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1.
Viruses ; 16(10)2024 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-39459900

RESUMO

Tsg101, a component of the endosomal sorting complex required for transport (ESCRT), is responsible for recognition of events requiring the machinery, as signaled by cargo tagging with ubiquitin (Ub), and for recruitment of downstream acting subunits to the site. Although much is known about the latter function, little is known about its role in the earlier event. The N-terminal domain of Tsg101 is a structural homologue of Ub conjugases (E2 enzymes) and the protein associates with Ub ligases (E3 enzymes) that regulate several cellular processes including virus budding. A pocket in the domain recognizes a motif, PT/SAP, that permits its recruitment. PT/SAP disruption makes budding dependent on Nedd4L E3 ligases. Using HIV-1 encoding a PT/SAP mutation that makes budding Nedd4L-dependent, we identified as critical for rescue the residues in the catalytic (HECT) domain of the E3 enzyme that lie in proximity to sites in Tsg101 that bind Ub non-covalently. Mutation of these residues impaired rescue by Nedd4L but the same mutations had no apparent effect in the context of a Nedd4 isomer, Nedd4-2s, whose N-terminal (C2) domain is naturally truncated, precluding C2-HECT auto-inhibition. Surprisingly, like small molecules that disrupt Tsg101 Ub-binding, small molecules that interfered with Nedd4 substrate recognition arrested budding at an early stage, supporting the conclusion that Tsg101-Ub-Nedd4 interaction promotes enzyme activation and regulates Nedd4 signaling for viral egress. Tsg101 regulation of E3 ligases may underlie its broad ability to function as an effector in various cellular activities, including viral particle assembly and budding.


Assuntos
Proteínas de Ligação a DNA , Complexos Endossomais de Distribuição Requeridos para Transporte , HIV-1 , Ubiquitina-Proteína Ligases Nedd4 , Fatores de Transcrição , Montagem de Vírus , Complexos Endossomais de Distribuição Requeridos para Transporte/metabolismo , Complexos Endossomais de Distribuição Requeridos para Transporte/genética , Humanos , Ubiquitina-Proteína Ligases Nedd4/metabolismo , Ubiquitina-Proteína Ligases Nedd4/genética , HIV-1/fisiologia , HIV-1/genética , Fatores de Transcrição/metabolismo , Fatores de Transcrição/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas de Ligação a DNA/genética , Ligação Proteica , Liberação de Vírus , Ubiquitina-Proteína Ligases/metabolismo , Ubiquitina-Proteína Ligases/genética , Mutação
2.
Viruses ; 16(9)2024 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-39339909

RESUMO

MoMo30 is an antiviral protein isolated from aqueous extracts of Momordica balsamina L. (Senegalese bitter melon). Previously, we demonstrated MoMo30's antiviral activity against HIV-1. Here, we explore whether MoMo30 has antiviral activity against the COVID-19 virus, SARS-CoV-2. MLV particles pseudotyped with the SARS-CoV-2 Spike glycoprotein and a Luciferase reporter gene (SARS2-PsV) were developed from a three-way co-transfection of HEK293-T17 cells. MoMo30's inhibition of SARS2-PsV infection was measured using a luciferase assay and its cytotoxicity using an XTT assay. Additionally, MoMo30's interactions with the variants and domains of Spike were determined by ELISA. We show that MoMo30 inhibits SARS2-PsV infection. We also report evidence of the direct interaction of MoMo30 and SARS-CoV-2 Spike from WH-1, Alpha, Delta, and Omicron variants. Furthermore, MoMo30 interacts with both the S1 and S2 domains of Spike but not the receptor binding domain (RBD), suggesting that MoMo30 inhibits SARS-CoV-2 infection by inhibiting fusion of the virus and the host cell via interactions with Spike.


