How the Knowledge of Interactions between Meningococcus and the Human Immune System Has Been Used to Prepare Effective Neisseria meningitidis Vaccines.

M Levi,D Panatto,A Bechini,D Amicizia,R Gasparini,P L Lai,N L Bragazzi,P Durando

doi:10.1155/2015/189153

M Levi, D Panatto + Show 6 more

Open Access

https://doi.org/10.1155/2015/189153

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Abstract

In the last decades, tremendous advancement in dissecting the mechanisms of pathogenicity of Neisseria meningitidis at a molecular level has been achieved, exploiting converging approaches of different disciplines, ranging from pathology to microbiology, immunology, and omics sciences (such as genomics and proteomics). Here, we review the molecular biology of the infectious agent and, in particular, its interactions with the immune system, focusing on both the innate and the adaptive responses. Meningococci exploit different mechanisms and complex machineries in order to subvert the immune system and to avoid being killed. Capsular polysaccharide and lipooligosaccharide glycan composition, in particular, play a major role in circumventing immune response. The understanding of these mechanisms has opened new horizons in the field of vaccinology. Nowadays different licensed meningococcal vaccines are available and used: conjugate meningococcal C vaccines, tetravalent conjugate vaccines, an affordable conjugate vaccine against the N. menigitidis serogroup A, and universal vaccines based on multiple antigens each one with a different and peculiar function against meningococcal group B strains.

Highlights

The immune system protects humans from attack by microorganisms such as bacteria, viruses, protozoa, fungi, parasites, and organisms such as helminths
The mucous membranes are protected by external and internal secretions, such as tears, saliva, and mucus, which contain molecules that can neutralize bacteria. Tissues such as the skin and mucous membranes are populated by immune cells, which can act against the microorganisms that circumvent the first physical and biochemical barriers
This paper provides an overview of the interaction between the immune system and Gram-negative bacteria with particular reference to Neisseria meningitidis in the perspective of developing new vaccines against this pathogen

Summary

Introduction

The immune system protects humans from attack by microorganisms such as bacteria, viruses, protozoa, fungi, parasites, and organisms such as helminths. The skin is the first barrier and its protective action is enhanced by bodily secretions, such as sweat and sebum, which exert a broad antimicrobial activity [1, 2]. The mucous membranes are protected by external and internal secretions, such as tears, saliva, and mucus, which contain molecules that can neutralize bacteria. Tissues such as the skin and mucous membranes are populated by immune cells, which can act against the microorganisms that circumvent the first physical and biochemical barriers. The innate response triggers an immediate, nonspecific, general action and is activated by typical signs of infection. The adaptive response is able to develop a highly specific, extremely accurate action, which is stored in the so-called immune memory. This paper provides an overview of the interaction between the immune system and Gram-negative bacteria with particular reference to Neisseria meningitidis in the perspective of developing new vaccines against this pathogen

Gram-Negative Bacteria and Immunity

Neisseria meningitidis and Immunity

Meningococcal Vaccines

Conclusions

Findings

C4: Human complement 4