Unraveling the host's immune response to infection: Seeing is believing

Abstract

It has long been appreciated that understanding the interactions between the host and the pathogens that make us sick is critical for the prevention and treatment of disease. As antibiotics become increasingly ineffective, targeting the host and specific bacterial evasion mechanisms are becoming novel therapeutic approaches. The technology used to understand host‐pathogen interactions has dramatically advanced over the last century. We have moved away from using simple in vitro assays focused on single‐cell events to technologies that allow us to observe complex multicellular interactions in real time in live animals. Specifically, intravital microscopy (IVM) has improved our understanding of infection, from viral to bacterial to parasitic, and how the host immune system responds to these infections. Yet, at the same time it has allowed us to appreciate just how complex these interactions are and that current experimental models still have a number of limitations. In this review, we will discuss the advances in vivo IVM has brought to the study of host‐pathogen interactions, focusing primarily on bacterial infections and innate immunity.

Effect of the CXCR4 antagonist plerixafor on endogenous neutrophil dynamics in the bone marrow, lung and spleen

“…The lung has a marginated pool of neutrophils present under homeostatic conditions that have recently been proposed to function as an important site of intravascular immunity in mice, for example, playing an essential role in bacterial surveillance in the lung 13,42 . Additionally, it has also been proposed that the lung constitutes a unique niche where neutrophil de‐priming takes place under inflammatory conditions 14 .…”

Antiviral strategies targeting host factors and mechanisms obliging +ssRNA viral pathogens

“…Comprehensive understanding of the molecular mechanisms involved in spread of viral infections has paved the way for discovering new antiviral therapies, either by targeting the viral proteins or by upregulation of host factors for alleviating host antiviral response. 7 Host innate immune system forms the first line of defence against viruses and is primarily responsible for recognizing pathogen-associated molecular patterns (PAMP) for initiating a strong antiviral response. 8 , 9 The second role is played by adaptive immune system which then kicks in to totally clear the virus infection and to build up prolonged memory response.…”

Polarization of Macrophages in Insects: Opening Gates for Immuno-Metabolic Research

“…Although it has been shown that macrophages are endowed with certain nutritional stores, they barely suffice for the initial few hours of their activation ( Ma et al, 2020 ). This fact has been documented by many clinical data as well as experimental studies describing the progress of infection ( Imran and Smith, 2007 ; Scott et al, 2019 ). Last, but not least, we should consider the potential of SIFs to spread through the body and affect systemic nutrient expenditure.…”