ABSTRACT
Objective: To evaluate the effect of short-Term and long-Term immunization of recombinant disorganized muscle protein-1 (rDIM-1) in rodents against human filarial parasite Brugia malayi. Methods: Recombinant Brugia malayi DIM-1 (rDIM-1bm) protein was cloned, expressed and purified using a Ni-NTA affinity column. Mastomys coucha were immunized with rDIM-1bm in three immunization schedules: short-Term (3-dose of rDIM-1bm), and long-Term (booster doses till 3-And 6-week) and subsequently challenged with infective third-stage larvae of filarial parasite Brugia malayi (L3). Microfilaraemia was monitored in L3 exposed groups on day 90 post larval inoculation (p.l.i.) and continued till day 205 p.l.i. On day 205 p.l.i. all the infected animals were killed and total worm burden was estimated. Cellular proliferative response, macrophage activity, nitric oxide (NO) release, specific IgG and its subtypes, IgE, IgA and Th1 (IFN-γ, TNF-α and IL-2) and Th2 (IL-4, IL-5, IL-6, IL-10 and IL-13) cytokine release were determined. Results: Of the 3 different immunization schedules, short-Term immunization (3-dose schedule) showed better reduction in microfilarial burden (36%-63%) in the peripheral circulation, adult worm load (52%), whereas long-Term immunization (3-And 6-week schedule) exerted less effect on peripheral microfilariae count (9%-58%), and adult worm burden (9%-12.5%). Short-Term immunization resulted in upregulation of cellular proliferation, macrophages activity, NO release, specific IgG, IgG1, IgG2a, IgG2b, IgE and IgA levels and both Th1 (IFN-γ, TNF-α and IL-2) and Th2 (IL-4, IL-5, IL-6, IL-10 and IL-13) cytokine release whereas long-Term immunization (3-And 6-week schedule) exerted less effect on parasite burden and showed mixed immunological responses. None of the rDIM-1bm administration schedules induced any pathology in lymphoid tissues, or alteration in mast cell number and granularity. Conclusions: The short-Term immunization with rDIM-1bm (3-dose schedule) induces robust immune responses and protects the host from filarial parasite infection.
ABSTRACT
Objective:To investigate the effect of saw palmetto extract ( SR ) on GL261 glioma in rats and immune system.Methods:The 40 rats were divided into 4 groups randomly,one was the control group without tumor( the blank group) ( n=10) ,the other 30 rats were given subcutaneous inoculation of tumor cells and then divided into 3 groups:the tumor-bearing group( n=10) ,low dose SR group( n=10) ,and high dose SR group( n=10).After 1 week fed,the rats of SR groups were given the saw palmetto extract,low dose group 50 mg/kg once a day every other day and 300 mg/kg of high dose group every other day.The tumor-bearing groups received the same dose of distilled water.After 4 weeks fed, we measured the tumor weight and the inhibition rate was calculated.The tumor cell apoptosis was detected by TUNEL staining.The activity of splenic macrophages was detected by macrophage phagocytosis of chicken erythrocytes and CD4+lymphocytes by flow cytometry.Results:①The SR groups compared with tumor group, the tumor weight was significantly reduced(F=62.678,P=0.000).The tumor inhibition rate was significantly higher in high dose group.②The apoptosis of tumor cells in tumor-bearing group was significantly less than SR groups and the apoptosis was significantly increased after treatment with SR ,especially in high dose SR group(F=1.287,P=0.000).③Compared with the blank group,the macrophage activity decreased remarkablely.SR enhanced the macrophage activity obviously, positively related to doses of SR ( F=141.205,P=0.000;F=126.903,P=0.000).④In the tumor-bearing group,the CD4+lymphocyte count decreased significantly.After SR treatment,the CD4+lymphocyte increased and were positively related to the dose of SR.Conclusion: Saw palmetto extract can strengthen the immune system.