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e-Mental Health in Central Massachusetts
e-Mental Health in Central Massachusetts (EMH) is a web-based resource designed to improve access to evidence-based mental health information and local resources for mental health professionals and consumers. The Lamar Soutter Library, University of Massachusetts Medical School (UMMS), in collaboration with the UMMS Department of Psychiatry and the Commonwealth of Massachusetts Department of Mental Health, developed EMH to meet the needs of practitioners, patients and caregivers. The project provides an integrative web-based information resource that includes searchable databases of (1) local mental health care services and (2) quality-filtered information about mental health conditions and diseases. Centralized access to professional resources, information literacy training, professional reference services and document delivery to a traditionally underserved population are also provided. After training, participants in the program use the resource regularly and demonstrate heightened awareness of reliable mental health information available to them. The collaborative spirit also continues and will surely benefit future endeavors
Dissecting the Role of a lncRNA and Involvement of \u3cem\u3ePlasmodium\u3c/em\u3e Infections in the Innate Immune Response: A Dissertation
The innate immune system is a multicomponent response governed by intricate mechanisms of induction, regulation and resolution to elicit antimicrobial defenses. In recent years, the complexity of eukaryotic transcriptomes has become the subject of intense scrutiny and curiosity. It has been established, that RNA polymerase II (RNAPII) transcribes hundreds to thousands of long noncoding RNAs (lncRNAs), often in a stimulus and cell-type specific manner. However, the functional significance of these transcripts has been particularly controversial. While the number of identified lncRNAs is growing, our understanding of how lncRNAs themselves regulate other genes is quite limited. In chapter 2, a novel lncRNA is identified, more specifically, a natural antisense transcript, that mediates the transcription of the pro-inflammatory cytokine IL-1α. Through loss-of-function studies, I report the necessity of this transcript in mediating IL-1α mRNA expression by affecting RNAPII binding to the IL-1α promoter after toll-like receptor signaling. For the first time, I show that IL-1α is regulated at the transcriptional level. As a second independent component of this thesis, we explore the role of the innate immune response after infection by the malaria-causing parasite, Plasmodium berghei ANKA (PbA), and how innate immune components are both beneficial and detrimental to the host depending on when and where inflammation is triggered during infection. We attempt to identify the “malarial toxin” responsible for aberrations in the immune response that is detrimental for disease outcomes and the innate signaling pathways that are involved. Many pathogens induce pathological inflammatory conditions that lead to irreparable homeostatic imbalances and become fatal to the host. Here, type I Interferon signaling is required to dampen parasite load during liver-stage infections, but leads to host mobidity if these pathways are activated in the erythrocytic phase of infection. Together, this thesis provides new insights on how components of the innate immune system are regulated, and how dysregulation of immunity can potentially lead to adverse effects during active infections
Characterization of functional antibody and memory B-cell responses to pH1N1 monovalent vaccine in HIV-infected children and youth
OBJECTIVES: We investigated immune determinants of antibody responses and B-cell memory to pH1N1 vaccine in HIV-infected children.
METHODS: Ninety subjects 4 to \u3c 25 years of age received two double doses of pH1N1 vaccine. Serum and cells were frozen at baseline, after each vaccination, and at 28 weeks post-immunization. Hemagglutination inhibition (HAI) titers, avidity indices (AI), B-cell subsets, and pH1N1 IgG and IgA antigen secreting cells (ASC) were measured at baseline and after each vaccination. Neutralizing antibodies and pH1N1-specific Th1, Th2 and Tfh cytokines were measured at baseline and post-dose 1.
RESULTS: At entry, 26 (29%) subjects had pH1N1 protective HAI titers ( \u3e /=1:40). pH1N1-specific HAI, neutralizing titers, AI, IgG ASC, IL-2 and IL-4 increased in response to vaccination (p /=1:40 had significantly greater increases in IgG ASC and AI after immunization compared with those with HAI \u3c 1:40. Neutralizing titers and AI after vaccination increased with older age. High pH1N1 HAI responses were associated with increased IgG ASC, IFNgamma, IL-2, microneutralizion titers, and AI. Microneutralization titers after vaccination increased with high IgG ASC and IL-2 responses. IgG ASC also increased with high IFNgamma responses. CD4% and viral load did not predict the immune responses post-vaccination, but the B-cell distribution did. Notably, vaccine immunogenicity increased with high CD19+CD21+CD27+% resting memory, high CD19+CD10+CD27+% immature activated, low CD19+CD21-CD27-CD20-% tissue-like, low CD19+CD21-CD27-CD20-% transitional and low CD19+CD38+HLADR+% activated B-cell subsets.
