Biology subjects

Gostick, E.

Publications and source records attributed to Gostick, E..

3 recordsLinked to original sources

bioRxiv2020

Altered basal lipid metabolism underlies the functional impairment of naive CD8+ T cells in elderly humans

BackgroundAging is associated with functional deficits in the naive T cell compartment, which compromise the generation of de novo immune responses against previously unencountered antigens. The mechanisms that underlie this phenomenon have nonetheless remained unclear. MethodsBiochemical and functional properties of naive CD8+ T cells were characterized and compared between middle aged and older individuals. FindingsWe identified an age-related link between altered basal lipid metabolism in naive CD8+ T cells and their impaired responsiveness to stimulation, characterized by low proliferative potential and susceptibility to apoptosis. Reversal of the bioenergetic anomalies with lipid-altering drugs, such as rosiglitazone, improved the functional capabilities of naive CD8+ T cells in elderly subjects. InterpretationInterventions that favor lipid catabolism may find utility as adjunctive therapies in the elderly to promote vaccine-induced immunity against emerging pathogens or tumors. FundingA full list of the funding sources is detailed in the Acknowledgment section of the manuscript. RESEARCH IN CONTEXTO_ST_ABSEvidence before this studyC_ST_ABSOld subjects are highly susceptible to infections and tumors and usually present with low responses to vaccine. This is mainly due to the age-related loss of primary immune resources, i.e. a quantitative decline of naive CD8+ T cells. Nonetheless, few studies have also underlined, within this cell subset, qualitative defects in elderly subjects. Added value of this studyConsidering the well-demonstrated link between nutrient usage and lymphocyte functions, we characterized the bioenergetics features of old naive CD8+ T cells. Our data show an age-dependent altered basal metabolism in this cell subset, mostly at the levels of fatty acids and mitochondrial functions. These alterations were associated with functional defects which were partially reverted through the use of lipid-lowering strategies. Implications of all the available evidenceThis study highlights the potential role of an altered cellular lipid metabolism in immunosenescence, providing clues to understand the epidemiological profile of emerging infections or tumors and to develop preventive and therapeutic strategies based on metabolic manipulation.

immunology↗

bioRxiv2020

The identity of human tissue-emigrant CD8+ T cells

Lymphocyte migration is essential for human adaptive immune surveillance. However, our current understanding of this process is rudimentary, because most human studies to date have been restricted to immunological analyses of blood and various tissues. To address this issue, we used an integrated approach to characterize tissue-emigrant immune cells in thoracic duct lymph (TDL). In humans and non-human primates, lymphocytes were by far the most abundant immune lineage population in efferent lymph, and a vast majority of these lymphocytes were T cells. Cytolytic CD8+ T cell subsets were clonotypically discrete and selectively confined to the intravascular circulation, persisting for months after inhibition of S1P-dependent tissue egress by FTY-720. In contrast, non-cytolytic CD8+ T cell subsets with stem-like epigenetic and transcriptional signatures predominated in tissues and TDL. Collectively, these data provide an atlas of the migratory immune system and define the nature of tissue-emigrant CD8+ T cells that recirculate via TDL.

immunology↗

bioRxiv2019

Optimal maturation of the SIV-specific CD8+ T-cell response after primary infection is associated with natural control of SIV. ANRS SIC study

Highly efficient virus-specific CD8+ T-cells are associated with immune control of HIV infection, but it remains unclear how these cells are generated and maintained over time. We used a macaque model of spontaneous control of SIVmac251 infection to monitor the development and evolution of potent antiviral CD8+ T-cell responses. SIV-specific CD8+ T-cells emerged during primary infection in all animals. However, the ability of CD8+ T cells to suppress SIV replication was low in early stages but increased after a period of maturation, temporally linked with the establishment of sustained low-level viremia in controller macaques. SIV-specific CD8+ T-cells with a central memory phenotype expressed higher levels of survival markers in controllers versus non-controllers. In contrast, a persistently skewed differentiation phenotype was observed among central memory SIV-specific CD8+ T-cells in non-controllers since primary infection, typified by relatively high expression levels of T-bet. Collectively, these data show that the phenotype of SIV-specific CD8+ T-cells defined early after SIV infection favor the gain of antiviral potency as a function of time in controllers, whereas SIV-specific CD8+ T-cell responses in non-controllers fail to gain antiviral potency due to early defects imprinted in the central memory pool.

immunology↗