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Biomedical subjects

Steven D Douglas

Publications and source records attributed to Steven D Douglas.

69 records · Page 4Linked to original sources
PubMed2002

A non-peptide substance P antagonist down-regulates SP mRNA expression in human mononuclear phagocytes.

Substance P (SP), a potent modulator of neuroimmunoregulation, exerts its activity by binding to the neurokinin-1 receptor (NK-1R). The SP-NK-1R interaction is important in inflammation and viral infections, including HIV infection of human immune cells. We recently demonstrated that SP modulates HIV replication and that a non-peptide SP antagonist CP-96,345 inhibits HIV replication in human monocyte-derived macrophages (MDM) by affecting the SP-NK-1R interaction. In order to examine the effect of the SP antagonist on SP mRNA expression, MDM was incubated with or without CP-96,345 in the presence or absence of HIV infection. SP mRNA expression in these cells was then determined by real-time PCR technology. The effect of CP-96,345 on chemokine gene expression was also investigated by using a cDNA array assay. CP-96,345 down-regulated SP mRNA expression and antagonized exogenous SP-enhanced SP expression at the mRNA level, suggesting that SP autocrine regulation was interrupted by CP-96,345. CP-96,345 inhibited HIV replication in MDM, associated with down-regulated SP mRNA expression in comparison to HIV infection controls. In parallel with down-regulated SP and CCR5 mRNA expression, cDNA array assays indicated that CP-96,345 treatment also inhibited IL-8 gene expression, while enhancing expression of fractalkine and monocyte chemotactic protein-3 (MCP-3). Since SP plays an important role in inflammation and viral infections, these studies may have potential applications for therapeutic intervention of inflammation and viral infection of immune cells.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2002

Substance P up-regulates macrophage inflammatory protein-1beta expression in human T lymphocytes.

Substance P (SP) is an important modulator of neuroimmunoregulation. We have demonstrated that human T lymphocytes express SP and neurokinin-1 receptor (NK-1R), a primary SP receptor. In the present study, we investigated whether SP stimulates synthesis of macrophage inflammatory protein-1beta (MIP-1beta) in human T lymphocytes. SP significantly enhanced MIP-1beta expression at both the mRNA and protein level in a human T cell line (Jurkat) containing the SP receptor gene (J-SPR) as determined by real-time PCR and ELISA assays. SP-induced MIP-1beta expression is abrogated by the specific NK-1R antagonist (CP-96,345). The supernatants from SP-stimulated J-SPR T cell cultures enhanced T lymphocyte chemotaxis in vitro, indicating functional activity of SP-induced MIP-1beta. In addition, SP augmented secretion of MIP-1beta from primary cultures of peripheral blood lymphocytes (PBL) isolated from some of the donors. This donor variability was due to differential expression of the primary SP receptor (NK-1R) on PBL from different donors. PBL from two of seven donors that did not respond to SP stimulation had undetectable NK-1R expression. Our mechanistic studies showed that SP activated NF-kappaB promoter-directed luciferase activity, which may be responsible for its effect on MIP-1beta expression in human T cells. Our data provide a potential mechanism by which SP selectively influences cellular immune responses such as beta-chemokine expression in human T lymphocytes through NK-1R, which may have an important in vivo implication in inflammatory diseases.

Adult↗
PubMed2002

Real-time RT-PCR for quantitation of hepatitis C virus RNA.

A newly developed real-time RT-polymerase chain reaction assay for quantitation of hepatitis C virus (HCV) RNA in human plasma and serum was applied. A pair of primers and a probe (molecular beacon) were designed that are specific for the recognition of a highly conservative 5'-non-coding region (5'-NCR) in HCV genome. HCV real-time RT-PCR assay had a sensitivity of 1000 RNA copies per reaction, with a dynamic range of detection between 10(3) and 10(7) RNA copies. The coefficient variation of threshold cycle (Ct) values in intra- and inter-runs were less than 1.37 and 4.66%, respectively. The real-time RT-PCR assay on the HCV sero-positive samples yielded reproducible data, with less than 2.09% of the inter-assay variation. In order to determine its potential for clinical diagnosis, real-time RT-PCR was used to examine the HCV RNA levels in plasma from sero-positive and negative subjects, showing that the assay is highly sensitive and has specificity of 100%. It was demonstrated that the real-time RT-PCR was able to amplify HCV RNA in reference sera with seven genotypes (1A, 1B, 2B, 3A, 4, 5A and 6A) that include six major HCV genotypes circulated in the world. Since HCV is a major pathogen of post-transfusion and community-transmitted non-A, non-B hepatitis, this assay has a broad application for basic and clinical investigations.

