RESUMO
In the absence of a proven effective vaccine preventing infection by SARS-CoV-2, or a proven drug to treat COVID-19, the positive results of passive immune therapy using convalescent serum provides a strong lead. We have developed a new class of tetravalent, biparatopic therapy, 89C8-ACE2. It combines the specificity of a monoclonal antibody (89C8) that recognizes the relatively conserved N-terminal domain (NTD) of the viral S glycoprotein, and the ectodomain of ACE2, which binds to the receptor-binding domain (RBD) of S. This molecule shows exceptional performance in vitro, inhibiting the interaction of recombinant S1 to ACE2 and transduction of ACE2-overexpressing cells by S-pseudotyped lentivirus with IC50s substantially below 100 pM, and with potency approximately 100-fold greater than ACE2-Fc itself. Moreover, 89C8-ACE2 was able to neutralize authentic virus infection in a standard assay at low nanomolar concentrations, making this class of molecule a promising lead for therapeutic applications.
RESUMO
BACKGROUND:Antibiotics are widely given for surgical patients to prevent infection. Because of the lack of study on the rational use of antibiotics in patients with human immunodeficiency virus (HIV) -infected during surgical procedures, we analyzed the risk factors affecting postoperative infectious complications in HIV-infected patients and explore the rational use of perioperative antibiotics. METHODS:This retrospective study consisted of 308 HIV-infected patients, 272 males and 36 females, who had undergone operation at the Shanghai Public Health Clinical Center from November 2008 to April 2012. The patients were divided into postoperative infection and non-infection groups. Their age and clinical variables were compared. The correlation between surgical incision, surgical site infection (SSI) and postoperative sepsis was analyzed. Prophylactic antibiotics were used for patients with type I and II incisions for less than 2 days. Patients with type III incisions were given antibiotics until the infection was controlled. Antiretroviral therapy (ART) was prescribed preoperatively for patients whose preoperative CD4 count was <350 cells/μL. For those patients whose preoperative CD4 count was <200 cells/μL, sulfamethoxazole and fluconazole were given preoperatively as prophylactic agents controllingPneumocystis carinii pneumonia and fungal infection. RESULTS:A total of 196 patients developed postoperative infectious complications, and 7 patients died. Preoperative CD4 counts, ratio of CD4/CD8 cels, hemoglobin level, and postoperative CD4 counts, hemoglobin and albumin levels were risk factors of perioperative infection in HIV-infected patients. Patients with a preoperative CD4 count <200 cel/μL, anemia, a postoperative CD4 count <200 cel/μL or albumin levels <35 g/L were correlated with a higher rate of perioperative infection. There was a significant correlation between SSI and the type of surgical incision. The rate of SSI in patients with type I surgical incision was 2％ and in those with type II surgical incision was 38％. Allthe patients who received type III surgical incision developed SSI, and they were more likely to develop postoperative sepsis. CONCLUSIONS:HIV-infected patients are more likely to develop postoperative infectious complications. The rational use of antibiotics in HIV-infected patients could help to reduce the rate of postoperative infectious complications in these patients.
RESUMO
Regulatory T (Treg) cells play an essential role in immune homeostasis by controlling the function of various immune effector cells, including RAR-related orphan receptor gammat(+) (RORγt(+)) T helper 17 (Th17) cells. Foekhead box P(3) (FoxP(3)) is the master regulator of Treg cell function, while RORγt is the key transcription factor for the induction of the interleukin (IL)-17 family of cytokines during Th17 cell differentiation. FoxP3 can directly interact with and negatively regulate the function of RORγt, to determine the balance between induced Treg (iTreg) and Th17 cell polarization. Two recent independent studies from the Pan and Chi Labs have shown how hypoxia-inducible factor 1 alpha (HIF1α) is able to tip the balance of T cell differentiation toward the Th17 lineage by responding to the local changes in metabolic shift or an increase in proinflammatory mediators in the microenvironment. By allying with HIF1α, RORγt wins the fight against FoxP3 and Treg cell commitment.
