The Malarial Metabolite Hemozoin and Its Potential Use as a Vaccine Adjuvant

Abstract

Hemozoin, a bio-crystalline substance, is a hemin detoxification by-product of malaria parasites. The role of hemozoin crystals in host immune system modulation by malaria parasites, and how they interact with the immune system has been enigmatic. Here, we summarize recent progress in our understanding of how hemozoin might be interacting with the host immune system. In particular, the potential application of hemozoin crystals as an adjuvant may provide insights into the molecular mechanisms involved in immune responses to malarial infection and provide a rationale for the design of vaccines against malaria as well as other immunological disorders such as allergies.

Selection of Adjuvants for Enhanced Vaccine Potency

“…It is expected that future comparative studies would be designed such that data could support selection of the right adjuvant. Novel adjuvants will be continually searched and evaluated, but their successes will be based on our further understanding of the interactions between human body and foreign microorganisms on a molecular level [460][461][462][463]. Ideally, such adjuvants would offer earlier, robust and durable immunity with less adverse events.…”

Current Advances in Cerebral Malaria Associated Encephalopathy

“…Protection was sustained for at least 15 months (Bejon, Cook et al 2011). Whole-parasite vaccine strategies (Coban, Igari et al 2010;Coban, Yagi et al 2010;Taylor-Robinson 2010) for malaria infection have attracted researchers' attention. They trigger parasite antigen-specific immune responses through TLR9 and NOD-like receptors (NLRs) (Coban, Igari et al 2010;Coban, Yagi et al 2010).…”

“…Whole-parasite vaccine strategies (Coban, Igari et al 2010;Coban, Yagi et al 2010;Taylor-Robinson 2010) for malaria infection have attracted researchers' attention. They trigger parasite antigen-specific immune responses through TLR9 and NOD-like receptors (NLRs) (Coban, Igari et al 2010;Coban, Yagi et al 2010). Heme-detoxification byproduct, hemozoin, is also being considered as a potential vaccine adjuvant against malaria (Coban, Igari et al 2010;Coban, Yagi et al 2010).…”

“…They trigger parasite antigen-specific immune responses through TLR9 and NOD-like receptors (NLRs) (Coban, Igari et al 2010;Coban, Yagi et al 2010). Heme-detoxification byproduct, hemozoin, is also being considered as a potential vaccine adjuvant against malaria (Coban, Igari et al 2010;Coban, Yagi et al 2010).…”

On the birefringence of healthy and malaria-infected red blood cells

“…11 Upon infection by a malarial parasite, the cell's hemoglobin content undergoes changes that affect birefringence: as the parasite grows (over 48 h), it crystallizes hemoglobin into hemozoin. 12,13 Hemozoin crystals are highly birefringent and they, thus, offer opportunities for studying malaria-infected RBCs through polarization microscopy. 13 Using polarized light microscopy, a method for localizing intracellular pigmented malaria parasites has been demonstrated in wet prepared blood samples at very low (0.01%) parasitemia.…”