5' Untranslated Regions↗
PubMed2002

Substance P and Human Immunodeficiency Virus Infection: Psychoneuroimmunology.

Effects on the immune system caused by changes in behavioral state or brain activity are mediated, at least in part, through neuroendocrine-immune pathways. Life stress and depression may be associated with altered blood levels of central nervous system-released neuropeptides, including substance P (SP). SP acts as a neuroregulator or neurotransmitter in the conduction of nociceptive stimuli, and is a modulator of neuroimmunoregulation. This review summarizes current knowledge regarding the role of the neuropeptide, SP, in psychoneuroimmunology, in particular as it relates to human immunodeficiency virus infection and acquired immunodeficiency disease syndrome. The association between depression, anxiety, and stress in HIV-disease progression suggests that neurobiologic and neurophysiologic factors play a role in modulating HIV infection and responses to antiretroviral therapy. Individuals with HIV or AIDS may experience stressful life circumstances that can result in increased symptoms of anxiety, stress, and/or depression. Furthermore, psychological and psychiatric symptoms, which occur in individuals with HIV and AIDS, may be related to the progression of AIDS disease. This review presents evidence from the literature, as well as findings from basic investigations conducted in the authors' laboratories, demonstrating that SP may play an important role in HIV pathophysiology. SP can impact the susceptibility of immune cells to HIV infection and modulate immune cell functions in ways that may affect the course of HIV in infected individuals. Moreover, modulation of SP activity and SP receptor is being explored for its potential as a novel therapeutic approach to the treatment of some psychological and psychiatric disorders and to the design of new anti-HIV therapy.

Journal Article↗
PubMed2002

HIV enhances substance P expression in human immune cells.

Substance P (SP), a potent modulator of neuroimmunoregulation, is expressed in human immune cells. We observed elevated plasma SP levels in HIV-infected men compared with uninfected subjects. In the present study, we investigated the possible cellular source of the increased SP level caused by HIV infection. Using real-time reverse transcriptase-polymerase chain reaction, we demonstrated that monocyte-derived macrophages (MDM) and lymphocytes from both placental cord blood and adult peripheral blood expressed SP mRNA, which was significantly increased by HIV infection. HIV-induced SP expression was positively related to virus replication in the infected MDM. Purified recombinant HIV envelope glycoprotein 120 (gp120) derived from both the macrophage-tropic strain (MN) and the T lymphocyte-tropic strain (IIIB), when added to MDM cultures, enhanced SP mRNA expression. The gp120-induced SP expression was abrogated by pretreating the cells with soluble CD4. Furthermore, the activation of HIV in the latently infected promonocytic cell line (U1) and T-cell line (ACH-2) up-regulated SP mRNA expression. These data support the hypothesis that interaction of HIV and SP may have significant in vivo relevance to the immunopathogenesis of HIV infection and AIDS.

Blood↗
PubMed2002

Efavirenz liquid formulation in human immunodeficiency virus-infected children.

