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ABSTRACT: Background and aims
Long-lasting immunological memory is the ultimate goal of vaccination. Homeostatic maintenance of memory CD8 + cytotoxic T cells (MemCD8TCs) is thought to be mediated by IL-15/IL-15R heterodimer (15HD)-expressing myeloid cells. Nonmyeloid hepatic stellate cells (HSCs) also express 15HD, but their role in maintaining MemCD8TC homeostasis is unknown.Approach and results
We engineered a genetically engineered mouse in which IL-15R complementary DNA (cDNA) had been inserted in-frame with lecithin-retinol acyltransferase gene and bred onto an IL-15R-KO (15R-KO) genetic background (L15R) that expressed IL-15R in HSCs at normal levels, but not in other liver cells. Outside of the liver of L15R mice, IL-15R expression was found in a number of organs, but not in dendritic cells and macrophages. The low IL-15R expression in the bone marrow (BM) of L15R mice was eliminated by the reconstitution of lethally-irradiated L15R mice with 15R-KO BM to generate L15RC mice. Because MemCD8TC maintenance is mediated by 15HD, not empty IL-15R, 15HD content in L15R mice was determined and found for liver, lung, kidney, and heart. L15R and L15RC mice developed and maintained long-lasting, systemic antigen-specific MemCD8TCs that were efficacious against tumor growth and Listeria monocytogenes infection in an antigen-specific manner. Among the four organs with 15HD content, liver-associated MemCD8TCs were different from those found in the lung, kidney, and heart in two ways: (1) they were quantitatively the most numerous, and (2) they appeared uniquely in the form of clusters in a specialized structure, sinusoidal niches of the liver.Conclusions
The liver, the largest organ of the body, is endowed with the capability of effectuating long-lasting functional cytotoxic T cell memory.
SUBMITTER: Chen YT
PROVIDER: S-EPMC10113002 | biostudies-literature | 2023 May
REPOSITORIES: biostudies-literature
Chen Yi-Ting YT Su Yu-Chia YC Or Yee-Ern YE Cheng Chin-Fu CF Kung John T JT
Hepatology (Baltimore, Md.) 20230417 5
<h4>Background and aims</h4>Long-lasting immunological memory is the ultimate goal of vaccination. Homeostatic maintenance of memory CD8 + cytotoxic T cells (MemCD8TCs) is thought to be mediated by IL-15/IL-15R heterodimer (15HD)-expressing myeloid cells. Nonmyeloid hepatic stellate cells (HSCs) also express 15HD, but their role in maintaining MemCD8TC homeostasis is unknown.<h4>Approach and results</h4>We engineered a genetically engineered mouse in which IL-15R complementary DNA (cDNA) had bee ...[more]