ABSTRACT
A novel coronavirus (COVID-19) that broke out in December 2019 has been declared a public health emergency of international concern. Nucleic acid detection has an irreplaceable role in the diagnosis of 2019-novel coronavirus (2019-nCoV) infection. However, due to the high requirements of laboratories and technicians, cumbersome operations, and the possibility of omission, nucleic acid detection should be combined with specific antibodies to achieve large-scale screening of suspected patients and close contacts. Moreover, antibody detection can reduce the exposure risk of medical personnel during the collection of respiratory tract samples.
ABSTRACT
Objective To investigate the role of interleukin-1 receptor type 1 (IL-1R1) signaling in H1N1 influenza virus infection. Methods IL-1R1 knockout ( IL-1R1-/-) mice and wild type ( WT) mice were infected intranasally with 2×104 TCID50(50% tissue culture infective dose) of influenza virus H1N1 PR8. Changes in clinical signs, survivals and bodyweights of those mice were monitored daily for 14 consecutive days. Three mice from each group were sacrificed at 3, 7 and 14 days post infection (d. p. i), from which whole lungs were harvested. A part of the lobes was fixed in 4% paraformaldehyde for histopatho-logical assessment and the rest were split and stored at-80 centigrade for further analysis. Real-time quanti-tative PCR and cytometric bead array ( CBA) were performed to detect viral loads in lungs and inflammatory cytokines in supernatants of lung homogenates. Results The mice in both groups showed severe symptoms after the infection of PR8. The maximum bodyweight loss of IL-1R1-/- mice [(24. 22±0. 80) % at 8 d. p. i] was lower than that of WT mice [(28. 03±1. 51)% at 9 d. p. i] (P<0. 05). The IL-1R1-/- mice with PR8 infection showed a higher survival rate (90%) as compared with that of the control group (40%) (P<0. 05). No statistical differences in virus loads were observed between the two groups at 3, 7 and 14 d. p. i. The lung weight to body weight ratio of IL-1R1-/-mice [(1. 42±0. 03) %] was lower than that of WT mice [(1. 79±0. 08) %] at 3 d. p. i (P<0. 05). Pathological changes in IL-1R1-/- mice were less severe than those in WT mice. CBA detection assay revealed that the proinflammatory cytokines in lungs of IL-1R1-/-mice were less than those in WT mice. Conclusion IL-1R1 signaling plays a pathogenic role in mice infec-ted with 2×104 TCID50 of influenza virus PR8 by promoting inflammatory responses.
ABSTRACT
Objective:To reveal the dynamic characteristics of the intracellular complement mRNA from mouse macrophage ANA-1 treated with LPS or IL-4. Methods:The polarization models of macrophage ANA-1 were established by treating with LPS(1μg/ml) and IL-4(20 ng/ml),respectively. After treating at 3,8,12 and 24 h,the total RNA were abstracted by Trizol lysis methods . The macrophage polarization were estimated by the expression of IL-1β, CCL2 and Arg-1 mRNA detected by Real-time fluorescent quantitative PCR. The intracellular complement C1q, C3, CfB and CRIg mRNA were quantitatively analyzed. Results: The mouse macrophage ANA-1 cells treated with LPS was polarized to M1 since the levels of IL-1β and CCL2 mRNA were up-regulated significantly,in which their 2-△△Ct value were up to 297. 0±31. 0 and 19. 9±3. 3 respectively at 12 h. On the other hand,the ANA-1 cells treated with IL-4 was polarized to M2 because the level of Arg-1 mRNA was obviously higher( the 2-△△Ct value of Arg-1 mRNA was up to 27.3±9.1 at 24 h)(P<0.05).The intracellular complement C1q,C3,CfB and CRIg mRNAs all were up-regulated in different polarized macrophages. The intracellular C1q and C3 mRNA in polarized M2 were significantly higher,in which the peak value of C1q and C3 were to 94. 9±12. 9 and 11. 3±2. 4 at 12 h,respectively(P<0. 05). Reversely,the CfB mRNA in polarized M1 increased obviously,in which its 2-△△Ct was to 61. 4±6. 2 at 12 h. In addition,the CRIg mRNA in both groups was only up-regulated at 24 h,in which the 2-△△Ct value was 6. 5±1. 8 in M1 and 10. 8±3. 2 in M2(P<0. 05). Conclusion: The macrophage ANA-1 cell polarization models were successfully established by treated with LPS or IL-4. The intracellular complement C1q,C3 and CRIg mRNA in polarized M2 were transcripted more than in M1. But the intracellular CfB mRNA in polarized M1 was up-regulated significantly. These results suggested that the dynamic characteristic of complement components in different polarized macrophage would be correlated with its fun-tions.