PMC3925152_01
PMC3925152_02
Innate immune response against MERS-CoV requires IFNalpha expression.. 
A,B,C,D,E,F qRTPCR analysis of RIG-1, MDA-5 IRF3, IRF7, IFNalpha and IFNbeta from first week broncho-alveolar lavage (BAL) cells of MERS-CoV infected patients, patient 1 and patient 2 (black columns), Control (white column), S. pneumoniae-induced pneumonia (dark grey column) and patient 2 Herpes simplex virus-induced pneumonia (light grey column) (n = 2 to 4, duplicates). G Assessment of IFNalpha protein in BAL supernatants from the first week following onset of clinical symptoms in samples from patient 1 and patient 2. Control group, HSV and bacterial samples from BALs of patients without infection, with lung HSV replication and with upper respiratory tract infection respectively. (n = 2 to 4, duplicates), and assessment of IFNalpha protein in sera of the 30 days following MERS-CoV infection in patient 1 (black line) and patient 2 (grey line). (n = 2 to 4, duplicates). Measurement obtained between D0-3: day 0 and day 3, D4-7: day 4 and 7, D8-14: day 8 and 14, D15-21: day 15 and 21, D22-30: day 22 and 30.
pone.0088716.g001.jpg
PMC3925152_02_pone.0088716.g001.jpg
pone-0088716-g001
MDA-5 (Figure 1A and 1B), in response to MERS-CoV infection. Moreover, IRF3 and IRF7 expression were decreased (Figure 1C and 1D) leading to a dramatically decreased IFNalpha expression (Figure 1E), without any difference in IFNbeta expression (Figure 1F). IFNalpha secretion in BAL supernatants and serum was consistent with the previous findings, IFNalpha levels were decreased in sera and BAL from patient 1 compared to patient 2 (Figure 1G).
Adaptive response to control MERS-CoV replication requires early IL-12/IFNgamma secretion.. 
A Assessment of IL-12 and IFNgamma protein in BAL supernatants of first week following onset of clinical symptoms of patient 1 and patient 2. Control group, HSV and bacterial were same samples as previously described. (n = 2 to 4, duplicates). B Assessment of IL-12 and IFNgamma protein in sera of the 30 days following MERS-CoV infection in Patient 1 (black line) and Patient 2 (grey line). (n = 2 to 4, duplicates). C Assessment of MERS-CoV viral load by quantitative PCR in threshold Cycle (Ct) in serum. Measurement obtained between D0-3: day 0 and day 3, D4-7: day 4 and 7, D8-14: day 8 and 14, D15-21: day 15 and 21, D22-30: day 22 and 30.
pone.0088716.g002.jpg
PMC3925152_02_pone.0088716.g002.jpg
pone-0088716-g002
Here we report that IL-12 and IFNgamma levels were decreased in BAL supernatants of patient 1 compared to patient 2 (Figure 2A). Furthermore, the kinetic analysis of IL-12 and IFNgamma levels in the sera after infection shows that patient 2 promoted an early Th1 response mediated by IL-12 and IFNgamma in response to MERS-CoV (Figure 2B).
Persistent increased levels of CXCL10 and IL-10 are found in the patient with poor outcome during MERS-CoV infection.. Assessment of CXCL10 and IL-10 protein in sera of the 30 days following MERS-CoV infection in patient 1 (black line) and patient 2 (grey line). (n = 2 to 4, duplicates). Measurement obtained between D0-3: day 0 and day 3, D4-7: day 4 and 7, D8-14: day 8 and 14, D15-21: day 15 and 21, D22-30: day 22 and 30.
pone.0088716.g003.jpg
PMC3925152_02_pone.0088716.g003.jpg
pone-0088716-g003
CXCL10 secretion. Consistent with these findings, we found that both patients initially promoted IL-10 and CXCL10 secretion in response to MERS-CoV (Figure 3).
MERS-CoV induces IL-17 secretion.. 
A, qRTPCR analysis of IL-17A from first week broncho-alveolar lavage (BAL) cells of MERS-CoV infected patients, Patient 1 and Patient 2 (black columns), Control (white column), S. Pneumoniae-induced pneumonia (dark grey column) and Patient 2 Herpes simplex virus-induced pneumonia (light grey column) (n = 2 to 4, duplicates). B, Assessment of IL-17A and IL-23 protein in BAL supernatants of first week following onset of clinical symptoms of patient 1 and patient 2. Control group, HSV and bacterial were same samples as previously described. (n = 2 to 4, duplicates) C, Assessment of IL-17A and IL-23 protein in sera of the 30 days following MERS-CoV infection in patient 1 (black line) and patient 2 (grey line). (n = 2 to 4, duplicates). Measurement obtained between D0-3: day 0 and day 3, D4-7: day 4 and 7, D8-14: day 8 and 14, D15-21: day 15 and 21, D22-30: day 22 and 30.
pone.0088716.g004.jpg
PMC3925152_02_pone.0088716.g004.jpg
pone-0088716-g004
Consistent with these findings, we report that MERS-CoV increases the expression of IL-17A in the lungs (Figure 4A). We assessed the secretion of IL-17A in BAL supernatants and showed that IL-17A secretion was increased in both patients in response to MERS-CoV (Figure 4B), with higher level for patient 1 compared to patient 2. To this end, we assessed IL-23 secretion in the lungs and found that IL-23 secretion was significantly increased in BAL from patient 1 compared to patient 2 (Figure 4B). IL-23 and IL-17A levels in the serum of patient 1, in the first days following the infection by MERS-CoV (Figure 4C). Interestingly, IL-23 secretion was increased in the BAL supernatant of patient 2 during HSV replication.