CONCLUSIONS: HIV-infected children on HAART mount a broad B-cell memory response to pH1N1 vaccine, which was higher for subjects with baseline HAI\u3e/=1:40 and increased with age, presumably due to prior exposure to pH1N1 or to other influenza vaccination/infection. The response to the vaccine was dependent on B-cell subset distribution, but not on CD4 counts or viral load.
TRIAL REGISTRATION: ClinicalTrials.gov NCT00992836
The Role of T Lymphocytes in the hu-PBMC-SCID Mouse Model of Epstein-Barr Virus-Associated Lymphoproliferative Disease
Epstein-Barr virus (EBV) is associated with a spectrum of benign and malignant lymphoproliferative disorders, including acute infectious mononucleosis (IM), Burkitt\u27s lymphoma (BL) and immunosuppression-associated B cell lymphoproliferative disease (LPD). Immunosurveillance mediated by virus-specific cytotoxic T lymphocytes is believed to protect immunocompetent hosts from EBV-associated lymphoma and LPD. Due to the lack of an adequate animal model, however, the precise immunologic mechanisms which provide this protection have not been directly demonstrated in vivo.
Human peripheral blood mononuclear cell-reconstituted C.B.-17-scid/scid mice (hu-PBMC-SCID mice) develop EBV-positive LPD following intraperitoneal injection of PBMC from EBV-seropositive donors. The SCID mouse disease mirrors human EBV-associated LPD in morphology, presence of the EBV genome, clonality, and patterns of expression of latent viral cellular differentiation antigens. The hu-PBMC-SCID mouse provides a unique small animal model of EBV+ LPD, and it was used in this study to examine the role of CD8+ CTL in controlling LPD. Survival time increase significantly when EBV-specific cytotoxic T-cell lines (CTL) are adoptive transferred into hu-PBMC-SCID mice, demonstrating suppression of LPD in vivoby a CTL-mediated virus-specific mechanism. Survival time also increases significantly with administration of alloreactive CTL lines, suggesting that a non-virus-specific mechanism also contributes to control of EBV-associated LPD by CTL.
NOD-SCID mice reconstituted with PBMC from donors with latent EBV infection develop EBV+ LPD with significantly less frequency than do C.B.17-SCID mice reconstituted with PBMC from the same donors. Administration of anti-CD8 mAb to these mice depletes human CD8+ cells and increases the incidence of LPD to 100%, demonstrating that CD8+ T cells are neccessary for protection from EBV-associated LPD. Adoptive transfer of human CD8+ T cells, but not CD4+ T cells, prevents LPD in CD8-depleted NOD-SCID mice. In vivo depletion of CD4+ T cells prevents engraftment of human T cells, and LPD does not develop in most mice after CD4+ cell depletion. These studies are the first to directly demonstrate both the protective role of CD8+ T cells and a requirement for CD4+ T cells in EBV -associated LPD in an in vivo model
A system for genome-wide histone variant dynamics in ES cells reveals dynamic MacroH2A2 replacement at promoters
Dynamic exchange of a subset of nucleosomes in vivo plays important roles in epigenetic inheritance of chromatin states, chromatin insulator function, chromosome folding, and the maintenance of the pluripotent state of embryonic stem cells. Here, we extend a pulse-chase strategy for carrying out genome-wide measurements of histone dynamics to several histone variants in murine embryonic stem cells and somatic tissues, recapitulating expected characteristics of the well characterized H3.3 histone variant. We extended this system to the less-studied MacroH2A2 variant, commonly described as a repressive histone variant whose accumulation in chromatin is thought to fix the epigenetic state of differentiated cells. Unexpectedly, we found that while large intergenic blocks of MacroH2A2 were stably associated with the genome, promoter-associated peaks of MacroH2A2 exhibited relatively rapid exchange dynamics in ES cells, particularly at highly-transcribed genes. Upon differentiation to embryonic fibroblasts, MacroH2A2 was gained primarily in additional long, stably associated blocks across gene-poor regions, while overall turnover at promoters was greatly dampened. Our results reveal unanticipated dynamic behavior of the MacroH2A2 variant in pluripotent cells, and provide a resource for future studies of tissue-specific histone dynamics in vivo
Psychosocial and Behavioral Determinants of Medication Nonadherence Among African Americans with Hypertension: A Dissertation
The overarching goal of this dissertation was to elucidate the psychosocial and behavioral determinants of medication nonadherence among African Americans with hypertension. One in three Americans in the United States has hypertension, and the prevalence of hypertension among African Americans is among the highest in the world. In addition to healthy behaviors such as following a low-salt and low-fat diet, getting regular exercise, and reducing stress, patients with hypertension must also adhere to antihypertensive medications. Poor medication adherence may be driven by psychosocial and behavioral factors; however, the impact of these factors on medication adherence is unclear especially within the African American community. To date, a paucity of research has examined the relationship between psychosocial and behavioral factors such as reported racial discrimination, John Henryism (a measure of active coping and an unhealthy response to stress) and home remedies with medication nonadherence. However, each of these factors has individually been linked with poorer health outcomes among African Americans.
