Meckert P C, Hontebeyrie-Joskowicz M, Chambo J, Levin M, Laguens R P
Cátedra de Patología II, Facultad de Ciencias Médicas, Universidad de La Plata, Argentina.
Exp Parasitol. 1991 Jan;72(1):8-14. doi: 10.1016/0014-4894(91)90115-d.
In isolated skeletal, heart, and smooth muscle cells from BALB/c and C3H/HeJ mice infected with different strains of Trypanosoma cruzi the presence of class II MHC molecules was investigated by immunocytochemical techniques. We employed single muscle fibers instead of conventional cryostat sections to obtain a more accurate antigen localization. Approximately half of the skeletal muscle cells isolated from the rectus femoris expressed Ia antigens on their surface, irrespective of the mouse or parasite strain combination. Ia expression was apparent only at 30 days postinfection and thereafter. The heart muscle cells expressed class II molecules only at 1 and 3 months postinfection. In no case did the smooth muscle cells from infected mice express Ia antigens. Studies of the same molecules in the noninfected animals gave constantly negative results. We conclude that in the course of the chronic infection of mice with T. cruzi, ectopic expression of class II MHC molecules occurs at the surface of skeletal and heart muscle cells, providing a possible mechanism for explaining the anti-striped muscle autoreactivity present in Chagas' disease.
利用免疫细胞化学技术，研究了感染不同克氏锥虫菌株的BALB/c和C3H/HeJ小鼠的分离骨骼肌、心肌和平滑肌细胞中II类主要组织相容性复合体（MHC）分子的存在情况。我们采用单根肌纤维而非传统的低温恒温器切片，以获得更精确的抗原定位。无论小鼠或寄生虫菌株组合如何，从股直肌分离的大约一半骨骼肌细胞在其表面表达Ia抗原。Ia表达仅在感染后30天及之后才明显。心肌细胞仅在感染后1个月和3个月表达II类分子。感染小鼠的平滑肌细胞在任何情况下均不表达Ia抗原。对未感染动物中相同分子的研究结果始终为阴性。我们得出结论，在小鼠慢性感染克氏锥虫的过程中，II类MHC分子在骨骼肌和心肌细胞表面发生异位表达，这为解释恰加斯病中存在的抗条纹肌自身反应性提供了一种可能的机制。
