CD4+ lymphocytes require platelets for adhesion to immobilized fibronectin in flow: role of beta(1) (CD29)-, beta(2) (CD18)-related integrins and non-integrin receptors.
The role of platelets in T-lymphocytes adhesion is not clear yet. Herpesvirus saimiri (HVS)-infected CD4(+) T-lymphocytes were placed into polystyrene plates pre-coated with fibronectin. The adherent T-cells were enumerated by image analysis. Under static condition, 38+/-10cells/mm(2) adhered and addition of gel-filtered platelets (GFP) and PMA enhanced cell adhesion 4.3- and 4.1-fold. Using PMA plus GFP 11.9-fold enhancement in cell adhesion was achieved. In contrast, under flow (200s(-1)), neither basal adhesion nor following separate addition of PMA or GFP was observed, whereas combined addition of PMA and GFP induced noticeable adhesion (34cells/mm(2)). The adhesion was inhibited by blockade of alpha(5)-integrin (CD49e, 87%), beta(2)-integrin (CD18, 78%), CD40L (60%), PSGL-1 (CD162, 60%), and CD40L plus PSGL-1 (83%). Thus, activated platelets promote activated T-cell adhesion to fibronectin under flow via integrins (alpha(5)beta(1), and alpha(L)beta(2)), CD40-CD40L and P-selectin-PSGL-1 mediated interactions.
Shenkman
Boris
B
Institute of Thrombosis and Haemostasis, Sheba Medical Center, Tel-Hashomer, Israel. borshenk@sheba.health.gov.il
Brill
Grigory
G
Solpov
Alexey
A
Vitkovsky
Yuri
Y
Kuznik
Boris
B
Koltakov
Alexander
A
Kotev-Emeth
Shlomo
S
Savion
Naphtali
N
Bank
Ilan
I
D001792:Blood Platelets / Q000378:metabolism*; D018821:CD18 Antigens / Q000378:metabolism; D015496:CD4-Positive T-Lymphocytes / Q000378:metabolism* / Q000821:virology; D002448:Cell Adhesion / Q000502:physiology*; D002450:Cell Communication / Q000502:physiology*; D005109:Extracellular Matrix / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism*; D006567:Herpesvirus 2, Saimiriine; D006801:Humans; D018189:Immunomagnetic Separation; D019012:Integrin beta1 / Q000378:metabolism; D008213:Lymphocyte Activation / Q000502:physiology
D018821:CD18 Antigens; D005353:Fibronectins; D019012:Integrin beta1