The Use of Xanthan Gum as Vaccine Adjuvant: An Evaluation of Immunostimulatory Potential in BALB/c Mice and Cytotoxicity In Vitro

Abstract

The successful production of new, safe, and effective vaccines that generate immunological memory is directly related to adjuvant feature, which is responsible for increasing and/or modulating the immune response. Several compounds display adjuvant activity, including carbohydrates. These compounds play important roles in the immune response, as well as having biocompatible properties in vaccine formulations. One such carbohydrate is xanthan gum, a polysaccharide that is produced by the plant-pathogenic bacterium Xanthomonas spp., which has adjuvant attributes. This study evaluated the immune response induced by xanthan gum associated with ovalbumin in BALB/c mice, which were subcutaneously immunized, in terms of antibody production (IgG1, IgG2a, IgG2b, and IgG3), and assessed the levels of IFN-γ in the splenocyte culture using indirect ELISA. Furthermore, we investigated in vitro cytotoxicity of xanthan in the embryo fibroblasts cell line of the NIH/3T3 mouse by MTT assay and propidium iodide uptake assay. The mice immunized with ovalbumin plus xanthan gum exhibited higher antibody IgG1 responses than control groups. Furthermore, the xanthan polysaccharide was capable of increasing the immunogenicity of antigens by producing IFN-γ and did not exhibit cytotoxicity effects in NIH/3T3 mouse fibroblast cells, considered a promising candidate for vaccine adjuvant.

Biopolymer Xanthan: A New Adjuvant for DNA Vaccines

“…A low incidence of adverse events is important for the advancement of new vaccine. The biosafety of xanthan biopolymer is evident in the fact it has been used as an FDA-approved food additive [5,25,26]. Moreover, previous studies have demonstrated that xanthan biopolymer preparations have a record of safety [8,27].…”

“…Adjuvants are natural or synthetic substances, which, when associated with antigens, can enhance the immune response [1,5]. Thus, they can reduce the number of vaccine doses required to achieve protection and the amount of antigen, thus also reducing vaccine production costs [6].…”

“…The biopolymer xanthan is an extracellular polysaccharide, produced by bacterial Xanthomonas spp., and was initially described as a lymphocyte activator [7]. Recently, its anti-tumor activity and ability to activate the immune system to production antibodies [5,8] and activate cytotoxic T lymphocytes were described [9]. Despite these characteristics, the xanthan biopolymer has so far not been evaluated as an adjuvant in DNA vaccines.…”

Chitosan, alginate, hyaluronic acid, gums, and β-glucan as potent adjuvants and vaccine delivery systems for viral threats including SARS-CoV-2: A review

“…Also, the cytotoxicity of this natural polymer in rat fetal fibroblast cells was also investigated in-vitro and according to the results, no cytotoxicity was observed. Mice immunized with xanthan-antigen showed higher antibody IgG1 production compared to controls [ 43 ].…”

A Review on Application of Nanoadjuvant as Delivery System

“…With the help of the mode of action of the adjuvants evaluate the safety and efficiency of new adjuvants [7,13,14].…”