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1.
Front Genet ; 15: 1396535, 2024.
Article in English | MEDLINE | ID: mdl-38660674
2.
J Med Case Rep ; 17(1): 489, 2023 Nov 10.
Article in English | MEDLINE | ID: mdl-37946248

ABSTRACT

BACKGROUND: We present a case report of an immunocompetent host with presumed sexually transmitted cytomegalovirus proctitis and epididymitis, where there currently is a sparsity of published data. CASE PRESENTATION: A 21-year-old previously healthy Caucasian individual was admitted for severe rectal and testicular pain in the setting of proctitis and epididymitis. Serology and rectal pathology confirmed acute primary cytomegalovirus infection. CONCLUSIONS: This report details his diagnostic workup and highlights cytomegalovirus as a rare cause of sexually transmitted disease among immunocompetent persons.


Subject(s)
Cytomegalovirus Infections , Epididymitis , Proctitis , Sexually Transmitted Diseases , Male , Humans , Young Adult , Adult , Cytomegalovirus , Epididymitis/diagnosis , Epididymitis/drug therapy , Epididymitis/complications , Proctitis/diagnosis , Proctitis/drug therapy , Proctitis/etiology , Sexually Transmitted Diseases/complications , Sexually Transmitted Diseases/diagnosis , Sexually Transmitted Diseases/pathology , Cytomegalovirus Infections/complications , Cytomegalovirus Infections/diagnosis , Cytomegalovirus Infections/drug therapy
3.
Aging (Albany NY) ; 15(16): 7866-7908, 2023 08 21.
Article in English | MEDLINE | ID: mdl-37606991

ABSTRACT

Dectin-1 is an innate immune receptor that recognizes and binds ß-1, 3/1, 6 glucans on fungi. We evaluated Dectin-1 function in myeloid cells in a cohort of HIV-positive and HIV-negative young and older adults. Stimulation of monocytes with ß-D-glucans induced a pro-inflammatory phenotype in monocytes of HIV-infected individuals that was characterized by increased levels of IL-12, TNF-α, and IL-6, with some age-associated cytokine increases also noted. Dendritic cells showed a striking HIV-associated increase in IFN-α production. These increases in cytokine production paralleled increases in Dectin-1 surface expression in both monocytes and dendritic cells that were noted with both HIV and aging. Differential gene expression analysis showed that HIV-positive older adults had a distinct gene signature compared to other cohorts characterized by a robust TNF-α and coagulation response (increased at baseline), a persistent IFN-α and IFN-γ response, and an activated dendritic cell signature/M1 macrophage signature upon Dectin-1 stimulation. Dectin-1 stimulation induced a strong upregulation of MTORC1 signaling in all cohorts, although increased in the HIV-Older cohort (stimulation and baseline). Overall, our study demonstrates that the HIV Aging population has a distinct immune signature in response to Dectin-1 stimulation. This signature may contribute to the pro-inflammatory environment that is associated with HIV and aging.


Subject(s)
HIV Infections , Tumor Necrosis Factor-alpha , Humans , Cytokines , Glucans
4.
Clin Infect Dis ; 77(5): 703-710, 2023 09 11.
Article in English | MEDLINE | ID: mdl-37078888

ABSTRACT

In response to longstanding healthcare inequities unmasked by the Coronavirus Disease 2019 pandemic, the infectious diseases (ID) section at the Yale School of Medicine designed and implemented a pilot curriculum integrating Infectious Disease Diversity, Equity, and Antiracism (ID2EA) into ID educational training and measured program outcomes. We herein describe a mixed-methods assessment of section members on whether the ID2EA curriculum affected their beliefs and behaviors regarding racism and healthcare inequities. Participants rated the curriculum as useful (92% averaging across sessions) and effective in achieving stated learning objectives (89% averaging across sessions), including fostering understanding of how inequities and racism are linked to health disparities and identifying strategies to effectively deal with racism and inequities. Despite limitations in response rates and assessment of longer-term behavioral change, this work demonstrates that training in diversity, equity, and antiracism can be successfully integrated into ID physicians' educational activities and affect physicians' perspectives on these topics.


