title: A novel adjuvant, the mixture of alum and naltrexone, augments vaccine-induced immunity against Plasmodium berghei.
abstract: We previously showed that the mixture of naltrexone (NLT), a general opioid antagonist, and alum, acts as an effective adjuvant in enhancing vaccine-induced T helper 1 (TH1) humoral immune responses against Toxoplasma gondii. Here, we tested the efficacy of the mixture of NLT and alum in the induction of immunity in response to blood stages of Plasmodium berghei (BSPb) as a model vaccine. BALB/c mice were divided into five vaccination groups. Mice in the experimental groups received the BSPb vaccine alone or in combination with the adjuvant alum, NLT or the alum-NLT mixture. Mice in the control group received PBS. All mice were immunized on days 0, 7 and 14. Two weeks after the last immunization, immune responses to Plasmodium berghei were assessed. Our results indicated that including the alum-NLT mixture as an adjuvant during vaccination increased the ability of the BSPb vaccine to enhance lymphocyte proliferation, shifted the immune response towards a TH1 profile and increased Plasmodium berghei-specific IgG2a. This resulted in improved protective immunity against Plasmodium berghei. In conclusion, administering alum-NLT mixture in combination with the BSPb vaccine enhanced the vaccine-induced immunity, and shifted the immune response toward TH1 pattern.
authors.affiliation: Cellular and Molecular Research Center, Urmia University of Medical Sciences , Urmia , Iran .
authors.forename: Shahram
authors.initials: S
authors.lastname: Shahabi
authors.forename: Hakim
authors.initials: H
authors.lastname: Azizi
authors.forename: Ebrahim
authors.initials: E
authors.lastname: Mazloomi
authors.forename: Khosrow Hazrati
authors.initials: KH
authors.lastname: Tappeh
authors.forename: Shahram
authors.initials: S
authors.lastname: Seyedi
authors.forename: Habib
authors.initials: H
authors.lastname: Mohammadzadeh
mesh_terms: D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000534:Alum Compounds / Q000494:pharmacology*; D000818:Animals; D007074:Immunoglobulin G / Q000097:blood; D007371:Interferon-gamma / Q000276:immunology; D015848:Interleukin-5 / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology; D017780:Malaria Vaccines / Q000494:pharmacology*; D008297:Male; D008807:Mice, Inbred BALB C; D009271:Naltrexone / Q000494:pharmacology*; D009292:Narcotic Antagonists / Q000494:pharmacology*; D010962:Plasmodium berghei
chemical_list: D000276:Adjuvants, Immunologic; D000534:Alum Compounds; D007074:Immunoglobulin G; D015848:Interleukin-5; D017780:Malaria Vaccines; D009292:Narcotic Antagonists; C041524:aluminum sulfate; D009271:Naltrexone; D007371:Interferon-gamma
keywords: Adjuvant; Plasmodium berghei; alum; malaria; naltrexone; vaccine