BACKGROUND: This study determined the safety, pharmacokinetics, antiviral activity and immunologic effects of efavirenz liquid formulation, nelfinavir and nucleoside reverse transcriptase inhibitors (NRTIs) in HIV-infected children, 3 to 9 years of age. METHODS: Plasma HIV-1 RNA and lymphocyte subsets were measured at various intervals after initiation of therapy. Pharmacokinetic studies were performed at Week 2, and doses of efavirenz and nelfinavir were adjusted if area under the curve values fell outside specified target ranges. RESULTS: This combination of antiretrovirals was well-tolerated. Pharmacokinetic values were similar to those observed in a previous study of older children who received efavirenz capsules in combination with nelfinavir and NRTIs. After 48 weeks of therapy 63% of subjects had plasma HIV RNA levels of <400 copies/ml, and 58% had <50 copies/ml in an intent-to-treat analysis. CD4 cell count and percentage rose significantly over this time, whereas the number of activated CD8 cells declined. CONCLUSIONS: Combination therapy with efavirenz liquid formulation, nelfinavir and NRTIs is an attractive treatment option for HIV-infected children >3 years of age who are unable to take efavirenz capsules.

Administration, Oral↗
PubMed2002

Alcohol potentiates HIV-1 infection of human blood mononuclear phagocytes.

BACKGROUND: Acute and chronic alcohol abuse impairs various functions of the immune system and thus has been implicated as a cofactor in HIV infection. The mechanisms by which alcohol affects the function of human immune cells that are the targets for HIV are unknown. METHODS: Human blood monocyte-derived macrophages (MDM) were incubated with or without alcohol (10-40 mM) for 24 hr and then infected with HIV for 24 hr. Culture supernatants were harvested for HIV reverse transcription assay. HIV entry receptor (CCR5, CD4, and CXCR4) expression was determined by reverse transcription-polymerase chain reaction and flow cytometry assays. Beta-chemokines were analyzed using enzyme-linked immunosorbent assay. Different HIV strains (Bal, SF-162, 89.6, and UG024) were used for infection experiments. In addition, ADA (macrophage-tropic strain) and murine leukemia virus envelope-pseudotyped HIV infection was carried out. RESULTS: Although alcohol had little effect on HIV T-lymphocyte-tropic strain infection, it significantly enhanced HIV R5 strain infection in MDM. The enhancing effect of alcohol on the HIV R5 strain was further evidenced by the observation that the R5 (ADA) strain envelope-pseudotyped HIV infection is markedly increased by alcohol, whereas murine leukemia virus envelope-pseudotyped HIV infection was not affected. Alcohol significantly up-regulated CCR5 receptor expression and inhibited the endogenous production of beta-chemokines by MDM. CONCLUSION: Alcohol, through the down-regulation of beta-chemokine production and the up-regulation of CCR5 receptor expression, enhances HIV R5 strain infection of MDM and may have an important role as a cofactor in the progression of HIV disease.

Cells, Cultured↗
PubMed2002

Quantification of substance p mRNA in human immune cells by real-time reverse transcriptase PCR assay.

We have applied a newly developed real-time reverse transcriptase (RT) PCR (RT-PCR) assay for quantification of substance P (SP) mRNA expression (the SP real-time RT-PCR assay) in human blood monocyte-derived macrophages, peripheral blood lymphocytes, and microglia isolated from fetal brain. The SP real-time RT-PCR assay had a sensitivity of 60 mRNA copies, with a dynamic range of detection between 60 and 600,000 copies of the SP gene transcript per reaction mixture. The coefficient of variation of the threshold cycle number between the SP real-time RT-PCR assays was less than 1.16%. This assay with an SP-specific primer pair efficiently recognizes all four isoforms of preprotachykinin A (the SP precursor) gene transcripts. In order to use this assay to measure the levels of SP mRNA in the human immune cells quantitatively, we designed a specific probe (molecular beacon) derived from exon 3 of the SP gene. We demonstrated that the real-time RT-PCR quantitatively detected SP mRNA in the human immune cells, among which the microglia isolated from fetal brain had the highest levels of SP mRNA. The SP real-time PCR assay yielded reproducible data, as the intra-assay variation was less than 1%. Thus, it is feasible to apply the real-time RT-PCR assay for quantification of SP mRNA levels in human immune cells, as well as in other nonneuronal cells. Since SP is a major modulator of neuroimmunoregulation, this assay has the potential for widespread application for basic and clinical investigations.