Subject(s)
COVID-19 , Communicable Diseases , Racism , Humans , Antiracism , Curriculum , Communicable Diseases/therapy
5.
BMC Infect Dis ; 22(1): 744, 2022 Sep 21.
Article in English | MEDLINE | ID: mdl-36131232

ABSTRACT

BACKGROUND: The durability of immune responses to COVID-19 vaccines among older people living with HIV (PWH) is clinically important. METHODS: We aimed to assess vaccine-induced humoral immunity and durability in older PWH (≥ 55 years, n = 26) over 6 months (post-initial BNT162b2 series). A secondary and exploratory objective was to assess T-cell response and BNT162b2 booster reactogenicity, respectively. Our Visit 1 (3 weeks post-initial BNT162b2 dose) SARS-CoV-2 humoral immunity results are previously reported; these subjects were recruited for Visit 2 [2 weeks (+ 1 week window) post-second vaccination] and Visit 3 [6 months (± 2 week window) post-initial vaccination] in a single-center longitudinal observational study. Twelve participants had paired Visit 2/3 SARS-CoV-2 Anti-Spike IgG data. At Visit 3, SARS-CoV-2 Anti-Spike IgG testing occurred, and 5 subjects underwent T-cell immune response evaluation. Thereafter, subjects were offered BNT162b2 booster (concurrent day outside our study) per US FDA/CDC guidance; reactogenicity was assessed. The primary study outcome was presence of detectable Visit 3 SARS-CoV-2 Anti-Spike-1-RBD IgG levels. Secondary and exploratory outcomes were T-cell immune response and BNT162b2 booster reactogenicity, respectively. Wilcoxon signed-rank tests analyzed median SARS-CoV-2 Anti-Spike IgG 6-month trends. RESULTS: At Visit 3, 26 subjects underwent primary analysis with demographics noted: Median age 61 years; male n = 16 (62%), female n = 10 (38%); Black n = 13 (50%), White n = 13 (50%). Most subjects (n = 20, 77%) had suppressed HIV viremia on antiretroviral therapy, majority (n = 24, 92%) with CD4 > 200 cells/µL. At Visit 3, 26/26 (100%) had detectable Anti-Spike-1-RBD (≥ 0.8 U/mL). Among 12 subjects presenting to Visit 2/3, median SARS-CoV-2 Anti-Spike 1-RBD was 2087 U/mL at Visit 2, falling to 581.5 U/mL at Visit 3 (p = 0.0923), with a median 3.305-fold decrease over 6 months. Among subjects (n = 5) with 6-month T-cell responses measured, all had detectable cytokine-secreting anti-spike CD4 responses; 3 had detectable CD4 + Activation induced marker (AIM) + cells. Two had detectable cytokine-secreting CD8 responses, but all had positive CD8 + AIM + cells. CONCLUSIONS: Among older PWH, SARS-CoV-2 Anti-Spike IgG and virus-specific T-cell responses are present 6 months post-primary BNT162b2 vaccination, and although waning, suggest retention of some degree of long-term protective immunity.


Subject(s)
COVID-19 , Viral Vaccines , Antibodies, Viral , BNT162 Vaccine , COVID-19/prevention & control , COVID-19 Vaccines , Cytokines , Female , Humans , Immunoglobulin G , Male , Middle Aged , SARS-CoV-2 , Spike Glycoprotein, Coronavirus , Vaccination
6.
HIV Med ; 23(2): 178-185, 2022 02.
Article in English | MEDLINE | ID: mdl-34632695