Assuntos
Antivirais , Ligação Proteica , SARS-CoV-2 , Glicoproteína da Espícula de Coronavírus , Glicoproteína da Espícula de Coronavírus/metabolismo , Glicoproteína da Espícula de Coronavírus/genética , Glicoproteína da Espícula de Coronavírus/química , Humanos , SARS-CoV-2/efeitos dos fármacos , SARS-CoV-2/fisiologia , Células HEK293 , Antivirais/farmacologia , COVID-19/virologia , Internalização do Vírus/efeitos dos fármacos , Pseudotipagem Viral
3.
Parkinsonism Relat Disord ; 122: 106036, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38462403

RESUMO

BACKGROUND: Although there are many possible causes for cervical dystonia (CD), a specific etiology cannot be identified in most cases. Prior studies have suggested a relationship between autoimmune disease and some cases of CD, pointing to possible immunological mechanisms. OBJECTIVE: The goal was to explore the potential role of multiple different immunological mechanisms in CD. METHODS: First, a broad screening test compared neuronal antibodies in controls and CD. Second, unbiased blood plasma proteomics provided a broad screen for potential biologic differences between controls and CD. Third, a multiplex immunoassay compared 37 markers associated with immunological processes in controls and CD. Fourth, relative immune cell frequencies were investigated in blood samples of controls and CD. Finally, sequencing studies investigated the association of HLA DQB1 and DRB1 alleles in controls versus CD. RESULTS: Screens for anti-neuronal antibodies did not reveal any obvious abnormalities. Plasma proteomics pointed towards certain abnormalities of immune mechanisms, and the multiplex assay pointed more specifically towards abnormalities in T lymphocytes. Abnormal immune cell frequencies were identified for some CD cases, and these cases clustered together as a potential subgroup. Studies of HLA alleles indicated a possible association between CD and DRB1*15:03, which is reported to mediate the penetrance of autoimmune disorders. CONCLUSIONS: Altogether, the association of CD with multiple different blood-based immune measures point to abnormalities in cell-mediated immunity that may play a pathogenic role for a subgroup of individuals with CD.


Assuntos
Torcicolo , Humanos , Torcicolo/imunologia , Torcicolo/genética , Masculino , Feminino , Pessoa de Meia-Idade , Proteômica , Adulto , Idoso , Cadeias beta de HLA-DQ/genética , Cadeias HLA-DRB1/genética , Autoanticorpos/sangue
4.
J Immunol ; 211(3): 365-376, 2023 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-37314436

RESUMO

The Ikaros zinc-finger transcription factor Eos has largely been associated with sustaining the immunosuppressive functions of regulatory T cells. Paradoxically, Eos has more recently been implicated in promoting proinflammatory responses in the dysregulated setting of autoimmunity. However, the precise role of Eos in regulating the differentiation and function of effector CD4+ T cell subsets remains unclear. In this study, we find that Eos is a positive regulator of the differentiation of murine CD4+ TH2 cells, an effector population that has been implicated in both immunity against helminthic parasites and the induction of allergic asthma. Using murine in vitro TH2 polarization and an in vivo house dust mite asthma model, we find that EosKO T cells exhibit reduced expression of key TH2 transcription factors, effector cytokines, and cytokine receptors. Mechanistically, we find that the IL-2/STAT5 axis and its downstream TH2 gene targets are one of the most significantly downregulated pathways in Eos-deficient cells. Consistent with these observations, we find that Eos forms, to our knowledge, a novel complex with and supports the tyrosine phosphorylation of STAT5. Collectively, these data define a regulatory mechanism whereby Eos propagates STAT5 activity to facilitate TH2 cell differentiation.


Assuntos
Asma , Fator de Transcrição STAT5 , Camundongos , Animais , Fator de Transcrição STAT5/metabolismo , Diferenciação Celular , Citocinas/metabolismo , Células Th2
5.
Commun Biol ; 6(1): 363, 2023 04 03.
Artigo em Inglês | MEDLINE | ID: mdl-37012418

RESUMO

Human memory T cells (MTC) are poised to rapidly respond to antigen re-exposure. Here, we derived the transcriptional and epigenetic programs of resting and ex vivo activated, circulating CD4+ and CD8+ MTC subsets. A progressive gradient of gene expression from naïve to TCM to TEM is observed, which is accompanied by corresponding changes in chromatin accessibility. Transcriptional changes suggest adaptations of metabolism that are reflected in altered metabolic capacity. Other differences involve regulatory modalities comprised of discrete accessible chromatin patterns, transcription factor binding motif enrichment, and evidence of epigenetic priming. Basic-helix-loop-helix factor motifs for AHR and HIF1A distinguish subsets and predict transcription networks to sense environmental changes. Following stimulation, primed accessible chromatin correlate with an augmentation of MTC gene expression as well as effector transcription factor gene expression. These results identify coordinated epigenetic remodeling, metabolic, and transcriptional changes that enable MTC subsets to ultimately respond to antigen re-encounters more efficiently.


