Selected Grantee Publications
Probiotic Therapy During Vaccination Alters Antibody Response to Simian-Human Immunodeficiency Virus Infection But Not to Commensals
Wilson et al., AIDS Research and Human Retroviruses. 2023.
https://www.doi.org/10.1089/AID.2022.0123
Strategies to boost vaccine-induced mucosal humoral responses are critical to developing an HIV-1 vaccine, and probiotic supplementation could help boost antibody responses. Researchers analyzed antibody titers to explore this topic in rhesus macaques (sex not specified) infected with simian–human immunodeficiency virus (SHIV). They reported that probiotic treatment during vaccination led to delayed kinetics in the circulating HIV-specific IgA response after breakthrough SHIV infection. These findings highlight the potential of probiotic supplementation for reducing IgA-specific HIV antibodies in the plasma, which could help reduce HIV acquisition in vaccinated individuals. Supported by ORIP (P51OD011104, R21OD031435) and NIAID.
HIV, Asymptomatic STI, and the Rectal Mucosal Immune Environment Among Young Men Who Have Sex With Men
Van Doren et al., PLOS Pathogens. 2023.
https://www.doi.org/10.1371/journal.ppat.1011219
Young men who have sex with men (YMSM) are affected disproportionately by HIV and bacterial sexually transmitted infections (STIs) and therefore are likely to face an increased burden of associated chronic inflammation. Researchers studied the immunologic effects and interactions of HIV and bacterial STIs, as well as their effects on the rectal mucosal immune environment, among various populations of YMSM. Their findings suggest that asymptomatic bacterial STIs could contribute to inflammation, particularly among YMSM with HIV. This study provides insights into the immunopathogenesis of asymptomatic bacterial STIs and identifies a syndemic interaction between HIV and bacterial STIs in YMSM. Supported by ORIP (P51OD011132), NIAID, and NICHD.
CD8+ T Cells Promote HIV Latency by Remodeling CD4+ T Cell Metabolism to Enhance Their Survival, Quiescence, and Stemness
Mutascio et al., Immunity. 2023.
https://www.doi.org/10.1016/j.immuni.2023.03.010
An HIV reservoir persists following antiretroviral therapy, representing the main barrier to an HIV cure. Using a validated in vitro model, investigators explored the mechanism by which CD8+ T cells promote HIV latency and inhibit latency reversal in HIV-infected CD4+ T cells. They reported that CD8+ T cells favor the establishment of HIV latency by modulating metabolic, stemness, and survival pathways that correlate with the downregulation of HIV expression and promote HIV latency. In future studies, comparative analyses may provide insight into common molecular mechanisms in the silencing of HIV expression by CD8+ T cells and macrophages, which can be applied to new intervention strategies that target the HIV reservoir. Supported by ORIP (P51OD011132, S10OD026799), NIAID, NIDDK, NIDA, NHLBI, and NINDS.
Effect of Viral Strain and Host Age on Clinical Disease and Viral Replication in Immunocompetent Mouse Models of Chikungunya Encephalomyelitis
Anderson et al., Viruses. 2023.
https://pubmed.ncbi.nlm.nih.gov/37243143/
Chikungunya virus (CHIKV) is associated with neurologic complications, but studies in the central nervous system are challenging to perform in humans. Using a mouse model of both sexes, researchers established the relative severity of neurological disease across multiple stages of neurodevelopment in three strains of CHIKV. The disease was found to be strain dependent, with differences in severity of neurological disease, viral titers in the brain and spinal cord, and proinflammatory gene expression and CD4+ T cell infiltration in the brain. This work provides a mouse model for future studies of CHIKV pathogenesis and the host immune response. Supported by ORIP (K01OD026529), NIAID, and NCI.
Cannabinoid Enhancement of lncRNA MMP25-AS1/MMP25 Interaction Reduces Neutrophil Infiltration and Intestinal Epithelial Injury in HIV/SIV Infection
Premadasa et al., Journal of Clinical Investigation Insight. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10132162/
Gastrointestinal CD4+ T cell depletion during acute simian immunodeficiency virus (SIV) and HIV infection causes significant structural and functional damage, disrupting intestinal immune homeostasis and leading to intestinal epithelial barrier dysfunction. Oral phytocannabinoids are safe and well tolerated in people with HIV, but more information is needed regarding the effects of long-term tetrahydrocannabinol (THC) use on the intestinal epithelial compartment. Investigators profiled gene expression in the colonic epithelium of SIV-infected rhesus macaques of both sexes that were administered THC. They reported that low-dose THC can reduce neutrophil infiltration and intestinal epithelial injury, potentially by downregulating MMP25 expression through modulation of a long noncoding RNA, MMP25-AS1. Supported by ORIP (P51OD011104, P51OD011103), NIAID, and NIDA.