ABSTRACT

OBJECTIVES: Effective and safe COVID-19 vaccines have been developed and have resulted in decreased incidence and severity of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and can decrease secondary transmission. However, there are concerns about dampened immune responses to COVID-19 vaccination among immunocompromised patients, including people living with HIV (PLWH), which may blunt the vaccine's efficacy and durability of protection. This study aimed to assess the qualitative SARS-CoV-2 vaccine immunogenicity among PLWH after vaccination. METHODS: We conducted targeted COVID-19 vaccination (all received BNT162b2 vaccine) of PLWH (aged ≥ 55 years per state guidelines) at Yale New Haven Health System and established a longitudinal survey to assess their qualitative antibody responses at 3 weeks after the first vaccination (and prior to receipt of the second dose of the COVID-19 vaccine) (visit 1) and at 2-3 weeks after the second vaccination (visit 2) but excluded patients with prior COVID-19 infection. Our goal was to assess vaccine-induced immunity in the population we studied. Qualitative immunogenicity testing was performed using Healgen COVID-19 anti-Spike IgG/IgM rapid testing. Poisson regression with robust standard errors was used to determine factors associated with a positive IgG response. RESULTS: At visit 1, 45 of 78 subjects (57.7%) tested positive for SARS-CoV-2 anti-Spike IgG after the first dose of COVID-19 vaccine. Thirty-nine subjects returned for visit 2. Of these, 38 had positive IgG (97.5%), including 20 of 21 subjects (95.2%) with an initial negative anti-Spike IgG. Our bivariate analysis suggested that participants on an antiretroviral regimen containing integrase strand transfer inhibitors [relative risk (RR) = 1.81, 95% confidence interval (CI): 0.92-3.56, p = 0.085] were more likely to seroconvert after the first dose of the COVID-19 vaccine, while those with a CD4 count < 500 cells/µL (RR = 0.59, 95% CI: 0.33-1.05, p = 0.071), and those diagnosed with cancer or another immunosuppressive condition (RR = 0.49, 95% CI: 0.18-1.28, p = 0.15) may have been less likely to seroconvert after the first dose of the COVID-19 vaccine. The direction of these associations was similar in the multivariate model, although none of these findings reached statistical significance (RRintegrase inhibitor  = 1.71, 95% CI: 0.90-3.25, p = 0.10; RRCD4 count  = 0.68, 95% CI: 0.39-1.19, p = 0.18; RRcancer or another immunosuppressive condition  = 0.50, 95% CI: 0.19-1.33, p = 0.16). With regard to immunogenicity, we were able to record very high rates of new seroconversion following the second dose of the COVID-19 vaccine. CONCLUSIONS: Our study suggests that completing a two-dose series of BNT162b2 vaccine is critical for PLWH given suboptimal seroconversion rates after the first dose and subsequent improved seroconversion rates after the second dose.


Subject(s)
BNT162 Vaccine , HIV Infections , Immunogenicity, Vaccine , Spike Glycoprotein, Coronavirus , Aged , BNT162 Vaccine/administration & dosage , HIV Infections/epidemiology , Humans , Qualitative Research , Spike Glycoprotein, Coronavirus/immunology
7.
J Immunol ; 204(6): 1661-1673, 2020 03 15.
Article in English | MEDLINE | ID: mdl-32060136

ABSTRACT

The seasonal influenza vaccine is an important public health tool but is only effective in a subset of individuals. The identification of molecular signatures provides a mechanism to understand the drivers of vaccine-induced immunity. Most previously reported molecular signatures of human influenza vaccination were derived from a single age group or season, ignoring the effects of immunosenescence or vaccine composition. Thus, it remains unclear how immune signatures of vaccine response change with age across multiple seasons. In this study we profile the transcriptional landscape of young and older adults over five consecutive vaccination seasons to identify shared signatures of vaccine response as well as marked seasonal differences. Along with substantial variability in vaccine-induced signatures across seasons, we uncovered a common transcriptional signature 28 days postvaccination in both young and older adults. However, gene expression patterns associated with vaccine-induced Ab responses were distinct in young and older adults; for example, increased expression of killer cell lectin-like receptor B1 (KLRB1; CD161) 28 days postvaccination positively and negatively predicted vaccine-induced Ab responses in young and older adults, respectively. These findings contribute new insights for developing more effective influenza vaccines, particularly in older adults.


