Selected Grantee Publications
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- 7 results found
- nhlbi
- COVID-19/Coronavirus
- Women's Health
Gut Microbiome Dysbiosis in Antibiotic-Treated COVID-19 Patients Is Associated with Microbial Translocation and Bacteremia
Bernard-Raichon et al., Nature Communications. 2022.
https://www.doi.org/10.1038/s41467-022-33395-6
The investigators demonstrated that SARS-CoV-2 infection induced gut microbiome dysbiosis in male mice. Samples collected from human COVID-19 patients of both sexes also revealed substantial gut microbiome dysbiosis. Analysis of blood culture results testing for secondary microbial bloodstream infections with paired microbiome data indicated that bacteria might translocate from the gut into the systemic circulation of COVID-19 patients. These results were consistent with a direct role for gut microbiome dysbiosis in enabling dangerous secondary infections during COVID-19. Supported by ORIP (S10OD021747), NCI, NHLBI, NIAID, and NIDDK.
X Chromosome Agents of Sexual Differentiation
Arnold et al., Nature Reviews Endocrinology. 2022.
https://www.doi.org/10.1038/s41574-022-00697-0
Many diseases affect one sex disproportionately. A major goal of biomedical research is to understand which sex-biasing factors influence disease severity and to develop therapeutic strategies to target these factors. Two groups of such agents are sex chromosome genes and gonadal hormones. Researchers use the “four core genotypes” model to enable comparisons among animals with different sex chromosomes but the same type of sex hormones, which allows investigators to distinguish disease mechanisms influenced by the sex chromosomes. Supported by ORIP (R01OD030496, R21OD026560), NICHD, NIDDK, and NHLBI.
Common and Divergent Features of T Cells From Blood, Gut, and Genital Tract of Antiretroviral Therapy–Treated HIV+ Women
Xie et al., Journal of Immunology. 2022.
https://www.doi.org/10.4049/jimmunol.2101102
T cells residing in mucosal tissues play important roles in homeostasis and defense against microbial pathogens, but how organ system environments affect the properties of resident T cells is relatively unknown. Researchers phenotyped T cells in the gut and reproductive tract using blood and tissue samples from women with HIV who have achieved viral suppression via antiretroviral therapy. The T cells exhibited differing expression of CD69 and CD103 markers, whereas resident memory CD8+ T cells from the female reproductive tract expressed PD1 preferentially. Additionally, CXCR4+ T inflammatory mucosal cells expressed multiple chemokine receptors differentially. These results suggest that T cells take on distinct properties in different mucosal sites, which allows them to tailor activities to their surrounding milieu. This study offers important insights for reproductive medicine in women. Supported by ORIP (S10OD018040), NHLBI, NIAID, and NIDDK.
CAR/CXCR5–T Cell Immunotherapy Is Safe and Potentially Efficacious in Promoting Sustained Remission of SIV Infection
Pampusch et al., PLOS Pathogens. 2022.
https://www.doi.org/10.1371/journal.ppat.1009831
HIV and simian immunodeficiency virus (SIV) replication are concentrated within the B cell follicles of secondary lymphoid tissues. In this study, the researchers developed immunotherapeutic chimeric antigen receptor (CAR) T cells that home to follicles and clear SIV-infected cells in a rhesus macaque model. The CAR T cells localized to the follicle, replicated, and interacted directly with infected cells. Most of the treated animals maintained lower viral loads in the blood and follicles, compared to control animals. These findings demonstrate the safety and potential efficacy of this immunotherapy approach for long-term remission of HIV without requiring the lifelong use of antiretroviral therapy. Supported by ORIP (P51OD011106), NIAID, and NHLBI.
Severely Ill COVID-19 Patients Display Impaired Exhaustion Features in SARS-CoV-2-Reactive CD8+ T Cells
Kusnadi et al., Science Immunology. 2021.
https://immunology.sciencemag.org/content/6/55/eabe4782.long
How CD8+ T cells respond to SARS-CoV-2 infection is not fully known. Investigators reported on the single-cell transcriptomes of >80,000 virus-reactive CD8+ T cells, obtained using a modified Antigen-Reactive T cell Enrichment assay, from 39 COVID-19 patients and 10 healthy subjects. COVID-19 patient cells were segregated into two groups based on whether the dominant CD8+ T cell response to SARS-CoV-2 was “exhausted” or not. SARS-CoV-2-reactive cells in the exhausted subset were increased in frequency and displayed less cytotoxicity and inflammatory features in COVID-19 patients with mild compared to severe illness. In contrast, SARS-CoV-2-reactive cells in the dominant non-exhausted subset from patients with severe disease showed enrichment of transcripts linked to co-stimulation, pro-survival Nuclear Factor κB signaling, and anti-apoptotic pathways, suggesting the generation of robust CD8+ T cell memory responses in patients with severe COVID-19 illness. Overall, this single-cell analysis revealed substantial diversity in the nature of CD8+ T cells responding to SARS-CoV-2. Supported by ORIP (S10RR027366 and S10OD025052), NIAID, NHLBI, and NIGMS.
Lung Expression of Human Angiotensin-Converting Enzyme 2 Sensitizes the Mouse to SARS-CoV-2 Infection
Han et al., American Journal of Respiratory Cell and Molecular Biology. 2021.
https://doi.org/10.1165/rcmb.2020-0354OC
A rapidly deployable mouse model that recapitulates a disease caused by a novel pathogen would be a valuable research tool during a pandemic. Researchers were able to produce C57BL/6J mice with lung expression of human angiotensin-converting enzyme 2 (hACE2), the receptor for SARS-CoV-2. They did so by oropharyngeal delivery of a recombinant human adenovirus type 5 expressing hACE2. The transduced mice were then infected with SARS-CoV-2. Thereafter, the mice developed interstitial pneumonia with perivascular inflammation, exhibited higher viral load in lungs compared to controls, and displayed a gene expression phenotype resembling the clinical response in lungs of humans with COVID-19. Supported by ORIP (P51OD011104, R21OD024931), NHLBI, and NIGMS.
Imbalance of Regulatory and Cytotoxic SARS-CoV-2-Reactive CD4+ T Cells in COVID-19
Meckiff et al., Cell. 2020.
https://pubmed.ncbi.nlm.nih.gov/33096020/
It is not clear why COVID-19 is deadly in some people and mild in others. To understand the underlying mechanism, investigators studied the contribution of CD4+ T cells in immune responses to SARS-CoV-2 infection. They analyzed single-cell transcriptomic data of >100,000 viral antigen-reactive CD4+ T cells from 40 COVID-19 patients. In hospitalized patients compared to non-hospitalized patients, they found increased proportions of cytotoxic follicular helper cells (TFH) and cytotoxic T helper (TH) cells responding to SARS-CoV-2 and reduced proportion of SARS-CoV-2-reactive regulatory T cells (TREG). Importantly, in hospitalized COVID-19 patients, a strong cytotoxic TFH response was observed early in the illness, which correlated negatively with antibody levels to SARS-CoV-2 spike protein. Polyfunctional TH1 and TH17 cell subsets were underrepresented in the repertoire of SARS-CoV-2-reactive CD4+ T cells compared to influenza-reactive CD4+ T cells. Together, these analyses provided insights into the gene expression patterns of SARS-CoV-2-reactive CD4+ T cells in distinct disease severities. Supported by ORIP (S10RR027366, S10OD025052), NIAID, NHLBI, and NIGMS.