Ixodes persulcatus tick salivary gland extract (SGE) inhibits IL-4 and IFN−/ secretion and CD69 expression by mitogen-stimulated murine splenocytes

V. Firstova, S. Biketov, E. Zyrina, A. Shtannikov, I. Vasiljeva
2010 International Journal of Infectious Diseases  
The tick Ixodes persulcatus are the main vector of Lyme disease and viral encephalitis in Europe and Asia. Immunosuppressive agents in tick saliva aid successful blood meal acquisition and appear critical to the transmission and establishment of pathogens, both viral and bacterial. Our present work was undertaken to investigate modulation of IL-4, IFN−/ production and CD69 expression of murine splenocytes byI. persulcatus SGE, derived from unfed and partially fed (3 days) I. persulcatus.
more » ... : Splenocytes were isolated from naive BALb/c mice. Cells (2 -5 x 106 /mL) were cultured in RPMI supplemented with 10% foetal bovine serum, 2 mM glutamine, 1 mM sodium pyruvate, 100 U/mL penicillin and streptomycin. Splenocytes were stimulated in triplicate by addition of ConA, LPS (Sigma) and LAC GP (Leukocyte activation Golgi Plug, BD) at a final concentration of 5 g/mL, 1 g/mL and 1 g/mL, respectively. Concentration of SGE in cell culture were 5, 25 or 50 mkg/ml. Splenocytes were harvested after 24-h stimulation and stained for surface markers CD3, CD4, CD19, CD69 and intracellular cytokines IL-4 and IFN−/. Cells were analysed by flow cytometry. Results: We found that SGE, derived from both unfed and partially fed I.persulcatus, reduced the early activation marker CD69 expression on ConA-or LPS-activated T-and B-cells in dose dependent manner. SGE reduced IL-4 and IFN-/ production by LAC GP stimulated CD4+splenocytes. SGE, derived from unfed I.persulcatus, markedly suppressed IL-4 and IFN-/ production by LPS-stimulated splenocytes by 35% and 55%, respectively, compared to the control condition without saliva. No significant modification of IL-4 and IFN-/ production was observed when SGE, derived from partially fed ticks, was added. Conclusion: Only SGE, derived from unfed I.persulcatus, inhibits IL-4 and IFN-/ production by CD4+ T cells in naive murine splenocytes. The inhibition of IL-4 and IFN-/ production by SGE appears to be due to a reduced level of activation in T and B cells: SGE treatment reduced the activationinduced CD69 expression on splenocytes. Transmission of pathogens into a site with lymphocyte unresponsiveness would have great advantages for the establishment and dissemination of the pathogen in the host. Background: Human toxocariasis is a helminthozoonosis due to the migration of Toxocara larvae in to human organs. Toxocariasis is one of the cause eosinophilia in peripheral blood, and provokes eosinophilic infiltration in internal organs. The aim of this study was to evaluate the prevalence of toxocariasis in hypereosinophilic individuals in Ahwaz city by Enzyme linked immunosorbent assay (ELISA) and Western blot techniques, using excretory-secretory Toxocaracanis antigen. Methods: Serum samples from 100 persons presenting with peripheral blood eosinophilia (>500 eosinophils/!l or more, equal or >10% of total white blood cells), and from 100 blank persons (without eosinophilia) were examined using ELISA technique (IBL Hambur). Sera with Toxocara antibodies underwent further conformative evaluations through Western immuno-blotting. Results then, were analyzed using statistical descriptive and Chi-Square test. Results: Seroprevalence antibodies against Toxocara in hypereosinophilic individuals, with ELISA test were obtained in 19% (19 persons) of wich, 12 persons (63.15%) were female and 7 persons (36.85%) were male. Positive sera were subsequently confirmed by Western blot. All of the observed bands ranged from 24 to 100 KDa. Antibodies against Toxocara among blank persons was 1% which did not confirmed by Western blot. There were significant differences between the frequency of infection with age and gender (P > 0.05). The highest prevalence of infection was seen in adult men and women. Also, in this study significant differences was observed between the hypereosinophilic and healthy individuals, in term of Toxocara infection frequency (P > 0.05). Conclusion: The present study confirms the significant prevalence of toxocariasis, as a hygiene problem, among hypereosinophilic individuals in this area, and it is necessary to examine the hypereosinophilic individuals for toxocariasis.
doi:10.1016/j.ijid.2010.02.2153 fatcat:trmb4bodqzdmvp74srir2a3qwi