Subject(s)
Antibodies, Viral/blood , Influenza A virus/immunology , Influenza Vaccines/immunology , Influenza, Human/prevention & control , Adult , Age Factors , Aged , Aging/immunology , Antibodies, Viral/immunology , Cohort Studies , Female , Gene Expression Profiling , Hemagglutination Inhibition Tests , Humans , Immunogenicity, Vaccine/genetics , Influenza Vaccines/administration & dosage , Influenza, Human/immunology , Influenza, Human/virology , Male , NK Cell Lectin-Like Receptor Subfamily B/genetics , Oligonucleotide Array Sequence Analysis , Seasons , Transcriptome/immunology , Vaccination , Vaccines, Inactivated/administration & dosage , Vaccines, Inactivated/immunology , Young Adult
8.
J Gerontol A Biol Sci Med Sci ; 74(6): 794-801, 2019 05 16.
Article in English | MEDLINE | ID: mdl-30239628

ABSTRACT

Both aging and HIV infection are associated with an enhanced pro-inflammatory environment that contributes to impaired immune responses and is mediated in part by innate immune pattern-recognition receptors. MINCLE is a C-type lectin receptor that recognizes trehalose-6,6'-dimycolate or "cord factor," the most abundant glycolipid in Mycobacterium tuberculosis. Here, we evaluated MINCLE function in monocytes in a cohort of HIV-infected and uninfected young (21-35 years) and older adults (≥60 years) via stimulation of peripheral blood mononuclear cells with trehalose-6,6-dibehenate, a synthetic analog of trehalose-6,6'-dimycolate and measurement of cytokine production (interleukin [IL]-10, IL-12, IL-6, tumor necrosis factor-α) by multicolor flow cytometry. Our studies show an age- and HIV-associated increase in cytokine multifunctionality of monocytes both at the population and single cell level that was dominated by IL-12, IL-10, and IL-6. These findings provide insight into the host response to M. tuberculosis and possible sources for the pro-inflammatory environment seen in aging and HIV infection.


Subject(s)
Aging/immunology , HIV Infections/immunology , Lectins, C-Type/metabolism , Monocytes/metabolism , Receptors, Immunologic/metabolism , Adult , Cohort Studies , Cytokines/metabolism , Female , Flow Cytometry , Humans , Male , Middle Aged , Young Adult
9.
Bioinformatics ; 33(14): i208-i216, 2017 Jul 15.
Article in English | MEDLINE | ID: mdl-28881994

ABSTRACT

MOTIVATION: Systems immunology leverages recent technological advancements that enable broad profiling of the immune system to better understand the response to infection and vaccination, as well as the dysregulation that occurs in disease. An increasingly common approach to gain insights from these large-scale profiling experiments involves the application of statistical learning methods to predict disease states or the immune response to perturbations. However, the goal of many systems studies is not to maximize accuracy, but rather to gain biological insights. The predictors identified using current approaches can be biologically uninterpretable or present only one of many equally predictive models, leading to a narrow understanding of the underlying biology. RESULTS: Here we show that incorporating prior biological knowledge within a logistic modeling framework by using network-level constraints on transcriptional profiling data significantly improves interpretability. Moreover, incorporating different types of biological knowledge produces models that highlight distinct aspects of the underlying biology, while maintaining predictive accuracy. We propose a new framework, Logistic Multiple Network-constrained Regression (LogMiNeR), and apply it to understand the mechanisms underlying differential responses to influenza vaccination. Although standard logistic regression approaches were predictive, they were minimally interpretable. Incorporating prior knowledge using LogMiNeR led to models that were equally predictive yet highly interpretable. In this context, B cell-specific genes and mTOR signaling were associated with an effective vaccination response in young adults. Overall, our results demonstrate a new paradigm for analyzing high-dimensional immune profiling data in which multiple networks encoding prior knowledge are incorporated to improve model interpretability. AVAILABILITY AND IMPLEMENTATION: The R source code described in this article is publicly available at https://bitbucket.org/kleinstein/logminer . CONTACT: steven.kleinstein@yale.edu or stefan.avey@yale.edu. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Subject(s)
Computational Biology/methods , Influenza, Human/prevention & control , Models, Biological , Vaccination , Gene Expression Regulation , Humans , Immune System , Influenza, Human/genetics , Influenza, Human/metabolism , Signal Transduction , Transcriptome
10.
J Am Geriatr Soc ; 63(4): 776-81, 2015 Apr.
Article in English | MEDLINE | ID: mdl-25851728

