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Biomedical subjects

Steven D Douglas

Publications and source records attributed to Steven D Douglas.

At least 37 records · Page 2Linked to original sources
PubMed2005

Alcohol suppresses IL-2-induced CC chemokine production by natural killer cells.

BACKGROUND: Natural killer (NK) cells are a critical component of the host innate immune system. We investigated whether alcohol impairs NK cell function, particularly production of CC chemokines induced by interleukin (IL)-2, the natural ligands for CCR5 receptor. METHODS: Primary NK cells and NK cell line (YTS) were cultured with or without alcohol (10 to 80 mM) for three hours. The culture supernatants were then harvested and used to treat human peripheral blood monocyte-derived macrophages and a HeLa cell line, which expresses CD4, CCR5, and CXCR4 receptors (MAGI cells). CC chemokine expression by YTS and primary NK cells treated with or without alcohol was analyzed with the real-time RT-PCR and ELISA. [Ca(2)(+)]i and Western blot assays were used to determine calcium-mediated intracellular signaling pathway and NF-kappaB p65 expression. HIV strains (Bal and UG024) were used to infect macrophages and MAGI cells. In addition, ADA (macrophage-tropic strain) and murine leukemia virus (MLV) envelope-pseudotyped HIV infection was carried out in macrophages. HIV infectivity was determined by HIV reverse transcriptase (RT) and beta-galactosidase activity assays. RESULTS: Alcohol inhibited IL-2-induced CC chemokine (CCL3 and CCL4) expression by NK cells. Functional tests demonstrated that this reduced expression of CC chemokines was associated with diminished anti-HIV ability of NK cells. Alcohol also reduced the ability of NK cells to response to CCL3-mediated chemotaxis. Alcohol inhibited IL-2-induced NF-kappaB p65 protein expression and calcium mobilization by NK cells. CONCLUSIONS: Alcohol, through the inhibition of IL-2-induced NF-kappaB p65 protein expression and intracellular calcium mobilization, suppressed NK cell production of CC chemokines. This suppression of CC chemokine production was associated with diminished anti-HIV activity of NK cells. Thus, by inhibiting NK cell-mediated innate immunity against HIV, alcohol consumption may have a cofactor role in the immunopathogenesis of HIV disease.

Adult↗
PubMed2005

Real-time reverse transcription-PCR quantitation of substance P receptor (NK-1R) mRNA.

The substance P (SP)-preferring receptor, neurokinin-1 receptor (NK-1R), has an important role in inflammation, immune regulation, and viral infection. We applied a newly developed real-time reverse transcription (RT)-PCR assay to quantify NK-1R mRNA in human neuronal cell line (NT-2N), a human B-cell line (IM9), monocyte-derived macrophages (MDM), peripheral blood lymphocytes (PBL), and human astroglioma cells (U87 MG). The NK-1R real-time RT-PCR assay has a sensitivity of 100 mRNA copies, with a dynamic range of detection between 10(2) and 10(7) copies of NK-1R gene transcripts per reaction. This assay is highly reproducible, with an intraassay coefficient variation of threshold cycle (Ct) of less than 1.9%. The NK-1R real-time RT-PCR is highly sensitive for quantitative determination of NK-1R mRNA in human immune cells (MDM and PBL) that express low levels of NK-1R mRNA. In addition, the assay has the ability to accurately quantitate the dynamic changes in NK-1R mRNA expression in interleukin-1beta-stimulated U87 MG. These data indicate that the NK-1R real-time RT-PCR has potential for a wide application in investigation of NK-1R expression at the mRNA level under physiological and pathological conditions in both the central nervous system and the immune system.

Cells, Cultured↗
PubMed2005

Association of resolution of major depression with increased natural killer cell activity among HIV-seropositive women.

