CD300 family receptors regulate eosinophil survival, chemotaxis, and effector functions

Abstract

The CD300 family of receptors is an evolutionary conserved receptor family that belongs to the Ig superfamily and is expressed predominantly by the myeloid lineage. Over the past couple of years, accumulating data have shown that eosinophils express various Ig superfamily receptors that regulate key checkpoints in their biology including their maturation, transition from the bone marrow to the peripheral blood, migration, adhesion, survival, and effector functions in response to numerous activating signals such as IL-4, IL-33, and bacteria. In this review, we will present the emerging roles of CD300 family receptors and specifically CD300a and CD300f in the regulation of these eosinophil activities. The structure and expression pattern of these molecules will be discussed and their involvement in suppressing or co-activating eosinophil functions in health and disease will be illustrated.

Analysis of the immune response to sciatic nerve injury identifies efferocytosis as a key mechanism of nerve debridement

“…Further evidence for an immunosuppressive environment is the strong expression of Pirb by myeloid cells, a type 1 membrane protein with four cytoplasmic immunoreceptor tyrosine-based inhibitory motifs (ITIMs) that inhibit immune cell activation (van der Touw et al, 2017). Myeloid inhibitory C-type lectin-like receptor (Clec12a), Lair1 (leukocyteassociated Ig-like receptor-1), Fcgr2b (low affinity immunoglobulin gamma Fc region receptor IIb), and the CD300 family receptors Cd300a and Cd300lf, all of which contain ITIMs (Rozenberg et al, 2018), are strongly expressed, and thus, may reduce nerve inflammation. TGFβ is expressed by efferocytotic Mac in the lung (Yoon et al, 2015).…”

CD300lf is the primary physiologic receptor of murine norovirus but not human norovirus

“…CD300lf is the primary receptor of murine norovirus There are eight CD300 family members in mice and seven in humans, each containing a conserved ectodomain, a single transmembrane domain, and a more variable cytoplasmic signaling domain [25,26]. The ectodomains bind diverse phospholipids found on dead and dying cells, resulting in activating or inhibitory signals depending upon the cellular and molecular context [26][27][28][29][30]. Both CD300ld and CD300lf are expressed in diverse myeloid cells, while CD300lf is additionally expressed in lymphoid cells and rare intestinal epithelial cells called tuft cells, which are the primary target cell of MNoV CR6 [25,31].…”

Analysis of the Immune Response to Sciatic Nerve Injury Identifies Efferocytosis as a Key Mechanism of Nerve Debridement

“…Further evidence for an immunosuppressive environment is the strong expression of Pirb in myeloid cells, a type 1 membrane protein with four cytoplasmic immunoreceptor tyrosine-based inhibitory motifs (ITIMs) that inhibit immune cell activation(van der Touw et al, 2017). Myeloid inhibitory C-type lectin-like receptor (Clec12a), Lair1 (leukocyteassociated Ig-like receptor-1), Fcgr2b (low affinity immunoglobulin gamma Fc region receptor IIb), and the CD300 family receptors Cd300a and Cd300lf, all of which contain ITIMs(Rozenberg et al, 2018), are strongly expressed, and thus, may reduce nerve inflammation. TGFβ is expressed by efferocytotic Macs in the lung…”