Boceta C, Alonso C, Jiménez-Ruiz A
Centro de Biología Molecular Severo Ochoa (Consejo Superior de Investigaciones Científicas, Universidad Autónoma de Madrid), Madrid, Spain.
Parasite Immunol. 2000 Feb;22(2):55-62. doi: 10.1046/j.1365-3024.2000.00269.x.
The PSA protein is one of the major antigens of the surface of the Leishmania infantum parasite membrane. We describe the immune humoral response against the PSA in dogs and human patients with visceral leishmaniasis caused by L. infantum. The immunodominant region of the PSA was determined by subcloning, expression and purification of three fragments covering the complete protein. The analysis revealed that the antibodies are mostly directed against the central region, which is formed exclusively by leucine rich repeats. This region is recognized by 100% of the sera from the infected dogs and 40% of the human sera. These percentages are significantly higher than those observed when the complete protein was used as antigen. The analysis of the isotype of the G immunoglobulins raised against the immunodominant determinants of the PSA indicates that both IgG1 and IgG2 classes are produced during natural infections but that the IgG2 predominates over that of the IgG1.
前列腺特异性抗原（PSA）蛋白是婴儿利什曼原虫寄生虫膜表面的主要抗原之一。我们描述了犬类和患有由婴儿利什曼原虫引起的内脏利什曼病的人类患者针对PSA的免疫体液反应。通过亚克隆、表达和纯化覆盖完整蛋白质的三个片段来确定PSA的免疫显性区域。分析表明，抗体主要针对中央区域，该区域仅由富含亮氨酸的重复序列组成。感染犬的100%血清和40%的人类血清可识别该区域。这些百分比显著高于将完整蛋白质用作抗原时观察到的百分比。针对PSA免疫显性决定簇产生的G免疫球蛋白的同种型分析表明，在自然感染期间会产生IgG1和IgG2两类，但IgG2比IgG1占优势。
