Survival and evasion of Neisseria meningitidis from macrophages

Human is a host to billions of microbes and has developed sophisticated defense systems to stave off infections. Macrophages, which are at the forefront of innate immune protection against bacterial invaders, play a critical role in host responses to intracellular bacteria. At the same time, these phagocytes are prime targets for intracellular bacteria seeking to exploit host cells. Neisseria meningitidis belongs to a select group of bacterial pathogens with a sophisticated arsenal of virulence factors that can disrupt macrophage defense mechanisms or counter-balance the host's immunological defense mechanisms in order to ensure survival or expansion in a hostile environment. Worldwide, meningococci continues to play a significant role in the development of severe sepsis and meningitis. There is still much to learn about the tactics N. meningitidis uses to avoid immune response, such as mimicking host molecules, expression of virulence factor, capsule switching, and lipopolysaccharide phase changes. The macrophage evasion mechanisms of meningococcal present significant challenges for therapy and treatments. This review provides an overview of factors that meningococci utilize to manipulate macrophage immune responses and understand the asymptomatic and infection phases. Knowledge of the intricate web of host-pathogen interaction can help us find new target sites to devise effective therapeutics.