Using data from the TRUST study (2006-2008) the association between these constructs and medication adherence was assessed within our sample of 788 African Americans and a comparison group of 137 White participants with hypertension. Ordinal logistic regression was used to assess the association between racial discrimination, John Henryism, home remedies, and medication adherence.
The findings from this research indicated more reported racial discrimination, higher John Henryism scores, and greater use of home remedies were associated with lower medication adherence. These findings yield new knowledge about medication adherence and provide practical insights about the psychosocial and behavioral determinants of medication adherence
Transport of Nucleotide Derivatives into Endoplasmic Reticulum and Golgiapparatus Derived Vesicles: a Dissertation
In mammals, newly synthesized proteins destined for secretion are translocated cotranslationally into the lumen of the Endoplasmic Reticulum (ER). Once inside, these nascent polypeptide chains are bound by a lumenal ER protein called BiP (Immunoglobulin Binding Protein) or Grp 78 (Glucose Regulated Protein 78). It is hypothesized that this binding is necessary to protect the nascent chains until they are properly folded or assembled with other subunits. When the proteins are folded and assembled, they are released from BiP by a process that is dependent on ATP hydrolysis. Since ATP is synthesized mainly in the mitochondria, we hypothesized that there must be an ATP transporter in the ER which would allow the protein mediated transport of ATP from the cytosol into the ER lumen. We studied the transport of ATP in vitro and found that ATP enters the lumen of the ER in a saturable manner with a Kmapp~3μM. ATP transport is dependent on time, protein, and vesicle integrity, it is also inhibited by the general anion transport inhibitor, 4,4\u27 diisothiocyano-2,2\u27-disulfonic acid stilbene (DIDS). We also found that the transport was inhibited by membrane impermeable protein modifying agents such as N-ethlymaleamide (NEM) and Pronase when added to intact ER vesicles. These results suggest that the transport is mediated by a protein with an active cytoplasmic face. Using monoclonal and polyclonal antibodies to BiP and Grp94 (another resident ER protein) and U.V. crosslinking, we demonstrated that after transport of ATPα32P into intact vesicles, radiolabeled BiP and Grp94 could be immunoprecipitated. We also found that labeling of lumenal proteins with ATP is dependent on the transport of ATP. Finally using ATP labeled with 35S, we concluded that BiP was able to bind intact ATP and we confirmed earlier work that BiP was thiophosphorylated while Grp94 is not.
The second area of study involves processes that occur further along the secretory pathway in the Golgi apparatus. It was known from previous work that the nucleotide sugar substrates necessary for the synthesis of the linkage region, UDP-xylose (UDP-Xyl), UDP-galactose (UDP-Gal) and UDP-glucuronic acid (UDP-GlcA) were transported into the Golgi apparatus from the cytosol via protein mediated transporters. In order to eventually purify one of these transporter proteins, we wanted to reconstitute their activities. We were able to reconstitute the activities that exhibited kinetic parameters and inhibitor sensitivities very similar to those seen in intact Golgi vesicles. In the case of UDP-xylose it was necessary to prepare the liposomes using endogenous Golgi lipids in order to get transport activity similar to that seen in the intact Golgi vesicles. This suggested a specific lipid requirement for the UDP-xylose transporter. These transporters seem to be antiporters, whereby the nucleotide sugar enters the lumen of the Golgi coupled to the equimolar exit of the corresponding nucleoside monophosphate (Hirschberg, C.B. and Snider, M.D. 1987). We also showed that we could reproduce the hypothesized antiporter system in the reconstituted proteoliposomes by preloading the proteoliposomes with the putative antiporter molecule UMP.
The rationale for developing the reconstituted system is eventually to use this system to purify one of these nucleotide sugar translocators. In the last set of studies, I have shown that this reconstituted system can be used to monitor the purification of the UDP-galactose translocator. Using column chromatography we were able to purify this membrane translocator protein 45,000 fold from a rat liver homogenate
Probing the Structural Topology of HIV-1 Virion Infectivity Factor (VIF): A Dissertation
Human Immunodeficiency Virus Type 1 (HIV-1), the virus that causes Acquired Immunodeficiency Syndrome (AIDS), attacks the immune system leaving patients susceptible to opportunistic infections that eventually cause death. Highly Active Antiretroviral Therapy, HAART, is the current drug strategy used to combat HIV. It is a combination therapy that includes HIV-1 Reverse Transcriptase and HIV-1 Protease inhibitors. Drug resistant strains arise that evade current HAART treatments; therefore novel drugs are needed.
