An immunohistochemical study of human platelets using a rabbit antibody against H18‐K24 of apolipoprotein CIII (HATKTAK)

Abstract

H18-K24 of human apolipopotein CIII (Apo CIII) (HATKTAK) is an activator of the macromolecular activators of phagocytosis from platelets (MAPPs). Using a rabbit antibody against HATKTAK, we performed an immunohistochemical study of human platelets. Indirect ELISA showed that this antibody reacts with Apo CIII-derived peptides with a C-terminal of HATKTAK, but not with Apo CIII. Immunoelectron microscopy revealed that reaction of anti-HATKTAK antibody occurred in the pseudopods of activated platelets. In blood coagula produced from the peripheral blood and formalin-fixed after various incubation periods, reaction of this antibody with platelets appeared rapidly with a peak at 3 to 6 h of incubation, and then diminished gradually. Leukocytes in the blood coagula were stained strongly positive. In tissue sections, fresh thrombi and hemorrhages with slight fibrin formation revealed a positive response of platelets to anti-HATKTAK antibody, whereas older ones with leukocytic infiltration, fibrin formation and organization did not. In addition to platelets, endothelial cells and leukocytes were stained positive by anti-HATKTAK antibody. All of the positive reactions by anti-HATKTAK antibody disappeared or diminished by co-incubation with HATKTAK. In conclusion, the anti-HATKTAK antibody reveals platelets during the early phase of activation.

The apolipoprotein CIII-derived peptide, HATKTAK, and stimulation of macromolecular activators of phagocytosis from platelets (MAPPs)

“…In immunohistochemistry using anti-HATKTAK IgG, a positive reaction was observed in platelets with blood coagulation and in thrombi that are relatively young (Yamanaka et al 2013). …”

“…As shown in an experiment on blood coagula, the positive reaction of platelets became weaker when thrombi aged (Yamanaka et al 2013). …”