Adverse childhood experiences and transcriptional response in school-age children.

This study evaluated whether children with higher adverse childhood experiences (ACE) scores had alterations in immune cell gene expression profiles. RNA sequencing was conducted on dried blood spot samples from 37 generally healthy English-speaking children (age 5-11) who were recruited from well-child visits at a university-affiliated pediatric practice. The Whole Child Assessment was used to assess ACE exposure. Primary analyses examined an a priori-specified composite of 19 pro-inflammatory gene transcripts. Secondary analyses examined a 34-gene composite assessing Type I interferon response, and used Transcript Origin Analyses to identify cellular mechanisms. After controlling for age, body mass index percentile, sex, race/ethnicity, current insurance status, and household smoking exposure, pro-inflammatory gene expression was elevated by 0.094 log2 RNA expression units with each Child-ACE total score point (p = .019). Type I interferon gene expression was similarly upregulated (0.103; p = .008). Transcript origin analyses implicated CD8+ T cell as the primary sources of gene transcripts upregulated, and nonclassical (CD16+) monocytes as sources of downregulated transcripts. These preliminary analyses suggest that parent-reported ACE exposures are associated with increased expression of both inflammatory and interferon gene transcripts in children's circulating blood cells.

Social regulation of the lymph node transcriptome in rhesus macaques (Macaca mulatta).

Previous research has shown that adverse social conditions may promote a conserved transcriptional response to adversity (CTRA) involving up-regulation of proinflammatory gene expression and down-regulation of Type I interferon anti-viral genes in circulating blood cells. However, the impact of social conditions on lymphoid tissue gene regulation remains largely unexplored. This project assessed how social instability in adult male rhesus macaques (N=10, 5 in unstable, and 5 in stable social conditions) might regulate gene expression within secondary lymphoid tissue (lymph nodes; LN). Unstable social conditions down-regulated axillary LN expression of genes involved in Type I interferon anti-viral responses. Transcript origin analyses implicated monocytes and B cells as cellular mediators of these effects, and promoter-based bioinformatics analyses indicated reduced activity of AP-1, NF-κB, IRF, and CREB transcription factors within the axillary LN microenvironment. Although the current study is limited in sample size, these results suggest that social influences on immune cell gene regulation extend beyond the circulating leukocyte pool to alter generalized transcriptome profiles in secondary lymphoid tissue, and they do so in a regulatory program that resembles the pattern of antiviral inhibition previously observed in circulating leukocytes.

Alterations in leukocyte transcriptional control pathway activity associated with major depressive disorder and antidepressant treatment.

Major depressive disorder (MDD) is associated with a significantly elevated risk of developing serious medical illnesses such as cardiovascular disease, immune impairments, infection, dementia and premature death. Previous work has demonstrated immune dysregulation in subjects with MDD. Using genome-wide transcriptional profiling and promoter-based bioinformatic strategies, we assessed leukocyte transcription factor (TF) activity in leukocytes from 20 unmedicated MDD subjects versus 20 age-, sex- and ethnicity-matched healthy controls, before initiation of antidepressant therapy, and in 17 of the MDD subjects after 8 weeks of sertraline treatment. In leukocytes from unmedicated MDD subjects, bioinformatic analysis of transcription control pathway activity indicated an increased transcriptional activity of cAMP response element-binding/activating TF (CREB/ATF) and increased activity of TFs associated with cellular responses to oxidative stress (nuclear factor erythroid-derived 2-like 2, NFE2l2 or NRF2). Eight weeks of antidepressant therapy was associated with significant reductions in Hamilton Depression Rating Scale scores and reduced activity of NRF2, but not in CREB/ATF activity. Several other transcriptional regulation pathways, including the glucocorticoid receptor (GR), nuclear factor kappa-B cells (NF-κB), early growth response proteins 1-4 (EGR1-4) and interferon-responsive TFs, showed either no significant differences as a function of disease or treatment, or activities that were opposite to those previously hypothesized to be involved in the etiology of MDD or effective treatment. Our results suggest that CREB/ATF and NRF2 signaling may contribute to MDD by activating immune cell transcriptome dynamics that ultimately influence central nervous system (CNS) motivational and affective processes via circulating mediators.

Sustained adrenergic signaling leads to increased metastasis in ovarian cancer via increased PGE2 synthesis.