OBJECTIVE: Depression is a potential risk factor for morbidity and mortality among patients with numerous medical conditions, including HIV disease, and it is also associated with decrements in immune function, such as natural killer (NK) cell activity. This study examined whether improvements in the diagnostic status of major depression are related to increases in NK cell activity among HIV-seropositive women. METHOD: HIV-seropositive women were recruited as part of a longitudinal cohort study and underwent comprehensive medical and psychiatric evaluations during a 2-year period. Fifty-seven women had complete NK cell activity and depression data measured at two time points and were examined for associations between changes in depression status and alterations in NK cell activity over time. RESULTS: Among the 57 HIV-seropositive women, improvements in the diagnostic status of depression and decreases in scores on the 17-item Hamilton Depression Rating Scale were significantly associated with increases in NK cell activity over time, as measured in lytic units. Eleven women (19.3%) had a major depression diagnosis that resolved over time, and this group also had a significant increase in cell activity measured in lytic units during this period. CONCLUSIONS: This study suggests that depression may impair certain aspects of innate cellular immunity relevant to delaying the progression of HIV disease and that these alterations are reversible with the resolution of a depressive episode. These findings support an examination of NK cell activity in assessments of the relationship between depression and morbidity and mortality in HIV disease.

Adult↗
PubMed2004

Interleukin-1beta upregulates functional expression of neurokinin-1 receptor (NK-1R) via NF-kappaB in astrocytes.

Cytokines and neuropeptides are modulators of neuroimmunoregulation in the central nervous system (CNS). The interaction of these modulators may have important implications in CNS diseases. We investigated whether interleukin-1beta (IL-1beta) modulates the expression of neurokinin-1 receptor (NK-1R), the primary receptor for substance P (SP), a potent neuropeptide in the CNS. IL-1beta upregulated NK-1R expression in human astroglioma cells (U87 MG) and primary rat astrocytes at both mRNA and protein levels. IL-1beta treatment of U87 MG cells and primary rat astrocytes led to an increase in cytosolic Ca(2+) in response to SP stimulation, indicating that IL-1beta-induced NK-1R is functional. CP-96,345, a specific non-peptide NK-1R antagonist, inhibited SP-induced rise of [Ca(2+)](i) in the astroglioma cells. Investigation of the mechanism responsible for IL-1beta action revealed that IL-1beta has the ability of activating nuclear factor-kappab (NF-kappaB). Caffeic acid phenethyl ester (CAPE), a specific inhibitor of NF-kappaB activation, not only abrogated IL-1beta-induced NF-kappaB promoter activation, but also blocked IL-1beta-mediated induction of NK-1R gene expression. These findings provide additional evidence that there is a biological interaction between IL-1beta and the neuropeptide SP in the CNS, which may have important implications in the inflammatory diseases in the CNS.

Animals↗
PubMed2004

Natural killer cells inhibit hepatitis C virus expression.

Natural killer (NK) cells are critical in host innate defense against certain viruses. The role of NK cells in controlling hepatitis C virus (HCV) remains obscure. We examined whether NK cells are capable of inhibiting HCV expression in human hepatic cells. When NK cells are cultured with the HCV replicon-containing hepatic cells, they have no direct cytolytic effect but release soluble factor(s) suppressing HCV RNA expression. Media conditioned by NK cell lines (NK-92 and YTS) or primary NK cells isolated from healthy donors contain interferon gamma (IFN-gamma) and potently inhibit HCV RNA expression. Ligation of CD81 on NK cells inhibits IFN-gamma production and results in decreased anti-HCV activity. In addition, the antibodies to IFN-gamma or IFN-gamma receptors abolish the anti-HCV activity of NK cell-conditioned media. The role of IFN-gamma in NK cell-mediated, anti-HCV activity is supported by the observation that NK cell-conditioned media enhanced expression of signal transducer and activator of transcription-1, a nuclear factor that is essential in IFN-gamma-mediated antiviral pathways. NK cell-conditioned media have the ability to stimulate intracellular IFN-alpha expression in the hepatic cells, suggesting a mechanism responsible for NK cell-mediated, anti-HCV activity. Thus, NK cells hold the potential to play a vital role in controlling HCV replication in hepatic cells using an IFN-gamma-dependent mechanism.

