Immunogenicity and Efficacy of Single Antigen Gp63, Polytope and PolytopeHSP70 DNA Vaccines against Visceral Leishmaniasis in Experimental Mouse Model

Polytope approach of genetic immunization is a promising strategy for the prevention of infectious disease as it is capable of generating effective cell mediated immunity by delivering the T cell epitopes assembled in series. Leishmaniasis is a significant world wide health problem for which no vaccine exists. In this study we have compared immunogenicity and efficacy of three types of DNA vaccines: single antigen Gp63 (Gp63/pcDNA), polytope (Poly/pcDNA) and Polytope fused with hsp70 (Poly/hsp/pcDNA) against visceral leishmaniasis in susceptible BALB/c mice. Mice vaccinated with these plasmids generated strong Th1 immune response as seen by dominating IFN-γ over IL-10 cytokine. Interestingly, cytotoxic responses generated by polytope DNA plasmid fused with hsp70 of Leishmania donovani were significantly higher when compared to polytope and single antigen Gp63 vaccine. Challenge studies revealed that the parasite load in liver and spleen was significantly lower with Poly/hsp/pcDNA vaccination compared to other vaccines. Therefore, our study indicates that polytope DNA vaccine is a feasible, practical and effective approach for visceral leishmaniasis

Original Article

Abstract Aims and Objectives: The study was conducted with the aim to find out the prevalence of diabetic retinopathy among diabetics on treatment, to find out the presence of associated risk factors and to determine the knowledge of diabetic retinopathy among patients with diabetic mellitus. Methodology: Cross sectional screening of 316 diabetic patients on treatment presenting to Kalimati Diabetic Clinic and Kathmandu Medical College was done over a period of 8 months for the presence of diabetic retinopathy, associated risk factors and the knowledge of diabetic retinopathy. Results: 21% of the known diabetics had evidence of various grades of diabetic retinopathy although 75.3% of the enrolled patients had history of diabetes mellitus of less than 10 years. Associated risk factors were present in 66.46%. However, only 50% diabetics had the knowledge of diabetic retinopathy. Conclusion: As 21% of the diabetic patients on treatment had various grades of diabetic retinopathy and 50% of the diabetic patients were not aware of diabetic retinopathy, emphasis has to be given for the awareness of ocular involvement in diabetes mellitus such that blindness from retinopathy can be prevented. The responsibility lies on treating physicians or Diabetic Centres for referral of diabetic patients for ophthalmic evaluation. Similarly, control of associated risk factors like hypertension, hyperlipidemia is equally important