Selected Grantee Publications
Enhanced IL-17 Producing and Maintained Cytolytic Effector Functions of Gut Mucosal CD161+ CD8+ T Cells in SIV-Infected Rhesus Macaques
Thirugnanam et al., Viruses. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10535321/
HIV infection is associated with the depletion of CD161-expressing CD4+ Th17 cells, but the effects on other IL-17–producing T cell subsets are not understood fully. Researchers characterized the functions of non-invariant CD161-expressing CD8+ T cell subpopulations in peripheral blood and mucosal tissues of rhesus macaques (sex not specified) during chronic simian immunodeficiency virus (SIV) infection. They demonstrated that cell frequencies and function were unaffected by infection, but enhanced IL-17 production capacity and sustained Th1-type and cytolytic functions were observed. This work suggests that CD161-expressing CD8+ T cells might have important functions in gut mucosal immunity during chronic HIV infection. Supported by ORIP (P51OD011104, S10OD026800), NIAID, NIDDK, and NIMH.
Host-Derived Growth Factors Drive ERK Phosphorylation and MCL1 Expression to Promote Osteosarcoma Cell Survival During Metastatic Lung Colonization
McAloney et al., Cellular Oncology. 2023.
https://pubmed.ncbi.nlm.nih.gov/37676378/
Mortality from osteosarcoma is closely linked to lung metastasis, even though the lung appears to be a hostile environment for tumor cells. Using female mice, researchers assessed changes in both host and tumor cells during colonization. Their findings suggest that the mitogen-activated protein kinase (MAPK) pathway is significantly elevated in early and established metastases, which correlates with expression of anti-apoptotic genes (e.g., MCL1). The authors conclude that niche-derived growth factors drive increased MAPK activity and MCL1 expression in osteosarcoma, promoting metastatic colonization. This gene is a promising target for future therapeutic development. Supported by ORIP (K01OD031811), NCI, and NCATS.
Antiretroviral Therapy Ameliorates Simian Immunodeficiency Virus–Associated Myocardial Inflammation by Dampening Interferon Signaling and Pathogen Response in the Heart
Robinson et al., The Journal of Infectious Diseases. 2023.
https://doi.org/10.1093/infdis/jiad105
HIV is associated with increased risk of cardiovascular disease, but the underlying mechanisms are not fully understood. Using RNA sequencing, investigators characterized the effects of simian immunodeficiency virus (SIV) infection on the hearts of male rhesus macaques. They demonstrated that SIV infection drives a canonical antiviral response in the heart, as well as dysregulation of genes involved in fatty acid shuttling and metabolism. Their findings suggest that antiretroviral therapy helps mitigate immune activation during viremic conditions and plays a cardioprotective role. Future studies are needed to assess the long-term effects of these dynamics. Supported by ORIP (P51OD011104), NIAID, NIMH, and NINDS.
SALL1 Enforces Microglia-Specific DNA Binding and Function of SMADs to Establish Microglia Identity
Fixsen et al., Nature Immunology. 2023.
https://doi.org/10.1038/s41590-023-01528-8
Microglia function is thought to play a role in neurodevelopmental, psychiatric, and neurodegenerative diseases. Using knockout mice, investigators explored functional interactions between spalt-like transcription factor 1 (SALL1) and SMAD4, which demonstrated that interactions are mediated by a conserved microglia-specific SALL1 super-enhancer and result in direct activation of regulatory elements. The concerted interactions induce a microglia lineage determining program of gene expression. These findings indicate that expression of SALL1 and associated genes could contribute to phenotypes of aging and neurodegenerative diseases. Supported by ORIP (S10OD026929), NIA, NIMH, and NINDS.