Antigens, CD↗
PubMed2004

Virologic and immunologic outcomes after 24 weeks in HIV type 1-infected adolescents receiving highly active antiretroviral therapy.

BACKGROUND: Adolescents represent the fastest growing demographic group of new human immunodeficiency virus (HIV) infections in the United States. At present, there is little information available about their response to therapy. METHODS: We studied 120 adolescents infected via high-risk behaviors who began receiving highly active antiretroviral therapy (HAART), to determine their virologic and immunologic response to therapy. RESULTS: Subjects were enrolled at 28 sites of the Pediatric Acquired Immunodeficiency Syndrome Clinical Trials Group. After 16-24 weeks of HAART, 59% of subjects had reproducible undetectable virus loads, according to repeat measurements (virologic success). As enumerated by flow-cytometric analysis, increases in levels of CD4 helper cells (both naive and memory) and decreases in levels of CD8 suppressor cells were observed. Partial restoration of some immunologic parameters for patients who did not achieve virologic success was also observed, but to a more limited extent than for adolescents with virologic success. Adherence to HAART was the only predictor of achieving undetectable virus loads. CONCLUSIONS: Adolescents have the capacity to improve their immunologic status with HAART. Lower than expected success in virologic control is related to lack of adherence, and efforts to improve treatment outcome must stress measures to assure adherence to medication.

Adolescent↗
PubMed2004

Cytokine and chemokine gene polymorphisms among ethnically diverse North Americans with HIV-1 infection.

Twenty-four common single nucleotide polymorphisms (SNPs) in 10 cytokine and chemokine genes were defined in 579 North Americans at high risk of HIV-1 infection due to sexual behavior and injection drug use. Among the 3 major ethnic (African-American, Hispanic/Latino, and other) groups involved, HIV-1-seropositive individuals differed significantly from ethnically matched HIV-1-seronegative individuals (odds ratios = 2.13-4.82; P = 0.003-0.05) for several SNPs and haplotypes defined at the IL4, IL4R, IL6, IL10, CCL5 (RANTES), and CXCL12 (SDF1) loci. In addition, the homozygous IL4-590T/T genotype was associated with higher (+87-131 cells/microL) CD4 T-cell counts in HIV-1-infected and AIDS-free adolescents not receiving antiretroviral therapy (adjusted P = 0.004). No SNPs at IFNG, IL2, IL12B, TNF, or CCL2 (MCP1) showed any association with HIV-related outcomes. Additional typing for IL1A, IL1B, IL1R1, IL1RN, and TGFB1 SNPs also failed to demonstrate any influence on HIV-1 infection or virologic/immunologic control in more selected patient groups. Coupled with previous findings, our data suggest that heritable IL4 and IL10 variations may contribute to the acquisition or progression of HIV infection and that the effects of other targeted loci in the cytokine and chemokine system cannot be established unequivocally in the study populations.

Adolescent↗
PubMed2004

Longitudinal analysis of lymphocyte ratios and HIV-1 intracellular DNA levels in children.

The associations between human immunodeficiency virus type 1 (HIV-1) intracellular DNA and immunological markers were analyzed longitudinally for children with sustained, undetectable RNA levels while receiving highly active antiretroviral therapy (HAART) for >2 years. When DNA levels reached a plateau at week 104 of therapy, in contrast to findings for adults, there was no correlation between the CD4(+) : CD8(+) ratio and DNA levels (r=-0.02; P=.95), and naive CD4(+)CD45RA(+) lymphocytes predominated. These data suggest that the increased proportion of naive lymphocytes found in children are less susceptible to HIV-1 infection than are the memory lymphocytes that dominate immune reconstitution in adults.

Adolescent↗
PubMed2004

A non-peptide substance P antagonist (CP-96,345) inhibits morphine-induced NF-kappa B promoter activation in human NT2-N neurons.

