Administration of naloxone in combination with recombinant Plasmodium vivax AMA‐1 in BALB/c mice induces mixed Th1/Th2 immune responses. (October 2015)

• Record Type: Journal Article
• Authors: Someabozorg, M. A.; Mirkazemi, S.; Mehrizi, A. A.; Shokri, F.; Djadid, N. D.; Zakeri, S.
• Is Part Of: Parasite immunology. Volume 37:Number 10(2015:Oct.)
• Page Start: 521
• Page End: 532
• Publication Date: 2015-10
• Subjects: Veterinary parasitology -- Immunological aspects -- Periodicals; Host-parasite relationships -- Immunological aspects -- Periodicals; 571.96
• DOI: 10.1111/pim.12220
• Languages: English
• ISSNs: 0141-9838

Abstract

<abstract abstract-type="main" id="pim12220-abs-0001"> <title>Summary</title> <p>Naloxone (NLX) has the ability to shift the immune response to a Th1 profile. Therefore, the adjuvant efficacy of NLX with recombinant P. vivax apical membrane antigen‐1(rPvAMA‐1) in BALB/c mice was evaluated. Mice were immunized subcutaneously with purified rPvAMA‐1 formulated with NLX (doses of 5 mg/kg body weight) alone or in combination with IFA. A significant increase in anti‐PvAMA‐1 IgG antibody after the second boost (mean OD<sub>490</sub> = 2·08 and 2·17, in groups received, rPvAMA‐1/NLX and rPvAMA‐1/NLX/IFA, respectively) was detected. IgG1 and IgG2b were the predominant isotypes in all immunized mouse groups. In immunized mice with rPvAMA‐1/NLX (mean: 1036 pg/mL) and with rPvAMA‐1/NLX/IFA (mean: 1024 pg/mL), IFN‐γ was elicited in response to rPvAMA‐1 after the second boost. No detectable IL‐4 secretion was determined in all tested groups. In conclusion, the administration of NLX alone or NLX/IFA with rPvAMA‐1 in BALB/c mice, which induced mixed Th1/Th2 immune responses, was comparable with that of the same recombinant antigen with CFA/IFA adjuvant. The results indicate that NLX alone may possibly not be considered as a potent Th1 adjuvant in PvAMA‐1‐based vaccine. However, in order to modulate immune responses from mixed Th1/Th2 to strong and protective Th1 response, further study is warranted on combination of NLX with other adjuvants such as CpG motifs or MPL in proper vaccine formulation. Additionally, dose–response study is necessary to determine the effect of different doses of antigen combined with NLX (at various doses) in Balb/c mice.</p> </abstract>