ADAP1 Promotes Latent HIV-1 Reactivation by Tuning the KRAS-ERK-AP-1 Signaling-Transcriptional Axis

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dc.contributor.advisorSchoggins, John W.en
dc.contributor.committeeMemberD'Orso, Ivánen
dc.contributor.committeeMemberPfeiffer, Julie K.en
dc.contributor.committeeMemberAlto, Nealen
dc.creatorRamirez, Nora-Guadalupe Piñaen
dc.creator.orcid0000-0002-7992-1683
dc.date.accessioned2024-01-11T20:19:53Z
dc.date.available2024-01-11T20:19:53Z
dc.date.created2021-12
dc.date.issuedDecember 2021
dc.date.submittedDecember 2021
dc.date.updated2024-01-11T20:19:53Z
dc.description.abstractImmune stimulation fuels cell signaling-transcriptional programs that induce biological responses to eliminate virus-infected cells. Yet, retroviruses that integrate into host cell chromatin, such as HIV-1, co-opt these programs to switch between latent and reactivated states. However, many regulatory mechanisms are still unfolding. As such, here I take advantage of the unique intrinsic reliance HIV-1 has on host cell signaling-transcriptional programs to discover undescribed cell signaling regulators. Specifically, I implemented a functional screening platform, given HIV-1 gene expression relies on CD4+ T cell activation state, to identify host factors modulating CD4+ T cell signaling-transcriptional axes and consequently HIV-1 fate. Among the hits, I focus on ADAP1 (ArfGAP with Dual PH Domains 1), a previously thought neuro-restricted factor, and discover it is an amplifier of select human CD4+ T cell signaling programs. Using physiological models, I characterize ADAP1 expression is low in naïve and memory CD4+ T cells, but largely induced upon immune stimulation where it interacts with the immune signalosome. Using complementary biochemical and cellular assays, I demonstrate ADAP1 directly stimulates the GTPase activity of KRAS to amplify CD4+ T cell signaling through targeted activation of ERK-AP-1 axis. In primary CD4+ T cells which I have genetically ablated ADAP1, I show loss of ADAP1 function blunts gene expression programs in response to stimulation thereby reducing CD4+ T cell expansion and dampening latent HIV-1 reactivation. Supporting the impact of these findings, I propose the reduced CD4+ T cell programs and proliferation upon ADAP1 loss validates Genome-wide Association Studies linking ADAP1 single nucleotide polymorphisms in non-coding enhancers to an altered T lymphocyte count trait, potentially attributed to ADAP1 haploinsufficiency. Through these combined experimental approaches, I was able to define ADAP1 as an unexpected tuner of CD4+ T cell activation programs and co-opted by HIV-1 to escape latency.en
dc.format.mimetypeapplication/pdfen
dc.identifier.oclc1417098746
dc.identifier.urihttps://hdl.handle.net/2152.5/10232
dc.language.isoenen
dc.subjectAdaptor Proteins, Signal Transducingen
dc.subjectHIV Infectionsen
dc.subjectHIV-1en
dc.subjectMAP Kinase Signaling Systemen
dc.subjectNerve Tissue Proteinsen
dc.subjectProto-Oncogene Proteins p21(ras)en
dc.subjectT-Lymphocytesen
dc.subjectTranscription Factor AP-1en
dc.titleADAP1 Promotes Latent HIV-1 Reactivation by Tuning the KRAS-ERK-AP-1 Signaling-Transcriptional Axisen
dc.typeThesisen
dc.type.materialtexten
thesis.degree.departmentGraduate School of Biomedical Sciencesen
thesis.degree.disciplineMolecular Microbiologyen
thesis.degree.grantorUT Southwestern Medical Centeren
thesis.degree.levelDoctoralen
thesis.degree.nameDoctor of Philosophyen

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