Selected Grantee Publications
A Novel DPH5-Related Diphthamide-Deficiency Syndrome Causing Embryonic Lethality or Profound Neurodevelopmental Disorder
Shankar et al., Genetics in Medicine. 2022.
https://www.doi.org/10.1016/j.gim.2022.03.014
Neurodevelopmental disorders (NDDs) affect more than 3% of the pediatric population and often have associated neurologic or multisystem involvement. The underlying genetic etiology of NDDs remains unknown in many individuals. Investigators characterized the molecular basis of NDDs in children of both sexes with nonverbal NDDs from three unrelated families with distinct overlapping craniofacial features. The investigators also used a mouse model of both sexes to determine the pathogenicity of variants of uncertain significance, as well as genes of uncertain significance, to advance translational genomics and provide precision health care. They identified several variants in DPH5 as a potential cause of profound NDD. Their findings provide strong clinical, biochemical, and functional evidence for DPH5 variants as a novel cause of embryonic lethality or profound NDD with multisystem involvement. Based on these findings, the authors propose that “DPH5-related diphthamide deficiency syndrome” is a novel autosomal-recessive Mendelian disorder. Supported by ORIP (K01OD026608, U42OD012210) and NHGRI.
Antiretroviral Therapy Timing Impacts Latent Tuberculosis Infection Reactivation in a Tuberculosis/Simian Immunodeficiency Virus Coinfection Model
Sharan et al., Journal of Clinical Investigation. 2021.
https://pubmed.ncbi.nlm.nih.gov/34855621/
In the rhesus macaque model for Mycobacterium tuberculosis plus simian immunodeficiency virus (SIV) co-infection, chronic immune activation rather than depletion of CD4+ T cells correlates with reactivation of latent tuberculosis infection (LTBI). Researchers administered combined antiretroviral therapy (cART) at 2 weeks post-SIV co-infection to study whether restoration of CD4+ T cell immunity occurred more broadly, and whether this prevented LTBI compared to cART initiated at 4 weeks post-SIV. Earlier initiation of cART enhanced survival led to better control of viral replication and reduced immune activation in the periphery and lung vasculature, thereby reducing the rate of SIV-induced reactivation. Supported by ORIP (K01OD031898, P51OD011133, P51OD011132, S10OD028653) and NIAID.
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.
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.