After experiments, the explants were snap frozen or embedded in paraffin. Paraffin-embedded sections or cryostatic sections were incubated with Abs against phospho-STAT1 (Tyr701) (Santa Cruz Biotechnology), ICAM-1

(clone HA58, BD Pharmingen), HLA-DR (clone G46–6, BD Pharmingen), CXCL10 (C-19, Santa Cruz Biotechnology). Secondary biotinylated mAbs and staining kits (Vector Laboratories, Burlinagame, CA, USA) were used to develop immunoreactivities, and 9-ethyl-3-aminocarbazole Trichostatin A solubility dmso was used as substrate. Sections were counterstained with hematoxylin. Statistical significance was evaluated using Wilcoxon’s signed rank test (SigmaStat; Jandel, San Rafael, CA, USA). Values of p ≤ 0.05 were considered significant. This work was supported by the Italian Ministry of Health and by Ministero dell’Università e della Ricerca Scientifica (MIUR). The authors declare no financial or commercial conflict of interest. “
“There is debate over whether effective T-cell mediated protection against a second infection, or post-vaccination, is better done

by central memory cells or effector memory cells. The former may have greater powers of expansion, whereas the latter may be closer to the site of pathogen entry and faster to respond. This review focuses on memory T cells which are not recirculating but which remain at the peripheral Lumacaftor concentration site of initial pathogen or vaccine encounter, so-called tissue-resident memory cells. They may play key roles in protection against re-eruption of latent viral infections and at mucosal surfaces. After leaving the thymus, newly generated T cells have a few steps of continued maturation or polishing to undergo before they become fully

mature naïve T cells 1. As naïve cells, peripheral T cells migrate between the blood and the lymphoid structures in the spleen and lymph nodes in search of their cognate antigen. When T cells do encounter antigen on activated DCs in central lymphoid organs, they proliferate Sorafenib cost and differentiate into effector T cells. While some antigen-activated T cells, such as CD4+ follicular helper T cells, may remain in the central lymphoid organs to deliver help to B cells 2, those effector cells whose work is at the peripheral site of antigen entry must travel to this site via the bloodstream. Using cues from activated endothelial cells at sites of inflammation 3, T cells leave the blood vessels and enter tissues once more in search of antigen. When antigen-bearing cells are killed or accessory cells are activated to degrade or contain antigen, effector cells egress from the tissues via the afferent lymphatics. In some cases, a few effector cells remain behind; these tissue-resident memory T cells are the subject of this review 4. When antigen has been cleared, a contraction phase follows during which time the number of effector cells declines through apoptosis leaving behind some survivors that go on to differentiate into memory T cells.