ABSTRACT

Advances in bacterial deoxyribonucleic acid sequencing allow for characterization of the human commensal bacterial community (microbiota) and its corresponding genome (microbiome). Surveys of healthy adults reveal that a signature composite of bacteria characterizes each unique body habitat (e.g., gut, skin, oral cavity, vagina). A myriad of clinical changes, including a basal proinflammatory state (inflamm-aging), that directly interface with the microbiota of older adults and enhance susceptibility to disease accompany aging. Studies in older adults demonstrate that the gut microbiota correlates with diet, location of residence (e.g., community dwelling, long-term care settings), and basal level of inflammation. Links exist between the microbiota and a variety of clinical problems plaguing older adults, including physical frailty, Clostridium difficile colitis, vulvovaginal atrophy, colorectal carcinoma, and atherosclerotic disease. Manipulation of the microbiota and microbiome of older adults holds promise as an innovative strategy to influence the development of comorbidities associated with aging.


Subject(s)
Aging/physiology , Microbiota/physiology , Aged , Clostridioides difficile , Colitis/microbiology , Disease Susceptibility/microbiology , Frail Elderly , Gastrointestinal Tract/microbiology , Humans , Inflammation/microbiology , Residence Characteristics
11.
J Virol ; 89(10): 5502-14, 2015 May.
Article in English | MEDLINE | ID: mdl-25740989

ABSTRACT

UNLABELLED: Elite controllers (ECs) are a rare group of HIV seropositive individuals who are able to control viral replication without antiretroviral therapy. The mechanisms responsible for this phenotype, however, have not been fully elucidated. In this study, we examined CD4(+) T cell resistance to HIV in a cohort of elite controllers and explored transcriptional signatures associated with cellular resistance. We demonstrate that a subgroup of elite controllers possess CD4(+) T cells that are specifically resistant to R5-tropic HIV while remaining fully susceptible to X4-tropic and vesicular stomatitis virus G (VSV-G)-pseudotyped viruses. Transcriptome analysis revealed 17 genes that were differentially regulated in resistant elite controllers relative to healthy controls. Notably, the genes encoding macrophage inflammatory protein 1α (MIP-1α), CCL3 and CCL3L1, were found to be upregulated. The MIP-1α, MIP-1ß, and RANTES chemokines are natural ligands of CCR5 and are known to interfere with HIV replication. For three elite controllers, we observed increased production of MIP-1α and/or MIP-1ß at the protein level. The supernatant from resistant EC cells contained MIP-1α and MIP-1ß and was sufficient to confer R5-tropic resistance to susceptible CD4(+) T cells. Additionally, this effect was reversed by using inhibitory anti-MIP antibodies. These results suggest that the T cells of these particular elite controllers may be naturally resistant to HIV infection by blocking R5-tropic viral entry. IMPORTANCE: HIV is a pandemic health problem, and the majority of seropositive individuals will eventually progress to AIDS unless antiretroviral therapy (ART) is administered. However, rare patients, termed elite controllers, have a natural ability to control HIV infection in the absence of ART, but the mechanisms by which they achieve this phenotype have not been fully explored. This paper identifies one mechanism that may contribute to this natural resistance: some elite controllers have CD4(+) T cells that produce high levels of MIP chemokines, which block R5-tropic HIV entry. This mechanism could potentially be exploited to achieve a therapeutic effect in other HIV-seropositive individuals.


Subject(s)
HIV Infections/immunology , HIV Long-Term Survivors , HIV-1 , Macrophage Inflammatory Proteins/blood , Adult , Aged , CD4-Positive T-Lymphocytes/immunology , CD4-Positive T-Lymphocytes/virology , Case-Control Studies , Chemokine CCL3/blood , Chemokine CCL3/genetics , Chemokine CCL4/blood , Chemokine CCL4/genetics , Chemokine CCL5/blood , Chemokine CCL5/genetics , Chemokines, CC/blood , Chemokines, CC/genetics , Cohort Studies , Female , Gene Dosage , HIV Infections/genetics , HIV Infections/virology , HIV-1/immunology , HIV-1/pathogenicity , Host-Pathogen Interactions , Humans , Macrophage Inflammatory Proteins/genetics , Male , Middle Aged , RNA, Messenger/blood , RNA, Messenger/genetics , Receptors, CCR5/blood , Receptors, CXCR4/blood , Up-Regulation
12.
Curr Opin Immunol ; 29: 127-36, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24997358

ABSTRACT

HIV infection is associated with a chronic inflammatory state arising from multiple factors, including innate immune recognition of HIV, increased microbial translocation, and release of endogenous ligands from damaged cells (such as CD4 T cells). In many respects, this heightened pro-inflammatory environment resembles that associated with aging in the absence of HIV infection, and evidence of dysregulated innate immune responses can be found in not only older HIV-negative adults, but also adults with HIV infection. While the study of innate immune aging in HIV infection is still in its early stages, it seems likely that at least additive, or potentially synergistic effects of aging and HIV infection will be found.


