) marker MyD88 was initially characterized as a primary response gene, upregulated in mouse M1 myeloleukemic cells in response to differentiation induced by interleukin-6. Subsequent analysis revealed that MyD88 possesses a unique modular structure, which consists of an N-terminal "death domain," similar to the intracellular segments of TNF receptor 1 and Fas, and a C-terminal region related to the cytoplasmic domains of the Drosophila morphogen Toll and vertebrate interleukin-1 receptors. In this report we describe the cloning and gene structure of mouse MyD88. The complete coding sequence of mouse MyD88 spans five exons, with the first exon encoding the complete death domain. Zooblot analysis revealed that MyD88 is an evolutionarily conserved gene. MyD88 was localized to the distal region of mouse chromosome 9 by interspecific backcross mapping. The human homolog (hMyD88) was mapped to chromosome 3p22-p21.3 by PCR analysis of a human chromosome 3 somatic cell hybrid mapping panel. Northern blot analysis revealed widespread expression of MyD88 in many adult mouse tissues, and RT-PCR studies detected MyD88 mRNA in T and B cell lines and differentiating embryonic stem cells. The broad expression pattern demonstrates that mouse MyD88 expression is not restricted to cells of myeloid lineage as was originally believed.


Asunto(s)
Antígenos de Diferenciación , Proteínas/genética , Receptores Inmunológicos , Proteínas Adaptadoras Transductoras de Señales , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Mapeo Cromosómico , Cromosomas Humanos Par 3/genética , Cruzamientos Genéticos , Cartilla de ADN/genética , ADN Complementario/genética , Evolución Molecular , Exones , Femenino , Expresión Génica , Marcadores Genéticos , Humanos , Células Híbridas , Masculino , Ratones , Ratones Endogámicos C57BL , Datos de Secuencia Molecular , Muridae , Factor 88 de Diferenciación Mieloide , Reacción en Cadena de la Polimerasa , ARN Mensajero/genética , ARN Mensajero/metabolismo , Distribución Tisular
20.
Nature ; 385(6617): 640-4, 1997 Feb 13.
Artículo en Inglés | MEDLINE | ID: mdl-9024663

RESUMEN

Chemokines direct the trafficking of white blood cells in immune surveillance, playing a key role in inflammatory and infectious diseases such as AIDS. All chemokines studied so far are secreted proteins of relative molecular mass approximately 7K-15K and fall into three families that are defined by a cysteine signature motif: CXC, CC and C (refs 3, 6, 7), where C is a cysteine and X any amino-acid residue. We report here the identification and characterization of a fourth human chemokine type, derived from non-haemopoietic cells and bearing a new CX3C fingerprint. Unlike other chemokine types, the polypeptide chain of the human CX3C chemokine is predicted to be part of a 373-amino-acid protein that carries the chemokine domain on top of an extended mucin-like stalk. This molecule can exist in two forms: either membrane-anchored or as a shed 95K glycoprotein. The soluble CX3C chemokine has potent chemoattractant activity for T cells and monocytes, and the cell-surface-bound protein, which is induced on activated primary endothelial cells, promotes strong adhesion of those leukocytes. The structure, biochemical features, tissue distribution and chromosomal localization of CX3C chemokine all indicate that it represents a unique class of chemokine that may constitute part of the molecular control of leukocyte traffic at the endothelium.


Asunto(s)
Quimiocinas CX3C , Quimiocinas/química , Proteínas de la Membrana/química , Secuencia de Aminoácidos , Línea Celular , Quimiocina CX3CL1 , Quimiocinas/genética , Quimiocinas/metabolismo , Mapeo Cromosómico , Clonación Molecular , ADN Complementario , Humanos , Células Híbridas , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Datos de Secuencia Molecular , Unión Proteica , ARN Mensajero/metabolismo , Distribución Tisular
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