Assuntos
Células T de Memória , Transcriptoma , Humanos , Epigenômica , Cromatina/genética , Fatores de Transcrição
6.
Nat Commun ; 14(1): 1652, 2023 03 24.
Artigo em Inglês | MEDLINE | ID: mdl-36964178

RESUMO

During intracellular infection, T follicular helper (TFH) and T helper 1 (TH1) cells promote humoral and cell-mediated responses, respectively. Another subset, CD4-cytotoxic T lymphocytes (CD4-CTLs), eliminate infected cells via functions typically associated with CD8+ T cells. The mechanisms underlying differentiation of these populations are incompletely understood. Here, we identify the transcription factor Aiolos as a reciprocal regulator of TFH and CD4-CTL programming. We find that Aiolos deficiency results in downregulation of key TFH transcription factors, and consequently reduced TFH differentiation and antibody production, during influenza virus infection. Conversely, CD4-CTL programming is elevated, including enhanced Eomes and cytolytic molecule expression. We further demonstrate that Aiolos deficiency allows for enhanced IL-2 sensitivity and increased STAT5 association with CD4-CTL gene targets, including Eomes, effector molecules, and IL2Ra. Thus, our collective findings identify Aiolos as a pivotal regulator of CD4-CTL and TFH programming and highlight its potential as a target for manipulating CD4+ T cell responses.


Assuntos
Linfócitos T Auxiliares-Indutores , Fatores de Transcrição , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Interleucina-2/genética , Interleucina-2/metabolismo , Linfócitos T CD8-Positivos , Linfócitos T CD4-Positivos , Diferenciação Celular
7.
Virol J ; 20(1): 50, 2023 03 22.
Artigo em Inglês | MEDLINE | ID: mdl-36949470

RESUMO

BACKGROUND: Plants are used in traditional healing practices of many cultures worldwide. Momordica balsamina is a plant commonly used by traditional African healers as a part of a treatment for HIV/AIDS. It is typically given as a tea to patients with HIV/AIDS. Water-soluble extracts of this plant were found to contain anti-HIV activity. METHODS: We employed cell-based infectivity assays, surface plasmon resonance, and a molecular-cell model of the gp120-CD4 interaction to study the mechanism of action of the MoMo30-plant protein. Using Edman degradation results of the 15 N-terminal amino acids, we determined the gene sequence of the MoMo30-plant protein from an RNAseq library from total RNA extracted from Momordica balsamina. RESULTS: Here, we identify the active ingredient of water extracts of the leaves of Momordica balsamina as a 30 kDa protein we call MoMo30-plant. We have identified the gene for MoMo30 and found it is homologous to a group of plant lectins known as Hevamine A-like proteins. MoMo30-plant is distinct from other proteins previously reported agents from the Momordica species, such as ribosome-inactivating proteins such as MAP30 and Balsamin. MoMo30-plant binds to gp120 through its glycan groups and functions as a lectin or carbohydrate-binding agent (CBA). It inhibits HIV-1 at nanomolar levels and has minimal cellular toxicity at inhibitory levels. CONCLUSIONS: CBAs like MoMo30 can bind to glycans on the surface of the enveloped glycoprotein of HIV (gp120) and block entry. Exposure to CBAs has two effects on the virus. First, it blocks infection of susceptible cells. Secondly, MoMo30 drives the selection of viruses with altered glycosylation patterns, potentially altering their immunogenicity. Such an agent could represent a change in the treatment strategy for HIV/AIDS that allows a rapid reduction in viral loads while selecting for an underglycosylated virus, potentially facilitating the host immune response.


