A Large Repertoire of B Cell Lineages Targeting One Cluster of Epitopes in a Vaccinated Rhesus Macaque
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A rhesus macaque that was serially immunized six times with the 8-mer epitope for human monoclonal antibody (mAb) 447-52D—specific to the V3 region of gp120 HIV-1—provided a rare opportunity to study the repertoire of antibodies produced upon vaccination against a particular antigenic site. From a blood sample taken 3 weeks after the last immunization, researchers produced 41 V3-specific recombinant mAbs by single B cell isolation and cloning. Sequence analysis revealed 21 B cell lineages (single and clonally related).
PD-1 Blockade and Vaccination Provide Therapeutic Benefit Against SIV by Inducing Broad and Functional CD8+ T Cells in Lymphoid Tissue
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Effective HIV therapies must induce functional CD8+ T cells and clear latent viral reservoirs during antiretroviral therapy (ART). Using a rhesus macaque model, researchers showed that therapeutic vaccination under ART using a CD40L plus TLR7 agonist-adjuvanted DNA/modified vaccinia Ankara vaccine regimen induced robust SIV-specific CD4+ and CD8+ T cell responses.
Neuropeptide S Receptor 1 is a Nonhormonal Treatment Target in Endometriosis
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Investigators analyzed genetic sequences of humans (n=32 families) and pedigree rhesus macaques (n=849) with spontaneous endometriosis to uncover potential targets for treatment. Target associations indicated a common insertion/deletion variant in NPSR1, the gene encoding neuropeptide S receptor 1. Immunocytochemistry, RT-PCR, and flow cytometry experiments indicated NPSR1 was expressed in the glandular epithelium of eutopic and ectopic endometrium.
Blocking α4β7 Integrin Delays Viral Rebound in SHIVSF162P3-Infected Macaques Treated with Anti-HIV Broadly Neutralizing Antibodies
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To explore therapeutic potentials of combining anti-HIV broadly neutralizing antibodies (bNAbs) with α4β7 integrin blockade using the monoclonal antibody Rh-α4β7, investigators treated SHIVSF162P3-infected, viremic macaques with bNAbs only or bNAbs and Rh-α4β7. Treatment with bNAbs alone decreased viremia below 200 copies/ml in eight out of eight macaques, but seven of the monkeys rebounded within 3 weeks. In contrast, three of six macaques treated with both Rh-α4β7 and bNAbs maintained viremia below 200 copies/ml for 21 weeks, whereas three of those monkeys rebounded after 6 weeks.
Effects of Early Daily Alcohol Exposure on Placental Function and Fetal Growth in a Rhesus Macaque Model
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In a rhesus macaque model for chronic prenatal alcohol exposure, daily consumption during early pregnancy significantly diminished placental perfusion at mid to late gestation and significantly decreased the oxygen supply to the fetal vasculature throughout pregnancy. These findings were associated with the presence of microscopic placental infarctions.
Cytomegalovirus Mediates Expansion of IL-15-Responsive Innate-Memory Cells with SIV Killing Function
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Researchers investigated the effects of rhesus cytomegalovirus (RhCMV) on the immune system in young rhesus macaques to determine if it could modulate the protection mediated by RhCMV-vectored vaccines. RhCMV was associated with dramatic changes in antigen presenting cells, T cells, and NK cells and marked expansion of innate-memory CD8+ T cells via host interleukin-15 (IL-15) production. The researchers also investigated immune changes following administration of RhCMV 68-1–vectored SIV vaccines, which led to expansion of CD8+ T cells with capacity to inhibit SIV replication ex vivo.
Previous Exposure to Dengue Virus Is Associated with Increased Zika Virus Burden at the Maternal-Fetal Interface in Rhesus Macaques
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Pre-existing immunity to dengue virus (DENV) results in antibody-dependent enhancement (ADE) among DENV serotypes; Zika virus (ZIKV) has homology with DENV suggesting pre-existing DENV immunity may have an impact on ZIKV pathogenesis during pregnancy. In a rhesus macaque model, prior DENV-2 exposure resulted in a higher burden of ZIKV viral RNA in maternal-fetal interface tissues as compared to DENV-naive macaques.
A Yeast Expressed RBD-Based SARS-CoV-2 Vaccine Formulated with 3M-052-alum Adjuvant Promotes Protective Efficacy in Non-Human Primates
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Using a rhesus macaque model (n=5 males per group), investigators tested a receptor binding domain (RBD) recombinant protein formulation COVID-19 vaccine candidate combined with an aluminum-based formulation of 3M’s Toll-like receptor 7 and 8 agonist 3M-052 (3M-052/Alum) and found the RBD+3M-052/Alum formulation produced a superior overall immune response than RBD+alum alone as demonstrated by higher SARS-CoV-2 neutralizing antibodies, improved Th1 biased CD4+ T cell reactions, and increased CD8+ T cell responses.
Systems Vaccinology of the BNT162b2 mRNA Vaccine in Humans
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It was poorly understood how mRNA vaccines against SARS-CoV-2 stimulate protective immune responses. To address this, researchers comprehensively profiled innate and adaptive immune responses of healthy volunteers vaccinated with the Pfizer-BioNTech mRNA vaccine (BNT162b2). Vaccination resulted in robust production of neutralizing antibodies against wild-type SARS-CoV-2, to a lesser extent, the beta variant, as well as significant increases in antigen-specific polyfunctional CD4+ and CD8+ T cells after the second dose.
Early Treatment With a Combination of Two Potent Neutralizing Antibodies Improves Clinical Outcomes and Reduces Virus Replication and Lung Inflammation in SARS CoV-2 Infected Macaques
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The therapeutic efficacy of a combination of two SARS-CoV-2 monoclonal antibodies (mAbs), C135-LS and C144-LS, were investigated in young adult macaques (3 groups of 4 animals; equal sex distribution). Animals were treated intravenously with low or high doses of C135-LS and C144-LS mAbs or control mAb 24 hours post-infection with SARS-CoV-2.