Adrenergic stimulation adversely affects tumor growth and metastasis, but the underlying mechanisms are not well understood. Here, we uncovered a novel mechanism by which catecholamines induce inflammation by increasing prostaglandin E2 (PGE2) levels in ovarian cancer cells. Metabolic changes in tumors isolated from patients with depression and mice subjected to restraint stress showed elevated PGE2 levels. Increased metabolites, PTGS2 and PTGES protein levels were found in Skov3-ip1 and HeyA8 cells treated with norepinephrine (NE), and these changes were shown to be mediated by ADRB2 receptor signaling. Silencing PTGS2 resulted in significantly decreased migration and invasion in ovarian cancer cells in the presence of NE and decreased tumor burden and metastasis in restraint stress orthotopic models. In human ovarian cancer samples, concurrent increased ADRB2, PTGS2 and PTGES expression was associated with reduced overall and progression-free patient survival. In conclusion, increased adrenergic stimulation results in increased PGE2 synthesis via ADRB2-Nf-kB-PTGS2 axis, which drives tumor growth and metastasis.

Depression and the risk of autoimmune disease: a nationally representative, prospective longitudinal study.

BACKGROUND: Autoimmune diseases are associated with substantial morbidity and mortality, yet the etiology remains unclear. Depression has been implicated as a risk factor for various immune-related disorders but little is known about the risk of autoimmune disease. This study examined the association between depression and the risk of autoimmune disease, and investigated the temporal and dose-response nature of these relationships. METHOD: A prospective population-based study including approximately 1.1 million people was conducted using linked Danish registries. Depression and autoimmune diseases were diagnosed by physicians and documented in medical records. In total, 145 217 individuals with depression were identified between 1995 and 2012. Survival analyses were used to estimate the relative risk of autoimmune disease among those with, compared to without, depression. Analyses were adjusted for gender, age, and co-morbid mental disorders. RESULTS: Depression was associated with a significantly increased risk of autoimmune disease [incidence rate ratio (IRR) 1.25, 95% CI 1.19-1.31], compared to those without a history of depression. Results suggest a general increased risk of autoimmune diseases following the onset of depression during first year (IRR 1.29, 95% CI 1.05-1.58), which remained elevated for the ensuing 11 years and beyond (IRR 1.53, 95% CI 1.34-1.76). Findings did not support a dose-response relationship. CONCLUSIONS: Depression appears to be associated with an increased risk of a range of autoimmune diseases. Depression may play a role in the etiology of certain autoimmune conditions. If replicated, findings could highlight additional clinical implications in the treatment and management of depression. Future studies are needed to investigate the possible social, genetic, and neurobiological underpinnings of these relationships.

Childhood and later life stressors and increased inflammatory gene expression at older ages.

Adverse experiences in early life have the ability to "get under the skin" and affect future health. This study examined the relative influence of adversities during childhood and adulthood in accounting for individual differences in pro-inflammatory gene expression in late life. Using a pilot-sample from the Health and Retirement Study (N = 114) aged from 51 to 95, OLS regression models were run to determine the association between a composite score from three proinflammatory gene expression levels (PTGS2, ILIB, and IL8) and 1) childhood trauma, 2) childhood SES, 3) childhood health, 4) adult traumas, and 5) low SES in adulthood. Our results showed that only childhood trauma was found to be associated with increased inflammatory transcription in late life. Furthermore, examination of interaction effects showed that childhood trauma exacerbated the influence of low SES in adulthood on elevated levels of inflammatory gene expression-signifying that having low SES in adulthood was most damaging for persons who had experienced traumatic events during their childhood. Overall our study suggests that traumas experienced during childhood may alter the stress response, leading to more sensitive reactivity throughout the lifespan. As a result, individuals who experienced greater adversity in early life may be at higher risk of late life health outcomes, particularly if adulthood adversity related to SES persists.

Does tumor necrosis factor-alpha (TNF-α) play a role in post-chemotherapy cerebral dysfunction?

