Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound   Target Concepts: Gene/Protein Disease Symptom Drug Enzyme Compound

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Query: UMLS:C0085110 (SCID)
11,041 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

IL-8 has been shown to be a human neutrophil and T cell chemoattractant in vitro. In an effort to assess the in vivo effects of IL-8 on human leukocyte migration, we examined the ability of rhIL-8 to induce human T cell infiltration using a human/mouse model in which SCID mice were administered human peripheral blood lymphocytes intraperitoneally, followed by subcutaneous injections of rhIL-8. rhIL-8 induced predominantly murine neutrophil accumulation by 4 h after administration while recombinant human macrophage inflammatory protein-1beta (rhMIP-1beta) induced both murine monocytes and human T cell infiltration during the same time period as determined by immunohistology. Interestingly, 72 h after chemokine administration, a marked human T cell infiltrate was observed in the IL-8 injection site suggesting that rhIL-8 may be acting indirectly possibly through a murine neutrophil-derived T cell chemoattractant. This hypothesis was confirmed using granulocyte-depleted SCID mice. Moreover, human neutrophils stimulated in vitro with IL-8 were found to release granule-derived factor(s) that induce in vitro T cell and monocyte chemotaxis and chemokinesis. This T cell and monocyte chemotactic activity was detected in extracts of both azurophilic and specific granules. Together, these results demonstrate that neutrophils store and release, upon stimulation with IL-8 or other neutrophil activators, chemoattractants that mediate T cell and monocyte accumulation at sites of inflammation.
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PMID:T lymphocyte recruitment by interleukin-8 (IL-8). IL-8-induced degranulation of neutrophils releases potent chemoattractants for human T lymphocytes both in vitro and in vivo. 862 78

Previous studies from this laboratory have demonstrated that the chemokines RANTES (recombinant human regulated upon activation, normally T cell expressed and presumably secreted), macrophage chemotactic peptide-1, recombinant human macrophage inflammatory protein-1 alpha (rhMIP-1 alpha) IL-8, and IP-10 are capable of inducing human T cell infiltration into the injection site of severe combined immunodeficiency (SCID) mice reconstituted with human PBL. However, the ability of these chemokines to facilitate T cell homing into various lymphoid tissues has not been examined. Initial studies focused on the ability of rhMIP-1 beta to induce human T cell infiltration into injection sites in human PBL-SCID mice. SCID mice received s.c. injections of rhMIP-1 beta or PBS (1 microgram/injection) in the hindflank for 4 h or sequential injections for 3 days. Biopsies of the MIP-1 beta injection site revealed the presence of significant mononuclear cell accumulation 72 h after injection. Immunohistologic evaluation determined that significant numbers of human CD3+ T cells were recruited in response to MIP-1 beta injections, and this infiltration could be specifically blocked by co-administration of anti-MIP-1 beta antiserum. We subsequently examined these chemokine-injected mice for the effect of trafficking of human T cells to peripheral lymphoid organs. Flow cytometric analysis of the thymus in human PBL-SCID mice revealed that treatment with rhMIP-1 beta or rhRANTES, but not platelet factor-4, resulted in improved thymic homing of the human T cells after 72 h. This trafficking effect was shown to be direct, as pretreatment of the human T cells with the chemokines in vitro also improved peripheral lymphoid trafficking of the human cells. In addition, co-injection of rhMIP-1 beta with anti-1 beta antiserum abrogated the increase in T cell homing to the thymus. These data demonstrate that MIP-1 beta and RANTES directly augment human T cell trafficking to peripheral murine lymphoid tissues. Chemokines may, therefore, under either isogeneic or xenogeneic conditions, play a role in normal lymphocyte recirculation and homing, and may be of potential clinical use in promoting immune cell trafficking and function.
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PMID:Chemokines and T lymphocyte activation: II. Facilitation of human T cell trafficking in severe combined immunodeficiency mice. 869 Aug 98

