Kalmar Isabelle, Berndt Angela, Yin Lizi, Chiers Koen, Sachse Konrad, Vanrompay Daisy
Department of Molecular Biotechnology and Immunology, Ghent University, Belgium.
Institute of Molecular Pathogenesis, Friedrich-Loeffler-Institut (Federal Research Institute for Animal Health), Jena, Germany.
Vet Immunol Immunopathol. 2015 Mar 15;164(1-2):30-9. doi: 10.1016/j.vetimm.2014.12.014. Epub 2015 Jan 10.
Although Chlamydia (C.) psittaci infections are recognized as an important factor causing economic losses and impairing animal welfare in poultry production, the specific mechanisms leading to severe clinical outcomes are poorly understood. In the present study, we comparatively investigated pathology and host immune response, as well as systemic dissemination and expression of essential chlamydial genes in the course of experimental aerogeneous infection with C. psittaci and the closely related C. abortus, respectively, in specific pathogen-free chicks. Clinical signs appeared sooner and were more severe in the C. psittaci-infected group. Compared to C. abortus infection, more intense systemic dissemination of C. psittaci correlated with higher and faster infiltration of immune cells, as well as more macroscopic lesions and epithelial pathology, such as hyperplasia and erosion. In thoracic air sac tissue, mRNA expression of immunologically relevant factors, such as IFN-γ, IL-1β, IL-6, IL-17, IL-22, LITAF and iNOS was significantly stronger up-regulated in C. psittaci- than in C. abortus-infected birds between 3 and 14 days post-infection. Likewise, transcription rates of the chlamydial genes groEL, cpaf and ftsW were consistently higher in C. psittaci during the acute phase. These findings illustrate that the stronger replication of C. psittaci in its natural host also evoked a more intense immune response than in the case of C. abortus infection.
虽然鹦鹉热衣原体感染被认为是导致家禽生产经济损失和损害动物福利的重要因素，但导致严重临床后果的具体机制却知之甚少。在本研究中，我们分别在无特定病原体的雏鸡中，对鹦鹉热衣原体和密切相关的流产衣原体进行实验性空气传播感染，比较研究了病理学和宿主免疫反应，以及衣原体重要基因的全身扩散和表达情况。鹦鹉热衣原体感染组的临床症状出现得更早且更严重。与流产衣原体感染相比，鹦鹉热衣原体更广泛的全身扩散与免疫细胞更高、更快的浸润相关，以及更多的宏观病变和上皮病理变化，如增生和糜烂。在胸气囊组织中，感染后3至14天，鹦鹉热衣原体感染的鸟类中免疫相关因子如IFN-γ、IL-1β、IL-6、IL-17、IL-22、LITAF和iNOS的mRNA表达上调明显强于流产衣原体感染的鸟类。同样，在急性期，鹦鹉热衣原体中衣原体基因groEL、cpaf和ftsW的转录率始终更高。这些发现表明，鹦鹉热衣原体在其自然宿主中更强的复制也比流产衣原体感染引发了更强烈的免疫反应。