Assuntos
Síndrome da Imunodeficiência Adquirida , HIV-1 , Momordica , Plantas Medicinais , Humanos , HIV-1/genética , Momordica/química , Momordica/metabolismo , Proteínas de Plantas/metabolismo , Proteína gp120 do Envelope de HIV/genética , Proteína gp120 do Envelope de HIV/metabolismo , Proteína gp120 do Envelope de HIV/farmacologia
8.
Immunohorizons ; 6(12): 872-882, 2022 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-36547389

RESUMO

CD8 cytotoxic T cells are a potent line of defense against invading pathogens. To aid in curtailing aberrant immune responses, the activation status of CD8 T cells is highly regulated. One mechanism in which CD8 T cell responses are dampened is via signaling through the immune-inhibitory receptor Programmed Cell Death Protein-1, encoded by Pdcd1. Pdcd1 expression is regulated through engagement of the TCR, as well as by signaling from extracellular cytokines. Understanding such pathways has influenced the development of numerous clinical treatments. In this study, we showed that signals from the cytokine IL-6 enhanced Pdcd1 expression when paired with TCR stimulation in murine CD8 T cells. Mechanistically, signals from IL-6 were propagated through activation of the transcription factor STAT3, resulting in IL-6-dependent binding of STAT3 to Pdcd1 cis-regulatory elements. Intriguingly, IL-6 stimulation overcame B Lymphocyte Maturation Protein 1-mediated epigenetic repression of Pdcd1, which resulted in a transcriptionally permissive landscape marked by heightened histone acetylation. Furthermore, in vivo-activated CD8 T cells derived from lymphocytic choriomeningitis virus infection required STAT3 for optimal Programmed Cell Death Protein-1 surface expression. Importantly, STAT3 was the only member of the STAT family present at Pdcd1 regulatory elements in lymphocytic choriomeningitis virus Ag-specific CD8 T cells. Collectively, these data define mechanisms by which the IL-6/STAT3 signaling axis can enhance and prolong Pdcd1 expression in murine CD8 T cells.


Assuntos
Linfócitos T CD8-Positivos , Interleucina-6 , Receptor de Morte Celular Programada 1 , Animais , Camundongos , Linfócitos T CD8-Positivos/imunologia , Linfócitos T CD8-Positivos/virologia , Interleucina-6/metabolismo , Coriomeningite Linfocítica/imunologia , Coriomeningite Linfocítica/virologia , Receptor de Morte Celular Programada 1/metabolismo , Receptores de Antígenos de Linfócitos T/metabolismo , Transdução de Sinais , Vírus da Coriomeningite Linfocítica/imunologia
9.
Artigo em Inglês | MEDLINE | ID: mdl-36554864

RESUMO

Funded by the National Institutes of Health (NIH), the Research Centers in Minority Institutions (RCMI) Program fosters the development and implementation of innovative research aimed at improving minority health and reducing or eliminating health disparities. Currently, there are 21 RCMI Specialized (U54) Centers that share the same framework, comprising four required core components, namely the Administrative, Research Infrastructure, Investigator Development, and Community Engagement Cores. The Research Infrastructure Core (RIC) is fundamentally important for biomedical and health disparities research as a critical function domain. This paper aims to assess the research resources and services provided and evaluate the best practices in research resources management and networking across the RCMI Consortium. We conducted a REDCap-based survey and collected responses from 57 RIC Directors and Co-Directors from 98 core leaders. Our findings indicated that the RIC facilities across the 21 RCMI Centers provide access to major research equipment and are managed by experienced faculty and staff who provide expert consultative and technical services. However, several impediments to RIC facilities operation and management have been identified, and these are currently being addressed through implementation of cost-effective strategies and best practices of laboratory management and operation.


Assuntos
Pesquisa Biomédica , Estados Unidos , Humanos , Grupos Minoritários , National Institutes of Health (U.S.) , Saúde das Minorias , Pesquisadores
10.
Artigo em Inglês | MEDLINE | ID: mdl-36429944

