Bacterial ghosts as adjuvant particles

Abstract

The development of more advanced and effective vaccines is of great interest in modern medicine. These new-generation vaccines, based on recombinant proteins or DNA, are often less reactogenic and immunogenic than traditional vaccines. Thus, there is an urgent need for the development of new and improved adjuvants. Besides many other immunostimulatory components, the bacterial ghost (BG) system is currently under investigation as a potent vaccine delivery system with intrinsic adjuvant properties. BGs are nonliving cell envelope preparations from Gram-negative cells, devoid of cytoplasmic contents, while their cellular morphology and native surface antigenic structures remain preserved. Owing to the particulate nature of BGs and the fact that they contain many well known immune-stimulating compounds, BGs have the potential to enhance immune responses against ghost-delivered target antigens.

The bacterial ghost platform system

“…25 The idea of utilizing BGs derived from different Gram-negative bacteria as candidate vaccines emerged due to the demand for both potent and safe new vaccines. [27][28][29][30][31] The BG system offers many advantages over traditional vaccination techniques including targeting and the intrinsic adjuvant properties of the BG particles. In addition, recombinant DNA technology facilitates the development of multivalent protein or DNA vaccines.…”

Preparation and Evaluation of Chemically Inactivated Salmonella Enteritidis Vaccine in Chickens

“…Our results suggest that the SEGs-induced immune responses provided protection against S. enteritidis infections. This immune response is an important consideration for salmonellosis [28].…”

Development of aChlamydia trachomatisbacterial ghost vaccine to fight human blindness

“…44 Although in the past different animal models and routes of immunization have been used to test the efficacy of BG vaccine candidates, [45][46][47][48][49][50] the main focus of our developmental work for BG vaccines is the mucosal application of BG vaccines in veterinary and human medicine. Mucosal vaccine application can be oral, intranasal, intra-ocular, intra-vaginal, rectal or aerogenic.…”

“…A recent review about BG as mucosal adjuvants provides more information. 49 Figure 2. Schematic line drawing of a longitudal cross section through a bacterial ghost.…”

“…By their own nature BG have intrinsic adjuvant properties and their particle character makes them attractive for key immune cells, such as dendritic cells, macrophages or monocytes which they address by recognition via toll-like receptors or opsonized antibody facilitated uptake. 49 …”