Shigella Outer Membrane Vesicles as Promising Targets for Vaccination

Muhammad Qasim,Björn Nüse,Jochen Mattner,Marius Wrage

doi:10.3390/ijms23020994

Abstract

The clinical symptoms of shigellosis, a gastrointestinal infection caused by Shigella spp. range from watery diarrhea to fulminant dysentery. Endemic infections, particularly among children in developing countries, represent the majority of clinical cases. The situation is aggravated due to the high mortality rate of shigellosis, the rapid dissemination of multi-resistant Shigella strains and the induction of only serotype-specific immunity. Thus, infection prevention due to vaccination, encompassing as many of the circulating serotypes as possible, has become a topic of interest. However, vaccines have turned out to be ineffective so far. Outer membrane vesicles (OMVs) are promising novel targets for vaccination. OMVs are constitutively secreted by Gram-negative bacteria including Shigella during growth. They are composed of soluble luminal portions and an insoluble membrane and can contain toxins, bioactive periplasmic and cytoplasmic (lipo-) proteins, (phospho-) lipids, nucleic acids and/or lipopolysaccharides. Thus, OMVs play an important role in bacterial cell–cell communication, growth, survival and pathogenesis. Furthermore, they modulate the secretion and transport of biomolecules, the stress response, antibiotic resistance and immune responses of the host. Thus, OMVs serve as novel secretion machinery. Here, we discuss the current literature and highlight the properties of OMVs as potent vaccine candidates because of their immunomodulatory, antigenic and adjuvant properties.

Highlights

IntroductionPublisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations
Infections with Shigella are among the leading causes of bacterial diarrhea world-wide, [1] and the mortality rate of shigellosis can be high, in epidemic infections with Shigella (S.) dysenteriae serotype 1 or endemic S. flexneri infections in children living in areas with a high prevalence of malnutrition [2]
We have summarized the findings on the immune-reactive properties of some of the outer membrane proteins (Table 2) as well as on surface proteins and polysaccharides

Summary

Introduction

Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affiliations. Shigella species invade the gut-lining epithelium and cause shigellosis, known as bacillary dysentery. Infections with Shigella are among the leading causes of bacterial diarrhea world-wide, [1] and the mortality rate of shigellosis can be high, in epidemic infections with Shigella (S.) dysenteriae serotype 1 or endemic S. flexneri infections in children living in areas with a high prevalence of malnutrition [2]. Shigellosis is a global health problem in all age groups, endemic infections in children, in developing countries with poor sanitation and/or with poor personal hygiene, constitute the main disease burden [3]

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