Targeting glycoproteins or glycolipids and their metabolic pathways for antiparasite therapy.

Carbohydrate-based therapy, known as glycotherapeutics, is a new and emerging field that promises to be the future hope for combating kinetoplastid infections more efficiently and effectively. Targeting novel glycoproteins/lipids, which are important disease determinants of kinetoplastid diseases, have helped in the development of this field. Better and refined understanding of all the available data would possibly help us in providing a future direction for rational drug design and better disease management. This review intends to focus on such lines, which will give us an insight into the future hope for development of novel therapeutic strategies through glycobiological platform for combating kinetoplastid infections.

Role of C-reactive protein in complement-mediated hemolysis in Malaria.

Human C-reactive protein (CRP) is a clinically important classical acute phase protein. Although CRP has been reported to bind with many nucleated cells, the direct binding of CRP to erythrocytes in diseases remains largely unexplored. The main focus of the present study was to investigate the binding of disease-specific CRP to erythrocytes of same patients. Distinct molecular variant of disease-specific CRP was affinity purified from sera of malaria patients (CRP(Mal)). This CRP showed strong binding with malaria erythrocytes (RBC(Mal)) as confirmed by flow cytometric analysis (FACS), enzyme-linked immunosorbent assays (ELISA), and radio binding assays. Calcium and phosphoryl choline (PC) were found to be essential for this interaction. A 2.3-fold increased binding of induced CRP to RBC(Mal) as compared to normal erythrocytes (RBC(N)) confirmed disease-specificity. Preincubation of RBC(Mal) with unconjugated CRP showed 3-5 fold inhibition. The association constant of CRP and RBC(Mal) was 4.7 x 10(6) cpm/microg with the corresponding number of receptors/cell being 4.3 x 10(5). The effector function of CRP(Mal) has been demonstrated by its potency to activate the complement pathway. An optimal dose of 10 microg/ml of CRP induced three-fold higher hemolysis of patient erythrocytes as compared to RBC(N). These studies provide direct evidence for an important phagocytic functional interaction of this acute-phase protein by triggering the CRP-complement pathway after the binding of CRP(Mal) with RBC(Mal). Hemolysis as triggered by this pathway may be one of the causative factors of anemia, a common clinical manifestation of this disease.