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Huang W, Tam K, Fernando J, Heffernan M, King J, DiFranza JR. Nicotine and Resting-State Functional Connectivity: Effects of Intermittent Doses. Nicotine Tob Res 2015; 17:1311-7. [PMID: 25646348 DOI: 10.1093/ntr/ntv009] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Accepted: 01/07/2015] [Indexed: 11/12/2022]
Abstract
INTRODUCTION It is unknown how the timing between doses might affect nicotine's impact on neural activity. Our objective was to examine how the interdose interval affects nicotine's impact on resting-state functional connectivity (rsFC). MATERIALS AND METHODS Adult male Sprague-Dawley rats were administered nicotine daily (0.4 mg/kg) over 6 days while control animals received saline vehicle. Functional magnetic resonance imaging was used to measure rsFC before and after a challenge dose of nicotine (0.4 mg/kg) delivered for the first time and 3, 6, 12, or 24hr after the previous dose. RESULTS As the interval between nicotine doses increased from 3 to 24hr, the strength of rsFC increased in some circuits, particularly the nucleus accumbens and prefrontal circuits, and decreased in others, namely the interpeduncular nucleus, hippocampus, caudoputamen, retrosplenial cortex, ventral tegmental, and the insular circuits. CONCLUSIONS These data indicate that the effect that nicotine has on the brain is affected by the amount of time that has passed since the previous dose. The effect on rsFC of cumulative doses is not additive. This may have important implications for the study of nicotine addiction as it implies that the same dose of nicotine might have a different impact on the brain depending on the time elapsed from the previous exposure.
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Affiliation(s)
- Wei Huang
- Center for Comparative NeuroImaging, Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA
| | - Kelly Tam
- Center for Comparative NeuroImaging, Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA
| | - Janaque Fernando
- Center for Comparative NeuroImaging, Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA
| | - Meghan Heffernan
- Center for Comparative NeuroImaging, Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA
| | | | - Joseph R DiFranza
- Center for Comparative NeuroImaging, Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA; Department of Family Medicine and Community Health, University of Massachusetts Medical School, Worcester, MA
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Dagna L, Pritchett JC, Lusso P. Immunomodulation and immunosuppression by human herpesvirus 6A and 6B. Future Virol 2013; 8:273-287. [PMID: 24163703 PMCID: PMC3806647 DOI: 10.2217/fvl.13.7] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Like other members of the Herpesviridae family, human herpesvirus (HHV)-6A and HHV-6B have developed a wide variety of strategies to modulate or suppress host immune responses and, thereby, facilitate their own spread and persistence in vivo. Long considered two variants of the same virus, HHV-6A and HHV-6B have recently been reclassified as distinct viral species, although the established nomenclature has been maintained. In this review, we summarize the distinctive profiles of interaction of these two viruses with the human immune system. Both HHV-6A and HHV-6B display a tropism for CD4+ T lymphocytes, but they can also infect, in a productive or nonproductive fashion, other cells of the immune system. However, there are important differences regarding the ability of each virus to infect cytotoxic effector cells, as HHV-6A has been shown to productively infect several of these cells, whereas HHV-6B infects them inefficiently at best. In addition to direct cytopathic effects, both HHV-6A and HHV-6B can interfere with immunologic functions to varying degrees via cytokine modulation, including blockade of IL-12 production by professional antigen-presenting cells, modulation of cell-surface molecules essential for T-cell activation, and expression of viral chemokines and chemokine receptors. Some of these effects are related to signaling through and downregulation of the viral receptor, CD46, a key molecule linking innate and adaptive immune responses. Increasing attention has recently been focused on the importance of viral interactions with dendritic cells, which may serve both as targets of virus-mediated immunosuppression and as vehicles for viral transfer to CD4+ T cells. Our deepening knowledge of the mechanisms developed by HHV-6A and HHV-6B to evade immunologic control may lead to new strategies for the prevention and treatment of the diseases associated with these viruses. Moreover, elucidation of these viral mechanisms may uncover new avenues to therapeutically manipulate or modulate the immune system in immunologically mediated human diseases.
