CgAATase with specific expression pattern can be used as a potential surface marker for oyster granulocytes

Granulocytes are known as the main immunocompetent hemocytes that play important roles in the immune defense of oyster Crassostrea gigas. In the present study, an alcohol acyltransferase (designed as CgAATase) with specific expression pattern was identified from oyster C. gigas, and it could be employed as a potential marker for the isolation of oyster granulocytes. The open reading frame (ORF) of CgAATase was of 1431 bp, encoding a peptide of 476 amino acids with a typically conserved AATase domain. The mRNA transcripts of CgAATase were highest expressed in hemocytes, lower expressed in hepatopancreas, mantle, gonad, gill, ganglion, adductor muscle, and labial palp. The mRNA expression level of CgAATase in hemocytes was significantly up-regulated at 3-12 h and reached the highest level (27.40-fold compared to control group, p < 0.05) at 6 h after Vibrio splendidus stimulation. The total hemocytes were sorted as granulocytes, semi-granulocytes and agranulocytes by Percoll^® density gradient centrifugation. CgAATase transcripts were dominantly observed in granulocytes, which was 8.26-fold (p < 0.05) and 2.80-fold (p < 0.05) of that in agranulocytes and semi-granulocytes, respectively. The monoclonal antibody against CgAATase was produced and employed for the isolation of granulocytes with the immunomagnetic bead. CgAATase protein was mainly detected on the cytomembrane of granulocytes. About 85.7 ± 4.60% of the granulocytes were positive for CgAATase and they could be successfully separated by flow cytometry with immunomagnetic bead coated with anti-CgAATase monoclonal antibody, and 97.7 ± 1.01% of the rest hemocytes (agranulocytes and semi-granulocytes) were negative for CgAATase. The isolated primary granulocytes could maintain cell activity for more than one week in vitro culture that exhibited numerous filopodia. These results collectively suggested that CgAATase was a potential marker of oyster granulocytes, and the granulocytes could be effectively isolated from total circulating hemocytes by immunomagnetic bead coated with the anti-CgAATase monoclonal antibody.

Separation of haemocyte subpopulations in shrimp Fenneropenaeus chinensis by immunomagnetic bead using monoclonal antibody against granulocytes

In our previous work, two monoclonal antibodies (Mabs) against granulocytes of shrimp (Fenneropenaeus chinensis) had been produced, in this paper, haemocyte subpopulations were analyzed by flow cytometry (FCM) using the Mabs. Then immunomagnetic bead (IMB) method was applied for separation hyalinocytes and granulocytes using the Mabs. The separated hyalinocytes and granulocytes were analyzed by FCM, indirect immunofluorescence assay, Giemsa staining and transmission electron microscopy, respectively. The results showed the proportion of hyalinocytes in haemolymph of F. chinensis was 15.14 ± 1.22%, and that of granulocytes was 75.43 ± 2.31%. After two times separation by IMB, the purity rate of hyalinocytes and granulocytes was 96.27 ± 1.06% and 98.13 ± 0.86%, respectively. The hyalinocytes possessed 0.60-0.85 in nucleus/cytoplasm (N/C) ratio and had few granule in cytoplasm, whereas the separated granulocytes with N/C ratio of 0.12-0.36 and high electronic density of double membrane granules. The results reported the separation of haemocyte subpopulations using Mabs in shrimp for the first time, and the hyalinocytes and granulocytes isolated by IMB could be used for their differential protein analysis.

Effect of radiofrequency ablation on the circulating hepatic carcinoma cells in peripheral blood of patients with recurrent hepatocellular carcinoma

AIM: To observe the change of hepatoma carcinoma cells (HCC) in the peripheral blood of recurrent hepatocellular carcinoma patients undergoing radiofrequency ablation.

METHODS: Peripheral blood samples were collected from 23 patients with recurrent hepatocellular carcinoma before and 1 and 3 d after radiofrequency ablation and 5 healthy volunteers. Circulating hepatic carcinoma cells were separated by immunomagnetic beads (IMB) technique and identified by conventional pathology and immuocytochemistry.

RESULTS: Before radiofrequency ablation, 15 (65.22%) out of the 23 patients with recurrent hepatocellular carcinoma were positive for hepatic carcinoma cells in peripheral blood. One and 3 d after radiofrequency ablation, 13 (56.52%) and 6 (26.09%) out of the 23 patients with recurrent hepatocellular carcinoma were positive hepatic carcinoma cells in peripheral blood respectively. There was no significant difference in the positive rates before and 1 d after radiofrequency ablation. The positive rates were significantly different before and 3 days after radiofrequency ablation (P < 0.05). There was also a significant difference in the positive rates 1 and 3 d after radiofrequency ablation (P < 0.05).

CONCLUSION: Radiofrequency ablation may effectively prevent hematogenous dissemination of hepatocellular carcinoma cells in peripheral blood.