Gene transcriptional profiles of porcine spleen and lung in response to H.parasuis infection
Through comparative analysis, we found that 264 transcripts showed a level of expression that differed significantly from that of the control group with H.parasuis serovar 5 SH0165 (HPS0165) strain infected group, while a total of 89 genes were identified in porcine lung infected with HPS0165 strain compared with uninfected tissues (Fig. 1A and 1B, Supplementary S1). At the same time, we integrated the DEGs of spleen and lung and found that There were 15 overlapping genes (ALAS2, SOD2, C4BPA, TCN1, CXCL2, LTF, PDK4, TGM3, TIMP1, CRABP1, NREP, RETN, DGAT2, UPP1 and CD163) between the two datasets (Fig. 1C). The volcano plot of the datasets was shown in Fig. 1D and E.
Gene transcriptional profiles of porcine alveolar macrophages in response to H.parasuis infection
Porcine alveolar macrophages (PAMs) are important lung tissue-resident professional phagocytes and play a central role in inflammation and host defense. Hence, to uncover the key genes of PAM in response to H.parasuis, we collected two different gene expression profiles of GSE30172 and GSE34544 infected by HPS5 and HPS4, respectively. The results showed that the screening of GSE30172 identified 257 DEGs, 204 genes which were up-regulated and 53which were down-regulated (Fig. 2A). Similarly, we obtained DEGs from GSE34544, only 20 genes which were up-regulated and 3 which were down- regulated (Fig. 2B). 11 overlapping genes (C1H15orf48, RNF128, TIMP1, CXCR6, CXCL14, IGHA, IGG2B, S100A4, GBP1, CALHM6 and LTB) were found between these two datasets (Fig. 2C). In the meantime, the overlap genes were shown using the volcano plot in Fig. 2D and E.
TIMP1 may be a key gene for H.parasuis infection
Comparing with the four datasets above, we found that TIMP1 was the only overlapping gene and significantly upregulated by H.parasuis in porcine diverse tissues or cells, indicating that TIMP1 could play an important role during H.parasuis invasion. Further, to verify this conjecture, we analyzed TIMP1 mRNA expression in porcine blood, peripheral blood mononuclear cell (PBMC) and aortic vascular endothelial cells (PAVECs), and found that TIMP1 mRNA was significantly overexpressed in all datasets (all P value < 0.01, Fig. 3A,3B and 3C), suggesting that TIMP1 may play an important role in H.parasuis infection.