Innate Immunity to Staphylococcus aureus: Evolving Paradigms in Soft Tissue and Invasive Infections

Abstract

causes a wide range of diseases that together embody a significant public health burden. Aided by metabolic flexibility and a large virulence repertoire, has the remarkable ability to hematogenously disseminate and infect various tissues, including skin, lung, heart, and bone, among others. The hallmark lesions of invasive staphylococcal infections, abscesses, simultaneously denote the powerful innate immune responses to tissue invasion as well as the ability of staphylococci to persist within these lesions. In this article, we review the innate immune responses to during infection of skin and bone, which serve as paradigms for soft tissue and bone disease, respectively.

Bioinspired interface design modulates pathogen and immunocyte responses in biomaterial-centered infection combination therapy

“…When bacterial infection occurs, innate immune cells, particularly macrophages, will be first recruited to the site of infection and polarize to the proinflammatory M1 phenotype, secrete cytokines to boost inflammation reaction, and then phagocytose and kill bacteria. 50 We have verified that the majority of macrophages in the TiO 2 :Co coating can be activated and polarize to the M1 phenotype, and then secrete a high level of inflammatory cytokines to create a proinflammatory microenvironment; the TiO 2 :Co coating can facilitate the MRSA phagocytosis by sample-conditioned macrophages and neutrophils. Therefore, such an immunomodulatory ability of the TiO 2 :Co coating can enhance the capability of phagocytes to phagocytose and kill bacteria, and contribute to the superior antiinfective function.…”

SOCS-1 inhibition of type I interferon limitsStaphylococcus aureusskin host defense

“…Macrophages orchestrate abscess formation by establishing the inflammatory tone, recruiting neutrophils, killing microbes, clearing dead cells, and initiating wound healing. Since the abscess harbors viable and necrotic neutrophils plus bacteria at its core, it must be tightly organized to prevent deeper infection and bacterial dissemination (Brandt, Putnam, et al, 2018;Cheng et al, 2011).…”

“…While skin resident macrophages are involved in the initial recognition and killing of the bacteria, these cells are primarily engaged in producing chemoattractants to promote neutrophil and monocyte recruitment to the skin. Recruited neutrophils are crucial in S. aureus elimination through phagocytosis and killing via the generation of antimicrobial peptides, reactive oxygen (ROS) and nitrogen (RNS) species, as well as neutrophil extracellular traps (NETs) within the abscess (Brandt, Putnam, et al, 2018;Liu et al, 2018).…”

CD8α− conventional dendritic cells control Vβ T‐cell immunity in response to Staphylococcus aureus infection in mice

“…It can infect almost all tissues and organs in humans, which leads to serious diseases such as endocarditis, pneumonia, and sepsis syndrome . Although the immune system evading mechanisms of S. aureus cause them to be highly pathogenic in humans, the bacteria can also promote immune activation . Staphylococcus aureus contains numerous types of toxins that induce the activation of the immune system.…”

“…9,10 Although the immune system evading mechanisms of S. aureus cause them to be highly pathogenic in humans, the bacteria can also promote immune activation. 11,12 Staphylococcus aureus contains numerous types of toxins that induce the activation of the immune system. Staphylococcal superantigens (SAgs), the potent immune stimulatory exotoxins, induce T-cell activation and proinflammatory cytokine production by directly cross-linking MHC class II on DCs.…”