Differential In Vivo Persistence of Two Subsets of Memory Phenotype CD8 T Cells Defined by CD44 and CD122 Expression Levels

Abstract

The existence of distinct subsets of memory CD8 T cells with different characteristics is now well established. In this work, we describe two subsets of mouse CD8 T cells with memory characteristics that coexist in primed thymectomized TCR-transgenic F5 mice and that share some properties with the human central and effector memory cells. The first subset corresponds to CD8 T cells generated following nucleoprotein 68 peptide priming which are CD44intCD122−nucleoprotein 68/H-2Db tetramer+ and express high levels of CCR7 mRNA. In contrast, CD8 T cells in the second subset are CD44highCD122+, are heterogeneous in terms of Ag specificity, and express low levels of CCR7 mRNA. We have studied the functional characteristics and the persistence of these two subsets in thymectomized mice. CD44int CD8 T cells persist like naive cells; i.e., they are slowly lost with time. However, surviving cells maintain their phenotype and memory characteristics for the entire life span of the animal. In contrast, CD44high CD8 T cells are persistent and accumulate in thymectomized but not euthymic mice. This is correlated with an increased in vivo proliferative and survival potential of these cells. These results show that acquisition of enhanced functional characteristics and long-term persistence by memory T cells are independent. This may have important consequences for the design of specific vaccine.

Restriction of De Novo Nucleotide Biosynthesis Interferes with Clonal Expansion and Differentiation into Effector and Memory CD8 T Cells

“…To determine to what extent nucleotide synthesis inhibitors could affect acquisition of effector functions, we analyzed the expression of IFN-␥ by F5 CD8 ϩ T cells. As reported previously (19,21), IFN-␥-positive CD8 ϩ CFSE ϩ cells could not be detected in naive mice after ex vivo restimulation with the peptide (Fig. 2A).…”

Negative Regulation of NKG2D Expression by IL-4 in Memory CD8 T Cells

“…To measure the effects of IL-4 in vitro, cells were cultured for 20 h at a concentration of 3 3 10 6 cells/ml in presence or absence of murine IL (mIL)-4 (PeproTech) at a concentration of 10 ng/ml. In some experiments, cells were activated in vitro at a concentration of 1 3 10 6 cells/ml in 96-well plates with 2% IL-2 and the indicated concentrations of NP68 for 24 or 72 h. For quantitative real-time PCR (qPCR) experiments, spleen and lymph node CD8 T cells were purified by magnetic bead depletion, as previously described (27). Purified CD8 T cells were then stained for cell surface expression of CD44, CD122, and CD8 and sorted by flow cytometry using a FACSAria (BD Biosciences): T IM were CD8 + /CD44 int /CD122 int , and antiviral T CM / T EM were CD8 + /CD44 high /GFP + .…”

Maintenance of CCL5 mRNA stores by post‐effector and memory CD8 T cells is dependent on transcription and is coupled to increased mRNA stability

“…Thymectomies were performed on 5-6-week-old mice. Three weeks after thymectomy, F5 or RAG -/-F5 mice were injected twice at 24-h interval with 50 nmol of the A/NT/60/ 68 influenza virus nucleoprotein peptide (NP-366-374: AlaSer-Asn-Glu-Asn-Met-Asp-Ala-Met, plateforme IFR128, IBCP, Dr. D. Ficheux) in PBS in the peritoneal cavity [30]. CD8 T cells were recovered 3 days (activated cells), 7 days (post-effector cells) or 40 days (memory cells) after peptide injection.…”

“…The expression of CCL5 was induced by growing cells for 24 h in the presence of IFN-c and TNF-a at concentrations of 50 and 20 ng/mL, respectively. CD8 T cells were purified from spleen and lymph nodes (mesenteric, inguinal, brachial and axillary) using a negative selection strategy as previously described [30]. …”