Subject(s)
Aging/immunology , HIV Infections/immunology , Immunity, Innate , Dendritic Cells/immunology , Humans , Inflammation/immunology , Toll-Like Receptors/immunology
13.
Infect Control Hosp Epidemiol ; 35(7): 810-7, 2014 Jul.
Article in English | MEDLINE | ID: mdl-24915208

ABSTRACT

OBJECTIVE: We describe the efficacy of enhanced infection control measures, including those recommended in the Centers for Disease Control and Prevention's 2012 carbapenem-resistant Enterobacteriaceae (CRE) toolkit, to control concurrent outbreaks of carbapenemase-producing Enterobacteriaceae (CPE) and extensively drug-resistant Acinetobacter baumannii (XDR-AB). DESIGN: Before-after intervention study. SETTING: Fifteen-bed surgical trauma intensive care unit (ICU). METHODS: We investigated the impact of enhanced infection control measures in response to clusters of CPE and XDR-AB infections in an ICU from April 2009 to March 2010. Polymerase chain reaction was used to detect the presence of blaKPC and resistance plasmids in CRE. Pulsed-field gel electrophoresis was performed to assess XDR-AB clonality. Enhanced infection-control measures were implemented in response to ongoing transmission of CPE and a new outbreak of XDR-AB. Efficacy was evaluated by comparing the incidence rate (IR) of CPE and XDR-AB before and after the implementation of these measures. RESULTS: The IR of CPE for the 12 months before the implementation of enhanced measures was 7.77 cases per 1,000 patient-days, whereas the IR of XDR-AB for the 3 months before implementation was 6.79 cases per 1,000 patient-days. All examined CPE shared endemic blaKPC resistance plasmids, and 6 of the 7 XDR-AB isolates were clonal. Following institution of enhanced infection control measures, the CPE IR decreased to 1.22 cases per 1,000 patient-days (P = .001), and no more cases of XDR-AB were identified. CONCLUSIONS: Use of infection control measures described in the Centers for Disease Control and Prevention's 2012 CRE toolkit was associated with a reduction in the IR of CPE and an interruption in XDR-AB transmission.


Subject(s)
Acinetobacter Infections/prevention & control , Acinetobacter baumannii/drug effects , Carbapenems/pharmacology , Cross Infection/prevention & control , Enterobacteriaceae Infections/prevention & control , Enterobacteriaceae/drug effects , Infection Control/methods , Academic Medical Centers , Acinetobacter baumannii/isolation & purification , Centers for Disease Control and Prevention, U.S. , Drug Resistance, Multiple, Bacterial , Enterobacteriaceae/isolation & purification , Humans , Intensive Care Units , Outcome Assessment, Health Care , United States , Virginia
14.
BMJ Case Rep ; 20132013 Nov 18.
Article in English | MEDLINE | ID: mdl-24248316

ABSTRACT

A 56-year-old Hispanic man with no significant medical problems presented with a 2-month history of a non-healing right forearm lesion that progressed despite several courses of empiric antibiotics. The patient underwent incision and drainage. Warthin-Starry stain with immunohistochemistry testing diagnosed bacillary angiomatosis secondary to Bartonella quintana. Subsequently, the patient was diagnosed with HIV, with a CD4 count of 68 cells/mm(3), and a HIV viral load of 47, 914 copies/mL. The patient was treated with doxycycline and started on antiretroviral therapy. The lesion has resolved and he has had no recurrence after 16 months of treatment.


