Immune response in hamsters immunised with a recombinant fragment of LigA from Leptospira interrogans, associated with carrier molecules

Abstract

Immunisation with the C-terminal region of leptospiral immunoglobulin-like A protein (LigANI) has shown promising results against leptospirosis. We evaluated the humoral immune response and protection induced by LigANI associated with carboxyl multi-walled carbon nanotubes (COOH-MWCNTs), CpG oligodeoxynucleotides (CpG ODNs), or Alhydrogel. Animals immunised with CpG ODNs were unable to develop a humoral immune response, whereas immunisation with LigANI and COOH-MWCNTs produced a high level of IgG antibodies, similar to that with LigANI and Alhydrogel, but it was not protective. The use of carbon nanotubes as an adjuvant in subunit vaccines against leptospirosis is a novel approach for improving specific IgG production.

DNA nanovaccines prepared using LemA antigen protect Golden Syrian hamsters against Leptospira lethal infection

“…Additionally, several studies have shown that functionalised CNTs do not cause cytotoxic effects (10,11,28,29) as observed in this work. Amino-functionalised NPs were found to interact with negatively charged DNA and the cell membrane, and through this interaction, these successfully delivered the pTARGET/lemA plasmid into mammalian cells without any cytotoxicity.…”

“…Nanotubes in vitro cytotoxicity -The viability of Chinese hamster ovary (CHO) cells was determined by measuring the reduction of soluble 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) compared with water-insoluble formazan. (11) . Briefly, cells were seeded at a density of 2 × 10 4 cells per well at a volume of 100 µL on 96-well plates and grown at 37ºC in a humidified atmosphere of 5% CO 2 for 24 h prior to performing the cell viability assay.…”

“…Freund's adjuvant, (7) aluminum hydroxide, (5) Ad-daVax ™ , (6) CpG oligodeoxynucleotides (or CpG ODN), xanthan gum, (8) mannosylated form, (9) and NPs. (10,11) NPs seemed to be potential antigen carriers for the development of new-generation vaccines, and combined nanovaccines have been known to induce more intense and long-lasting antigen-specific immune responses. NPs can induce a robust innate immunity response by causing abundant initial antigen exposure and long-term immunity through the sustained release of antigens via two types of activation modes: dendritic cell (DC) and T-cell differentiation.…”

“…NPs can induce a robust innate immunity response by causing abundant initial antigen exposure and long-term immunity through the sustained release of antigens via two types of activation modes: dendritic cell (DC) and T-cell differentiation. (12,13,14) In previous studies, we demonstrated that subunit vaccines containing recombinant proteins, LipL32 (10) and LigAni, (11) with halloysite nanotubes (HNTs) and carboxylated multi-walled carbon nanotubes (COOH-MWCNTs) as carriers induced a strong IgG immune response in Golden Syrian hamsters.…”

The interaction of two novel putative proteins of Leptospira interrogans with E-cadherin, plasminogen and complement components with potential role in bacterial infection

“…Furthermore, leptospiral proteins interact with regulators or components of the complement system pathways present in host serum as a possible mechanism to evade the innate immune system and lytic activity [16,17]. Interaction of Leptospira to fibrinogen (Fg) leading to a partial inhibition of fibrin clotting formation through Fg/thrombincatalyzed reaction may help the bacterial dissemination [18]. Several proteins have the capacity to binding Fg but only in a few cases this interaction leads to fibrin clot inhibition [14,19].…”