The carotid body: A novel key player in neuroimmune interactions

Abstract

United States; The idea that the nervous system communicates with the immune system to regulate physiological and pathological processes is not new. However, there is still much to learn about how these interactions occur under different conditions. The carotid body (CB) is a sensory organ located in the neck, classically known as the primary sensor of the oxygen (O2) levels in the organism of mammals. When the partial pressure of O2 in the arterial blood falls, the CB alerts the brain which coordinates cardiorespiratory responses to ensure adequate O2 supply to all tissues and organs in the body. A growing body of evidence, however, has demonstrated that the CB is much more than an O2 sensor. Actually, the CB is a multimodal sensor with the extraordinary ability to detect a wide diversity of circulating molecules in the arterial blood, including inflammatory mediators. In this review, we introduce the literature supporting the role of the CB as a critical component of neuroimmune interactions. Based on ours and other studies, we propose a novel neuroimmune pathway in which the CB acts as a sensor of circulating inflammatory mediators and, in conditions of systemic inflammation, recruits a sympathetic-mediated counteracting mechanism that appears to be a protective response.

Transcriptomic Analysis of Postnatal Rat Carotid Body Development

“…This pathway is known to be regulated by a wide range of cytokines like Tnfα as well as growth factors. Importantly, recent studies have shown that CB is a key player in neuro-immune interactions [ 32 , 33 ], and the presence of functional Tnf-α and interleukins (Il-1β, Il-6) receptors that activate CB have been reported [ 34 , 35 ]. Whether the upregulation of the cytokine signaling pathway represents a more generalized pattern of age-dependent development of functional immune competence or contributes to heightened CB hypoxic sensitivity in adults needs further investigation.…”

‘Inflammation, nitro‐oxidative stress and altered autonomic outflow in obstructive sleep apnoea: an assault on homeostasis’

“…The CB expresses multiple cytokines (e.g. TNF‐α, IL‐1β, IL‐6) and their receptors and can be activated by increases in these and other blood‐borne inflammatory mediators, causing a compensatory anti‐inflammatory response mediated through sympathetic efferents (Katayama et al., 2022). In the current issue of the Journal of Physiology , a review by Rodrigo Iturriaga, a pioneer in the chemoreception field, discusses the evidence that inflammatory mechanisms reinforce CIH‐induced hypersensitivity of the chemoreflex.…”