Adult↗
PubMed2002

Peripheral blood lymphocyte subsets in adolescents: a longitudinal analysis from the REACH project.

Flow cytometry analysis of lymphocyte subset markers was performed for a group of sexually active, human immunodeficiency virus (HIV)-negative adolescents over a 2-year period to establish normative data. Data were collected in the REACH Project (Reaching for Excellence in Adolescent Care and Health), a multicenter, longitudinal study of HIV-positive and high-risk HIV-negative adolescents. Two- and three-color flow cytometry data were collected every 6 months for these subjects. We determined the effects of gender, race, and age on the following lymphocyte subset markers: total CD4(+) cells, CD4(+) naïve cells, CD4(+) memory cells, all CD8(+) cells, CD8(+) naïve cells, CD8(+) memory cells, CD16(+) natural killer cells, and CD19(+) B cells. Gender was the demographic characteristic most frequently associated with differences in lymphocyte subset measures. Females had higher total CD4(+) cell and CD4(+) memory cells counts and lower CD16(+) cell counts than males. Age was associated with higher CD4(+) memory cell counts as well as higher CD8(+) memory cell counts. For CD19(+) cells, there was an interaction between age and gender, with males having significantly lower CD19(+) cell counts with increasing age, whereas there was no age effect for females. Race and/or ethnicity was associated with differences in total CD8(+) cell counts and CD8(+) memory cell counts, although both of these associations involved an interaction with gender.

Adolescent↗
PubMed2002

Morphine enhances HIV infection of human blood mononuclear phagocytes through modulation of beta-chemokines and CCR5 receptor.

BACKGROUND: Injection drug use remains a significant risk for acquiring HIV infection. The mechanisms by which morphine enhances HIV infection of human immune cells are largely unknown. OBJECTIVE: In this study, we sought to determine the possible mechanisms by which morphine upregulates HIV infection of human blood monocyte-derived macrophages (MDM). METHODS: In this study, MDM were infected with the R5, X4, and R5X4 HIV strains. HIV replication was determined by performing reverse transcriptase activity assays. HIV receptors were determined by performing reverse transcriptase polymerase chain reactions and flow cytometry assays. beta-chemokines were analyzed by performing enzyme-linked immunosorbent assays. In addition, HIV R5 strain and murine leukemia virus envelope-pseudotyped HIV infection was performed to determine whether morphine affects HIV infection of macrophages at entry level. RESULTS: Morphine significantly enhanced HIV R5 strain infection of MDM but had little effect on X4 strain infection. The macrophage-tropic R5 strain envelope-pseudotyped HIV infection was markedly increased by morphine, whereas murine leukemia virus envelope-pseudotyped HIV infection was not significantly affected. Furthermore, morphine significantly upregulated CCR5 receptor expression and inhibited the endogenous production of beta-chemokines in MDM. The opioid receptor antagonist naltrexone blocked the effects of morphine on the production of beta-chemokines. CONCLUSION: Opiates enhance HIV R5 strain infection of macrophages through the downregulation of beta-chemokine production and upregulation of CCR5 receptor expression and may have an important role in HIV immunopathogenesis.

Chemokines, CC↗
PubMed2002

Association of depression with viral load, CD8 T lymphocytes, and natural killer cells in women with HIV infection.