RESUMO

Our lab investigates the anti-HIV-1 activity in Momordica balsamina (M. balsamina) leaf extract. Traditional Senegalese healers have used M. balsamina leaf extract as a part of a plant-based treatment for HIV/AIDS infections. Our overall goal is to define and validate the scientific basis for using M. balsamina leaf extract as a part of the traditional Senegalese treatment. As an initial characterization of this extract, we used activity-guided fractionation to determine the active ingredient's solubility and relative size. We found that M. balsamina leaf extract inhibits HIV-1 infection by >50% at concentrations of 0.02 mg/mL and above and is not toxic over its inhibitory range (0-0.5 mg/mL). We observed significantly more antiviral activity in direct water and acetonitrile extractions (p ≤ 0.05). We also observed significantly more antiviral activity in the aqueous phases of ethyl acetate, chloroform, and diethyl ether extractions (p ≤ 0.05). Though most of the antiviral activity partitioned into the aqueous layers, some antiviral activity was present in the organic layers. We show that the active agent in the plant extracts is at least 30 kD in size. Significantly more antiviral activity was retained in 3, 10, and 30 kD molecular weight cutoff filters (p ≤ 0.05). In contrast, most of the antiviral activity passed through the 100 kD filter (p ≤ 0.05). Because the active anti-HIV-1 agent presented as a large, amphiphilic molecule we ran the purified extract on an SDS-page gel. We show that the anti-HIV-1 activity in the leaf extracts is attributed to a 30 kDa protein we call MoMo30. This article describes how MoMo30 was determined to be responsible for its anti-HIV-1 activity.


Assuntos
Infecções por HIV , Soropositividade para HIV , HIV-1 , Momordica , Extratos Vegetais/farmacologia , Infecções por HIV/tratamento farmacológico , Antivirais
11.
Sci Rep ; 12(1): 12377, 2022 07 20.
Artigo em Inglês | MEDLINE | ID: mdl-35858977

RESUMO

The vaccine Mycobacterium bovis Bacillus Calmette-Guérin (BCG) elicits an immune response that is protective against certain forms of tuberculosis (TB); however, because BCG efficacy is limited it is important to identify alternative TB vaccine candidates. Recently, the BCG deletion mutant and vaccine candidate BCGΔBCG1419c was demonstrated to survive longer in intravenously infected BALB/c mice due to enhanced biofilm formation, and better protected both BALB/c and C57BL/6 mice against TB-induced lung pathology during chronic stages of infection, relative to BCG controls. BCGΔBCG1419c-elicited protection also associated with lower levels of proinflammatory cytokines (i.e. IL6, TNFα) at the site of infection in C57BL/6 mice. Given the distinct immune profiles of BCG- and BCGΔBCG1419c-immunized mice during chronic TB, we set out to determine if there are early immunological events which distinguish these two groups, using multi-dimensional flow cytometric analysis of the lungs and other tissues soon after immunization. Our results demonstrate a number of innate and adaptive response differences between BCG- and BCGΔBCG1419c-immunized mice which are consistent with the latter being longer lasting and potentially less inflammatory, including lower frequencies of exhausted CD4+ T helper (TH) cells and higher frequencies of IL10-producing T cells, respectively. These studies suggest the use of BCGΔBCG1419c may be advantageous as an alternative TB vaccine candidate.


Assuntos
Mycobacterium bovis , Mycobacterium tuberculosis , Vacinas contra a Tuberculose , Tuberculose Pulmonar , Tuberculose , Animais , Vacina BCG , Imunidade , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Tuberculose/prevenção & controle , Tuberculose Pulmonar/microbiologia
12.
Arterioscler Thromb Vasc Biol ; 42(4): e96-e114, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35139658

RESUMO

BACKGROUND: Vascular pericytes stabilize blood vessels and contribute to their maturation, while playing other key roles in microvascular function. Nevertheless, relatively little is known about involvement of their precursors in the earliest stages of vascular development, specifically during vasculogenesis. METHODS: We combined high-power, time-lapse imaging with transcriptional profiling of emerging pericytes and endothelial cells in reporter mouse and cell lines. We also analyzed conditional transgenic animals deficient in Cx43/Gja1 (connexin 43/gap junction alpha-1) expression within Ng2+ cells. RESULTS: A subset of Ng2-DsRed+ cells, likely pericyte/mural cell precursors, arose alongside endothelial cell differentiation and organization and physically engaged vasculogenic endothelium in vivo and in vitro. We found no overlap between this population of differentiating pericyte/mural progenitors and other lineages including hemangiogenic and neuronal/glial cell types. We also observed cell-cell coupling and identified Cx43-based gap junctions contributing to pericyte-endothelial cell precursor communication during vascular assembly. Genetic loss of Cx43/Gja1 in Ng2+ pericyte progenitors compromised embryonic blood vessel formation in a subset of animals, while surviving mutants displayed little-to-no vessel abnormalities, suggesting a resilience to Cx43/Gja1 loss in Ng2+ cells or potential compensation by additional connexin isoforms. CONCLUSIONS: Together, our data suggest that a distinct pericyte lineage emerges alongside vasculogenesis and directly communicates with the nascent endothelium via Cx43 during early vessel formation. Cx43/Gja1 loss in pericyte/mural cell progenitors can induce embryonic vessel dysmorphogenesis, but alternate connexin isoforms may be able to compensate. These data provide insight that may reshape the current framework of vascular development and may also inform tissue revascularization/vascularization strategies.