Post-chemotherapy treated cancer patients frequently report cognitive difficulties. The biology of this phenomenon is poorly understood, with uncertainty about possible direct toxic effects on the brain, secondary effects from systemic inflammation, host factors/genetic predisposition to cognitive complaints, or hormonal changes influencing cognitive function. To elucidate possible mechanisms associated with post-treatment cognitive dysfunction among breast cancer survivors, in 2007 we established a prospective, longitudinal, observational cohort study of early stage breast cancer patients, recruited at the end of initial treatments (primary treatment exposure included surgery, ± radiation, ± chemotherapy), and prior to the initiation of adjuvant endocrine therapy. We assessed cognitive complaints, neuropsychological (NP) test performance, markers of inflammation, and brain imaging at baseline, 6 months and 12 months after enrollment. In this analysis of data from the first 93 patients enrolled in the cohort study, we focus on the relationship of circulating levels of proinflammatory cytokines to cerebral functioning and chemotherapy exposure. Among the proinflammatory cytokines tested (IL-1 ra, sTNF-RII, CRP, and IL-6) at baseline, only sTNF-RII was increased among chemotherapy exposed patients, with a significant decline in the year after treatment (p=0.003). Higher baseline sTNF-RII in chemotherapy patients was significantly associated with increased memory complaints. In chemotherapy exposed patients, the longitudinal decline in sTNF-RII was significantly correlated with fewer memory complaints over 12 months (r=-0.34, p=0.04). Higher baseline sTNF-RII was also associated with relatively diminished brain metabolism in the inferior frontal cortex (r=-0.55, p=0.02), as well as relatively increased inferior frontal metabolism after 1 year, in chemotherapy-exposed subjects. These preliminary findings suggest that post-chemotherapy increases in TNF-α may be playing an important role in the manifestations of cognitive complaints in breast cancer survivors.

Molecular signatures of peripheral blood mononuclear cells during chronic interferon-α treatment: relationship with depression and fatigue.

BACKGROUND: Interferon-alpha (IFN-α) treatment for infectious disease and cancer causes high rates of depression and fatigue, and has been used to investigate the impact of inflammatory cytokines on brain and behavior. However, little is known about the transcriptional impact of chronic IFN-α on immune cells in vivo and its relationship to IFN-α-induced behavioral changes. METHOD: Genome-wide transcriptional profiling was performed on peripheral blood mononuclear cells (PBMCs) from 21 patients with chronic hepatitis C virus (HCV) either awaiting IFN-α therapy (n=10) or at 12 weeks of IFN-α treatment (n=11). RESULTS: Significance analysis of microarray data identified 252 up-regulated and 116 down-regulated gene transcripts. Of the up-regulated genes, 2'-5'-oligoadenylate synthetase 2 (OAS2), a gene linked to chronic fatigue syndrome (CFS), was the only gene that was differentially expressed in patients with IFN-α-induced depression/fatigue, and correlated with depression and fatigue scores at 12 weeks (r=0.80, p=0.003 and r=0.70, p=0.017 respectively). Promoter-based bioinformatic analyses linked IFN-α-related transcriptional alterations to transcription factors involved in myeloid differentiation, IFN-α signaling, activator protein-1 (AP1) and cAMP responsive element binding protein/activation transcription factor (CREB/ATF) pathways, which were derived primarily from monocytes and plasmacytoid dendritic cells. IFN-α-treated patients with high depression/fatigue scores demonstrated up-regulation of genes bearing promoter motifs for transcription factors involved in myeloid differentiation, IFN-α and AP1 signaling, and reduced prevalence of motifs for CREB/ATF, which has been implicated in major depression. CONCLUSIONS: Depression and fatigue during chronic IFN-α administration were associated with alterations in the expression (OAS2) and transcriptional control (CREB/ATF) of genes linked to behavioral disorders including CFS and major depression, further supporting an immune contribution to these diseases.

Maternal warmth buffers the effects of low early-life socioeconomic status on pro-inflammatory signaling in adulthood.

The notion that family support may buffer individuals under adversity from poor outcomes has been theorized to have important implications for mental and physical health, but little is known about the biological mechanisms that explain these links. We hypothesized that adults who grew up in low socioeconomic status (SES) households but who experienced high levels of maternal warmth would be protected from the pro-inflammatory states typically associated with low SES. A total of 53 healthy adults (aged 25-40 years) low in SES early in life were assessed on markers of immune activation and systemic inflammation. Genome-wide transcriptional profiling also was conducted. Low early-life SES individuals who had mothers, who expressed high warmth toward them, exhibited less Toll-like receptor-stimulated production of interleukin 6, and reduced bioinformatic indications of pro-inflammatory transcription factor activity (NF-κB) and immune activating transcription factor activity (AP-1) compared to those who were low in SES early in life but experienced low maternal warmth. To the extent that such effects are causal, they suggest the possibility that the detrimental immunologic effects of low early-life SES environments may be partly diminished through supportive family climates.

