Page 162 - Haematologica August 2018

A. Roberto et al.
we found the degree of CD107a degranulation against Considering that the cytolytic activity of NK cells is K562 cell line of uCD56dim cells purified from hHSCT licensed by the dominant regulation of iNKRs over
recipients after six weeks from transplant is significantly lower compared to that of their counterparts from healthy donors (Figure 7A,B).
aNKRs,10,11 we screened the expression of a large panel of inhibitory receptors, over time, that could likely explain the anergy of donor-derived uCD56dim NK cells from
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Figure 7. Cytotoxicity of NKp46neg-low/uCD56dim from hHSCT patients expressing transient high levels of NK2A early after hHSCT. A) Representative example from a healthy donor (HD) (lower line) of flow cytometry dot plots showing the expression of CD107a (i.e., cytotoxic natural killer [NK] cells) on cCD56bright (left), cCD56dim (mid- dle) and uCD56dim (right) (left column) either in the absence (upper line) or in the presence (lower line) of K562. (B) Summary statistical graph showing the percentage of CD107apos (median ± SEM) on cCD56bright (blue), cCD56dim (black) and uCD56dim (red) from five HDs and four patients after six weeks from haploidentical HSCT (hHSCT). The background of CD107apos NK cells present in the spontaneous degranulation has been subtracted for the analyses performed in the presence of K562 cell line. (C) Summary statistical graph showing the expression of NKG2A on cCD56bright (blue), cCD56dim (black) and uCD56dim (red) from HSC HDs and their recipients at different time points up to six months after hHSCT (medians ± SEM). (D) Summary statistical graph showing the percentage of CD107apos (median ± SEM) on cCD56bright and uCD56dim NK cells from eight HDs and five patients after six weeks from hHSCT alone (-) or incubated (+) with 721.221G cell line, and either in the absence (-) or in the presence (+) of the masking anti-CD94/NKG2A mAb (Y9). *P<0.05; **P<0.01. ns: not significant.
haematologica | 2018; 103(8)