Assuntos
Conexina 43 , Pericitos , Animais , Diferenciação Celular , Conexina 43/genética , Conexinas/genética , Células Endoteliais , Camundongos
13.
Cancers (Basel) ; 13(24)2021 Dec 07.
Artigo em Inglês | MEDLINE | ID: mdl-34944790

RESUMO

Glioblastoma multiforme (GBM) is a deadly brain tumor with a large unmet therapeutic need. Here, we tested the hypothesis that wild-type p53 is a negative transcriptional regulator of SLC7A11, the gene encoding the System xc- (SXC) catalytic subunit, xCT, in GBM. We demonstrate that xCT expression is inversely correlated with p53 expression in patient tissue. Using representative patient derived (PDX) tumor xenolines with wild-type, null, and mutant p53 we show that p53 expression negatively correlates with xCT expression. Using chromatin immunoprecipitation studies, we present a molecular interaction whereby p53 binds to the SLC7A11 promoter, suppressing gene expression in PDX GBM cells. Accordingly, genetic knockdown of p53 increases SLC7A11 transcript levels; conversely, over-expressing p53 in p53-null GBM cells downregulates xCT expression and glutamate release. Proof of principal studies in mice with flank gliomas demonstrate that daily treatment with the mutant p53 reactivator, PRIMA-1Met, results in reduced tumor growth associated with reduced xCT expression. These findings suggest that p53 is a molecular switch for GBM glutamate biology, with potential therapeutic utility.

14.
Sci Rep ; 9(1): 13991, 2019 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-31570752

RESUMO

CD4+ T follicular helper (TFH) cells provide help to B cells and promote antibody-mediated immune responses. Increasing evidence supports the existence of TFH populations that secrete cytokines typically associated with the effector functions of other CD4+ T cell subsets. These include T helper 1 (TH1)-biased TFH (TFH1) cells that have recognized roles in both immune responses to pathogens and also the pathogenesis of autoimmune disease. Given their apparent importance to human health, there is interest in understanding the mechanisms that regulate TFH1 cell formation and function. However, their origin and the molecular requirements for their differentiation are unclear. Here, we describe a population of murine TH1-derived, TFH1-like cells that express the chemokine receptor Cxcr3 and produce both the TH1 cytokine interferon-γ and the TFH-associated cytokine interleukin-21 (IL-21). Furthermore, these TFH1-like cells promote B cell activation and antibody production at levels indistinguishable from conventional IL-6-derived TFH-like cells. Regarding their regulatory requirements, we find that IL-12 signaling is necessary for the differentiation and function of this TFH1-like cell population. Specifically, IL-12-dependent activation of STAT4, and unexpectedly STAT3, promotes increased expression of IL-21 and the TFH lineage-defining transcription factor Bcl-6 in TFH1-like cells. Taken together, these findings provide insight into the potential origin and differentiation requirements of TFH1 cells.


Assuntos
Interleucina-12/metabolismo , Transdução de Sinais , Células Th1/fisiologia , Animais , Diferenciação Celular , Citometria de Fluxo , Regulação da Expressão Gênica , Interferon gama/metabolismo , Interleucina-12/fisiologia , Interleucinas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Reação em Cadeia da Polimerase , Fator de Transcrição STAT3/metabolismo , Fator de Transcrição STAT4/metabolismo , Células Th1/metabolismo
15.
Sci Immunol ; 4(39)2019 09 13.
Artigo em Inglês | MEDLINE | ID: mdl-31519812

