Kosciuczuk Ewa M, Lisowski Paweł, Jarczak Justyna, Majewska Alicja, Rzewuska Magdalena, Zwierzchowski Lech, Bagnicka Emilia
Department of Animal Improvement, Institute of Genetics and Animal Breeding Polish Academy of Sciences, 36a Postepu str., Jastrzebiec, 05-552, Poland.
Present address: Robert H. Lurie Comprehensive Cancer Center, Northwestern University, Chicago, IL, USA.
BMC Vet Res. 2017 Jun 6;13(1):161. doi: 10.1186/s12917-017-1088-2.
Genome-wide gene expression profiling allows for identification of genes involved in the defense response of the host against pathogens. As presented here, transcriptomic analysis and bioinformatics tools were applied in order to identify genes expressed in the mammary gland parenchyma of cows naturally infected with coagulase-positive and coagulase-negative Staphylococci.
In cows infected with coagulase-positive Staphylococci, being in 1st or 2nd lactation, 1700 differentially expressed genes (DEGs) were identified. However, examination of the 3rd or 4th lactations revealed 2200 DEGs. Gene ontology functional classification showed the molecular functions of the DEGs overrepresented the activity of cytokines, chemokines, and their receptors. In cows infected with coagulase-negative Staphylococci, in the 1st or 2nd lactations 418 DEGs, while in the 3rd or 4th lactations, 1200 DEGs were identified that involved in molecular functions such as protein, calcium ion and lipid binding, chemokine activity, and protein homodimerization. Gene network analysis showed DEGs associated with inflammation, cell migration, and immune response to infection, development of cells and tissues, and humoral responses to infections caused by both types of Staphylococci.
A coagulase-positive Staphylococci infection caused a markedly stronger host response than that of coagulase-negative, resulting in vastly increased DEGs. A significant increase in the expression of the FOS, TNF, and genes encoding the major histocompatibility complex proteins (MHC) was observed. It suggests these genes play a key role in the synchronization of the immune response of the cow's parenchyma against mastitis-causing bacteria. Moreover, the following genes that belong to several physiological pathways (KEGG pathways) were selected for further studies as candidate genes of mammary gland immune response for use in Marker Assisted Selection (MAS): chemokine signaling pathway (CCL2, CXCL5, HCK, CCR1), cell adhesion molecules (CAMs) pathway (BOLA-DQA2, BOLA-DQA1, F11R, ITGAL, CD86), antigen processing and presentation pathway (CD8A, PDIA3, LGMN, IFI30, HSPA1A), and NOD-like receptor signaling pathway (TNF, IL8, IL18, NFKBIA).
全基因组基因表达谱分析有助于鉴定宿主针对病原体的防御反应中涉及的基因。本文介绍了转录组分析和生物信息学工具的应用，以鉴定自然感染凝固酶阳性和凝固酶阴性葡萄球菌的奶牛乳腺实质中表达的基因。
在感染凝固酶阳性葡萄球菌的第1或第2胎奶牛中，鉴定出1700个差异表达基因（DEG）。然而，对第3或第4胎奶牛的检查发现了2200个DEG。基因本体功能分类显示，DEG的分子功能在细胞因子、趋化因子及其受体的活性方面表现出过度富集。在感染凝固酶阴性葡萄球菌的奶牛中，第1或第2胎有418个DEG，而在第3或第4胎中，鉴定出1200个DEG，这些DEG涉及蛋白质、钙离子和脂质结合、趋化因子活性以及蛋白质同二聚化等分子功能。基因网络分析显示，DEG与炎症、细胞迁移、对感染的免疫反应、细胞和组织发育以及对两种葡萄球菌引起的感染的体液反应相关。
凝固酶阳性葡萄球菌感染引起的宿主反应比凝固酶阴性葡萄球菌明显更强，导致DEG大量增加。观察到FOS、TNF以及编码主要组织相容性复合体蛋白（MHC）的基因表达显著增加。这表明这些基因在奶牛乳腺实质针对引起乳腺炎的细菌的免疫反应同步中起关键作用。此外，选择了属于几种生理途径（KEGG途径）的以下基因作为乳腺免疫反应的候选基因进行进一步研究，以用于标记辅助选择（MAS）：趋化因子信号通路（CCL2、CXCL5、HCK、CCR1）、细胞粘附分子（CAMs）通路（BOLA - DQA2、BOLA - DQA1、F11R、ITGAL、CD86）、抗原加工和呈递通路（CD8A、PDIA3、LGMN、IFI30、HSPA1A）以及NOD样受体信号通路（TNF、IL8、IL18、NFKBIA）。