The identification of fusin and other chemokine receptors as coreceptors for HIV-1 has renewed the interest in agents that may prevent viral entry. Polyanionic compounds such as dextran sulfate, curdian sulfate, and suramin act on the V3 loop of the viral envelope and may prevent its interaction with fusin. These agents show activity against a wide range of HIV-1 strains, but have undesirable circulating half-life, bioavailability, and toxicity. We have developed a small molecule inhibitor of HIV-1 that has several advantages over these other agents. FP-21399 is a novel compound of the bis(disulfonaphthalene) dimethoxybenzene class that blocks entry of HIV into CD4+ cells and blocks fusion of infected and noninfected CD4+ cells. This compound only weakly inhibits binding of CD4 and gp120, at concentrations much greater than are required to block viral entry. Furthermore, FP-21399 can block the interaction between gp120 and antibodies directed against the V3 loop, but does not block binding of antibodies directed against the V4 loop. Animal studies demonstrate that FP-21399 is concentrated in lymph nodes, making it a promising compound for anti-HIV therapy. In SCID mice reconstituted with human immune cells, maintenance of HIV-1 infection was blocked by a 5-day treatment with low doses of FP-21399, suggesting that lymph node accumulation may contribute to antiviral activity. Finally, attempts to generate drug-resistant virus in cell culture resulted in only weakly resistant variants with IC90 values that are much lower than concentrations of FP-21399 found in lymph nodes.
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PMID:FP-21399 blocks HIV envelope protein-mediated membrane fusion and concentrates in lymph nodes. 909 35

By reverse transcriptase-polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemistry, MGSA-alpha, -beta, -gamma, and CXCR2 mRNA expression and proteins are detected in 7 out of 10 human melanoma lesions. The biological consequence of constitutive expression of the MGSA/GRO chemokine in immortalized melanocytes was tested in SCID and nude mouse models. Continuous expression of MGSA/GRO-alpha, -beta, or -gamma in immortalized melan-a mouse melanocytes results in nearly 100% tumor formation for each of the clones tested, whereas clones expressing only the neomycin resistance vector form tumors <10% of the time. Moreover, antibodies to the MGSA/GRO proteins slow or inhibit the formation of tumors in the SCID mouse model and block the angiogenic response to conditioned medium from the tumor-producing clones. Transcription of the MGSA/GRO chemokines is regulated by an enhancesome-like complex comprised of the nuclear factor-kappaB (NF-kappaB), HMG(I)Y, IUR, and Sp1 elements. In Hs294T melanoma cells the half life of the IKB protein is shortened in comparison to normal retinal epithelial cells, facilitating the endogenous nuclear localization of NF-kappaB. We propose that this endogenous nuclear NF-kappaB, working in concert with the 115-kDa IUR-binding factor, promotes constitutive expression of MGSA/GRO genes.
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PMID:Mechanism and biological significance of constitutive expression of MGSA/GRO chemokines in malignant melanoma tumor progression. 936 13

Cryptosporidium parvum infects intestinal epithelial cells and does not invade deeper layers of the intestinal mucosa. Nonetheless, an inflammatory cell infiltrate that consists of neutrophils and mononuclear cells is often present in the lamina propria, which underlies the epithelium. This study investigated the host epithelial cell response to C. parvum by assessing in vitro and in vivo the expression and production of proinflammatory cytokines by intestinal epithelial cells after infection. The human colon epithelial cell lines HCT-8 and Caco-2 and human intestinal xenografts in SCID mice were infected with C. parvum. The expression and secretion of the C-X-C chemokines interleukin-8 (IL-8) and GROalpha were determined by reverse transcription-PCR analysis and enzyme-linked immunosorbent assay. Our results demonstrate that upregulated expression and secretion of IL-8 and GROalpha after C. parvum infection of intestinal epithelial cells first occurred 16 to 24 h after infection and increased over the ensuing 1 to 2 days. The kinetics of C-X-C chemokine production by C. parvum-infected epithelial cells contrast markedly with the rapid but transient expression of C-X-C chemokines by epithelial cells infected with invasive enteric bacteria. C-X-C chemokine secretion in C. parvum-infected epithelial cells occurred predominantly from the basolateral surface in polarized monolayers of Caco-2 cells grown in Transwell cultures, whereas cell lysis occurred at the apical surface. The basolateral secretion of IL-8 and GROalpha from C. parvum-infected epithelial cells suggests that C-X-C chemokines produced by those cells contribute to the mucosal inflammatory cell infiltrate in the underlying intestinal mucosa.
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PMID:Cryptosporidium parvum infection of human intestinal epithelial cells induces the polarized secretion of C-X-C chemokines. 939 97