HIV-1 regulatory proteins such as Tat, Rev, Nef, Vpr, Vpu, and Vif are attractive new drug targets. Of particular interest is the HIV-1 Vif protein and its cellular binding partner APOBEC3G. In the absence of HIV-1 Vif, APOBEC3G, a cytidine deaminase, is able to mutate the viral cDNA and render the virus noninfectious. HIV-1 Vif binds to APOBEC3G and targets it for proteosomal degradation through an interaction with a Cullin-RING ligase complex. Blocking the HIV-1 Vif APOBEC3G interaction would allow APOBEC3G to perform its antiviral function.
An attractive strategy to target the HIV-1 Vif APOBEC3G interaction would be a structure-based one. To apply structure-based drug design approaches to HIV-1 Vif and APOBEC3G, I attempted to collect high resolution structural data on HIV-1 Vif and APOBEC3G. My attempts were unsuccessful because the milligram quantities of soluble protein required were not obtained.
Therefore, in Chapter III I used chemical cross-linking and mass spectrometry to probe the structural topology of HIV-1 Vif obtaining low resolution structural data. Chemical cross-linking formed HIV-1 Vif multimers including dimers, trimers, and tetramers. Analysis of the cross-linked monomer revealed that HIV-1 Vif’s N-terminal domain is a well-folded, compact, globular domain, where as the C-teriminal domain is predicted to be disordered. In addition, disorder prediction programs predicted the C-terminal domain of HIV-1 Vif to be disordered. Upon oligomerization the C-terminal domain undergoes a disorder-to-order transition that not only facilitates oligomerization but may facilitate other protein-protein interactions. In addition, HIV-1 Vif oligomerization bring Lys34 and Glu134 in close proximity to each other likely creating one molecular surface forming a “hot spot” of biological activity.
In Chapter IV I confirmed my low resolution structural data via peptide competition experiments where I identified peptides that can be used as scaffolds for future drug design. HIV-1 Vif oligomerization is concentration dependent. The HIV-1 Vif peptides Vif(29-43) and Vif(125-139) were able to disrupt HIV-1 Vif oligomerization, which confirms the low resolution structural data. HIV-1 Vif peptides Vif(25-39) and Vif(29-43) reduced the amount of APOBEC3G immobilized on the Protein A beads, reduced the amount of HIV-1 Vif interacting with APOBEC3G, or degraded APOBEC3G itself. These peptides could be used as scaffolds to design novel drugs that disrupt the function of HIV-1 Vif and or APOBEC3G.
Therefore, low resolution structural data and peptide competition experiments were successful in identifying structurally important domains in HIV-1 Vif. They also provided insight into a possible mechanism for HIV-1 Vif function where a disorder-to-order transition facilitates HIV-1 Vif’s ability to interact with a diverse set of macromolecules. These data advance our structural understanding of HIV-1 Vif and they will facilitate future highresolution studies and novel drug designs
MIRAGE DNA Transposon Silencing by C. elegans Condensin II Subunit HCP-6: A Masters Thesis
Mobile genetic elements represent a large portion of the genome in many species. Posing a danger to the integrity of genetic information, silencing and structural machinery has evolved to suppress the mobility of foreign and transposable elements within the genome. Condensin proteins – which regulate chromosome structure to promote chromosome segregation – have been demonstrated to function in repetitive gene regulation and transposon silencing in several species. In model system Caenorhabditis elegans, microarray analysis studies have implicated Condensin II subunit HCP-6 in the silencing of multiple loci, including DNA transposon MIRAGE. To address the hypothesis that HCP-6 has a direct function in transcriptional gene silencing of the MIRAGE transposon, we queried MIRAGE expression and chromatin profiles in wild-type and hcp-6 mutant animals. Our evidence confirms that HCP-6 does indeed function during silencing of MIRAGE. However, we found no significant indication that HCP-6 binds to MIRAGE, nor that HCP-6 mediates MIRAGE enrichment of H3K9me3, the repressive heterochromatin mark observed at regions undergoing transcriptional silencing. We suggest that the silencing of MIRAGE, a newly evolved transposon and the only tested mobile element considerably derepressed upon loss of HCP-6, is managed by HCP-6 indirectly