Plant Derived Recombinant HSA OsrHSA Displays The Same Immunogenicity As pHSA

Plant derived recombinant human serum albumin HSA displays the same immunogenicity as pHSA

Description

Human serum albumin is the most abundant protein in human plasma. It can transport hormones, lipds and other molecules and maintain osmotic pressure.

Healthgen Biotech uses State-of-the-art platform called Oryz^HiExp, having high capacity to express proteins and peptides in the rice grain. The platform uses rice endosperm cells as a bioreactor to specifically and highly express various recombinant proteins and small peptides. The platform is a rice-specific endosperm cell-specific expression platform that focuses on the expression of animal-free products, safe recombinant proteins and peptides. We use this technique to express recombinant human serum albumin to achieve higher safety and biosafety.

Recombinant human serum albumin (OsrHSA) has good efficacy, such as OsrHSA has the same second and tertiary structure, physiological and biochemical properties with HSA from plasma. In addition, compared with HSA from plasma, OsrHSA has a lower immune source stimulation.

Physiological and Biochemical Properties of rHSA and pHSA

Analysis of the antibody titer in rabbit serum following immunization with OsrHSA revealed that specific IgGs against HSA increased quickly 21d after the first immunization. The antibody titers demonstrated a significant increase in IgG against HSA in the first 3 wk after immunization with either rHSA (P, rHSA vs. saline) or pHSA (P’, pHSA vs. saline) compared with a saline control, whereas no significant difference was found between antibody titers for rabbits immunized with OsrHSA or pHSA. The total antiserum titer in pHSAor rHSA-treated groups also displayed a similar antibody level as that in the saline group. Furthermore, the titers of individual immunoglobulins IgG, IgM, IgE and IgA showed no significant difference among the pHSA, rHSA, and saline groups (Fig. 6 D and E), and the titers of C4 complement were not significantly different among the rHSA, pHSA, and saline groups. However, the titers of C3 complement in the pHSA-immunized group were significantly higher than those in the rHSA group, which results from the presence of human blood impurities in the pHSA sample. To further assess the immunogenicity of rHSA, passive cutaneous anaphylaxis (PCA) was performed on guinea pigs. Anti-rHSA serum neutralized by pHSA or rHSA gave a negative response compared with the saline control, again indicating that rHSA displays the same immunogenicity as pHSA in vivo.

The titers of individual immunoglobulins IgG, IgM, IgE, and IgA showed no significant difference among the pHSA, rHSA, and saline groups, and the titers of C4 complement were not significantly different.