Xidieh C F, Lenzi H L, Calich V L, Burger E
Departamento de Imunologia, Instituto de Ciências Biomédicas, Universidade de São Paulo, SP, Brazil.
Med Microbiol Immunol. 1999 Aug;188(1):41-9. doi: 10.1007/s004300050103.
To compare the sequential evolution of lesions developed by resistant (A/Sn) and susceptible (B10.A) mice to Paracoccidioides brasiliensis infection we inoculated a virulent isolate of the fungus and collected the pancreas/peripancreatic omentum monthly (from 1 to 6 months) post infection. After fixation, tissue sections were stained by conventional methods for light microscopy to investigate the cellular composition, the extracellular matrix (ECM) patterns and the morphology of the yeasts in the lesions. In both strains, the fungal lesions were localized mostly in the omentum; a few lesions in the pancreatic parenchyma were observed, mostly in B10.A mice. In both strains, macrophages and plasmocytes were the predominant cells in all lesions, followed by neutrophils (PMN) and macrophages transformed into giant and epithelioid cells. Remarkable differences were observed between resistant and susceptible mice, specially related to the ECM structure of the granulomatous lesions. In A/Sn mice, from the 1st month on, the coexistence of two types of lesions was observed: one type showed a well-defined encapsulated nodule, constituted mainly of type I collagen. Neutrophils were abundant in areas of massive fungal destruction and few viable yeasts were observed. The other type showed residual characteristics, with sparse collagen deposits and presence of xantomatous-like macrophages, containing degenerated fungi. Such residual lesions predominated after the 2nd month and were the only type observed from the 4th month on, indicating the control of the infection. In B10.A mice, on the contrary, only one type of lesion was observed, showing less tendency to encapsulation and the formation of multiple small granulomatous foci, individualized by reticular type III collagen fibers. There were many plasmocytes in the periphery and large numbers of budding yeasts, with no evidence of fungal destruction. In the course of the infection the lesions progressively increased in number and size. Altogether, the comparative histopathological analysis demonstrates the influence of the genetic pattern of the host on the lesions developed by resistant and susceptible mice to P. brasiliensis infection.
为比较抗性（A/Sn）和易感（B10.A）小鼠感染巴西副球孢子菌后病变的连续演变情况，我们接种了该真菌的一个强毒株，并在感染后每月（1至6个月）采集胰腺/胰腺周围网膜。固定后，组织切片用常规方法染色用于光学显微镜检查，以研究病变中的细胞组成、细胞外基质（ECM）模式和酵母形态。在两种品系中，真菌病变主要位于网膜；在胰腺实质中观察到少数病变，主要见于B10.A小鼠。在两种品系中，巨噬细胞和浆细胞是所有病变中的主要细胞，其次是中性粒细胞（PMN）和转化为巨细胞和上皮样细胞的巨噬细胞。在抗性和易感小鼠之间观察到显著差异，特别是与肉芽肿性病变的ECM结构有关。在A/Sn小鼠中，从第1个月开始，观察到两种类型病变的共存：一种类型表现为界限分明的包膜结节，主要由I型胶原组成。在大量真菌破坏区域中性粒细胞丰富，观察到少量存活酵母。另一种类型表现为残留特征，胶原沉积稀疏，存在含退化真菌的黄色瘤样巨噬细胞。这种残留病变在第2个月后占主导地位，并且是从第4个月开始观察到的唯一类型，表明感染得到控制。相反，在B10.A小鼠中，仅观察到一种类型的病变，显示出较少的包膜形成倾向和多个小肉芽肿灶的形成，由网状III型胶原纤维分隔。周边有许多浆细胞和大量芽生酵母，没有真菌破坏的迹象。在感染过程中，病变的数量和大小逐渐增加。总之，比较组织病理学分析证明了宿主遗传模式对抗性和易感小鼠感染巴西副球孢子菌后形成的病变的影响。
