Three Distinct Subsets of Thymic Epithelial Cells in Rats and Mice Defined by Novel Antibodies

Abstract

AimThymic epithelial cells (TECs) are thought to play an essential role in T cell development and have been detected mainly in mice using lectin binding and antibodies to keratins. Our aim in the present study was to create a precise map of rat TECs using antibodies to putative markers and novel monoclonal antibodies (i.e., ED 18/19/21 and anti-CD205 antibodies) and compare it with a map from mouse counterparts and that of rat thymic dendritic cells.ResultsRat TECs were subdivided on the basis of phenotype into three subsets; ED18+ED19+/−keratin 5 (K5)+K8+CD205+ class II MHC (MHCII)+ cortical TECs (cTECs), ED18+ED21−K5−K8+ Ulex europaeus lectin 1 (UEA-1)+CD205− medullary TECs (mTEC1s), and ED18+ED21+K5+K8dullUEA-1−CD205− medullary TECs (mTEC2s). Thymic nurse cells were defined in cytosmears as an ED18+ED19+/−K5+K8+ subset of cTECs. mTEC1s preferentially expressed MHCII, claudin-3, claudin-4, and autoimmune regulator (AIRE). Use of ED18 and ED21 antibodies revealed three subsets of TECs in mice as well. We also detected two distinct TEC-free areas in the subcapsular cortex and in the medulla. Rat dendritic cells in the cortex were MHCII+CD103+ but negative for TEC markers, including CD205. Those in the medulla were MHCII+CD103+ and CD205+ cells were found only in the TEC-free area.ConclusionBoth rats and mice have three TEC subsets with similar phenotypes that can be identified using known markers and new monoclonal antibodies. These findings will facilitate further analysis of TEC subsets and DCs and help to define their roles in thymic selection and in pathological states such as autoimmune disorders.

Compartmentalization of Human Thymic Medulla: Facts and Hypotheses

“…Secondary septae appear after formation of the cortex and medulla, and they are just small invaginations of the capsule and usually do not reach the medulla and do not receive blood vessels. The medullary EFA occupies about one-fifth of the rat thymus [18]. In chicken our morphometric studies confirm the considerable size of the KNA, that is, close to 50% of the medulla [2].…”

Eph/Ephrins-Mediated Thymocyte–Thymic Epithelial Cell Interactions Control Numerous Processes of Thymus Biology

“…These latter areas, of unknown significance, also exist in WT thymuses and in other mice with defects in molecules, such as Foxn1, Kremen 1, or Stat3, involved in TEC maturation ( 32 – 34 ), but are specially developed in EphB-deficient thymuses. They contain thymocytes and blood vessels, frequently surrounded by enlarged sheaths of connective tissue, and are different in cortex and medulla: the former ones contain thymocytes and some sheathed blood vessels, whereas in the medulla mTECs delimit areas with enlarged blood vessels, increased numbers of ER-TR7 + fibroblasts, components of the ECM (collagen IV, fibronectin, and laminin) ( 35 ), dendritic cells ( 36 ), and thymocytes in some areas ( 37 – 39 ).…”

A novel multicolor immunostaining method using ethynyl deoxyuridine for analysis of in situ immunoproliferative response

“…In the present study, by applying our original multicolor immunoenzyme (Saiki et al 2001 ; Ueta et al 2008 ) and immunofluorescence (Sawanobori et al 2014 ) staining methods, we have tried to develop a new method of simultaneous multicolor immunofluorescence staining using EdU for up to four colors for immunohistology and up to three colors for FCM. Two models for assessing the in vivo proliferative response of immune cells were examined.…”