Opioids and the neuropeptide substance P (SP) modulate the expression of inflammatory cytokines and chemokines, which are under the control of nuclear factor kappaB (NF-kappaB). We investigated whether the neurokinin-1 receptor (SP receptor) pathway is biologically involved in morphine-mediated modulation of NF-kappaB promoter activation in a human neuronal cell line (NT2-N) that expresses both the mu-opioid receptor (MOR) and the SP receptor. Morphine significantly enhanced NF-kappaB promoter-directed luciferase activity in NT2-N neurons. DAMGO, a selective mu-opioid receptor agonist, also induced NF-kappaB promoter activation. The induced activation of NF-kappaB promoter by morphine or DAMGO was abolished not only by naltrexone (a opioid receptor antagonist) and CTAP (a selective, competitive mu-opioid receptor antagonist), but also by CP-96,345, a non-peptide SP receptor antagonist. Investigation of the mechanism responsible for morphine-induced activation of NF-kappaB promoter in NT2-N neurons demonstrated that morphine activates the SP promoter and induces SP expression in these cells. We also observed that SP activated NF-kappaB promoter and that CP-96,345 downregulated the expression of endogenous SP. Furthermore, dual immunofluorescent labeling revealed that there is co-expression of NK-1R and MOR in the processes of NT-2N neurons. These results suggest that morphine, by activating MOR, engages a positive feedback loop between NK-1R and SP. Activation of NK-1R could then impact NF-kappaB expression and therefore may be an important participant in the effect of morphine on immune responses in the central nervous system.

Biphenyl Compounds↗
PubMed2004

Relationship of plasma HIV-1 RNA dynamics to baseline factors and virological responses to highly active antiretroviral therapy in adolescents (aged 12-22 years) infected through high-risk behavior.

We characterized the viral dynamics of human immunodeficiency virus (HIV) type 1-infected adolescents receiving highly active antiretroviral therapy regimens (lamivudine [3TC]/zidovudine [ZDV]/efavirenz [EFV], 3TC/ZDV/nelfinavir [NFV], or other regimens) and studied the relationship of viral dynamics with baseline factors and virological responses. Viral decay rates for 115 evaluable subjects were estimated from a viral dynamic model. Viral dynamics in HIV-1-infected individuals aged 12-22 years were similar to those of HIV-1-infected adults and infants. Individuals who received 3TC/ZDV/EFV had a more rapid phase 1 viral decay rate than those who received 3TC/ZDV/NFV or other regimens. Phase 1 viral decay rates were positively correlated with baseline RNA levels and week 1 virus load reductions. Our findings indicate that the 3TC/ZDV/EFV regimen may be more potent than 3TC/ZDV/NFV or other regimens and that early viral dynamics or week 1 virus load reduction measurements may be useful in evaluating the potency of antiretroviral regimens.

Acquired Immunodeficiency Syndrome↗
PubMed2004

Substance P and neurokinin-1 receptor modulation of HIV.

There is a high incidence of life event stress, depression, and associated symptoms in individuals with HIV infection/AIDS. Psychological and psychiatric symptomatology in individuals with HIV and AIDS may be related to the progression of AIDS disease. The association between depression, anxiety, and stress with HIV disease progression suggests that neurobiologic and neurophysiologic factors have an important role in modulating HIV. The immune effects caused by changes in behavioral state or brain activity are affected, at least in part, through the neuroendocrine-immune pathways. Life stress and depression may be associated with altered blood levels of CNS-released neuropeptides, including substance P (SP). SP is a powerful immunomodulator which is a critical link between the nervous and immune system. We have investigated the role of the neuropeptide SP and its preferred receptor, neurokinin-1, in HIV infection and AIDS. There are compelling data from our laboratories, as well as the findings in the literature, which demonstrate that SP may play an important role in the pathophysiology of neuropsychiatric disorders, including stress and depression in HIV-infected individuals and in the immunopathogenesis of HIV disease. Modulation of SP activity and SP receptor may offer a novel approach to the treatment of psychiatric disorders and to the design of new anti-HIV therapy.

