Selected Grantee Publications
Circulating Integrin α4β7+ CD4 T Cells Are Enriched for Proliferative Transcriptional Programs in HIV Infection
Lakshmanappa et al., Federation of European Biochemical Societies Letters. 2021.
https://doi.org/10.1002/1873-3468.14163
HIV preferentially infects α4β7+ CD4 T cells, forming latent reservoirs that contribute to HIV persistence, yet the properties of α4β7+ CD4 T cells are poorly understood. Investigating HIV-infected humans and SHIV-infected rhesus macaques, investigators demonstrated that α4β7+ CD4 T cells in blood are enriched for genes regulating cell cycle progression and cellular metabolism. In contrast, rectal α4β7+ CD4 T cells exhibited a core tissue-residency gene expression program. These features were conserved across primate species, suggesting that the tissue environment influences memory T-cell transcriptional networks. These findings provide an important foundation for understanding the role of α4β7 in HIV infection. Supported by ORIP (K01OD023034, R24OD010976) and NIAID.
PD-1 Blockade and Vaccination Provide Therapeutic Benefit Against SIV by Inducing Broad and Functional CD8+ T Cells in Lymphoid Tissue
Rahman et al., Science Immunology. 2021.
https://doi.org/10.1126/sciimmunol.abh3034
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. Addition of an anti-PD-1 antibody to the SIV vaccine increased cytotoxic CD8+ T cells in lymph nodes after ART interruption, correlating to the control of virus and prolonged survival compared with the vaccine alone. Thus, combining immune checkpoint blockade with vaccination may be a promising avenue toward an HIV cure. Supported by ORIP (P51OD011132) and NIAID.
Blocking α4β7 Integrin Delays Viral Rebound in SHIVSF162P3-Infected Macaques Treated with Anti-HIV Broadly Neutralizing Antibodies
Frank et al., Science Translational Medicine. 2021.
https://doi.org/10.1126/scitranslmed.abf7201
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. These findings suggest that α4β7 integrin blockade may prolong virologic control by bNAbs in SHIVSF162P3-infected macaques. Supported by ORIP (P51OD011104, U42OD010568, U42OD024282, P40OD028116), NIAID, and NCI.
Cytomegalovirus Mediates Expansion of IL-15-Responsive Innate-Memory Cells with SIV Killing Function
Méndez-Lagares et al., Journal of Clinical Investigation. 2021.
https://doi.org/10.1172/JCI148542
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. These results suggest that innate-memory expansion could be achieved by other vaccine platforms expressing IL-15. Supported by ORIP (P51OD011107) and NIAID.
Previous Exposure to Dengue Virus Is Associated with Increased Zika Virus Burden at the Maternal-Fetal Interface in Rhesus Macaques
Crooks et al., PLOS Neglected Tropical Diseases. 2021.
https://journals.plos.org/plosntds/article?id=10.1371/journal.pntd.0009641
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. However, pre-existing DENV immunity had no detectable impact on ZIKV replication kinetics in maternal plasma; all pregnancies progressed to term without adverse outcomes at delivery. Investigating potential ADE in pregnant women is important as vaccines against DENV and ZIKV are developed. Supported by ORIP (P51OD011106) and NIAID.
Factor XII Plays a Pathogenic Role in Organ Failure and Death in Baboons Challenged with Staphylococcus aureus
Silasi et al., Blood. 2021.
https://pubmed.ncbi.nlm.nih.gov/33598692/
Activation of coagulation factor (F) XI promotes multiorgan failure in rodent models of sepsis and in a baboon model for lethal systemic inflammation induced by infusion of heat-inactivated Staphylococcus aureus. The authors used the anticoagulant FXII-neutralizing antibody 5C12 to verify the mechanistic role of FXII. Inhibition of FXII prevented fever, terminal hypotension, respiratory distress, and multiorgan failure. All animals receiving 5C12 had milder and transient clinical symptoms; untreated control animals suffered irreversible multiorgan failure. This study confirms their previous finding that at least two enzymes of FXIa and FXIIa play critical roles in the development of an acute and terminal inflammatory response. Supported by ORIP (P40OD024628), NIAID, NHLBI, and NIGMS.
A Yeast Expressed RBD-Based SARS-CoV-2 Vaccine Formulated with 3M-052-alum Adjuvant Promotes Protective Efficacy in Non-Human Primates
Pino et al., Science Immunology. 2021.
https://immunology.sciencemag.org/content/6/61/eabh3634
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. Collectively, these data suggest that the RBD+3M-052-alum formulation provides robust immune responses against SARS-CoV-2 and supports the development of this potential effective and easy to scale COVID-19 vaccine candidate. Supported by ORIP (P51OD011132) and NIAID.
Systems Vaccinology of the BNT162b2 mRNA Vaccine in Humans
Arunachalam et al., Nature . 2021.
https://doi.org/10.1038/s41586-021-03791-x
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. Booster vaccination stimulated an enhanced innate immune response compared to primary vaccination, demonstrating the capacity of BNT162b2 to prime the innate immune system to mount a more potent response after booster immunization. Supported by ORIP (P51OD011132, S10OD026799) and NIAID.
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
Van Rompay et al., PLOS Pathogens. 2021.
https://journals.plos.org/plospathogens/article?id=10.1371/journal.ppat.1009688
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. Compared to controls, animals treated with either dose of the anti-SARS-CoV-2 mAbs showed improved clinical scores, lower levels of virus replication in upper and lower respiratory tract, and reduced interstitial pneumonia, as measured by lung histology. The study provides proof-of-concept for development of these mAbs for treatment of COVID-19 during early infection. Supported by ORIP (P51OD011107) and NIAID.
Interleukin-15 Response Signature Predicts RhCMV/SIV Vaccine Efficacy
Barrenäs et al., PLOS Pathogens. 2021.
https://doi.org/10.1371/journal.ppat.1009278
Standard immunogenicity measures do not predict efficacy of a vaccine based on strain 68-1 rhesus cytomegalovirus (RhCMV) vectors expressing SIV proteins (RhCMV/SIV). This vaccine robustly protects just over half of immunized monkeys. Using functional genomics, researchers found that RhCMV/SIV efficacy is correlated with a vaccine-induced response to interleukin-15 (IL-15) that includes modulation of immune cell, inflammation, toll-like receptor signaling, and cell death programming pathways. RhCMV/SIV imparts a coordinated and persistent induction of innate and adaptive immune pathways featuring IL-15, a known regulator of CD8+ T cell function, that support the ability of vaccine-elicited CD8+ T cells to mediate protection against SIV. Supported by ORIP (P51OD010425, P51OD011092), NIAID, and NCI.