Genome-wide transcriptional profiling linked to social class in asthma.

OBJECTIVES: Low socioeconomic status (SES) is one of the most robust social factors associated with disease morbidity, including more severe asthma in childhood. However, our understanding of the biological processes that explain this link is limited. This study tested whether the social environment could get "under the skin" to alter genomic activity in children with asthma. DESIGN AND PARTICIPANTS: Two group design of children with physician diagnosed asthma who came from low or high SES families. OUTCOMES: Genome-wide transcriptional profiles from T lymphocytes of children with asthma. RESULTS: Children with asthma from a low SES background showed overexpression of genes regulating inflammatory processes, including those involved in chemokine activity, stress responses and wound responses, compared with children with asthma from a high SES background. Bioinformatic analysis suggested that decreased activity of cyclic AMP response element binding protein and nuclear factor Y and increased nuclear factor kappaB transcriptional signalling mediated these effects. These pathways are known to regulate catecholamine and inflammatory signalling in immune cells. CONCLUSIONS: This study provides the first evidence in a sample of paediatric patients diagnosed with asthma that the larger social environment can affect processes at the genomic level. Specifically, gene transcription control pathways that regulate inflammation and catecholamine signalling were found to vary by SES in children with asthma. Because these pathways are the primary targets of many asthma medications, these findings suggest that the larger social environment may alter molecular mechanisms that have implications for the efficacy of asthma therapeutics.

Identification of discrete chromosomal deletion by binary recursive partitioning of microarray differential expression data.

DNA copy number abnormalities (CNA) are characteristic of tumours, and are also found in association with congenital anomalies and mental retardation. The ultimate impact of copy number abnormalities is manifested by the altered expression of the encoded genes. We previously developed a statistical method for the detection of simple chromosomal amplification using microarray expression data. In this study, we significantly advanced those analytical techniques to allow detection of localised chromosomal deletions based on differential gene expression data. Using three cell lines with known chromosomal deletions as model system, mRNA expression in those cells was compared with that observed in diploid cell lines of matched tissue origin. Results show that genes from deleted chromosomal regions are substantially over-represented (p<0.000001 by chi2) among genes identified as underexpressed in deletion cell lines relative to normal matching cells. Using a likelihood based statistical model, we were able to identify the breakpoint of the chromosomal deletion and match with the karyotype data in each cell line. In one such cell line, our analyses refined a previously identified 10p chromosomal deletion region. The deletion region was mapped to between 10p14 and 10p12, which was further confirmed by subtelomeric fluorescence in situ hybridisation. These data show that microarray differential expression data can be used to detect and map the boundaries of submicroscopic chromosomal deletions.

Impaired response to HAART in HIV-infected individuals with high autonomic nervous system activity.

Neurotransmitters can accelerate HIV-1 replication in vitro, leading us to examine whether differences in autonomic nervous system (ANS) activity might promote residual HIV-1 replication in patients treated with highly active antiretroviral therapy. Patients who showed constitutively high levels of ANS activity before highly active antiretroviral therapy experienced poorer suppression of plasma viral load and poorer CD4(+) T cell recovery over 3-11 months of therapy. ANS activity was not related to demographic or behavioral characteristics that might influence pathogenesis. However, the ANS neurotransmitter norepinephrine enhanced replication of both CCR5- and CXCR4-tropic strains of HIV-1 in vitro via chemokine receptor up-regulation and enhanced viral gene expression, suggesting that neural activity may directly promote residual viral replication.

Simultaneous flow cytometric measurement of viability and lymphocyte subset proliferation.

