Biology subjects

Kaseke, C.

Publications and source records attributed to Kaseke, C..

4 recordsLinked to original sources

bioRxiv2026

NK-like and networked CD8+ T cell immunity mediates exceptional HIV control

Durable treatment-free remission remains a defining goal for people living with HIV (PLWH). Studies of spontaneous elite controllers have revealed that functional CD8 T cells targeting structurally networked viral epitopes can mediate durable viral suppression1,2. However, rare reservoir-defined exceptional controllers within the spectrum of elite control3-5, characterized by the absence of intact provirus or proviruses confined to transcriptionally repressed genomic regions6, provide a unique opportunity to define mechanisms of cure-like immunity. Here, we integrate functional epitope mapping, single-cell transcriptomics, and infected cell elimination assays to identify networked HIV epitope targeting and a natural killer (NK)-like killer-cell immunoglobulin-like receptor (KIR) CD8 T cell subset as key features of exceptional control. This NK-like subset was selectively enriched within HIV-specific, but not CMV-specific, CD8 T cells from controllers, and was transcriptionally similar to highly cytotoxic subsets within the broader KIR+ CD8+ T cell compartment. Flow cytometry revealed increased frequencies of KIR CD8 T cells in exceptional controllers relative to antiretroviral therapy (ART)-suppressed individuals, and unexpectedly, enrichment of dual KIR+ NKG2A+ CD8 T cells. Functional depletion of KIR CD8 T cells significantly impaired the elimination of autologous HIV-infected CD4 T cells, despite preserved recognition by proliferative networked HIV-specific CD8 T cells. These findings thereby identify an NK-like KIR CD8 T cell state as a previously unrecognized component of exceptional HIV immunity that complements networked epitope targeting, providing a novel framework for immunotherapeutic HIV cure strategies.

immunology↗

bioRxiv2024

Two distinct durable human class-switched memory B cell populations are induced by vaccination and infection

Memory lymphocytes are durable cells that persist in the absence of antigen, but few human B cell subsets have been characterized in terms of durability. The relative durability of eight non-overlapping human B cell sub-populations covering 100% of all human class-switched B cells was interrogated. Only two long-lived B cell populations persisted in the relative absence of antigen. In addition to canonical germinal center-derived switched-memory B cells with an IgD-CD27+ CXCR5+ phenotype, a second, non-canonical, but distinct memory population of IgD-CD27- CXCR5+ DN1 B cells was also durable, exhibited a unique TP63-linked transcriptional and anti-apoptotic signature, had low levels of somatic hypermutation, but was more clonally expanded than canonical switched-memory B cells. DN1 B cells likely evolved to preserve immunological breadth and may represent the human counterparts of rodent extrafollicular memory B cells that, unlike canonical memory B cells, can enter germinal centers and facilitate B cell and antibody evolution. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=140 SRC="FIGDIR/small/624972v1_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@169c77forg.highwire.dtl.DTLVardef@1a872f5org.highwire.dtl.DTLVardef@1360cforg.highwire.dtl.DTLVardef@38d7ed_HPS_FORMAT_FIGEXP M_FIG C_FIG

immunology↗

bioRxiv2022

A pan-variant mRNA-LNP T cell vaccine protects HLA transgenic mice from mortality after infection with SARS-CoV-2 Beta

Clinically licensed COVID-19 vaccines ameliorate viral infection by inducing vaccinee production of neutralizing antibodies that bind to the SARS-CoV-2 Spike protein to inhibit viral cellular entry (Walsh et al., 2020; Baden et al., 2021), however the clinical effectiveness of these vaccines is transitory as viral variants arise that escape antibody neutralization (Tregoning et al., 2021; Willett et al., 2022). Vaccines that solely rely upon a T cell response to combat viral infection could be transformational because they can be based on highly conserved short peptide epitopes that hold the potential for pan-variant immunity, but a mRNA-LNP T cell vaccine has not been shown to be sufficient for effective antiviral prophylaxis. Here we show that a mRNA-LNP vaccine based on highly conserved short peptide epitopes activates a CD8+ and CD4+ T cell response that prevents mortality in HLA-A*02:01 transgenic mice infected with the SARS-CoV-2 Beta variant of concern (B.1.351). In mice vaccinated with the T cell vaccine, 24% of the nucleated cells in lung were CD8+ T cells on day 7 post infection. This was 5.5 times more CD8+ T cell infiltration of the lungs in response to infection compared to the Pfizer-BioNTech Comirnaty(R) vaccine. Between days 2 and 7 post infection, the number of CD8+ T cells in the lung increased in mice vaccinated with the T cell vaccine and decreased in mice vaccinated with Comirnaty(R). The T cell vaccine did not produce neutralizing antibodies, and thus our results demonstrate that SARS-CoV-2 viral infection can be controlled by a T cell response alone. Our results suggest that further study is merited for pan-variant T cell vaccines, and that T cell vaccines may be relevant for individuals that cannot produce neutralizing antibodies or to help mitigate Long COVID.

immunology↗

bioRxiv2021

Preliminary Immunogenicity of a Pan-COVID-19 T Cell Vaccine in HLA-A*02:01 Mice

New strains of SARS-CoV-2 have emerged, including B.1.351 and P.1, that demonstrate increased transmissibility and the potential of rendering current SARS-CoV-2 vaccines less effective. A concern is that existing SARS-CoV-2 spike subunit vaccines produce neutralizing antibodies to three dimensional spike epitopes that are subject to change during viral drift. Here we provide an initial report on the hypothesis that adaptive T cell based immunity may provide a path for a pan-COVID-19 vaccine that is resilient to viral drift. T cell based adaptive immunity can be based on short peptide sequences selected from the viral proteome that are less subject to drift, and can utilize multiple such epitopes to provide redundancy in the event of drift. We find that SARS-CoV-2 peptides contained in a mRNA-LNP T cell vaccine for SARS-CoV-2 are immunogenic in mice transgenic for the human HLA-A*02:01 gene. We plan to test the efficacy of this vaccine with SARS-CoV-2 B.1.351 challenge trials with HLA-A*02:01 mice.

immunology↗