Osteopontin Is an Integral Mediator of Cardiac Interstitial Fibrosis in Models of Human Immunodeficiency Virus Infection
Robinson et al., The Journal of Infectious Diseases. 2023.
https://www.doi.org/10.1093/infdis/jiad149
HIV infection is associated with increased risk of cardiovascular disease. Plasma osteopontin (Opn) is correlated with cardiac pathology, but more work is needed to understand the underlying mechanisms driving cardiac fibrosis. Researchers explored this topic using mouse embryonic fibroblasts, male macaques, and humanized mice of both sexes. They reported the accumulation of Opn in the heart with simian immunodeficiency virus infection. Systemic inhibition of Opn can prevent HIV-associated interstitial fibrosis in the left ventricle. These findings suggest that Opn could be a potential target for adjunctive therapies to reduce cardiac fibrosis in people with HIV. Supported by ORIP (P51OD011104), NIAID, NHLBI, NIMH, and NINDS.
Sequential Intrahost Evolution and Onward Transmission of SARS-CoV-2 Variants
Gonzalez-Reiche et al., Nature Communications. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10239218/
Most patients with COVID-19 clear the virus upon resolution of acute infection, but a subset of immunocompromised individuals develop persistent SARS-CoV-2 infections. In this study, investigators describe sequential persistent SARS-CoV-2 infections in three individuals that led to the emergence, forward transmission, and continued evolution of the Omicron BA.1 variant Omicron BA.1.23. The study demonstrated that in the presence of suboptimal immune responses, persistent viral replication is an important driver of SARS-CoV-2 diversification. This and other studies also highlight that strategies to prevent virus persistence and shedding and more effective therapies are needed to limit the spread of newly emerging, neutralization-resistant variants in vulnerable patients. Supported by ORIP (S10OD026880, S10OD030463), NIAID, and NCATS.
Brain Microglia Serve as a Persistent HIV Reservoir Despite Durable Antiretroviral Therapy
Tang et al., The Journal of Clinical Investigation. 2023.
https://www.doi.org/10.1172/JCI167417
Brain microglia are likely to play a role in rebound viremia following the cessation of antiretroviral therapy, but more work is needed to fully understand HIV persistence in the central nervous system (CNS). The investigators developed a protocol to isolate highly pure populations of brain myeloid cells and microglia from the tissues of male rhesus macaques, as well as from rapid autopsies of men and women with HIV. Their observations support the concept that brain microglia are a stable reservoir of quiescent infection. Thus, this work provides a physiologically relevant platform for studies of the biology of CNS reservoirs. Supported by ORIP (P51OD011132), NIAID, and NIMH.
Effects of Acute Femoral Head Ischemia on the Growth Plate and Metaphysis in a Piglet Model of Legg-Calvé-Perthes Disease
Armstrong et al., Osteoarthritis and Cartilage. 2023.
https://pubmed.ncbi.nlm.nih.gov/36696941/
Legg-Calvé-Perthes disease (LCPD) can lead to permanent deformity of the femoral head and premature osteoarthritis, but the underlying cause remains unknown. More work is needed to determine optimal treatment methods for LCPD. Using a piglet model for LCPD, researchers assessed the effects of acute femoral head ischemia on the proximal femoral growth plate and metaphysis. They reported that alterations to the growth plate zones and metaphysis occurred by 2 days post-ischemia and persisted at 7 days post-ischemia. These findings suggest that growth disruption may occur sooner after the onset of ischemia than researchers had hypothesized previously. Supported by ORIP (T32OD010993, K01OD021293), NIAMS, and NCATS.
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.
Late Gene Expression–Deficient Cytomegalovirus Vectors Elicit Conventional T Cells That Do Not Protect Against SIV
Hansen et al., Journal of Clinical Investigation Insight. 2023.
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10070102/
Cytomegalovirus (CMV)–based vaccines aim to exploit unique immunological adaptations, including host manipulation and immune evasion strategies. Translating CMV-based vaccines from rhesus macaques to humans requires translating the immune factors responsible for efficacy, as well as vaccine vectors that are sufficiently safe for widespread use. Researchers examined the impact of a stringent attenuation strategy on vector-induced immune protection against simian immunodeficiency virus (SIV) in rhesus macaques of both sexes. They reported that elicited CD8+ T cells exclusively failed to protect against SIV challenge. These data suggest that late viral gene expression and/or residual in vivo spreading are required to induce protective CD8+ T cell responses. Supported by ORIP (P51OD011092, P51OD011107, S10OD016261), NCI, NIAID, and NCATS.