Animals↗
PubMed2004

CD8+CD38+ T cells but not HIV type 1 RNA viral load predict CD4+ T cell loss in a predominantly minority female HIV+ adolescent population.

The purpose of this study was to evaluate predictors of HIV-1 disease progression in a cohort of predominantly female and minority adolescents who had acquired their HIV-1 infections through sexual risk behaviors. Subjects were identified from the REACH cohort who were not on antiretroviral therapy for at least 1 year and whose baseline CD4(+) T cells were >300 cells/mm(3). Biomedical and demographic characteristics of the subjects at the start of the study period were evaluated as predictors of CD4(+) T cell loss in univariate and multivariate models. Two-thirds of the 99 subjects meeting the selection criteria were female and 87% were black or Hispanic similar to the REACH cohort as a whole. Higher absolute CD8(+) CD38(+) T cell counts at the start of the assessment period were associated with a greater rate of loss of CD4(+) T cells. HIV-1 RNA viral load was among other potential predictors of HIV-1 disease progression that had no association with the rate of CD4(+) T cell loss in this cohort. This study extends the observed association of higher CD8(+) CD38(+) T cells numbers being predictive of HIV-1 disease progression into predominantly female, minority youth.

ADP-ribosyl Cyclase↗
PubMed2003

Phase I/II trial of intravenous recombinant interleukin-2 in HIV-infected children.

OBJECTIVES: To define the tolerated dose of recombinant interleukin-2 (rIL-2) in HIV-infected children (part A), and to determine the safety and immunologic effects of the tolerated rIL-2 dose in a cohort of HIV-infected children (part B). DESIGN: Open-label, dose-escalation. SETTING: Multiple center study. SUBJECTS: Twenty HIV-infected children, aged 3-12 years. INTERVENTION: In part A six subjects received 1 x 10(6) IU/m2 and four subjects received 4 x 10(6) IU/m2 rIL-2 by continuous intravenous infusion for 5 days every 8 weeks for three cycles. In part B 10 different subjects received 1 x 10(6) IU/m2 for 5 days every 8 weeks for six cycles. MAIN OUTCOME MEASURES: Toxicity, CD4 cell count and percentage, and viral load. RESULTS: The tolerated dose of rIL-2 was 1 x 10(6) IU/m2. The most common side effects were fever and vomiting. Of 10 subjects enrolled in part B of the study, five discontinued rIL-2 therapy for a variety of reasons, most related to administration of study drug. Comparable rises in CD4 cell count and percentage were observed in each of the treatment arms. Six cycles of rIL-2 therapy did not appear to be better than three cycles with respect to improvement of CD4 parameters. Transient rises in plasma HIV-1 RNA levels were detected in some subjects. CONCLUSIONS: These results suggest that rIL-2 therapy can raise CD4 cell counts and percentages in some HIV-infected children, although a high proportion of HIV-infected children may have to discontinue intravenous therapy because of drug- or administration-related toxicity. Controlled trials of rIL-2 in this patient population are warranted.

Anti-HIV Agents↗
PubMed2003

Methylnaltrexone antagonizes opioid-mediated enhancement of HIV infection of human blood mononuclear phagocytes.

