Cellular immunity survey against urinary tract infection using pVAX/fimH cassette with mammalian and wild type codon usage as a DNA vaccine

Abstract

PurposeFimH (the adhesion fragment of type 1 fimbriae) is implicated in uropathogenic Escherichia coli (UPEC) attachment to epithelial cells through interaction with mannose. Recently, some studies have found that UPEC can thrive intracellularly causing recurrent urinary tract infection (UTI). Almost all vaccines have been designed to induce antibodies against UPEC. Yet, the humoral immune response is not potent enough to overcome neither the primary UTI nor recurrent infections. However, DNA vaccines offer the possibility of inducing cell mediated immune responses and may be a promising preventive tool.Materials and MethodsIn this study, we employed two different open reading frames within mammalian (mam) and wild type (wt) codons of fimH gene. Optimized fragments were cloned in pVAX-1. Expression of the protein in COS-7 was confirmed by western blot analysis after assessing pVAX/fimH(mam) and pVAX/fimH(wt). The constructs were injected to BALB/c mice at plantar surface of feet followed by electroporation.ResultsThe mice immunized with both constructs following booster injection with recombinant FimH showed increased interferon-γ and interleukin-12 responses significantly higher than non-immunized ones (p<0.05). The immunized mice were challenged with UPEC and then the number of bacteria recovered from the immunized mice was compared with the non-immunized ones. Decreased colony count in immunized mice along with cytokine responses confirmed the promising immune response by the DNA vaccines developed in this study.ConclusionIn conclusion, DNA vaccines of UPEC proteins may confer some levels of protection which can be improved by multiple constructs or boosters.

Staphylococcal enterotoxin B as DNA vaccine against breast cancer in a murine model

“…Generally, the first injection transfers more gene cassette to the host cells. However, the subsequent subcutaneous injections stimulate the immune system (Imani Fooladi et al 2014 ).…”

“…Evaluation of cytokine response patterns was performed by ELISA assay in the supernatants of the 4T1 cell culture (in vitro) and the cultured spleen cells (in vivo). A kit of ELISA Antibodies (R&D System) was used to determine the levels of IL-4 and IFN-γ, keeping with the manufacturer’s protocol with some modifications (Imani Fooladi et al 2014 ). Briefly, a 96-well microtiter ELISA plate (MaxiSorb, Nunc, Denmark) was coated with a capture antibody of the relative cytokine and incubated overnight at 4 °C.…”

“…The absorbance was measured at 450 nm using a Microplate Reader (Bio-Rad Laboratories) 30 min after completing the reaction. The concentrations of cytokines in the culture supernatants were calculated using a linear regression equation following the standards given by kit manufacturer (Imani Fooladi et al 2014 ). Levels of IL-4 and IFN-γ in the supernatant of cultured spleen cells were assessed by the mouse ELISA Kit (R&D System), according to the manufacturer’s protocol for ELISA assay of the 4T1 cells (Imani Fooladi et al 2014 ).…”

“…Increased T cell activity is associated with increased production of Th1 cell cytokines such as IFN-γ, IL-2, and TNF-α. The increased T cell activity usually occurs within 24 h after superantigen exposure (Imani Fooladi et al 2014 ). It had been shown that SEB-activated peripheral blood mononuclear cells extensively secrete the cytokines IL-2, IFN-γ, and TNF-α and induce apoptosis in bladder cancer cells (Xu et al 2011 ).…”

“…SEB has been reported to be effective against fibrosarcoma. Tumor cell death is attributed to increased cytotoxic T cell activity and increased cytokine levels due to intravenous injection of SEB (Imani Fooladi et al 2014 ).…”