Pengaruh Pemberian Dosis Bertingkat Protein Rekombinan DBL2β-PfEMP1 terhadap Gambaran Histopatologi Hepar Tikus Wistar (Rattus norvegicus)

Abstract

Malaria is a serious global health problem, and Plasmodium falciparum is the most prevalent and causing severe cases. Vaccination is a key preventive strategy. The Duffy binding-like 2β (DBL2β) domain is a protein of Plasmodium falciparum Erythrocyte Membrane Protein-1 (PfEMP1) that can potentially become a malaria vaccine candidate. The recombinant DBL2β-PfEMP1 protein has been shown to elicit humoral and cellular immune responses. Therefore, further study on the safety of the protein to various organs, including the liver, needs to be conducted. The liver is a detoxification organ. Exposure to any substances potentially affects the liver structure. This study aimed to determine the effect of recombinant DBL2β-PfEMP1 protein injection at gradual doses on the liver histopathology of Wistar rats. The protein is produced, purified, and finally measured for its concentration using Bradford protein assay. The protein was injected subcutaneously at the dose of 100, 150, and 200 μg/kgBW to each treatment group and NaCl 0.9% to the control group. The injections were done on days 0, 21, and 42 and terminated on day 56 for organ harvesting. The parameters of liver histopathology were changes in hepatocyte shape and widening of the hepatic sinusoids were examined using a light microscope and an Optilab camera with the Fiji ImageJ software. Each slide was observed in 5 fields of view from zone III. The hepatocyte was observed using 400× magnification and scored based on the Manja Roenigk classification, and the sinusoid dilatation was assessed using 100× magnification and scored based on the hepatic sinusoid lesion classification. Statistical analysis using the One-Way ANOVA test for hepatocytes showed p=0.461, indicating no significant difference between the control and treatment groups, and the Post-Hoc Tukey test results in p>0.05, indicating no significant difference between the individual groups on hepatocyte features. Analysis of hepatic sinusoids using the Kruskal-Wallis test showed p=0.260, indicating no significant difference between the control and treatment groups, and the Post-Hoc Mann- Whitney test results in p>0.05, indicating no significant difference between the individual groups on hepatic sinusoid features. The study concluded that the injection of recombinant DBL2β-PfEMP1 protein at gradual dose did not affecting the liver structure and indicating its safety as malaria vaccine candidate.