Differential expression of CD45R0 on natural killer (NK) cells in patients with an NK lymphocytosis

Abstract

Summary NK cells from three donors with a NK (CD3 -CD56 " CD 16 ") lymphoeytosis of unknown aetiology showed differential expression of CD45R0, an isoform of CD45 not expressed by NK cells from normal donors unless stimulated to proliferate in vitro. For donor FC, 60% of NK cells expressed CD45R0 over a 16 month period during which there was a partial resolution of the NK lymphoeytosis. For donor SW, 37% of NK cells expressed CD45R0. increasing to 87% over a 14 month period during which the NK lymphoeytosis increased. For donor RN few if any NK cells expressed CD45R0. After in vitro proliferation, 100% of NK cells generated from all donors expressed CD45R0. For donors FC and SW, CD45R0 remained expressed on more than 90% of cells at 3-4 weeks following eessation of proliferation. By contrast CD45R0 expression was gradually lost during long-term culture of NK cells from donor RN, with 58% of NK cells regaining the pre-culture CD45R0-phenotype. NK cells from normal donors also varied in the extent to which activation acquired CD45R0 was lost during long-term culture. The results obtained are consistent with the notion that NK eells from the NK lymphoeytosis donors studied have previously undergone proliferation in vivo.

Functional inhibitory human leucocyte antigen class I receptors on natural killer (NK) cells in patients with chronic NK lymphocytosis

“…The possibility that IL‐15 is involved in NK cell expansion in patients with chronic NK lymphocytosis has been suggested (Zambello et al , 1997b). However, the NK cells in patients with chronic NK lymphocytosis are quiescent and lack the markers (CD25, CD71) of proliferation (Warren et al , 1994). An alternative possibility is that the increased number of NK cells is maintained because normal apoptotic mechanisms are either inhibited, as suggested in the case of NK cell leukaemia (Mizuno et al , 1999), or defective, as suggested for T‐cell LGL leukaemias (Lamy & Loughran, 1999; Greer et al, 2001).…”

“…NK lymphocytosis patients and control subjects. Three patients (patients 1, 2 and 3) were part of an earlier study (Warren et al, 1994). In all patients, NK lymphocytosis was diagnosed as chronic and the condition stable for at least 1 year.…”

Role of NK Cells in Tuberculous Pleurisy as Innate Promoters of Local Type 1 Immunity with Potential Application on Differential Diagnosis

“…Simultaneously, we observed a subpopulation of pleural NK cells expressing Toll-like Receptor 2 (TLR2), a molecule undetectable in resting NK cells but upregulated in response to IL-12 and protozoan glycolipids (Becker et al, 2003;Lindgren et al, 2010;Schierloh et al, 2007). Furthermore, we and others recently identified a subpopulation of pleural NK that down-modulates the CD45RA and up-regulates CD45R0 isoform, resembling the well known phenomenon that takes places during memory differentiation of T lymphocytes (Warren et al, 1994;Fu et al, 2011). Immunophenotypic analysis of peripheral blood (PB) and pleural fluid (PF) NK cells (CD56 + /CD3 -).…”