Most individuals infected with human immunodeficiency virus type 1 (HIV-1) initially harbor macrophage-tropic, non-syncytium-inducing (M-tropic, NSI) viruses that may evolve into T-cell-tropic, syncytium-inducing viruses (T-tropic, SI) after several years. The reasons for the more efficient transmission of M-tropic, NSI viruses and the slow evolution ofT-tropic, SI viruses remain unclear, although they may be linked to expression of appropriate chemokine coreceptors for virus entry. We have examined plasma viral RNA levels and the extent of CD4+ T-cell depletion in SCID mice reconstituted with human peripheral blood leukocytes following infection with M-tropic, dual-tropic, or T-tropic HIV-1 isolates. The cell tropism was found to determine the course of viremia, with M-tropic viruses producing sustained high viral RNA levels and sparing some CD4+ T cells, dual-tropic viruses producing a transient and lower viral RNA spike and extremely rapid depletion of CD4+ T cells, and T-tropic viruses causing similarly lower viral RNA levels and rapid-intermediate rates of CD4+ T-cell depletion. A single amino acid change in the V3 region of gp120 was sufficient to cause one isolate to switch from M-tropic to dual-tropic and acquire the ability to rapidly deplete all CD4+ T cells.
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PMID:The cell tropism of human immunodeficiency virus type 1 determines the kinetics of plasma viremia in SCID mice reconstituted with human peripheral blood leukocytes. 949 54

In this article, we show that passage in SCID mice rendered a human CD4(+) T-cell line (CEM cells) highly susceptible to infection by macrophage-tropic (M-tropic) strains and primary clinical isolates of human immunodeficiency virus type 1 (HIV-1). This in vivo-acquired permissiveness of CEM cells was associated with the induction of a CD45RO+ phenotype as well as of some beta-chemokine receptors. Regulated upon activation, normal T-cell expressed and secreted chemokine entirely inhibited the ability of M-tropic HIV-1 strains to infect these cells. These findings may lead to new approaches in investigating in vivo the capacity of different HIV strains to exploit chemokine receptors in relation to the dynamics of the activation and/or differentiation state of human CD4(+) T cells.
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PMID:Human lymphoblastoid CD4(+) T cells become permissive to macrophage-tropic strains of human immunodeficiency virus type 1 after passage into severe combined immunodeficient mice through in vivo upregulation of CCR5: in vivo dynamics of CD4(+) T-cell differentiation in pathogenesis of AIDS. 981 84

The numbers of immune-activated brain mononuclear phagocytes (MPs) affect the progression of human immunodeficiency virus (HIV)-1-associated dementia (HAD). Such MPs originate, in measure, from a pool of circulating monocytes. To address the mechanism(s) for monocyte penetration across the blood-brain barrier (BBB), we performed cross-validating laboratory, animal model, and human brain tissue investigations into HAD pathogenesis. First, an artificial BBB was constructed in which human brain microvascular endothelial and glial cells-astrocytes, microglia, and/or monocyte-derived macrophages (MDM)-were placed on opposite sides of a matrix-coated porous membrane. Second, a SCID mouse model of HIV-1 encephalitis (HIVE) was used to determine in vivo monocyte blood-to-brain migration. Third, immunohistochemical analyses of human HIVE tissue defined the relationships between astrogliosis, activation of microglia, virus infection, monocyte brain infiltration, and beta-chemokine expression. The results, taken together, showed that HIV-1-infected microglia increased monocyte migration through an artificial BBB 2 to 3.5 times more than replicate numbers of MDM. In the HIVE SCID mice, a marked accumulation of murine MDM was found in areas surrounding virus-infected human microglia but not MDM. For human HIVE, microglial activation and virus infection correlated with astrogliosis, monocyte transendothelial migration, and beta-chemokine expression. Pure cultures of virus-infected and activated microglia or astrocytes exposed to microglial conditioned media produced significant quantities of beta-chemokines. We conclude that microglial activation alone and/or through its interactions with astrocytes induces beta-chemokine-mediated monocyte migration in HAD.
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PMID:Microglial and astrocyte chemokines regulate monocyte migration through the blood-brain barrier in human immunodeficiency virus-1 encephalitis. 1055 Mar 17