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Affiliation(s)
- Lorenzo Dagna
- Department of Medicine & Clinical Immunology, Vita-Salute San Raffaele University, San Raffaele Scientific Institute, Via Olgettina 60, 20132 Milano, Italy
| | | | - Paolo Lusso
- Viral Pathogenesis Section, Laboratory of Immunoregulation, NIAID, NIH, 9000 Rockville Pike, Bethesda, MD 20892, USA
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Cermelli C, Orsi CF, Cuoghi A, Ardizzoni A, Tagliafico E, Neglia R, Peppoloni S, Blasi E. Gene expression profiling of monocytes displaying herpes simplex virus 1 induced dysregulation of antifungal defences. J Med Microbiol 2009; 58:1283-1290. [PMID: 19608693 DOI: 10.1099/jmm.0.011023-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Recently, we showed that herpes simplex virus 1 (HSV-1)-infected monocytes have altered antifungal defences, in particular they show augmented phagocytosis of Candida albicans followed by a failure of the intracellular killing of the ingested fungi. On the basis of these functional data, comparative studies were carried out on the gene expression profile of cells infected with HSV-1 and/or C. albicans in order to investigate the molecular mechanisms underlying such virus-induced dysfunction. Affymetrix GeneChip technology was used to evaluate the cell transcription pattern, focusing on genes involved in phagocytosis, fungal adhesion, antimicrobial activity and apoptosis. The results indicated there was: (a) prevalent inhibition of opsonin-mediated phagocytosis, (b) upregulation of several pathways of antibody- and complement-independent phagocytosis, (c) inhibition of macrophage activation, (d) marked dysregulation of oxidative burst, (e) induction of apoptosis.
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Affiliation(s)
- Claudio Cermelli
- Department of Public Health Sciences, University of Modena and Reggio Emilia, Via Campi 287, Modena, Italy
| | - Carlotta Francesca Orsi
- Department of Public Health Sciences, University of Modena and Reggio Emilia, Via Campi 287, Modena, Italy
| | - Alessandro Cuoghi
- Department of Public Health Sciences, University of Modena and Reggio Emilia, Via Campi 287, Modena, Italy
| | - Andrea Ardizzoni
- Department of Public Health Sciences, University of Modena and Reggio Emilia, Via Campi 287, Modena, Italy
| | - Enrico Tagliafico
- Department of Biomedical Sciences, University of Modena and Reggio Emilia, Via Campi 287, Modena, Italy
| | - Rachele Neglia
- Department of Public Health Sciences, University of Modena and Reggio Emilia, Via Campi 287, Modena, Italy
| | - Samuele Peppoloni
- Department of Public Health Sciences, University of Modena and Reggio Emilia, Via Campi 287, Modena, Italy
| | - Elisabetta Blasi
- Department of Public Health Sciences, University of Modena and Reggio Emilia, Via Campi 287, Modena, Italy
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Cermelli C, Orsi CF, Ardizzoni A, Lugli E, Cenacchi V, Cossarizza A, Blasi E. Herpes simplex virus type 1 dysregulates anti-fungal defenses preventing monocyte activation and downregulating toll-like receptor-2. Microbiol Immunol 2009; 52:575-84. [PMID: 19120971 DOI: 10.1111/j.1348-0421.2008.00074.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
We investigated the interplay occurring between pathogens in the course of dual infections, using an in vitro model in which the THP-1 monocytic cell line is first infected with HSV-1 and then exposed to Ca or Cn. These three pathogens share some pathogenic features: they cause opportunistic infections, target macrophages and are neurotropic. Here, we show that HSV-1-infected THP-1 cells exhibited augmented phagocytosis against the two opportunistic fungi but reduced capability to counteract fungal infection: the better ingestion by monocytes was followed by facilitated fungal survival and replication. Reduced IL-12 production was also observed. Cytofluorimetric analysis showed that HSV-1-infected monocytes exhibit: (i) downregulated TLR-2 and TLR-4, critical structures in fungal recognition; (ii) reduced expression of CD38 and CD69, known to be important markers of monocyte activation; and (iii) enhanced expression of apoptosis and necrosis markers, in the absence of altered cell proliferation. Overall, these findings imply that HSV-1 infection prevents monocyte activation, thus leading to a significant dysfunction of the monocyte-mediated anti-Candida response; HSV-1 induced apoptosis and necrosis of monocytes further contribute to this impairment.
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Affiliation(s)
- Claudio Cermelli
- Department of Public Health Sciences, University of Modena and Reggio Emilia, Modena, Italy.
