Development and Homeostasis of T Cell Memory in Rhesus Macaque

Abstract

The rhesus macaque (RM) is a critical animal model for studies of viral pathogenesis and immunity, yet fundamental aspects of their cellular immune response remain poorly defined. One such deficiency is the lack of validated phenotypic signatures for their naive and memory T cell subsets, and the resultant unavailability of accurate information on their memory T cell development, homeostasis, and function. In this study, we report a phenotypic paradigm allowing definitive characterization of these subsets and their comprehensive functional analysis. Naive T cells are optimally delineated by their homogeneous CD95lowCD28highβ7 integrinint (CD4+) or CD95lowCD28intCD11alow (CD8+) phenotypes. This subset 1) was present in blood and secondary lymph tissues, but not effector sites; 2) vastly predominated in the fetal/neonatal immune system, but rapidly diminished with postnatal age; 3) lacked IFN-γ production capability, and specific responses to RM CMV; and 4) demonstrated low in vivo proliferative activity. CD4+ and CD8+ memory subsets were CD95high, but otherwise phenotypically heterogeneous and included all IFN-γ production, RM CMV-specific responses, effector site T cells, and demonstrated high in vivo proliferative activity (∼10 times the naive subset). These analyses also revealed the RM “effector memory” subset within the overall memory population. This population, best defined by lack of CD28 expression, contained the majority of RM CMV-specific cells, was highly enriched in extralymphoid effector sites, and comprised an increasing proportion of total memory cells with age. The effector memory subset demonstrated similar in vivo proliferative activity and survival as CD28+ “central memory” T cells, consistent with independent homeostatic regulation.

Intestinal double‐positive CD4+CD8+ T cells are highly activated memory cells with an increased capacity to produce cytokines

“…Memory cell differentiation was performed using CD28 and CD95 phenotypic markers as described elsewhere [29]. Fig.…”

“…Cells were then treated with fixation/permeabilization solution (BD Biosciences) at 2Â concentration for 10 min in the dark at room temperature as described earlier [29,48]. Following two washes with dPBS/BSA, mAb anti-CD69-allophycocyanin-Cy7 (clone FN50)/anti-IFN-c-FITC (clone 4S.B3)/anti-TNF-a-FITC (clone Mab11) or anti-MIP-1b-PE (clone D21-1351) were added at room temperature for 30 min.…”

“…Jejunum LPL were found to have more DP T cells (mean value 19.3% of (Fig. 1B).Memory phenotype of SP and DP CD4 + /CD8 + T cellsMemory cell differentiation was performed using CD28 and CD95 phenotypic markers as described elsewhere [29]. Fig.…”

“…Cells were washed once with PBS and fixed with 2% paraformaldehyde (Sigma) in PBS. For Ki67 staining, the cells were fixed and permeabilized with fixation/ permeabilization solution (BD Biosciences, San Jose, CA) at 1Â concentration for 10 min as described earlier [29,48]. Following two washes with Dulbecco PBS with 0.1% BSA (dPBS/BSA) wash buffer, the cells were incubated with antiKi67 mAb for 30 min.…”

Accelerated immune senescence and reduced response to vaccination in ovariectomized female rhesus macaques

“…CD4 and CD8 T cells can be subdivided into three major subsets using antibodies directed against surface markers CD28 and CD95: (1) naïve T cells (Na, CD28+CD95−), (2) central memory T cells (CM, CD28+CD95+), and (3) effector memory T cells (EM, CD28−CD95+) as illustrated in Fig. 1a (Jankovic et al 2003;Pitcher et al 2002). We have previously shown that, as described for humans (Pawelec et al 2009), increasing age results in a decreased frequency of naïve T cells and an accumulation of memory cells, especially EM T cells in rhesus macaques (Jankovic et al 2003).…”