Contents lists available at ScienceDirect Cytokine journal homepage: www.elsevier.com/locate/cytokine Short communication High TARC plasma levels confer protection to long living individuals by inducing M2 profile Francesco Montella a , Valentina Lopardo a , Carmine Vecchione a,b , Annibale Alessandro Puca a,c, ⁎ , Elena Ciaglia a, ⁎ a Department of Medicine, Surgery and Dentistry “Scuola Medica Salernitana”, University of Salerno, Via Salvatore Allende, 84081 Baronissi, Salerno, Italy b Department of Vascular Physiopathology, IRCCS Neuromed, 86077 Pozzilli, Italy c Cardiovascular Research Unit, IRCCS MultiMedica, 20138 Milan, Italy ARTICLE INFO Keywords: Longevity TARC M2 macrophages FACS Plasma profile ABSTRACT A way to delay aging and the related low-grade chronic inflammatory state is to study the model of positive physiology such as the Long-Living Individuals (LLIs). Our recent studies have shown higher levels of the host defense BPI Fold-Containing Family B Member 4 (BPIFB4) protein in the LLIs’ blood. Notably, BPIFB4 has been shown to influence monocytes typesetting and M2 anti-inflammatory phenotype (CD206+CD163++) macro- phages skewing. According to the role of a complex cytokine milieu in guiding the macrophage polarization, here we found that circulating concentrations of thymus and activation regulated chemokine (TARC)/CCL17 and small-in- ducible cytokine B10 (IP-10)/CXCL10) cytokines, were additionally associated with the LLIs’ state. In a differentiation process in vitro, the addition of LLIs’ plasma to the cell culture medium, enhanced the ability of monocytes, either from LLIs or controls, to acquire a M2 phenotype. Interestingly, a neutralizing antibody against TARC blunted the M2 skewing effect of the LLIs’ plasma. Collectively, these data indicate that exceptional longevity may associate with a peculiar anti-inflammatory myeloid profile responsible for improved reparative processes and reduced inflammatory status mediated in part by TARC and M2 generation. 1. Introduction Long Living Individuals (LLIs) represent a very interesting genomic model to underpin the mechanisms that lead to longevity and so, a great tool for understanding healthy aging [1]. Our latest research demonstrates that the addition of LLIs’ plasma to the cell culture medium supporting mono-macrophages differentiation in vitro, en- hanced the ability of primary monocytes, either from LLIs or controls, to acquire a M2 pro-resolving phenotype [2]. Macrophages guarantee human health, contributing both to the immune defense, through a M1 pro-inflammatory state, and to the maintenance of tissue homeostasis through a M2 pro-resolving activity. To rapidly change their phy- siology, macrophages are activated by a peculiar environment mainly consisting of cellular interactions and soluble factors which human plasma may be enriched for [3]. In this context the M2 polarizing effect of LLIs’ plasma has been recently associated with and possibly enhanced by high circulating levels of the host defense BPI Fold-Containing Fa- mily B Member 4 (BPIFB4) protein endowed with immunomodulatory properties [4–7]. As macrophage polarization depends on the amount of several cy- tokines, the exposure time and their proper balance [8], here we show an extensive analysis of the LLIs’ plasma looking for additional mole- cules contributing to the entire process. 2. Results and discussion To give more insights into the functional LLIs’ blood, we moved to profile plasma from LLIs (n = 52: 37 women and 15 men) recruited in the Cilento area of Southern Italy (median age 97, range 95–99) with respect to control adults (35–75 years, n = 52). Multiplex bead-based immunoassay revealed that thymus and activation regulated chemokine (TARC)/CCL17 and small-inducible cytokine B10 (IP-10)/CXCL10) cy- tokines had selectively strong expression in LLIs as compared with all controls (Fig. 1A). To confirm the data, we performed an ELISA assay of TARC and IP-10 (Fig. 1B-C). Further, among the longevity group, no difference was found between male and female LLIs subjects regarding https://doi.org/10.1016/j.cyto.2020.155305 Received 30 July 2020; Received in revised form 17 September 2020; Accepted 18 September 2020 ⁎ Corresponding authors at: Department of Medicine, Surgery and Dentistry “Scuola Medica Salernitana”, University of Salerno, Via Salvatore Allende, 84081 Baronissi, Salerno, Italy. E-mail addresses: apuca@unisa.it (A.A. Puca), eciaglia@unisa.it (E. Ciaglia). Cytokine 137 (2021) 155305 Available online 29 September 2020 1043-4666/ © 2020 Elsevier Ltd. All rights reserved. T