Immunotoxicity assessment of rice-derived recombinant human serum albumin using human peripheral blood mononuclear cells

Abstract

Human serum albumin (HSA) is extensively used in clinics to treat a variety of diseases, such as hypoproteinemia, hemorrhagic shock, serious burn injuries, cirrhotic ascites and fetal erythroblastosis. To address supply shortages and high safety risks from limited human donors, we recently developed recombinant technology to produce HSA from rice endosperm. To assess the risk potential of HSA derived from Oryza sativa (OsrHSA) before a First-in-human (FIH) trial, we compared OsrHSA and plasma-derived HSA (pHSA), evaluating the potential for an immune reaction and toxicity using human peripheral blood mononuclear cells (PBMCs). The results indicated that neither OsrHSA nor pHSA stimulated T cell proliferation at 1x and 5x dosages. We also found no significant differences in the profiles of the CD4(+) and CD8(+) T cell subsets between OsrHSA- and pHSA-treated cells. Furthermore, the results showed that there were no significant differences between OsrHSA and pHSA in the production of cytokines such as interferon-gamma (IFN-γ), tumor necrosis factor-alpha (TNF-α), interleukin (IL)-10 and IL-4. Our results demonstrated that OsrHSA has equivalent immunotoxicity to pHSA when using the PBMC model. Moreover, this ex vivo system could provide an alternative approach to predict potential risks in novel biopharmaceutical development.

Figure 1. Measurement of T cell proliferation using CFSE.

The PBMCs were labeled with CFSE and then treated with PHA, PBS, pHSA and OsrHSA for 24, 48 and 72

Figure 2. A proliferation assay was performed using a CCK-8 kit.

Panel a presents the data with a 1x dosage, and panel b indicates the data with a 5x dosage. Each error bar with the same letter has the same significant level of p value.

Figure 3. The profiles of four cytokines in PBMCs following different treatments.

The levels of cytokines were assayed using a CBA kit. Panels a, b, c and d present the data for the cytokines IFN-γ, TNF-α, IL-10 and IL-4, respectively. Each error bar with the same letter has the same significant level of p value.