Adhesion of MNC to extracellular matrix proteins following in vitro photochemotherapy.
BACKGROUND
Photochemotherapy is a safe and effective treatment for patients with drug-resistant severe GvHD. The technique involves the exposure of MNC to psoralen and UVA light (PUVA). We have investigated the effect of in vitro PUVA on MNC adhesion to extracellular matrix (ECM) proteins.


METHODS
MNC were isolated from peripheral blood (PB) and umbilical cord blood (UCB), and treated with PUVA. After labeling by a chemiluminescent probe, MNC were plated on ECM proteins (collagen, fibronectin, vitronectin and laminin) and the number of adherent cells was measured.


RESULTS
Untreated MNC from both PB and UCB showed a similar adhesion to the substrates. As a consequence of exposure to PUVA, most of PB samples showed significantly enhanced adhesion to the ECM proteins; on the other hand, UCB-recovered MNC did not significantly modify their adhesion.


CONCLUSIONS
MNC adhesion to ECM components is mediated by integrins, a family of cell membrane receptors; the ligand-binding affinity of certain integrins may be modulated by different stimuli. PUVA treatment of PB-recovered MNC may induce the up-regulation of the ligand-binding affinity of the integrins involved in the adhesion to ECM proteins. The finding of unmodified UCB cell adhesion after PUVA, may be related to the functional immaturity of lymphocytes at birth.
Perutelli
P
P
Hematology Laboratory, Hematology and Oncology Department, G. Gaslini Children's Hospital, Genova, Italy.
Murugesan
S
S
Dini
G
G
D002448:Cell Adhesion / Q000187:drug effects / Q000528:radiation effects; D016326:Extracellular Matrix Proteins / Q000378:metabolism*; D005260:Female; D005312:Fetal Blood / Q000166:cytology; D005363:Ficusin / Q000494:pharmacology*; D006086:Graft vs Host Disease / Q000188:drug therapy / Q000276:immunology / Q000532:radiotherapy; D006801:Humans; D007963:Leukocytes, Mononuclear / Q000166:cytology* / Q000187:drug effects* / Q000276:immunology / Q000528:radiation effects; D010778:Photochemotherapy / Q000379:methods*; D011247:Pregnancy; D014466:Ultraviolet Rays
D016326:Extracellular Matrix Proteins; D005363:Ficusin