Altered cytokine expression in mesenteric lymph nodes in a rat strain (Matsumoto Eosinophilic Shinshu) that spontaneously develops hypereosinophilia

Abstract

Summary The Matsumoto Eosinophilic Shinshu (MES) rat is an inbred mutant strain that spontaneously develops systemic hypereosinophilia with eosinophilic inflammatory lesions similar to those associated with hypereosinophilic syndrome in humans and other mammals. To elucidate the pathogenic mechanisms that underlie these features of MES rats, we examined the pattern of cytokine gene expression in mesenteric lymph nodes (MLNs), the thymus, and peripheral blood mononuclear cells as well as the blood clinicopathology and MLN lymphocytic subsets of these animals. MES rats exhibited both leucocytosis, attributable in large part to hypereosinophilia and neutrophilia, and immunoglobulin M (IgM) and IgA gammaglobulinaemia, with increased titres of IgM autoantibodies to nuclear antigens. Reverse transcription and polymerase chain reaction analysis revealed that the amounts of interleukin (IL)‐5, IL‐4, eotaxin, and interferon‐γ mRNAs were increased in the MLN lymphocytes of MES rats compared with the corresponding values for Sprague‐Dawley rats. Intraperitoneal administration of a monoclonal antibody specific for IL‐5 resulted in an immediate suppression of hypereosinophilia and a delayed suppression of neutrophilia in MES rats. Flow cytometry revealed an increased percentage of CD3+ CD4– CD8– T lymphocytes in MLNs of MES rats. Our results suggest that the hypereosinophilia of MES rats results from an increased production of IL‐5, and that the eosinophilic inflammatory lesions of these animals, which are largely restricted to the gut, may be related both to cytokine overexpression in MLNs and to T helper 1 and 2 immunological responses.

Synthetic double-stranded RNA enhances airway inflammation and remodelling in a rat model of asthma

“…Complementary DNA was synthesized using Superscript III first‐strand synthesis supermix (Invitrogen) and the PCR was performed with the Miniopticon real‐time detection system (Bio‐Rad, Hercules, CA) using iQ SYBR Green Supermix (Bio‐Rad). The sequences and annealing temperatures of rat primers are shown in Table 1 17–24 . The size of each PCR product was confirmed by agarose gel electrophoresis.…”

BN.MES-Cybames Congenic Rats Manifest Focal Necrosis with Eosinophilic Infiltration in the Liver without Blood Eosinophilia

“…The Matsumoto Eosinophilia Shinshu (MES) rat strain genetically develops eosinophilia [12,[16][17][18]23]. In these rats, a marked increase in peripheral blood eosinophils (>500/µl) occurs at about nine weeks of age, with eosinophilia progressing with age until the number of eosinophils eventually exceeds the level that is characteristic of human idiopathic hypereosinophilia (>1,500/ µl).…”

A Third Locus for Eosinophilia on Chromosome 1 of the MES Rats

“…Matsumoto Eosinophilia Shinshu (MES) is a rat strain that develops eosinophilia spontaneously [3][4][5][6]8]. In these rats a marked increase in peripheral blood eosinophils (>500/µl) occurs at about 9 weeks of age, with eosinophilia progressing with age until the number of eosinophils eventually exceeds the level that is characteristic of human hypereosinophilia (>1,500/µl).…”

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Abstract: Matsumoto Eosinophilia Shinshu (MES) is a rat strain that spontaneously develops eosinophilia and eosinophil-related inflammatory lesions in many organsThe etiology of the majority of idiopathic HES cases and the mechanisms of eosinophilopoiesis remain poorly understood.Matsumoto Eosinophilia Shinshu (MES) is a rat strain that develops eosinophilia spontaneously [3][4][5][6]8]. In these rats a marked increase in peripheral blood eosinophils (>500/µl) occurs at about 9 weeks of age, with eosinophilia progressing with age until the number of eosinophils eventually exceeds the level that is characteristic of human hypereosinophilia (>1,500/µl).

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