Effect of Passive Administration of Monoclonal Antibodies Recognizing Simian Immunodeficiency Virus (SIV) V2 in CH59-Like Coil/Helical or β-Sheet Conformations on Time of SIVmac251 Acquisition
Stamos et al., Journal of Virology. 2023.
https://journals.asm.org/doi/10.1128/jvi.01864-22
Research suggests that the SIV variable region 2 (V2) is a region of virus vulnerability, likely because of its exposure on the apex of virions and on the surfaces of SIV-infected cells. Researchers examined the effects of two monoclonal antibodies, NCI05 and NCI09, on the acquisition of SIV using rhesus macaques (sex not specified). They found that NCI05, but not NCI09, delays SIV acquisition, highlighting the complexity of antibody responses to V2. Both antibodies were unable to decrease the risk of viral acquisition. This study demonstrates that such antibodies as NCI05 alone are insufficient to protect against SIV acquisition. Supported by ORIP (S10OD027000), NIAID, and NCI.
Hematopoietic Stem Cells Preferentially Traffic Misfolded Proteins to Aggresomes and Depend on Aggrephagy to Maintain Protein Homeostasis
Chua et al., Cell Stem Cell. 2023.
https://pubmed.ncbi.nlm.nih.gov/36948186/
Investigators studied the mechanism of hematopoietic stem cells (HSCs) being dependent on managing proteostasis. Their findings demonstrated that HSCs preferentially depend on aggrephagy, a form of autophagy, to maintain proteostasis. When aggrephagy is disabled, HSCs compensate by increasing proteasome activity, but proteostasis is ultimately disrupted as protein aggregates accumulate and HSC function is impaired. The investigators also showed that Bag3 deficiency blunts aggresome formation in HSCs, resulting in protein aggregate accumulation, myeloid-biased differentiation, and diminished self-renewal activity, thus demonstrating Bag3 as a regulator of HSC proteostasis. HSC aging is associated with loss of aggresomes and reduced autophagic flux. Protein degradation pathways are thus configured in young-adult HSCs to preserve proteostasis and fitness but become dysregulated during aging. Supported by ORIP (S10OD032316, S10OD021831), NCI, and NIDDK.
The Incompetence of Mosquitoes—Can Zika Virus Be Adapted to Infect Culex tarsalis Cells?
Gallichotte et al., mSphere . 2023.
Zika virus (ZIKV) is transmitted between humans by Aedes aegypti mosquitoes. However, the 2015 to 2017 outbreak raised questions regarding the role of Culex species mosquitoes in transmission. Investigators attempted to adapt ZIKV to C. tarsalis by serially passaging the virus on cocultured A. aegypti and C. tarsalis cells to identify viral determinants of species specificity. Next-generation sequencing of cocultured virus passages revealed variants of interest that were engineered into nine recombinant viruses. None of these viruses showed increased infection of Culex cells or mosquitoes. Thus, although ZIKV might infect Culex mosquitoes occasionally, Aedes mosquitoes likely drive transmission and human risk. Supported by ORIP (T32OD010437) and NIAID.
Structural Insights Into the Broad Protection Against H1 Influenza Viruses by a Computationally Optimized Hemagglutinin Vaccine
Dzimianski et al., Communications Biology. 2023.
https://pubmed.ncbi.nlm.nih.gov/37185989/
Influenza is an ongoing public health concern, and computationally optimized broadly reactive antigen (COBRA) hemagglutinin proteins represent a potential strategy for formulating broadly effective influenza vaccines. Researchers determined the crystal structure of COBRA P1, as well as its binding to 1F8, a broadly neutralizing antibody. This work provides valuable insights into the underlying molecular basis for the broad effectiveness of P1, and these insights can be applied to future vaccine designs. Supported by ORIP (K01OD026569), NIAID, and NIGMS.
Longitudinal Characterization of Circulating Extracellular Vesicles and Small RNA During Simian Immunodeficiency Virus Infection and Antiretroviral Therapy
Huang et al., AIDS. 2023.
https://www.doi.org/10.1097/QAD.0000000000003487
Antiretroviral therapy is effective for controlling HIV infection but does not fully prevent early aging disorders or serious non-AIDS events among people with HIV. Using pigtail and rhesus macaques (sex not specified), researchers profiled extracellular vesicle small RNAs during different phases of simian immunodeficiency virus infection to explore the potential relationship between extracellular vesicle–associated small RNAs and the infection process. They reported that average particle counts correlated with infection, but the trend could not be explained fully by virions. These findings raise new questions about the distribution of extracellular vesicle RNAs in HIV latent infection. Supported by ORIP (U42OD013117), NIDA, NIMH, NIAID, NCI, and NINDS.