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No association between human herpesvirus 6 reactivation and cryptococcosis in human immunodeficiency virus-infected patients. J Med Microbiol 2009; 58:276-277. [DOI: 10.1099/jmm.0.000992-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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Beretti F, Cenacchi V, Portolani M, Ardizzoni A, Blasi E, Cermelli C. A Transmissible Cytotoxic Activity Isolated from a Patient with Brain Ischemia Causes Microglial Cell Activation and Dysfunction. Cell Mol Neurobiol 2007; 27:517-28. [PMID: 17380379 DOI: 10.1007/s10571-007-9142-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2006] [Accepted: 02/14/2007] [Indexed: 01/04/2023]
Abstract
1. Microglial cell activation occurs during brain injury, ischemia, and in several neurologic disorders. Recently, we isolated a transmissible cytotoxic activity (TCA) from the cerebrospinal fluid of a patient with brain ischemia. Such a TCA, associated with one or more protein(s) that supposedly had undergone in vivo misfolding, causes apoptosis in vitro in different cell lines, including microglial cells. The TCA producing cells and the potential in vivo role of such cytotoxic activity remains to be elucidated. Here, we investigated the in vitro effects of TCA on microglial cell immune functions.2. The murine microglial cell line RR4 was exposed to TCA, and then its response was evaluated as: (a) phagocytosis and antifungal activity against Candida albicans; (b) secretory pattern; and (c) levels of p38 phosphorylation.3. Unlike mock-treated controls, microglial cells exposed to TCA showed an increase in phagocytic activity. Unexpectedly, their capability to kill the ingested fungi significantly diminished. Moreover, TCA-treated cells produced amounts of macrophage inflammatory protein 1-alpha, tumor necrosis factor-alpha, and nitric oxide significantly higher than mock-treated cells. Finally, phosphorylation of p38 mitogen-activated protein kinase (MAPK) was detected in TCA-treated but not in mock-treated controls as early as 30 min after treatment.4. Overall, these results indicate that TCA causes a rapid molecular response in microglial cells, by the time, leading to an intriguing effector and secretory dysfunction.
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Affiliation(s)
- F Beretti
- Dipartimento Integrato dei Servizi Diagnostici, di Laboratorio e di Medicina Legale, Università degli Studi di Modena e Reggio Emilia, Via del Pozzo 87, 41100 Modena, Italy
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Kogelnik AM, Loomis K, Hoegh-Petersen M, Rosso F, Hischier C, Montoya JG. Use of valganciclovir in patients with elevated antibody titers against Human Herpesvirus-6 (HHV-6) and Epstein—Barr Virus (EBV) who were experiencing central nervous system dysfunction including long-standing fatigue. J Clin Virol 2006; 37 Suppl 1:S33-8. [PMID: 17276366 DOI: 10.1016/s1386-6532(06)70009-9] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Twelve patients with long-standing symptoms of central nervous system (CNS) dysfunction were found to have elevated antibody titres to human herpesvirus-6 (HHV-6) and Epstein-Barr virus (EBV). All patients had four or more of the following neurocognitive symptoms: impaired cognitive functioning, slowed processing speed, sleep disturbance, short-term memory deficit, fatigue and symptoms consistent with depression. OBJECTIVES We sought to determine whether elevated antibodies to EBV and HHV-6 indicated chronic viral activation in patients with CNS dysfunction and if their symptoms could be improved by suppressing viral activity with oral valganciclovir. STUDY DESIGN Patients with high IgG antibody titers against HHV-6 and EBV who were suffering from central nervous system dysfunction and debilitating fatigue for more than one year (median 3 years, range 1-8 years) were treated with 6 months of valganciclovir in an open label study. RESULTS Nine out of 12 (75%) patients experienced near resolution of their symptoms, allowing them all to return to the workforce or full time activites. In the nine patients with a symptomatic response to treatment, EBV VCA IgG titers dropped from 1:2560 to 1:640 (p = 0.008) and HHV-6 IgG titers dropped from a median value of 1:1280 to 1:320 (p = 0.271). Clinically significant hematological toxicity or serious adverse events were not observed among the 12 patients. CONCLUSION These preliminary clinical and laboratory observations merit additional studies to establish whether this clinical response is mediated by an antiviral effect of the drug, indirectly via immunomodulation or by placebo effect.
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