ABSTRACT
We studied the production of anti parasite antibodies and the resistance against A. lumbricoides infection among the school population of three different Venezuelan ethnic groups: Warao Amerindians, Afro- Americans and white 'Creole' descendents. The prevalence and intensity of A. lumbricoides were determined before and after 1 year of anthelminthic treatment. Parasitic loads were associated to pre-treatment serum levels of anti A. lumbricoides IgE and IgG4 antibodies. The intensity of the infection and the proportion of re-infected children were significantly lower (p < 0.0001) among the Warao Amerindians, exhibiting higher levels of IgE (p < 0.0001) and lower levels of IgG4 (p < 0.0001) compared to their non-Amerindian counterparts. IgE levels correlated inversely with the proportion of re-infected children, whereas the levels of IgG4 were positively associated. These results suggest that ethnicity may influence the balance of IgE/IgG4 levels, modulating the intensity of A. lumbricoides and the resistance to the infection.
Subject(s)
Ascariasis/ethnology , Ascariasis/immunology , Ascaris lumbricoides/immunology , Immunoglobulin E/blood , Immunoglobulin G/blood , Rural Population/statistics & numerical data , Adolescent , Albendazole/therapeutic use , Animals , Anthelmintics/therapeutic use , Ascariasis/drug therapy , Biomarkers/blood , Child , Feces/parasitology , Humans , Schools , Treatment Outcome , Venezuela/ethnologyABSTRACT
Proteases are well-recognized as virulence factors in different pathologies, resulting in tissue damage potential. Despite efforts over the past few years to identify mycobacterial protein antigens, there is little information regarding the role of mycobacterial proteinase activities. In this study, by zymography techniques, we have detected and partially studied some biochemical properties of Mycobacterium bovis proteases, such as pH dependency of activity and susceptibility to classical proteinase inhibitors. We observed optimal proteolytic activity at pH 8. Some proteinases were inhibited by classic inhibitors of serine proteases, such as PMSF, AEBSF, and 3-4 DCI. In some AEBSF pre-treated preparations we observed residual gelatinase activity in Rf 0.32. This gelatinase was stimulated by Zn2+ and inhibited by OPA (1 mM). This last effect was reversed by exposure to equimolar quantitative OPA/Zn+2 (1 mM/1 mM). These results suggest the existence of serine proteinase and metalloproteinase types in protein extracts of Mycobacterium bovis.
Subject(s)
Gelatinases/biosynthesis , Gelatinases/physiology , Gelatinases/genetics , Gelatinases/immunology , Mycobacterium bovis/physiology , Mycobacterium bovis/geneticsABSTRACT
Proteases are well-recognized as virulence factors in different pathologies, resulting in tissue damage potential. Despite efforts over the past few years to identify mycobacterial protein antigens, there is little information regarding the role of mycobacterial proteinase activities. In this study, by zymography techniques, we have detected and partially studied some biochemical properties of Mycobacterium bovis proteases, such as pH dependency of activity and susceptibility to classical proteinase inhibitors. We observed optimal proteolytic activity at pH 8. Some proteinases were inhibited by classic inhibitors of serine proteases, such as PMSF, AEBSF, and 3-4 DCI. In some AEBSF pre-treated preparations we observed residual gelatinase activity in Rf 0.32. This gelatinase was stimulated by Zn2+ and inhibited by OPA (1 mM). This last effect was reversed by exposure to equimolar quantitative OPA/Zn+2 (1 mM/1 mM). These results suggest the existence of serine proteinase and metalloproteinase types in protein extracts of Mycobacterium bovis.