RESUMO

Sustained T cell receptor (TCR) stimulation is required for maintaining germinal center T follicular helper (GC-TFH) cells. Paradoxically, TCR activation induces interleukin-2 receptor (IL-2R) expression and IL-2 production, thereby initiating a feedback loop of IL-2 signaling that normally inhibits TFH cells. It is unclear how GC-TFH cells can receive prolonged TCR signaling without succumbing to the detrimental effects of IL-2. Using an influenza infection model, we show here that GC-TFH cells secreted large amounts of IL-2 but responded poorly to it. To maintain their IL-2 hyporesponsiveness, GC-TFH cells required intrinsic IL-6 signaling. Mechanistically, we found that IL-6 inhibited up-regulation of IL-2Rß (CD122) by preventing association of STAT5 with the Il2rb locus, thus allowing GC-TFH cells to receive sustained TCR signaling and produce IL-2 without initiating a TCR/IL-2 inhibitory feedback loop. Collectively, our results identify a regulatory mechanism that controls the generation of GC-TFH cells.


Assuntos
Centro Germinativo/imunologia , Interleucina-2/imunologia , Interleucina-6/imunologia , Linfócitos T Auxiliares-Indutores/imunologia , Animais , Centro Germinativo/citologia , Interleucina-2/antagonistas & inibidores , Interleucina-2/biossíntese , Interleucina-6/deficiência , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Receptores de Antígenos de Linfócitos T/imunologia , Transdução de Sinais/imunologia , Linfócitos T Auxiliares-Indutores/citologia
16.
Front Immunol ; 10: 1299, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31244845

RESUMO

CD4+ T helper cells are capable of differentiating into a number of effector subsets that perform diverse functions during adaptive immune responses. The differentiation of each of these subsets is governed, in large part, by environmental cytokine signals and the subsequent activation of downstream, cell-intrinsic transcription factor networks. Ikaros zinc finger (IkZF) transcription factors are known regulators of immune cell development, including that of CD4+ T cell subsets. Over the past decade, members of the IkZF family have also been implicated in the differentiation and function of individual T helper cell subsets, including T helper 1 (TH1), TH2, TH17, T follicular (TFH), and T regulatory (TREG) cells. Now, an increasing body of literature suggests that the distinct cell-specific cytokine environments responsible for the development of each subset result in differential expression of IkZF factors across T helper populations. Intriguingly, recent studies suggest that IkZF members influence T helper subset differentiation in a feed-forward fashion through the regulation of these same cytokine-signaling pathways. Here, we review the increasingly prominent role for IkZF transcription factors in the differentiation of effector CD4+ T helper cell subsets.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/metabolismo , Citocinas/metabolismo , Fator de Transcrição Ikaros/metabolismo , Imunomodulação , Transdução de Sinais , Dedos de Zinco , Animais , Linfócitos T CD4-Positivos/citologia , Diferenciação Celular , Humanos , Fator de Transcrição Ikaros/genética , Fatores de Transcrição STAT/metabolismo , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo
17.
Methods Mol Biol ; 1960: 75-84, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30798522

RESUMO

CD4+ T "helper" cells are key orchestrators of adaptive immune responses. Upon activation, naïve CD4+ T cells are capable of differentiating into a number of effector subsets that perform distinct immune functions. These subsets include T helper 1 (TH1), TH2, TH9, TH17, TH22, T follicular helper (TFH), and regulatory T cell (TREG) populations. The differentiation of these subsets is dependent, in large part, on the coordinated interplay between signals from the extracellular cytokine environment and downstream transcriptional networks. The use of in vitro T helper cell culture systems has been extensively employed to aid in the elucidation of the molecular mechanisms that govern the differentiation of each effector subset. Here, we provide a detailed summary of the differentiation conditions that are utilized to generate effector CD4+ T cell populations in vitro.


Assuntos
Linfócitos T CD4-Positivos/citologia , Linfócitos T CD4-Positivos/imunologia , Subpopulações de Linfócitos T/citologia , Linfócitos T Auxiliares-Indutores/citologia , Linfócitos T Auxiliares-Indutores/metabolismo , Linfócitos T Reguladores/citologia , Animais , Linfócitos T CD4-Positivos/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Humanos , Subpopulações de Linfócitos T/imunologia , Subpopulações de Linfócitos T/metabolismo , Linfócitos T Auxiliares-Indutores/imunologia , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo , Células Th1/citologia , Células Th1/imunologia , Células Th1/metabolismo , Células Th2/citologia , Células Th2/imunologia , Células Th2/metabolismo
18.
Methods Mol Biol ; 1960: 149-160, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30798529

RESUMO

Listeria monocytogenes, a Gram-positive facultative intracellular pathogen, has been widely used as a model for studying the immune response. Here, we describe a protocol for the systemic infection of mice with L. monocytogenes, followed by isolation of lymphocytes from spleens and lymph nodes. We also include details on how to culture and store L. monocytogenes, as well as the specifics for fluorescence-activated cell sorting (FACS) for CD4+ cells in response to the systemic infection. This protocol can be adapted by changing the dosage of L. monocytogenes for a more or less aggressive infection and/or sorting for other immune cell subtypes of interest.