Combined analysis of DNA content and immunofluorescence on single cells by flow cytometry provides information on the proliferative response of cellular sub-populations in mixed cell preparations. However, the presence of considerable numbers of dead (nonviable) cells impairs accurate flow cytometric data analysis, mainly, because dead cells can bind antibodies non-specifically and show alterations in their DNA staining profiles. We developed a rapid method for identification of dead cells by fluorescence in cell preparations that are stained simultaneously for two-color immunofluorescence and DNA content. Cells are stained with 7-aminoactinomycin D (7-AAD) for dead cell discrimination and with fluorescein-isothiocyanate (FITC) and phycoerythrin (PE)-labeled monoclonal antibodies (mAb) for cell surface immunofluorescence. Diffusion of 7-AAD from stained, dead cells into unstained, live cells after cell permeabilization is blocked by the addition of its non-fluorescent analogue actinomycin D (AD). DNA is stained with red-excitable TO-PRO-3 iodide (TP3) which has an emission spectrum that can be effectively separated from the emissions of FITC, PE, and 7-AAD. TP3 staining is performed in the presence of ribonuclease A (RNAse) in phosphate-citrate buffer containing saponin (PCBS) at low pH. FITC fluorescence is sensitive to acid pH; therefore, PCBS is replaced after DNA staining with 1x PBS at pH 7.2 containing saponin to permit accurate detection of FITC immunofluorescence on the flow cytometer. We apply this method to the analysis of differential proliferation of lymphocyte subsets in cultures of human peripheral blood mononuclear cells (PBMC) with low viability.

Measurement of lymphocyte subset proliferation by three-color immunofluorescence and DNA flow cytometry.

We developed a method for simultaneous flow cytometric analysis of three-color immunofluorescence and DNA content. We show here that staining with 7-amino-actinomycin D (7-AAD) at 10 microg/ml using a phosphate-citrate buffer at low pH containing saponin for cell membrane permeabilization yields good resolution DNA histograms with low coefficients of variation. Furthermore, light scatter properties of cells are preserved after permeabilization; this permits gating on cell populations that differ in scatter signals on the flow cytometer. Because of the low pH of the phosphate-citrate staining buffer, Alexa488, a pH-independent green-fluorescent fluorochrome is used instead of fluorescein-isothiocyanate (FITC) for cell surface staining in combination with phycoerythrin (PE) and with allophycocyanin (APC) which are both pH insensitive. Removal of 7-AAD after staining and replacing it with non-fluorescent actinomycin D (AD) retains DNA staining and allows detection of Alexa488, PE and APC cell surface immunofluorescence without interference from fluorescent 7-AAD in solution for clear identification of cell subpopulations even after prolonged stimulation in culture. Thus, using a four-color benchtop flow cytometer, measurement of Alexa488, PE and APC three-color immunofluorescence can be combined with 7-AAD DNA content analysis. Furthermore, we demonstrate that sample storage overnight without fixation for later analysis on the flow cytometer is possible without compromising results. Application of the method to the assessment of the differential proliferative responses of lymphocyte subsets of human peripheral blood mononuclear cells (PBMC) that were costimulated with CD3 and with CD28.2 is presented.

Detection of cell cycle subcompartments by flow cytometric estimation of DNA-RNA content in combination with dual-color immunofluorescence.

BACKGROUND: Correlated flow cytometric measurements of phenotype and DNA-RNA content offer detailed information on cell cycle status of subpopulations in heterogeneous cell preparations in response to stimulation. We have developed a method for flow cytometric analysis of DNA-RNA content that has been optimized for simultaneous measurement of dual-color immunofluorescence. METHODS: Nucleic acid staining was performed at low pH in the presence of saponin. DNA was stained with 7-aminoactinomycin D (7-AAD) and RNA with pyronin Y(G) (PY); both dyes were used at low concentrations, and 7-AAD was exchanged with nonfluorescent actinomycin D after DNA staining to minimize fluorochrome-fluorochrome interactions. For cell surface antigen staining, allophycocyanin was combined with pH-independent Alexa488 instead of fluorescein-isothiocyanate (FITC) because FITC is pH sensitive. RESULTS: This method identified cell cycle subcompartments in CEM cells comparable to published results on cell lines using other dyes and staining methods. Measurement of DNA-RNA content in CD8 lymphocyte subsets of human peripheral blood mononuclear cells costimulated with CD3/CD28.2 showed that, after 48 h of stimulation, 80% of CD8(+) T cells were in the proliferative state, whereas 86% of CD8(+) non-T cells remained in G(0). CONCLUSIONS: This technique permits the clear identification of cellular subpopulations by phenotype and assessment of their cell cycle status.

Reconstitution of human thymic implants is limited by human immunodeficiency virus breakthrough during antiretroviral therapy.

