将中文句子翻译为英文段落使逻辑清晰更加学术化：本章旨在研究体外LNT对于地塞米松处理后的T淋巴细胞的作用。首先通过MTT法测定LNT在小鼠脾脏淋巴细胞上的最大安全浓度范围并构建体外免疫抑制模型。利用流式细胞术探究LNT对DEX处理后的淋巴细胞的增殖与分化的影响。通过RT-PCR检测细胞因子mRNA水平的变化。

The aim of this chapter is to investigate the effect of ex vivo Lentinan (LNT) on T lymphocytes treated with dexamethasone (DEX). Firstly, the maximum safe concentration range of LNT on mouse splenic lymphocytes was determined using the MTT assay, and an ex vivo immune suppression model was established. Flow cytometry was used to explore the effects of LNT on the proliferation and differentiation of lymphocytes treated with DEX. Changes in cytokine mRNA levels were detected using RT-PCR.