Fcγ receptors on aging neutrophils

Abstract

Fcγ receptors on aging neutrophilsObjective: Neutrophils are key effector cells of the innate immune system.They recognize antigens through membrane receptors, which are expressed during their maturation and activation. Neutrophils express FcγRII (CD32), FcγRIII (CD16), and FcγRI (CD64) after being activated by different factors such as cytokines and bacterial products. These receptors are involved with phagocytosis of IgG-opsonized microbes and enhance defense mechanisms.Based on that, our study seeks to compare the expression of FcγRII, FcγRIII, FcγRI, and CD11b on neutrophils from elderly and young subjects and their expression after in vitro activation with cytokines and LPS. Methodology: Neutrophils were isolated from human peripheral blood and from mice bone marrow by density gradient. After isolation, FCγRs expression was immediately analyzed by flow cytometry or after in vitro stimulation. Results:In freshly isolated cells, the percentage of FcγRIIIb + and CD11b + neutrophils were higher in samples from young individuals; FcγRIIIa expression was more prominent on aged neutrophils; FcγRIA expression was similar in all samples analyzed. Exposure to CXCL8 and LPS resulted in a higher percentage of FcγRIa + neutrophils on elderly individuals' samples but lower when compared with neutrophils from young donors. We observed that LPS caused an increase in FcγRIIa expression on aging human neutrophils. In contrast, FcγRIIIb expression in response to CXCL8 and LPS stimulation was not altered in the four groups. CD11b expression was lower in neutrophils from elderly individuals even in response to LPS and CXCL8. In mice, we observed differences only regarding CD11b expression, which was increased on aged neutrophils. LPS exposure caused an increase in all FcγRs. Conclusions:Our results suggest that, in humans, the overall pattern of FcγR expression and integrin CD11b are altered during aging and immunosenescence might contribute to age-related infection.

Identification of the common differentially expressed genes and pathogenesis between neuropathic pain and aging

“…Valziflocept is a recombinant soluble FcγIIb receptor that targets Fc and 10.3389/fnins.2022.994575 FcγR (Zuercher et al, 2019). FcγR has been reported as a potential therapeutic target for pain in autoimmune diseases (Bersellini Farinotti et al, 2019;Peyrin-Biroulet et al, 2019), and it was also crucial in aging neutrophils (Gasparoto et al, 2021). There is no doubt that Valziflocept may benefit patients with comorbidities of pain and aging to some extent.…”

Human endoderm stem cells reverse inflammation-related acute liver failure through cystatin SN-mediated inhibition of interferon signaling

“…S7b ), while we observed significant downregulations of Cd16 and Cd32 (two genes that encode Fc Gamma Receptor IIIa (FCGR3A) and Fc Gamma Receptor IIa (FCGR2A), respectively and are known to be important for the activation of neutrophils) in the hEnSC group, which indicates that neutrophils generally remained inflammatory with some changes upon hEnSC transplantation. 61 These findings clearly demonstrated that the activation state of macrophages/Kupffer cells and the general hepatic immune micromilieu were skewed towards an anti-inflammatory state after hEnSC transplantation and that IFN signaling was significantly downregulated in liver macrophage populations. It would be interesting to interrogate whether or how hEnSCs or their derivatives were efferocytosed by macrophages/ Kupffer cells which might have a major effect on the latter.…”

Host’s Immunity and Candida Species Associated with Denture Stomatitis: A Narrative Review

“…Immunosenescence changes the phenotype neutrophils from the bloodstream as well as those entering the tissues. These modifications coupled with dysbiosis of the oral microbiota will promote DRCS [ 97 , 152 , 153 ]. DRCS neutrophils are not fully primed by the process of extravasion, but are more affected by the local inflammatory environment of the DRCS.…”