Biology subjects

Potter, E. L.

Publications and source records attributed to Potter, E. L..

3 recordsLinked to original sources

bioRxiv2024

Intravenous BCG induces a more potent airway and lung immune response than intradermal BCG in SIV-infected macaques

Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb), is one of the leading causes of death due to an infectious agent. Coinfection with HIV exacerbates Mtb infection outcomes in people living with HIV (PLWH). Bacillus Calmette-Guerin (BCG), the only approved TB vaccine, is effective in infants, but its efficacy in adolescents and adults is limited. Here, we investigated the immune responses elicited by BCG administered via intravenous (IV) or intradermal (ID) routes in Simian Immunodeficiency Virus (SIV)-infected Mauritian cynomolgus macaques (MCM) without the confounding effects of Mtb challenge. We assessed the impact of vaccination on T cell responses in the airway, blood, and tissues (lung, thoracic lymph nodes, and spleen), as well as the expression of cytokines, cytotoxic molecules, and key transcription factors. Our results showed that IV BCG induces a robust and sustained immune response, including tissue-resident memory T (TRM) cells in lungs, polyfunctional CD4+ and CD8{beta}+ T cells expressing multiple cytokines, and CD8{beta}+ T cells and NK cells expressing cytotoxic effectors in airways. We also detected higher levels of mycobacteria-specific IgG and IgM in the airways of IV BCG-vaccinated MCM. Although IV BCG vaccination resulted in an influx of TRM cells in lungs of MCM with controlled SIV replication, MCM with high plasma SIV RNA (>105 copies/mL) typically displayed reduced T cell responses, suggesting that uncontrolled SIV or HIV replication would have a detrimental effect on IV BCG-induced protection against Mtb.

immunology↗

bioRxiv2022

Mild SARS-CoV-2 infection in rhesus macaques is associated with viral control prior to antigen-specific T cell responses in tissues

SARS-CoV-2 primarily replicates in mucosal sites, and more information is needed about immune responses in infected tissues. We used rhesus macaques to model protective primary immune responses in tissues during mild COVID-19. Viral RNA levels were highest on days 1-2 post-infection and fell precipitously thereafter. 18F-fluorodeoxyglucose (FDG)-avid lung abnormalities and interferon (IFN)-activated myeloid cells in the bronchoalveolar lavage (BAL) were found on days [~]3-4. Virus-specific effector CD8 and CD4 T cells were detectable in the BAL and lung tissue on days [~]7-10, after viral RNA, lung inflammation, and IFN-activated myeloid cells had declined. Notably, SARS-CoV-2-specific T cells were not detectable in the nasal turbinates, salivary glands, and tonsils on day 10 post-infection. Thus, SARS-CoV-2 replication wanes in the lungs prior to T cell responses, and in the nasal and oral mucosa despite the apparent lack of Ag-specific T cells, suggesting that innate immunity efficiently restricts viral replication during mild COVID-19. ONE SENTENCE SUMMARYSARS-CoV-2 infection leads to mild, focal lung inflammation, and type I IFN activated myeloid cells that mostly resolve prior to the influx of virus-specific effector T cells or antibody responses in rhesus macaques.

immunology↗

bioRxiv2020

Spatiotemporal single-cell profiling of gastrointestinal GVHD reveals invasive and resident memory T cell states.

One of the central challenges in the field of allo-immunity is deciphering the mechanisms driving T cells to infiltrate and subsequently occupy target organs to cause disease. The act of CD8-dominated T cell infiltration is critical to acute graft-versus-host disease (aGVHD), wherein donor T cells become activated, tissue-infiltrating and highly cytotoxic, causing wide-spread tissue damage after allogeneic hematopoietic stem cell transplant (allo-HCT). However, in human and non-human primate studies, deconvolving the transcriptional programs of newly recruited relative to resident memory T cells in the gastrointestinal (GI) tract has remained a challenge. In this study, we combined the novel technique of Serial Intravascular Staining (SIVS) with single-cell RNA-Seq (scRNA-seq) to enable detailed dissection of the tightly connected processes by which T cells first infiltrate tissues and then establish a pathogenic tissue residency program after allo-HCT in non-human primates. Our results have enabled the creation of a spatiotemporal map of the transcriptional drivers of CD8 T cell infiltration into the primary aGVHD target-organ, the GI tract. We identify the large and small intestines as the only two sites demonstrating allo-specific, rather than lymphdepletion-driven T cell infiltration. The donor CD8 T cells that infiltrate the GI tract demonstrate a highly activated, cytotoxic phenotype while simultaneously rapidly developing canonical tissue-resident memory (TRM) protein expression and transcriptional signatures, driven by IL-15/IL-21 signaling. Moreover, by combining SIVS and transcriptomic analysis, we have been able to work backwards from this pathogenic TRM programing, and, for the first time, identify a cluster of genes directly associated with tissue invasiveness, prominently including specific chemokines and adhesion molecules and their receptors, as well as a central cytoskeletal transcriptional node. The clinical relevance of this new tissue invasion signature was validated by its ability to discriminate the CD8 T cell transcriptome of patients with GI aGVHD. These results provide new insights into the mechanisms controlling tissue infiltration and pathogenic CD8 TRM transcriptional programing, uncovering critical transitions in allo-immune tissue invasion and destruction. One sentence summaryFlow cytometric and transcriptomic analysis reveals coordinated tissue-infiltration and tissue-residency programs driving gastrointestinal aGVHD.

immunology↗