Expression of p75 chain of IL-2 receptor in the early immunological reconstitution after allogeneic bone marrow transplantation

Abstract

SUMMARYExpressioti of p55 and p75 chains of IL-2 receptor (IL-2R) on the surface of both T and natural killer (NK) circulating lymphocytes was investigated in 14 paediatric patients given allogeneic bone marrow transplantation (BMT) from HLA-idcntical sibling or partially matched family donors. IL-2-induced proliferative and cytotoxic responses were also studied and all analysis was performed within 45 days from transplant. We found that, early after transplant, the percentage of p55"*" and of p75' peripheral blood lymphocytes (PBL) was not significantly difFerent in patients who had received HLA-identical BMT (p55^ 8-04 ± 4'87%; p75+ 28 27 ± 18-85%) compared with healthy controls (p55' 7'26±617%; p75' 1942± 1049%), while recipients ofT cell-depleted marrow included a remarkably high percentage (76 90%) of p75" PBL, which were mostly CD3" and co-expressed CD56 molecule. Comparable values of p55* lymphocytes were observed in all patients and controls. However, in contrast to ihe other two groups, in recipients ofT cell-depleted BMT the majority of these cells co-expressed p75 chain and CD56 antigen. rL-2-induced proliferation and lymphokine-activated killer (LAK) activity were detectable in all patients, and their values did not correlate with expression of p55 or p75 chains. Our data suggest that expansion of NK subsets expressing IL-2R chains after T cell-depleted BMT may be related to early reconstitution of natural immunity in the presence of ailogeneic stimuli.

Microenvironment in neuroblastoma: isolation and characterization of tumor-derived mesenchymal stromal cells

“…After 4 h incubation, 25 μl of the supernatant was collected from each well and counted for 1 min in a gamma-counter (Topcount, Packard, Downers Grove, Illinois). Results were expressed as the percentage of T lysis calculated with the formula: [(experimental release – spontaneous T release)/(total T release – spontaneous T release)] × 100 [ 20 ].…”

Analysis of immune reconstitution in children undergoing cord blood transplantation

“…Cell populations were identified on the basis of forward and side scatter analysis; CD45 mAb was used to exclude residual red blood cells. Phenotypic analysis of previously cryopreserved PBMC populations was performed by direct immunofluorescence in two-color analysis using directly labeled antibodies on a FACScan flow cytometer [32]. Data were calculated using CellQuest software (Becton Dickinson).…”

“…LAK activation, NK activity, and cytotoxicity assays PBMC were cultured in 24-well plates at a concentration of 2 ϫ 10 6 /mL in 2 mL of RPMI 1640 supplemented with 2 mM L-glutamine, 50 g/mL gentamicin, 10% pooled human sera, and 200 U/mL rIL-2 (Chiron Co., Amsterdam, Holland). After a 5-day incubation at 37 Њ C in a humidified 5% CO 2 atmosphere, cells were recovered, and LAK activity was measured against Daudi target cells as previously described [32].…”

“…NK activity of PBMC was assessed, using K562 as target cells, according to a method previously described [32]. Results are expressed as percent of specific lysis.…”