Assuntos
Linfócitos T CD4-Positivos/metabolismo , Listeria monocytogenes/imunologia , Listeria monocytogenes/patogenicidade , Linfócitos T Auxiliares-Indutores/metabolismo , Animais , Citometria de Fluxo , Listeriose/imunologia , Listeriose/microbiologia , Camundongos
19.
Lab Chip ; 18(14): 2087-2098, 2018 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-29897358

RESUMO

Three-dimensional (3D) printing now enables the fabrication of 3D structural electronics and microfluidics. Further, conventional subtractive manufacturing processes for microelectromechanical systems (MEMS) relatively limit device structure to two dimensions and require post-processing steps for interface with microfluidics. Thus, the objective of this work is to create an additive manufacturing approach for fabrication of 3D microfluidic-based MEMS devices that enables 3D configurations of electromechanical systems and simultaneous integration of microfluidics. Here, we demonstrate the ability to fabricate microfluidic-based acoustofluidic devices that contain orthogonal out-of-plane piezoelectric sensors and actuators using additive manufacturing. The devices were fabricated using a microextrusion 3D printing system that contained integrated pick-and-place functionality. Additively assembled materials and components included 3D printed epoxy, polydimethylsiloxane (PDMS), silver nanoparticles, and eutectic gallium-indium as well as robotically embedded piezoelectric chips (lead zirconate titanate (PZT)). Electrical impedance spectroscopy and finite element modeling studies showed the embedded PZT chips exhibited multiple resonant modes of varying mode shape over the 0-20 MHz frequency range. Flow visualization studies using neutrally buoyant particles (diameter = 0.8-70 µm) confirmed the 3D printed devices generated bulk acoustic waves (BAWs) capable of size-selective manipulation, trapping, and separation of suspended particles in droplets and microchannels. Flow visualization studies in a continuous flow format showed suspended particles could be moved toward or away from the walls of microfluidic channels based on selective actuation of in-plane or out-of-plane PZT chips. This work suggests additive manufacturing potentially provides new opportunities for the design and fabrication of acoustofluidic and microfluidic devices.


Assuntos
Acústica , Dispositivos Lab-On-A-Chip , Sistemas Microeletromecânicos/instrumentação , Dimetilpolisiloxanos , Desenho de Equipamento , Impressão Tridimensional
20.
Adv Virol ; 2018: 7863412, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29721020

RESUMO

BACKGROUND: Extracellular vesicles (EVs) are membrane bound, secreted by cells, and detected in bodily fluids, including urine, and contain proteins, RNA, and DNA. Our goal was to identify HIV and human proteins (HPs) in urinary EVs from HIV+ patients and compare them to HIV- samples. METHODS: Urine samples were collected from HIV+ (n = 35) and HIV- (n = 12) individuals. EVs were isolated by ultrafiltration and characterized using transmission electron microscopy, tandem mass spectrometry (LC/MS/MS), and nanoparticle tracking analysis (NTA). Western blots confirmed the presence of HIV proteins. Gene ontology (GO) analysis was performed using FunRich and HIV Human Interaction database (HHID). RESULTS: EVs from urine were 30-400 nm in size. More EVs were in HIV+ patients, P < 0.05, by NTA. HIV+ samples had 14,475 HPs using LC/MS/MS, while only 111 were in HIV-. HPs in the EVs were of exosomal origin. LC/MS/MS showed all HIV+ samples contained at least one HIV protein. GO analysis showed differences in proteins between HIV+ and HIV- samples and more than 50% of the published HPs in the HHID interacted with EV HIV proteins. CONCLUSION: Differences in the proteomic profile of EVs from HIV+ versus HIV- samples were found. HIV and HPs in EVs could be used to detect infection and/or diagnose HIV disease syndromes.

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