To study the mechanisms underlying the development of interstitial pneumonia in autoimmune disease, we analyzed bronchoalveolar lavage fluid (BALF) in an animal model of interstitial pneumonia in which an intratracheal instillation of staphylococcal enterotoxin B (SEB) induced interstitial pneumonia in autoimmune-prone mice. Increases in the numbers of total cells, macrophages, lymphocytes, and neutrophils were observed in BALF from SEB-treated MRL +/+ mice, and peaked at 3 d after SEB administration (Day 3). Flow cytometric analyses revealed increases in SEB-reactive Vbeta8(+) T cells, indicating that SEB-reactive cells play an important role in bronchoalveolar space. The expressions of tumor necrosis factor (TNF)-alpha, interferon (IFN)-gamma, JE/monocyte chemoattractant protein-1, regulated on activation, normal T cells expressed and secreted, and KC/gro messenger RNA (mRNA) in BALF cells from SEB-treated mice peaked at Day 3. Increased expression of TNF-alpha mRNA was observed mainly in macrophages and CD8(+) T cells, and the increase in IFN-gamma mRNA was observed mainly in CD8(+) T cells in BALF at Day 3. The expression of platelet-derived growth factor mRNA was very weak at Day 3 but strongly expressed at Day 14. An immunosuppressant, FK506, but not corticosteroid, suppressed SEB-induced T-cell expansion in BALF as well as increased cytokine and chemokine production in the bronchoalveolar space of SEB-treated mice. Histologically, FK506 but not corticosteroid significantly reduced both the cell infiltration to alveolar septal walls and the synthesis of pulmonary collagen fibers. Further, transfer of T cells of MRL +/+ mice with SEB into SCID mice gave rise to interstitial pneumonia. These results suggest that superantigen-reactive T cells in the bronchoalveolar space may trigger the development of interstitial pneumonia in this model.
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PMID:Role of T cells in bronchoalveolar space in the development of interstitial pneumonia induced by superantigen in autoimmune-prone mice. 1057 64

The in vivo function of the CXC chemokines interferon-inducible protein-10 (IP-10) and monokine induced by gamma (MIG) was examined using replication-deficient adenoviral vectors expressing human IP-10 (AdIP-10) or murine MIG (AdMIG). Intratracheal and intranasal administration of AdIP-10 or AdMIG into rats and mice produced transient chemokine overexpression from the bronchial epithelium. IP-10 concentrations in the bronchoalveolar lavage fluid (BAL) of AdIP-10-treated animals showed peak expression (>2 ng/ml) 24-48 h after AdIP-10 administration. Dramatic transient increases in BAL cellularity (macrophages, monocytes, lymphocytes, and neutrophils) were observed in AdIP-10-treated and AdMIG-treated animals, and histologic examination of AdIP-10-treated lungs revealed transient infiltrations of mononuclear cells primarily localized around the bronchus and extending throughout the lung parenchyma. However, in immunocomprised SCID mice, only increases in natural killer cell populations were detected in BAL following AdIP-10 intranasal administration, indicating that monocyte/macrophage and neutrophil accumulation was likely the result of factors released from activated lymphocytes.
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PMID:Transient gene transfer of non-ELR chemokines to rodent lung induces mononuclear cell accumulation and activation. 1063 7


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