Modelling approaches to predict and evaluate schistosomiasis immunization utilizing SEA loaded on chitosan nanoparticles via liver tissue differentiation and angiogenesis

Abstract

Schistosomiasis is caused by blood flukes including all Schistosoma species. It affects about 207 million persons in 76 countries across the world, and is more prevalent in developing countries where about 800 million people are at the risk of schistosomiasis [1]. Following oviposition, schistosomes eggs that failed to exit with either urine or stools are carried back into the liver to be lodged in the pre-sinusoidal capillaries. The eggs are in intimate contact with the capillary endothelium before and during the generation of the granulomatous response [2]. Schistosoma miracidium inside the ovum secretes glycoprotein antigens that pass through microscopic pores within the egg shell, so are called SEA. These antigens elicit a vigorous immune response that encapsulates the ova in pre-granuloma collagen fibers and immune cells, predominantly eosinophils and macrophages. The granuloma formation presents a barrier to sequester egg toxicity and antigenicity. Fibrosis of granulation tissues leads to disturbance of hepatic parenchymal architecture including its vasculature [3]. Despite portal vascular impairment, it was found that the total hepatic blood flow remained within normal limits with normal parenchymal cell perfusion, accompanied by absent gross changes in hepatic function tests. This was attributed to hepatic neovascular formation in the

Evaluation of schistosomula lung antigen preparation and soluble egg antigen vaccines on experimental schistosomiasis mansoni

“…The combination of SLAP and SEA resulted in a significant reduction in egg count per gram of liver and intestine tissues (59% and 60.59%, respectively). Our results were in accordance with those of Etewa et al [9], who observed a significant reduction of S. mansoni eggs in the liver. Lower values were obtained by El-Ahwany et al [29], with 42.8% and 8.4% reduction of eggs in the liver and tissue, respectively.…”

“…This indicates a good protective immune response to the combined vaccine in our study. In Etewa et al’s study [ 9 ], the liver sections of the SEA-vaccinated group had fewer numbers and smaller sizes of granuloma; degenerated ova surrounded by empty spaces were enclosed in fibrocellular granulomas in addition to mild lobular inflammation.…”

“…This could be due to the augmentation of immune response or a result of primary infection. According to Etewa et al [ 9 ], SEA is preferable than SWAP. The ovum’s Schistosoma miracidium (SEA) secretes glycoprotein antigens, which pass through tiny openings in the eggshell.…”

“…The efficacy of a vaccine depends on the choice of parasite stage and use of an effective adjuvant [ 8 ]. Soluble egg antigen (SEA) acts as a potential anti-schistosome immunization candidate [ 9 ]. Schistosoma miracidium inside the ovum secretes glycoprotein antigens that pass through microscopic pores within the eggshell, hence the term SEA.…”