Adipocytes are present inside immune-stimulated lymph nodes

Abstract

White adipose tissue is involved in localised paracrine interactions with lymph node lymphoid cells. In this adipocyte-lymph node relationship, localised immune challenges stimulate the release of inflammatory cytokines (1,2). These cytokines direct neighbouring adipocytes to respond by releasing fatty acids from their triacylglycerol stores (2,3). This mechanism is believed to be of great importance as it provides precursors for eicosanoid and plasma membrane synthesis, as well as a fuel source to lymph node lymphoid cells (4). The mechanism of transport of fatty acids from adipocytes across the lymph node capsule and into lymphoid cells remains to be elucidated. Here we present evidence that a population of small adipocytes is found deep within the lymph node. We suggest that these small adipocytes are loaded with triacylglycerol fatty acids which are released during an immune response