• Newman Shah a publié une note il y a 6 jours et 1 heure

    There were higher levels of total protein, IgA, albumin, antitrypsin, IgG and haptoglobin, and lower levels of ceruloplasmin and transferrin in the NIF group, in comparison with the C group (Fig. 1). There was no significant difference (p<0.05) in the serum concentration of dna ligase glycoprotein between the NIF and C groups.In the 120kDa band, the most abundant protein was inter α trypsin inhibitor heavy chain H4, followed by α2-macroglobulin, complement C6 and ceruloplasmin. There were significant reductions (p<0.05) in the serum levels of these proteins in the NIF group, in comparison with the C group.The 95 and 88kDa bands were analyzed together with complement C3, which was the most abundant protein. It was identified as C3 β chain due to its molecular weight. Similarly, in the 37kDa band, complement C3 was the most abundant protein, identified as complement C3 α chain. Thus, there was a significant increase (p<0.05) in complement C3 in the NIF group.In the 23kDa band, the predominant protein was apolipoprotein A1, which appeared reduced in the NIF group, compared with the C group. Finally, in the 20.5kDa band, the predominant protein was protein HP-20, with higher levels in the NIF group than in the C group.DiscussionPositivity according to ELISA and IFAT indicates that the animals have had previous exposure to T. vivax, considering that these are sensitive and specific serological methods for detecting this hemoprotozoon (Cadioli et al., 2012).Cattle naturally infected with T. vivax may present total protein values that are higher, lower or within normal parameters (Schenk et al., 2001; Cadioli et al., 2012). In the present study, the mean serum concentration of total protein was higher within the NIF group, which can be attributed to the greater production of immunoglobulins against trypanosomes. IgA and IgG were elevated (p<0.05), which may have been the result of the constant antigenic stimulation that T. vivax causes, due to continuous changes in the expression of surface-variant glycoproteins (Lalor et al., 1984)Ceruloplasmin, a copper carrier protein that acts toward oxidation of ferrous ions and has antioxidant and anti-inflammatory activity (Murata et al., 2004), was significantly reduced in the NIF group, consistent with previous observations among sheep experimentally infected with T. vivax (Almeida et al., 2012). Cattle infected with Anaplasma marginale showed higher levels of ceruloplasmin during the acute phase (Nazifi et al., 2012), thus allowing differentiation between these two diseases. This reduction, associated with the release of ferrous iron through hemolysis, may promote greater entry of iron ions to cells (Attieh et al., 1999; Ke et al., 2006). T. vivax could be using this condition to acquire more iron from the host, which is essential for its growth (Schell et al., 1991). However, the exact role of this protein still unclear, such that it may act either on iron influx to or efflux from the cell (Attieh et al., 1999; Ke et al., 2006).The mean serum concentration of transferrin, a protein that sequesters iron ions to prevent their use by pathogens (Murata et al., 2004), was significantly lower in the NIF group. However, sheep experimentally infected with T. vivax in the chronic phase (Almeida et al., 2012) and rats infected by T. evansi (Da Silva et al., 2013) showed higher levels of this protein, thus behaving typically as a positive APP (Murata et al., 2004). Despite this classification, in the present study, transferrin levels were lower. The presence of this APP is essential for the growth of T. brucei among cattle, which use the iron present in this APP for their growth. Therefore, we can suggest that reduction of transferrin occurred as a mechanism for evading the parasite (Schell et al., 1991) or even that the hemolysis triggered by the parasite might inhibit release of transferrin by hepatocytes (Lescoat et al., 1989).

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