ABSTRACT
The beta-glucans derived from yeast cell walls have been reported for having many immunomodulatory activities in vivo and in vitro. In this study, Aureobasidium-derived soluble branched (1,3-1,6) beta-glucan (Sophy beta-glucan) was checked for natural killer (NK) activity and for the production of IFN-gamma and IL-4 in Leishmania amazonensis infection. The main experiment was performed with a group of female C57BL/6 and BALB/c mice, orally supplemented with 5% of Sophy beta-glucan and infected with promastogotes of L. amazonensis (1 x 10(7)) into the footpad. Increase in the footpad thickness with time was observed in BALB/c mice in spite of the oral Sophy beta-glucan supplement, but it was less in C57BL/6 mice. The difference in overall mean footpad thickness between 'infection only' versus 'infection + glucan' groups was statistically significant (P < 0.001). High NK activity in C57BL/6 than BALB/c mice was observed in 'glucan only' group compared to the control group and also in 'infection + glucan' group compared to 'infection only' group. The difference in the NK activity among these groups was significant (P < 0.05). The IFN-gamma level increased at weeks 7 and 8 post-infection in C57BL/6 mice and was significantly high in 'infection + glucan' group compared to the 'infection only' group (P < 0.05). IL-4 levels did not increase up to detectable levels throughout the study. The results led a conclusion that Sophy beta-glucan enhances NK activity and cellular immunity in L. amazonensis-infected mice.
Subject(s)
Ascomycota/chemistry , Glucans/isolation & purification , Glucans/therapeutic use , Immunologic Factors/isolation & purification , Immunologic Factors/therapeutic use , Killer Cells, Natural/immunology , Leishmania mexicana/immunology , Leishmaniasis, Cutaneous/drug therapy , Administration, Oral , Animals , Cytotoxicity Tests, Immunologic , Female , Foot/pathology , Glucans/administration & dosage , Glucans/pharmacology , Immunologic Factors/administration & dosage , Immunologic Factors/pharmacology , Interferon-gamma/biosynthesis , Interleukin-4/biosynthesis , Killer Cells, Natural/drug effects , Leishmaniasis, Cutaneous/immunology , Leishmaniasis, Cutaneous/pathology , Mice , Mice, Inbred BALB C , Mice, Inbred C57BL , Severity of Illness Index , Time FactorsABSTRACT
Toxocariasis is a worldwide zoonotic disease caused by the ascarid nematode Toxocara canis. The most common method available for serodiagnosis of toxocariasis is an enzyme-linked immunosorbent assay (ELISA) test using Toxocara excretory-secretory antigen (TES). The present study describes the development of IgG-ELISA based on antiserum prepared against the recombinant arginine kinase of Toxocara canis. Antiserum was prepared against the purified recombinant arginine kinase (AK) using 6-week-old female Japanese white rabbits. Serum samples were collected from experimentally infected BALB/c and C57BL/6 mice at different time periods. The IgG-ELISA was performed using serum samples from mice (infected/uninfected) and TES antigen with antiserum prepared against the recombinant-AK. The optical density (OD450) was measured at 450 nm using a micro-plate ELISA reader. There were significant differences (P<0.01) in the absorbance between infected and control serum samples. Further, we obtained 100% sensitivity for the serum samples from T. canis-infected mice. Therefore, it is suggested that the recombinant-AK based IgG-ELISA could be applied for immunodiagnosis of human toxocariasis. However, it is necessary to evaluate the specificity of this recombinant antigen with similar geohelminth infections.