Subject(s)
AIDS-Related Opportunistic Infections/diagnosis , Angiomatosis, Bacillary/etiology , Anti-Bacterial Agents/therapeutic use , Bartonella Infections/etiology , Bartonella quintana/isolation & purification , Doxycycline/therapeutic use , HIV Infections/diagnosis , AIDS-Related Opportunistic Infections/drug therapy , Angiomatosis, Bacillary/diagnosis , Bartonella Infections/drug therapy , CD4 Lymphocyte Count , Forearm/pathology , HIV Infections/complications , Humans , Immunocompromised Host , Male , Middle Aged
15.
Biochemistry ; 50(32): 6763-73, 2011 Aug 16.
Article in English | MEDLINE | ID: mdl-21688771

ABSTRACT

The role of the extracellular loop region of a short-wavelength sensitive pigment, Xenopus violet cone opsin, is investigated via computational modeling, mutagenesis, and spectroscopy. The computational models predict a complex H-bonding network that stabilizes and connects the EC2-EC3 loop and the N-terminus. Mutations that are predicted to disrupt the H-bonding network are shown to produce visual pigments that do not stably bind chromophore and exhibit properties of a misfolded protein. The potential role of a disulfide bond between two conserved Cys residues, Cys(105) in TM3 and Cys(182) in EC2, is necessary for proper folding and trafficking in VCOP. Lastly, certain residues in the EC2 loop are predicted to stabilize the formation of two antiparallel ß-strands joined by a hairpin turn, which interact with the chromophore via H-bonding or van der Waals interactions. Mutations of conserved residues result in a decrease in the level of chromophore binding. These results demonstrate that the extracellular loops are crucial for the formation of this cone visual pigment. Moreover, there are significant differences in the structure and function of this region in VCOP compared to that in rhodopsin.


Subject(s)
Conserved Sequence , Retinal Pigments/chemistry , Amino Acid Sequence , Disulfides/chemistry , Hydrogen Bonding , Models, Molecular , Molecular Dynamics Simulation , Molecular Sequence Data , Mutagenesis, Site-Directed , Retinal Pigments/genetics , Sequence Homology, Amino Acid , Spectrophotometry, Ultraviolet
16.
J Virol ; 81(2): 977-90, 2007 Jan.
Article in English | MEDLINE | ID: mdl-17079291

ABSTRACT

The transcription factors ATF-2 and c-Jun are important for transactivation of varicella-zoster virus (VZV) genes. c-Jun is activated by the c-Jun N-terminal kinase (JNK), a member of the mitogen-activated protein kinase pathway that responds to stress and cytokines. To study the effects of VZV on this pathway, confluent human foreskin fibroblasts were infected with cell-associated VZV for 1 to 4 days. Immunoblots showed that phosphorylated JNK and c-Jun levels increased in VZV-infected cells, and kinase assays determined that phospho-JNK was active. Phospho-JNK was detected after 24 h, and levels rose steadily over 4 days in parallel with accumulation of VZV antigen. The two main activators of JNK are MKK4 and MKK7, and levels of their active, phosphorylated forms also increased. The competitive inhibitor of JNK, SP600125, caused a dose-dependent reduction in VZV yield (50% effective concentration, congruent with 8 microM). Specificity was verified by immunoblotting; phospho-c-Jun was eliminated by 18 microM SP600125 in VZV-infected cells. Immunofluorescent confocal microscopy showed that phospho-c-Jun and most of phospho-JNK were in the nuclei of VZV-infected cells; some phospho-JNK was in the cytoplasm. MKK4, MKK7, JNK, and phospho-JNK were detected by immunoblotting in purified preparations of VZV virions, but c-Jun was absent. JNK was located in the virion tegument, as determined by biochemical fractionation and immunogold transmission electron microscopy. Overall, these results demonstrate the importance of the JNK pathway for VZV replication and advance the idea that JNK is a useful drug target against VZV.


Subject(s)
Fibroblasts/virology , Herpesvirus 3, Human/pathogenicity , JNK Mitogen-Activated Protein Kinases/metabolism , Cell Line , Enzyme Activation , Humans , MAP Kinase Kinase 4/metabolism , MAP Kinase Kinase 7/metabolism , Proto-Oncogene Proteins c-jun/metabolism , Virion/metabolism
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