Functional Convergence of a Germline-Encoded Neutralizing Antibody Response in Rhesus Macaques Immunized with HCV Envelope Glycoproteins
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Immunoglobulin heavy chain variable gene IGHV1-69-encoded broadly neutralizing antibodies (bnAbs) targeting the hepatitis C virus (HCV) envelope glycoprotein (Env) E2 are important for protection against HCV infection in humans. An IGHV1-69 ortholog, VH1.36, is preferentially used for bnAbs isolated from rhesus macaques immunized against HCV Env. Researchers investigated the genetic, structural, and functional properties of VH1.36-encoded bnAbs generated by HCV Env vaccination of macaques and compared their findings to IGHV1-69-encoded bnAbs from HCV patients.
Interneuron Origins in the Embryonic Porcine Medial Ganglionic Eminence
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The authors report that transcription factor expression patterns in porcine embryonic subpallium are similar to rodents. Their findings reveal that porcine embryonic MGE progenitors could serve as a valuable source for interneuron-based xenotransplantation therapies. They demonstrate that porcine medial ganglionic eminence exhibits a distinct transcriptional and interneuron-specific antibody profile, in vitro migratory capacity, and are amenable to xenotransplantation.
Cytomegaloviral Determinants of CD8+ T Cell Programming and RhCMV/SIV Vaccine Efficacy
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Cytomegalovirus (CMV)-based vaccine vectors were developed to leverage the ability of CMVs to elicit sustained CD4+ and CD8+ T cell responses with broad tissue distribution. The 68-1 rhesus cytomegalovirus (RhCMV) vectors that express simian immunodeficiency virus (SIV) inserts induce major histocompatibility complex E (MHC-E)- and MHC-II-restricted, SIV-specific CD8+T cell responses. The contribution of this unconventional MHC restriction to RhCMV/SIV vaccine efficacy are poorly understood.
Creb5 Establishes the Competence for Prg4 Expression in Articular Cartilage
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Cells comprising the superficial zone of articular cartilage express lubricin, encoded by the Prg4 gene, that lubricates joints. Researchers identified Creb5 as a transcription factor that is required for TGF-β and EGFR signaling to induce Prg4 expression. Forced expression of Creb5 in deep-zone chondrocytes of articular cartilage confers competence for TGF-β and EGFR signals to induce Prg4 expression.
New SHIVs and Improved Design Strategy for Modeling HIV-1 Transmission, Immunopathogenesis, Prevention, and Cure
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Researchers knew that substitution of HIV-1 Env residue 375-serine by aromatic residues enhances binding to rhesus CD4 enabling primary HIV-1 Envs to support replication as simian-human immunodeficiency virus (SHIV) chimeras in rhesus monkeys. The investigators constructed SHIVs containing 10 primary Envs corresponding to HIV-1 subtypes A, B, C, AE, and AG. Only one with histidine at Env375 replicated efficiently in rhesus cells. Replacement of wild-type Env375 residues by tryptophan, tyrosine, phenylalanine, or histidine in the other 9 SHIVs led to efficient replication.
Modified Adenovirus Prime–Protein Boost Clade C HIV Vaccine Strategy Results in Reduced Viral DNA in Blood and Tissues Following Tier 2 SHIV Challenge
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Researchers conducted a comparative vaccine challenge study in rhesus macaques. One group of monkeys was vaccinated using co-immunization with DNA Gag and Env expression plasmids and trimeric Env gp140 glycoprotein. The other group was primed with two replicating simian adenovirus-vectored vaccines expressing Gag and boosted with trimeric Env gp140. Both strategies elicited antigen-specific humoral and cellular immune responses, but neither approach provided significant protection from viral acquisition upon repeated mucosal challenges with a heterologous Tier 2 SHIV.
Transfer Efficiency and Impact on Disease Phenotype of Differing Methods of Gut Microbiota Transfer
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To test causal relationships between complex gut microbiota (GM) and host outcomes, researchers frequently transfer GM between donor and recipient mice via embryo transfer (ET) rederivation, cross-fostering (CF), and co‑housing. In this study, the investigators assessed the influence of transfer method and differences in baseline donor and recipient microbiota richness on transfer efficiency in mice of both sexes. Their results demonstrate that both transfer method and transfer direction influence experimental GM transfer efficiency.
Effect of Single Housing on Innate Immune Activation in Immunodeficiency Virus–Infected Pigtail Macaques (Macaca nemestrina) as a Model of Psychosocial Stress in Acute HIV Infection
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Psychosocial stress is associated with immune system dysregulation and worsened clinical outcomes in people with HIV. Investigators performed a retrospective analysis of acute simian immunodeficiency virus (SIV) infection of male pigtail macaques to compare the innate immune responses of social and single housing. The singly housed macaques showed reduced expansion of classical and intermediate monocytes, prolonged thrombocytopenia, and suppression of platelet activation during the first 2 weeks after inoculation.
System-Wide Identification of Myeloid Markers of TB Disease and HIV-Induced Reactivation in the Macaque Model of Mtb Infection and Mtb/SIV Co-Infection
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HIV is known to catalyze the reactivation of latent tuberculosis (TB) infection. The investigators characterized Mycobacterium tuberculosis (Mtb) and simian immunodeficiency virus (SIV) coinfection using a rhesus macaque model of both sexes, with a focus on pathways relevant to myeloid origin cells (e.g., macrophages). They identified gene signatures of host disease state and progression, as well as clustering algorithms for differentiation between host disease states and relationships among genes.
Mendelian Gene Identification through Mouse Embryo Viability Screening
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The investigators dissected phenotypic similarities between patients and model organisms by assessing the embryonic stage at which homozygous loss of function results in lethality in mice of both sexes obtained from the International Mouse Phenotyping Consortium. Information on knockout mouse embryo lethality can be used to prioritize candidate genes associated with certain disorders.