A Survey on the Adjuvant Role of Naloxone Alone or Combined With Alum in Vaccination Against Fasciolosis in Balb/C Mice Publisher Pubmed



Azizi H¹ ; Mirzaeei H² ; Bagheri A³ ; Bazi A⁴ ; Khamesipour A⁵ ; Yaghoobi H⁶ ; Mirzapour A⁷ ; Khatami M⁸ ; Elikaee S⁹
Source: Acta Parasitologica Published:2019

Abstract

Background: Fasciolosis is a zoonotic parasitic disease imposing a heavy load of livestock losses worldwide. Purpose: We aimed to evaluate immune-stimulatory effects of naloxone (NLX), an opioid receptor antagonist, in combination with alum in mice vaccinated with excretory–secretory antigens (E/S) of Fasciola hepatica. Methods: 8-week-old female BALB/c mice were subcutaneously vaccinated using E/S antigens of F. hepatica. Experimental groups (14 mice per group) included: vaccine (E/S antigen), alum vaccine (E/S antigen plus alum), NLX vaccine (E/S antigen plus NLX), and alum–NLX vaccine (E/S antigen plus a mixture of alum–NLX). The control group was infused with PBS. Lymphocyte proliferation and the levels of IFN-γ, IL-4, IgG2a, IgG1, and total IgG were measured. Results: Mice vaccinated with NLX or alum–NLX adjuvants showed significantly higher rates of lymphocyte proliferation, IFN-γ, total IgG, and IgG2a levels. The mice that were injected with alum showed a significantly higher concentration of IL-4. Ratios of IFN-γ/Il-4 and IgG2a/IgG1 were significantly higher in the NLX and alum–NLX groups in comparison with the groups vaccinated either with alum or without any adjuvant. A significantly higher protection rate (62.5%) was seen in mice vaccinated with the alum–NLX adjuvant compared to the other groups. Conclusion: NLX can be effective in conferring cellular immunity and protection against F. hepatica. It is recommended to consider this agent as a potential adjuvant in vaccines against fasciolosis. © 2019, Witold Stefanski Institute of Parasitology, Polish Academy of Sciences.