Human immunodeficiency virus type 1 (HIV-1)-infected SCID-hu thymic implants depleted of CD4(+) cells can support renewed thymopoiesis derived from both endogenous and exogenous T-cell progenitors after combination antiretroviral therapy. However, successful production of new thymocytes occurs transiently. Possible explanations for the temporary nature of this thymic reconstitution include cessation of the thymic stromal support function, exhaustion of T-cell progenitors, and viral resurgence. Distinguishing between these processes is important for the development of therapeutic strategies aimed at reconstituting the CD4(+) T-cell compartment in HIV-1 infection. Using an HIV-1 strain engineered to express the murine HSA heat-stable antigen surface marker, we explored the relationship between HIV-1 expression and CD4(+) cell resurgence kinetics in HIV-1-depleted SCID-hu implants following drug therapy. Antiviral therapy significantly suppressed HIV-1 expression in double-positive (DP) CD4/CD8 thymocytes, and the eventual secondary decline of DP thymocytes following therapy was associated with renewed viral expression in this cell subset. Thymocytes derived from exogenous T-cell progenitors induced to differentiate in HIV-1-depleted, drug-treated thymic implants also became infected. These results indicate that in this model, suppression of viral replication occurs transiently and that, in spite of drug therapy, virus resurgence contributes to the transient nature of the renewed thymic function.

Socially inhibited individuals show heightened DTH response during intense social engagement.

To determine whether altered cellular immune response might mediate the increased health risks associated with social inhibition, we examined delayed type hypersensitivity (DTH) responses in 36 adults under conditions of low and high intensity social engagement. Participants come from a study of psychological factors in functional bowel disease and fibromyalgia. Under high engagement conditions, socially inhibited individuals showed significantly increased induration in response to intradermal tetanus toxoid. Under low engagement conditions, these individuals showed less pronounced DTH responses that did not differ in magnitude from those of uninhibited individuals. This pattern of results was found using two different measures of social inhibition and was independent of social inhibition's definition as a continuously distributed trait vs a discrete category. These data are consistent with the general hypothesis that social inhibition represents a predisposition to physiologic hyperresponsiveness that requires an exogenous social trigger for expression.

cAMP up-regulates cell surface expression of lymphocyte CXCR4: implications for chemotaxis and HIV-1 infection.

The chemokine receptor CXCR4 mediates lymphocyte chemotaxis in response to stromal cell-derived factor-1 (SDF-1) and functions as a coreceptor for T cell-tropic strains of HIV-1. We examined the role of the cAMP-protein kinase A (PKA) signaling pathway in regulating expression of CXCR4. In response to exogenous dibutyryl cAMP or cAMP-inducing ligands, cell surface expression of CXCR4 was increased by up to 10-fold on CD3/CD28-stimulated PBMC and by up to sixfold on unstimulated PBMC. cAMP did not alter receptor mRNA levels or affect the size of the total CXCR4 pool. However, cAMP did significantly reduce CXCR4 internalization rates and thereby increased the fraction of the total CXCR4 pool expressed on the cell surface. cAMP-induced increases in CXCR4 expression counteracted SDF-1-induced receptor internalization and enhanced both chemotactic response to SDF-1 and cellular vulnerability to HIV-1 infection. Thus, altered chemokine receptor expression may provide one mechanism by which cAMP-inducing ligands influence lymphocyte localization and HIV pathogenesis.

Norepinephrine accelerates HIV replication via protein kinase A-dependent effects on cytokine production.

To explore the role of sympathetic nervous system activation in HIV pathogenesis, we examined the effect of the neuroeffector molecule norepinephrine (NE) on HIV-1 replication in quiescently infected PBMCs that were subsequently activated with Abs to CD3 and CD28. NE accelerated HIV-1 replication at concentrations ranging from 10(-8) to 10(-5) M. This effect could be mimicked by protein kinase A (PKA) activators (forskolin or dibutyryl-cAMP) and abrogated by beta-adrenoreceptor antagonists or the PKA inhibitor rp-cAMP, indicating transduction via the adrenoreceptor signaling pathway. NE reduced cellular activation and altered the production of several HIV-modulating cytokines: IL-10 and IFN-gamma were markedly suppressed; TNF-alpha, IL-1beta, IL-2, IL-4, and IL-6 were mildly suppressed; and levels of IL-12 were not significantly altered. The addition of either exogenous IFN-gamma or IL-10 abrogated the effect of NE on virus production. Thus PKA-dependent suppression of cytokine production appears to mediate the enhancement of HIV-1 replication by NE.