OBJECTIVE: Clinical and epidemiology studies have implicated depression as a risk factor in the morbidity and mortality of many human diseases. This study sought to determine if depression was associated with alterations in cellular immunity variables-specifically, natural killer (NK) cells and CD8 T lymphocytes-in women with HIV infection. METHOD: Ninety-three women (63 HIV-seropositive, 30 HIV-seronegative) were studied as part of an ongoing longitudinal study conducted at two sites. Subjects underwent extensive clinical, psychiatric, and immunological evaluations. CBC counts and flow cytometry panels were conducted and NK cell activity assayed for all subjects; viral load was determined for HIV-seropositive subjects. RESULTS: The overall rate of major depression in the HIV-seropositive and HIV-seronegative women was 15.87% (N=10 of 63) and 10.00% (N=3 of 30), respectively. HIV-seropositive women had higher depressive symptom scores than did the comparison subjects (Hamilton depression scale: mean=8.62 [SD=7.26] versus mean=5.67 [SD=7.33], respectively). Both groups had similar anxiety scores. Depressive and anxiety symptoms were significantly associated with higher activated CD8 T lymphocyte counts and higher viral load levels. Major depression was associated with significantly lower natural killer cell activity, and depressive and anxiety symptom scores showed a similar correlation. CONCLUSIONS: Our findings provide the first evidence that depression may alter the function of killer lymphocytes in HIV-infected women and suggest that depression may decrease natural killer cell activity and lead to an increase in activated CD8 T lymphocytes and viral load. The rate of current major depression in these HIV-seropositive women (none of whom had current substance abuse) is approximately twice that reported for HIV-seropositive men. The rate is also consistent with studies of women with other medical illnesses and with a recent epidemiology study that associated depression with mortality in HIV-infected women with chronic depressive symptoms. Depression may have a negative impact on innate immunity. Examination of killer lymphocytes may prove useful in assessing the potential relationship between depression, immunity, and HIV disease progression in women.

Adult↗
PubMed2002

Depressive and anxiety disorders in women with HIV infection.

OBJECTIVE: This study examined whether there were differences in the rate of depressive and anxiety disorders between HIV-infected women (N=93) and a comparison group of uninfected women (N=62). Secondary objectives were to examine correlates of depression in HIV-infected women-including HIV disease stage and protease inhibitor use-and the associations between symptoms of depression or anxiety and other potential predictor variables. METHOD: Subjects underwent extensive semiannual clinical, psychiatric, neuropsychological, and immunological evaluations. Depressive and anxiety disorder diagnoses were assessed by using the Structured Clinical Interview for DSM-IV. Symptoms of depression and anxiety were evaluated with the Hamilton Depression Rating Scale (the 17-item version and a modified 11-item version) and the Hamilton Anxiety Rating Scale, respectively. RESULTS: The rate of current major depressive disorder was four times higher in HIV-seropositive women (19.4%) than in HIV-seronegative women (4.8%). Mean depressive symptom scores on the 17-item Hamilton depression scale also were significantly higher, overall, in the HIV-infected women (mean=8.7, SD=8.0) relative to comparison subjects (mean=3.3, SD=5.8). There was no significant between-group difference in the rate of anxiety disorders. However, HIV-seropositive women had significantly higher anxiety symptom scores (mean=8.8, SD=8.9) than did HIV-seronegative women (mean=3.6, SD=5.5). Both groups had similar substance abuse/dependence histories, but adjusting for this factor had little impact on the relationship of HIV status to current major depressive disorder. CONCLUSIONS: HIV-seropositive women without current substance abuse exhibited a significantly higher rate of major depressive disorder and more symptoms of depression and anxiety than did a group of HIV-seronegative women with similar demographic characteristics. These controlled, clinical findings extend recent epidemiologic findings and underscore the importance of adequate assessment and treatment of depression and anxiety in HIV-infected women.

Adolescent↗
PubMed2001

Methadone enhances human immunodeficiency virus infection of human immune cells.

Opiate abuse has been postulated to be a cofactor in the immunopathogenesis of acquired immunodeficiency syndrome (AIDS). This study evaluated whether methadone, a drug widely prescribed for the treatment of drug abusers with opioid dependence, affects human immunodeficiency virus (HIV) infection of human immune cells. When added to human fetal microglia and blood monocyte-derived macrophage cultures, methadone significantly enhanced HIV infection of these cells. This enhancement was associated with the up-regulation of expression of CCR5, a primary coreceptor for macrophage-tropic HIV entry into macrophages. Most importantly, the addition of methadone to the cultures of latently infected peripheral blood mononuclear cells from HIV-infected patients enhanced viral activation and replication. Although the in vivo relevance of these findings remains to be determined, the data underscore the necessity of further studies to define the role of opioids, including methadone, in the immunopathogenesis of HIV infection and AIDS.

Adult↗