Opioid abuse has been postulated as a cofactor in the immunopathogenesis of human immunodeficiency virus (HIV) infection and AIDS. We and others have recently demonstrated that opioid enhances HIV infection of human macrophages through modulation of beta-chemokines and the CCR5 receptor and that this effect is reversed by naltrexone, a tertiary opioid antagonist. Tertiary opioid antagonists cannot be used in opioid-dependent patients because they precipitate withdrawal or reversal of analgesia. We determined whether the quaternary opioid antagonist methylnaltrexone (MNTX), now in phase III clinical trials for opioid-induced constipation, reverses the opioid-mediated enhancement of HIV infection of macrophages at clinically relevant doses. MNTX completely abrogated morphine-induced HIV Bal strain infection of macrophages. MNTX also inhibited the R5 strain (ADA) envelope-pseudotyped HIV replication induced by morphine. Furthermore, MNTX abolished morphine-mediated up-regulation of CCR5 receptor expression. The ability of MNTX to block opioid-induced CCR5 expression and HIV replication at clinically relevant doses may have additional benefit for opioid abusers with HIV infection, or patients with AIDS pain receiving opioids.

Cells, Cultured↗
PubMed2003

Prevalence, diagnosis, and pharmacological treatment of mood disorders in HIV disease.

Human immunodeficiency virus seropositive (HIV+) individuals are at a heightened risk of developing mood disorders and related syndromes. Over the past several decades, increased rates of mood disorders, including depression and mania, have been reported among HIV+ individuals. Because alterations in mood may impact on quality of life and perhaps reduce adherence to antiretroviral treatment regimens that are critical for preventing disease progression, recognition and effective treatment of mood disorders is essential. There are accumulating data showing that antidepressants and mood stabilizers, as well as other novel agents, might benefit HIV+ individuals suffering from a concomitant mood disturbance. This review highlights the relevant studies that have examined prevalence rates of mood disorders in HIV+ individuals, characteristics of HIV disease that influence the diagnosis and psychopharmacologic treatment of mood disorders, including complex interactions with antiretroviral medications, as well as the available evidence regarding the efficacy of agents used to treat depression and mania in the context of HIV disease.

Antidepressive Agents↗
PubMed2003

Morphine enhances HIV infection of neonatal macrophages.

Perinatal transmission of HIV accounts for almost all new HIV infections in children. There is an increased risk of perinatal transmission of HIV with maternal illicit substance abuse. Little is known about neonatal immune system alteration and subsequent susceptibility to HIV infection after morphine exposure. We investigated the effects of morphine on HIV infection of neonatal monocyte-derived macrophages (MDM). Morphine significantly enhanced HIV infection of neonatal MDM. Morphine-induced HIV replication in neonatal MDM was completely suppressed by naltrexone, the opioid receptor antagonist. Morphine significantly up-regulated CCR5 receptor expression and inhibited the endogenous production of macrophage inflammatory protein-1beta in neonatal MDM. Thus, morphine, most likely through alteration of beta-chemokines and CCR5 receptor expression, enhances the susceptibility of neonatal MDM to HIV infection, and may have a cofactor role in perinatal HIV transmission and infection.

Analgesics, Opioid↗
PubMed2003

CCR5 expression and beta-chemokine production during placental neonatal monocyte differentiation.

The stage of maturation of monocytes affects their susceptibility to HIV infection. The beta-chemokines and their receptor CCR5 play a crucial role in inflammatory reactions and HIV infection. We therefore examined the correlation between the expression of CCR5 and beta-chemokine production and the susceptibility to HIV infection during cord monocyte (CM) differentiation into macrophages. CM and CM-derived macrophages (CMDM) were examined for beta-chemokine and CCR5 expression. The susceptibility of the CM cultured in vitro at different time points to HIV infection was also determined. Although the levels of CCR5 mRNA expression in freshly isolated CM are comparable to those in CMDM, CM had significantly lower levels of CCR5 protein on the cell surface than CMDM did. Steady increase of CCR5 protein expression on the cell surface was observed during CM differentiation into macrophages. The CCR5 expression correlated with the increased susceptibility to HIV infection by CMDM. Although there was no significant difference in endogenous beta-chemokine production between CM and CMDM, HIV infection of CMDM significantly enhanced production of macrophage inflammatory protein-1alpha and -1beta. CCR5 receptor plays a critical role in HIV infection of neonatal blood monocyte/macrophages.

Cell Differentiation↗