Selected Grantee Publications
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- 27 results found
- Infectious Diseases
- P40
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.
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.
In Vitro and In Vivo Functions of SARS-CoV-2 Infection-Enhancing and Neutralizing Antibodies
Li et al., Cell. 2021.
https://doi.org/10.1016/j.cell.2021.06.021
Antibody-dependent enhancement of infection is a concern for clinical use of antibodies. Researchers isolated neutralizing antibodies against the receptor-binding domain (RBD) or N-terminal domain (NTD) of SARS-CoV-2 spike from COVID-19 patients. Cryo-electron microscopy of RBD and NTD antibodies demonstrated function-specific binding modes. RBD and NTD antibodies mediated both neutralization and infection enhancement in vitro. However, infusion of these antibodies into mice or macaques resulted in suppression of virus replication, demonstrating that antibody-enhanced infection in vitro does not necessarily predict enhanced infection in vivo. RBD-neutralizing antibodies having cross-reactivity against coronaviruses were protective against SARS-CoV-2, the most potent of which was DH1047. Supported by ORIP (P40OD012217, U42OD021458, S10OD018164), NIAID, NCI, NIGMS, and NIH Common Fund.
Antibody-Based CCR5 Blockade Protects Macaques From Mucosal SHIV Transmission
Chang et al., Nature Communications. 2021.
https://doi.org/10.1038/s41467-021-23697-6
The efficacy of antiretroviral therapy (ART) as pre-exposure prophylaxis against HIV is hindered by incomplete patient adherence and ART-resistant variants. Researchers found that competitive inhibition of HIV Env-CCR5 binding via the CCR5-specific antibody Leronlimab protects rhesus macaques against infection following repeated intrarectal challenges with a CCR5-tropic simian-human immunodeficiency virus (SHIVSF162P3). Biweekly injection of Leronlimab at 50 mg/kg provided complete protection from SHIV infection. Tissue biopsies from protected macaques post-challenge revealed complete CCR5 receptor occupancy and an absence of viral DNA. After Leronlimab washout, transfer of hematologic cells into naïve monkeys did not transmit infection, supporting the initiation of clinical trials. Supported by ORIP (P51OD011092, K01OD026561, P40OD028116) and NIAID.
Psychosocial Stress Alters the Immune Response and Results in Higher Viral Load During Acute SIV Infection in a Pigtailed Macaque Model of HIV
Guerrero-Martin et al., Journal of Infectious Diseases. 2021.
https://doi.org/10.1093/infdis/jiab252
Social distancing is an important countermeasure for a pandemic, but social isolation may also have adverse health outcomes in the context of infectious diseases, such as HIV. Researchers compared commonly measured parameters of HIV progression between singly and socially housed simian immunodeficiency virus (SIV)-infected pigtailed macaques. Throughout acute SIV infection, singly housed pigtailed macaques had a higher viral load in the plasma and cerebrospinal fluid and demonstrated greater CD4+ T cell declines and more CD4+ and CD8+ T cell activation compared to socially housed macaques. These findings suggest that psychosocial stress could augment the progression of HIV infection. Supported by ORIP (U42OD013117, P40OD013117, K01OD018244), NIAID, NINDS, and NIMH.
SARS-CoV-2 Induces Robust Germinal Center CD4 T Follicular Helper Cell Responses in Rhesus Macaques
Lakshmanappa et al., Nature Communications. 2021.
https://www.nature.com/articles/s41467-020-20642-x
SARS-CoV-2 infection in both sexes of rhesus macaques, either infused with convalescent plasma, normal plasma, or receiving no infusion, resulted in transient accumulation of pro-inflammatory monocytes and proliferating CD4 T follicular helper (Tfh) cells, which are critical for persistent antibody responses. CD4 helper cell responses skewed predominantly toward a Th1 response in blood, lung, and lymph nodes. This skewing is important to note, as weak interferon responses observed in COVID patients could hamper effective antiviral antibody and CD8 T-cell responses. Collectively, the data show induction of GC responses in a rhesus model of mild COVID-19. Supported by ORIP (P51OD011107 and P40OD010976) and NIAID.
Epidemiological and Molecular Characterization of a Novel Adenovirus of Squirrel Monkeys After Fatal Infection During Immunosuppression
Rogers et al., Microbial Genomics. 2020.
https://pubmed.ncbi.nlm.nih.gov/32614763/
Adenoviruses frequently cause upper respiratory tract infections, often causing disseminated disease in immunosuppressed patients. A novel adenovirus was identified, squirrel monkey adenovirus 1 (SqMAdV-1), as the cause of a fatal infection in an immunocompromised squirrel monkey (Saimiri boliviensis). A nucleotide polymorphism at the stop codon of the DNA polymerase gene results in a 126 amino acid extension at the carboxy terminus. A single adenovirus variant, SqMAdV-3, has similarity to tufted capuchin (Sapajus apella) adenoviruses. The largest group of adenovirus variants detected, SqMAdV-2.0-2.16, has high similarity (93-99%) to the TMAdV, suggesting that squirrel monkeys may be the natural host of the TMAdV. Supported by ORIP (P40OD010938, R24OD018553), and NIAID.