Rewiring PBMC responses to prevent CHIKV infection-specific monocyte subset redistribution and cytokine responses

Abstract

19Infection with the mosquito-borne Chikungunya virus (CHIKV) causes acute or chronic 20 arthritis in humans. Inflammatory responses mediated by monocytes, the primary target 21 cells of CHIKV infection in the blood, are considered to play an important role in CHIKV 22 pathogenesis. A recent study revealed that the acute phase of CHIKV infection is 23 characterized by a monocyte-driven response, with an expansion of the intermediate 24 monocyte (IM) subset. In this study, we adopted a previously established in vitro model 25 of CHIKV infection in peripheral blood mononuclear cells, to elucidate the mechanism and 26 relevance of IM expansion in CHIKV replication and associated inflammatory responses. 27 Our data show that infectious but not replication-incompetent CHIKV increases the 28 frequency of IM and to a lesser extent, non-classical (NM) monocytes while reducing the 29 number of classical monocytes (CM). The increase of IM or NM frequency coincided with 30 the activation of inflammatory response and occurred in the absence of lymphocytes 31 implying that monocyte-derived cues are sufficient to drive this effect. Importantly, 32 priming of monocytes with LPS prevented expansion of IM and NM but had no effect on 33 viral replication. It did however alter CHIKV-induced cytokine signature. Taken together, 34 our data delineate the role of IM in CHIKV infection-specific innate immune responses 35 and provide insight for the development of therapeutic strategies that may focus on 36 rewiring monocyte immune responses to prevent CHIKV-mediated arthralgia and 37 arthritis. 38 39 Over the last decade, chikungunya virus (CHIKV) infection has affected millions of people 40 worldwide[1]. The vast majority of infected patients experience a febrile illness with 41 painful joints. A substantial number of these individuals, however, develop persistent 42 arthritis-like manifestations (12-49%)[1]. The exact mechanism underlying CHIKV-43 mediated pathogenesis is not completely understood, however, clinical and in vivo 44 studies describe local joint inflammation, infiltration of monocytes into the synovial 45 cavity and bone resorption due to increased osteoclast activity[1-3]. Monocytes 46 represent important cellular targets of CHIKV replication in the blood[4,5], and tissue 47 infiltrating monocytes and tissue-resident macrophages have been postulated to act as a 48 vehicles and a reservoir for chronic CHIKV RNA/antigens, respectively [6,7]. 49 As innate sentinels of their host, blood monocytes sense invading pathogens and 50 orchestrate innate immune responses to contain their spread as well as setting the scene 51 for the activation of adaptive immune responses[8]. Via a set of pathogen recognition 52 receptors (PRRs), monocytes are able to detect a variety of complex pathogen associated 53 molecular patterns (PAMPS). Engagement of PRRs triggers several cellular signaling 54 cascades resulting in cell differentiation, release of inflammatory mediators and/or 55 programmed cell death[8-10]. 56 Monocytes can be divi...

Overview on Chikungunya Virus Infection: From Epidemiology to State-of-the-Art Experimental Models

“…Therefore, other tropism cells can also be used. Blood monocytes are much easier to be obtained, are susceptible to CHIKV, and constitute an excellent model to study the innate immune response against the virus (Her et al, 2010;Aguilar-Briseño et al, 2020). Epithelial fibroblast is also an interesting primary cell line to evaluate first steps of CHIKV infection and the mechanisms that trigger cartilage damage (Ekchariyawat et al, 2015).…”

Abnormal Blood Bacteriome, Gut Dysbiosis, and Progression to Severe Dengue Disease

“…Not only bacterial DNA (Kaewduangduen et al, 2022), but LPS andBG (Issara-Amphorn et al, 2018) in serum from dengue-induced leaky gut syndrome also induce proinflammatory effect and more profoundly activate monocytes (Wu et al, 2013) and NK cells (Poggi et al, 2019;Chapuy & Sarfati, 2020) compared with patients without gut barrier defect. Indeed, monocytes are important immune cells that recognize pathogen molecules in several inflammatory diseases in either sepsis (Aguilar-Briseño et al, 2020) or non-sepsis (Grip et al, 2007;Mukherjee et al, 2015;Weldon et al, 2015). Although both LPS and BG can stimulate monocytes (Chan et al, 2009;Kew et al, 2017), the simultaneous presence of LPS with BG synergistically activates inflammation (Issara-Amphorn et al, 2018) which might be similar to the condition of dengue-induced leaky gut.…”