ABSTRACT
As SARS-CoV-2 variants emerge, there is a critical need to understand the effectiveness of serum elicited by different SARS-CoV-2 vaccines. A reference reagent comprised of post-vaccination sera from recipients of different vaccines allows evaluation of in vitro variant neutralization, and provides a reference for comparing assay results across laboratories. We prepared and pooled >1 L serum from donors who received the SARS-CoV-2 mRNA vaccines (BNT162b2, Pfizer and mRNA-1273, Moderna), a replication-incompetent adenovirus type 26 vaccine (Ad26.COV2.S, Johnson and Johnson), or recombinant spike protein expressed by baculovirus incorporated into a nanoparticle vaccine plus Matrix-M adjuvant (NVX-CoV2373, Novavax). Twice frozen sera were aliquoted and are available for distribution to the research community (BEI Resources). The calculated WHO titer of pooled sera to spike protein was 1,312, 1,447, 1,936, and 587 and the reciprocal RBD binding to ACE-2 IC90-titers were 60, 64, 118, and 46 for BNT162b2, mRNA1273, Ad26.CoV2373, and NVX-CoV2373 sera, respectively.
ABSTRACT
Objective:To investigate the effects of Cordyceps sinensis (CS) on cellular apoptosis and Sirt1 expression in HK2 cells followed by ischemia-reperfusion (I/R).Methods:HK2 cells were incubated with different concentrations of CS (10,20,40,80,160,320 mg/L) for 24 hours,and the optimal concentration of CS was selected by measuring cell proliferation.The confluent HK2 cells were incubated with 0.01 μmol/L antimycin A for 2 hours to induce ischemia in vitro,and then the reperfusion was achieved by incubating cells with glucose-replete complete growth medium for 24 hours.HK2 cells were divided into 4 groups:a control group,an I/R group,an I/R+CS (160 mg/L) group,and an I/R+CS (160 mg/L)+Sirtinol (25 μtmol/L) group.Twenty-four hours later,total RNA and protein were collected.The cell proliferation was evaluated by MTT assay;the mRNA and protein expression of Sirtl and the cleaved caspase-3 were measured by qRT-PCR and Western blot,respectively.The cellular apoptosis rate was determined by Annexin V-FITC/PI double staining and flow cytometry.Results:Certain concentrations (10-160 mg/L) of CS did not show effect on the proliferation of HK2 cells (P＞0.05),while 320 mg/L of CS inhibited cell proliferation significantly (P＜0.01);compared with the control group,the mRNA and protein expressions of Sirtl and the cleaved caspase-3 in the I/R group were up-regulated (P＜0.01) and the apoptosis rate was extremely high;compared with the I/R group,CS significantly up-regulated Sirt1 mRNA and protein expression (P＜0.01) while down-regulated cleaved caspase-3 mRNA and protein levels (P＜0.01),and reduced apoptosis rate (P＜0.05).The effects of CS were blocked in the presence of sirtinol,an inhibitor of CS.Conclusion:CS protects HK2 cells from I/R injury through activation of Sirt 1 pathway.
