ABSTRACT
Objective To evaluate the efficacy and safety of tacrolimus extended-release (Tac-ER) in the early stage after kidney transplantation. Methods Clinical data of 68 recipients undergoing kidney transplantation from 34 pairs of renal allografts were retrospectively analyzed. Two recipients who received bilateral kidneys from the same donor were treated with Tac-ER (Tac-ER group) and tacrolimus immediate-release (Tac-IR) (Tac-IR group) as one of the basic immunosuppressant. The changes of tacrolimus dosage and blood concentration, intra-patient variability (IPV), renal function, incidence of acute rejection, recipient and allograft survival rates and adverse events were statistically compared between two groups. Results The average daily dose of tacrolimus in the Tac-ER group was significantly higher than that in the Tac-IR group (F=8.386, P=0.005). In the Tac-ER group, the mean trough concentration at postoperative 4 d was (6.14±4.04) ng/mL, did not reach the target concentration, significantly lower than (9.41±5.47) ng/mL in the Tac-IR group (F=7.854, P=0.007). In the Tac-ER group, the IPV of trough concentration of tacrolimus within postoperative 1 month was significantly higher than that in the Tac-IR group (0.44±0.15 vs. 0.36±0.12, P=0.032). At postoperative 6 months, there was no significant difference in the renal function between two groups [serum creatinine level was (126±26) μmol/L vs. (120±28) μmol/L, and the estimated glomerular filtration rate was (56±13) mL/(min·1.73 m2) vs. (60±15) mL/(min·1.73 m2), both P > 0.05]. The allograft and recipient survival rates were 100% in both groups. The incidence of acute rejection within postoperative 1 month was 18% in the Tac-ER group and 3% in the Tac-IR group, with no significant difference (P > 0.05). The overall incidence of adverse events was 94% in the Tac-ER group and 97% in the Tac-IR group, with no significant difference (P > 0.05). Conclusions The efficacy and safety of Tac-ER are equivalent to those of Tac-IR, whereas a higher dose of Tac-ER should be orally given to reach the blood concentration similar to that of Tac-IR. During early-stage drug treatment, Tac-ER should be orally given before kidney transplantation or inittally with loading dose, aiming to increase the systemic exposure to tacrolimus early after kidney transplantation and prevent acute rejection caused by insufficient exposure.
ABSTRACT
Objective:To prepare pH-sensitive liposomes to avoid the degradation of monophosphoryl lipid A (MPLA) by lysosomes.Methods:Using DOPE and CHEMS as carrier materials, pH-sensitive liposomes were prepared by thin-film dispersion method. Particle sizes and Zeta potential of the liposomes were detected by dynamic light scattering. The morphological features of pH-sensitive liposomes under different pH conditions were observed by transmission electron microscopy. Flow cytometry was performed to detect the phagocytosis of liposomes by THP-1 and DC2.4 cells. Confocal laser microscopy was used to observed the colocalization of liposomes and lysosomes. BALB/c mice were immunized with hepatitis B surface antigen (HBsAg) using MPLA pH-sensitive liposome as an adjuvant. The levels of serum anti-HBs were quantitatively detected by ELISA. IFN-γ and IL-2 spot forming cells (SFCs) in mouse splenic lymphocytes were detected by ELISPOT.Results:The pH-sensitive liposomes were constructed with an average particle size of (90.90±1.13) nm, polydispersity index (PDI) of 0.076±0.013 and Zeta potential of (-27.900±0.666) mV. As the pH value of the solution decreased, the particle size increased significantly and the liposomes presented irregular shapes, indicating the pH-sensitive features. The phagocytosis rates by THP-1 cells and DC2.4 cells were 10.40% and 12.40% for pH-sensitive fluorescent liposomes, and 1.09% and 0.28% for fluorescent liposomes. Confocal laser microscopy revealed that pH-sensitive fluorescent liposomes were phagocytosed by THP-1 cells and existed in the cytoplasm, while fluorescent liposomes existed in lysosomes. Compared with MPLA liposomes, MPLA pH-sensitive liposomes could significantly improve the cellular immune response in mice. The levels of IFN-γ and IL-2 SFCs in the MPLA pH-sensitive liposome group were significantly higher than those in the MPLA liposome group ( P<0.01) and the non-adjuvant group ( P<0.001). Conclusions:The pH-sensitive liposome delivery system could improve the utilization of MPLA as an adjuvant.
ABSTRACT
Objective:To express the recombinant varicella-zoster virus (VZV) gE Δ-Fc fusion protein using CHO cell expression system, and provide reference for screening candidate antigens of recombinant herpes zoster vaccines. Methods:A eukaryotic expression plasmid containing the gE Δ-Fc gene was transfected into CHO cells. Monoclonal cells were selected by methionine sulfoximine (MSX) pressure screening and limited dilution method to obtain the CHO cells secreting and expressing the gE Δ-Fc fusion protein. The expressed gE Δ-Fc fusion protein was purified by MabSelect SuRe affinity chromatography. The binding activity of gE Δ-Fc fusion protein to Fc receptors was identified by ELISA. Flow cytometry was used to detect the phagocytosis of antigens by DC2.4 cells. Antibody titers in serum samples of BALB/c mice immunized with the gE Δ-Fc fusion protein were detect by ELISA. Results:A CHO cell line stably expressing the gE Δ-Fc fusion protein was obtained. Flow cytometry suggested that the phagocytotic activity of DC2.4 cells against the gE Δ-Fc fusion protein was stronger than that against gE. Moreover, the gE Δ-Fc fusion protein could induce BALB/c mice to produce high titers of specific anti-VZV antibodies. Conclusions:The recombinant VZV gE Δ-Fc fusion protein expressed in CHO cells had a good immunogenicity. This study provided reference for screening candidate antigens of recombinant herpes zoster vaccines.