Brennan F R, Negroiu G, Buzás E I, Fülöp C, Holló K, Mikecz K, Glant T T
Department of Biochemistry, Rush Medical University at Rush-Presbyterian-St Luke's Medical Centre, Chicago, IL 60612, USA.
Clin Exp Immunol. 1995 Apr;100(1):104-10. doi: 10.1111/j.1365-2249.1995.tb03610.x.
Immunization of BALB/c mice with human fetal cartilage proteoglycan (PG) produces progressive polyarthritis, and T cells play key roles in the development of the disease. To gain an understanding of how PG is presented to autoreactive T cells by synovial antigen-presenting cells (APC), we examined the abilities of various syngeneic APC in presenting PG to a specific T cell hybridoma 5/4E8, derived from a mouse with PG-induced arthritis. A20 B lymphoma cells and spleen cells were strong presenters of PG, but synoviocytes and P388D1 macrophages could only present PG effectively after stimulation with interferon-gamma (IFN-gamma). The IFN-gamma exerted its effect by up-regulating both MHC class II and intercellular adhesion molecule-1 (ICAM-1) expression by these cells as neutralizing antibodies to Ia, LFA-1 and ICAM-1 inhibited presentation. Our studies also showed that synoviocytes and spleen cells took up and processed PG more rapidly than the cell lines. Cysteine and serine protease-dependent antigen presentation of PG was blocked at 4 degrees C, 18 degrees C and by chloroquine treatment, indicating that presentation required active uptake and processing in an acidic compartment, probably in lysosomes. Also, keratan sulphate-depleted and cyanogen bromide (CNBr) and 2-nitro-5-thiocyanobenzoic acid (NTCB)-cleaved PG elicited stronger T cell responses, as they were more easily processed than the native molecule. Furthermore, CNBr-generated peptides were presented by fixed APC, indicating that core protein fragments of cartilage PG can be presented directly by APC in context with MHC class II molecules.
用人胎儿软骨蛋白聚糖（PG）免疫BALB/c小鼠可引发进行性多关节炎，T细胞在该疾病的发展中起关键作用。为了解PG如何由滑膜抗原呈递细胞（APC）呈递给自身反应性T细胞，我们检测了各种同基因APC将PG呈递给源自PG诱导性关节炎小鼠的特异性T细胞杂交瘤5/4E8的能力。A20 B淋巴瘤细胞和脾细胞是PG的强呈递细胞，但滑膜细胞和P388D1巨噬细胞只有在用干扰素-γ（IFN-γ）刺激后才能有效呈递PG。IFN-γ通过上调这些细胞的MHC II类分子和细胞间黏附分子-1（ICAM-1）的表达发挥作用，因为针对Ia、LFA-1和ICAM-1的中和抗体可抑制呈递。我们的研究还表明，滑膜细胞和脾细胞比细胞系更快地摄取和处理PG。PG的半胱氨酸和丝氨酸蛋白酶依赖性抗原呈递在4℃、18℃以及用氯喹处理时被阻断，这表明呈递需要在酸性区室（可能是溶酶体）中进行主动摄取和处理。此外，硫酸角质素缺失以及经溴化氰（CNBr）和2-硝基-5-硫氰基苯甲酸（NTCB）裂解的PG引发更强的T细胞反应，因为它们比天然分子更容易被处理。此外，固定的APC可呈递CNBr产生的肽，这表明软骨PG的核心蛋白片段可与MHC II类分子结合由APC直接呈递。
