INTRODUCTION
Cell death is a physiological event essential for homeostasis in
multicellular organisms. However, it is also implicated in multiple
pathological conditions such as neurodegenerative and ischemic
disorders, cancer, auto-inflammatory and autoimmune diseases
(Allam, Kumar, Darisipudi, & Anders,
2014; Godlewski & Kobylińska, 2016;
Linkermann, Stockwell, Krautwald, &
Anders, 2014). Consequently, cell death is tightly regulated by a
strict biochemical program which depends on regulatory pathways and
protein interaction networks. This programmed cell death (PCD) exhibits
various types or modalities, according to the stimulus that triggers it
and the molecular pathways that result activated
(Galluzzi et al., 2018;
Pasparakis & Vandenabeele, 2015). The
multiple forms of PCD are in constant update by recent findings in this
field, which are revealing the connections and molecular crosstalk
between cell death programs, as well as their implication in a wide
variety of biological processes (Yan,
Elbadawi, & Efferth, 2020).
PCD is involved in several physiological functions such as organ
development, tissue remodeling and epithelial cell renewal. It is also
essential for cellular homeostasis and cell response to stress, acting
as an intrinsic mechanism to prevent malignant transformation and cancer
development (Godlewski & Kobylińska,
2016). In addition to its role in tissue maintenance, PCD is a crucial
biological response for immunity and host defense. It is part of various
innate and adaptive immune mechanisms/processes such as antiviral
defense, killing of intracellular pathogens, inflammation,
chemoattraction, lymphocyte selection and immune tolerance
(Miao, Rajan, & Aderem, 2011;
Sumpter Jr & Levine, 2010;
Zhou & Fang, 2019). Increasing evidence
is revealing novel functions of different cell death types in innate
immunity, including the regulation and/or amplification of the
inflammatory response, the modulation of cytokine production and
release, as well as diverse microbe-killing strategies in specialized
immune cells (Andrade & Darrah, 2013;
Burgener & Schroder, 2020;
H. Chen, Ning, & Jiang, 2017;
Humphries, Yang, Wang, & Moynagh, 2015).
This review will be focus in important findings that highlight the
interconnection between various forms of PCD and their roles in innate
immunity.