Author/Editor | Pavlović, Miloš D; Čolić, MMiodrag; Pejnović, Nada; Tamatani, Takuya; Miyasaka, Masayuki; Dujić, Aleksandar | |
Title | A novel anti-rat CD18 monoclonal antibody triggers lymphocyte homotypic aggregation and granulocyte adhesion to plastic: different intracellular signaling pathways in resting versus activated thymocytes | |
Type | članek | |
Source | Eur J Immunol | |
Vol. and No. | Letnik 24, št. 7 | |
Publication year | 1994 | |
Volume | str. 1640-8 | |
Language | eng | |
Abstract | We have raised a monoclonal antibody (mAb), NG2B12, directed against rat CD18, capable of inducing lymphocyte homotypic adhesion and granulocyte adherence to plastic. NG2B12-induced aggregation is temperature sensitive and requires metabolic energy, an intact cytoskeleton and the presence of Mg2+, but is independent of protein synthesis. Ca2+ is not only dispensable but exerts a suppressive effect on the NG2B12-induced adhesion. The adhesion is readily observed in thymocytes and concanavalin A blasts of thymocytes and splenocytes but is very weak in resting spleen and lymph node cells. NG2B12 also enhances phorbol 12-myristate 13-acetate (PMA)-induced aggregation in an additive fashion. The NG2B12-induced homotypic adhesion is mediated by LFA-1. mAb against ICAM-1 completely inhibited the induced adhesion of activated cells but inhibited only partially and in a time-dependent manner the adhesion of resting thymocytes. The activation of protein phosphatases 1 and 2A (as assessed by the use of okadaic acid) is necessary for the NG2B12-induced adhesion of both resting and activated thymocytes. In contrast, H-7 (an inhibitor of protein kinase C and A), substantially suppressed the adhesion of resting thymocytes, whereas W-7 (an inhibitor of calmodulin-dependent protein kinase) inhibited the adhesion of activated thymocytes. NG2B12 induces both adherence to plastic and homotypic aggregation of granulocytes; the events being blocked by anti-CD18 (WT.3) and anti-CD11b/CD11c (OX-42) mAb, augmented by okadaic acid and not modified by H-7 and W-7. Additionally, we have demonstrated that NG2B12 and PMA employ distinct intracellular signaling pathways in inducing adhesion of both thymocytes and granulocytes. | |
Descriptors | ANIMALS ANTIBODIES, MONOCLONAL ANTIGENS, CD ANTIGENS, CD18 CELL ADHESION CELL ADHESION MOLECULES CELL AGGREGATION CELLS, CULTURED COLORIMETRY GRANULOCYTES INTERCELLULAR ADHESION MOLECULE-1 LEUKOCYTES LYMPHOCYTE FUNCTION-ASSOCIATED ANTIGEN-1 LYMPHOCYTES RATS SIGNAL TRANSDUCTION THYMUS GLAND |