Potential Role of Gut Microbiota in Induction and Regulation of Innate Immune Memory

Abstract

The gut microbiota significantly regulates the development and function of the innate and adaptive immune system. The attribute of immunological memory has long been linked only with adaptive immunity. Recent evidence indicates that memory is also present in the innate immune cells such as monocytes/macrophages and natural killer cells. These cells exhibit pattern recognition receptors (PRRs) that recognize microbe- or pathogen-associated molecular patterns (MAMPs or PAMPs) expressed by the microbes. Interaction between PRRs and MAMPs is quite crucial since it triggers the sequence of signaling events and epigenetic rewiring that not only play a cardinal role in modulating the activation and function of the innate cells but also impart a sense of memory response. We discuss here how gut microbiota can influence the generation of innate memory and functional reprogramming of bone marrow progenitors that helps in protection against infections. This article will broaden our current perspective of association between the gut microbiome and innate memory. In the future, this knowledge may pave avenues for development and designing of novel immunotherapies and vaccination strategies.

Memory CD4+ T Cells in Immunity and Autoimmune Diseases

“…Taken together, several models have been proposed for the generation of memory T lymphocytes. It is conceivable that more than one of these models contribute to memory T cell development in vivo, and may be influenced by factors such as TCR signal strength and inflammatory conditions in the microenvironment (cytokines), and in addition, costimulatory signals (e.g., CD28 family) [77] and other environmental cues, such as chemokines and even the microbiota from the tissue in which a T cell is activated [78][79][80].…”

Gut Microbiome in Children from Indigenous and Urban Communities in México: Different Subsistence Models, Different Microbiomes

“…The human gastrointestinal tract is colonized by an abundant and diverse assemblage of microorganisms collectively known as the gut microbiota (GM) which impact host physiology [ 1 ]. GM are composed of more than 2000 genera with an incredible diversity of functions that influence host health [ 2 , 3 ]. GM synthesize a huge number of peptides (more than are encoded in the human genome) [ 4 ] and participate in the biosynthesis of vitamins, fermentation of dietary polysaccharides, absorption of ions, and regulation of a number of host metabolic pathways [ 4 , 5 ].…”

“…GM synthesize a huge number of peptides (more than are encoded in the human genome) [ 4 ] and participate in the biosynthesis of vitamins, fermentation of dietary polysaccharides, absorption of ions, and regulation of a number of host metabolic pathways [ 4 , 5 ]. Moreover, GM secrete antimicrobial peptides that help to maintain homeostasis [ 6 ] and regulate the development, function, and adaptation of the innate immune system [ 3 ]. To date, at least 50 human pathologies have been associated with changes in the abundance, composition, and dynamics of GM [ 7 ].…”

Trained Immunity for Personalized Cancer Immunotherapy: Current Knowledge and Future Opportunities

“…Further, commensals such as Bacteroides, Lactobacillus, and Bifidobacteria species synthesize secondary bile acids that are derived from the metabolism of primary bile acids (53-55). Binding of these bioactive molecules to the receptors on the innate cells regulate their metabolism and functions (Negi et al, 2019). Cancer associated microbiomes have recently been linked to clinical outcomes in pancreatic cancer: The mycobiome (fungal components of the microbiome) has been shown to accelerate pancreatic cancer, via a carbohydrate moiety on Malassezia that activates the complement pathway (Aykut et al, 2019).…”