Xiaoli Zhang

TGF-beta can be a potent suppressor of lymphocyte effector cell functions and can mediate these effects via distinct molecular pathways. The role of TGF-beta in regulating CD16-mediated NK cell IFN-gamma production and antibody-dependent cellular cytotoxicity (ADCC) is unclear, as are the signaling pathways that may be utilized. Treatment of primary human NK cells with TGF-beta inhibited IFN-gamma production induced by CD16 activation with or without IL-12 or IL-2, and it did so without affecting the phosphorylation/activation of MAP kinases ERK and p38, as well as STAT4. TGF-beta treatment induced SMAD3 phosphorylation, and ectopic overexpression of SMAD3 resulted in a significant decrease in IFN-gamma gene expression following CD16 activation with or without IL-12 or IL-2. Likewise, NK cells obtained from smad3(-/-) mice produced more IFN-gamma in response to CD16 activation plus IL-12 when compared with NK cells obtained from wild-type mice. Coactivation of human NK cells via CD16 and IL-12 induced expression of T-BET, the positive regulator of IFN-gamma, and T-BET was suppressed by TGF-beta and by SMAD3 overexpression. An extended treatment of primary NK cells with TGF-beta was required to inhibit ADCC, and it did so by inhibiting granzyme A and granzyme B expression. This effect was accentuated in cells overexpressing SMAD3. Collectively, our results indicate that TGF-beta inhibits CD16-mediated human NK cell IFN-gamma production and ADCC, and these effects are mediated via SMAD3.

Abstract Background We aim to investigate the profile of acute antibody response in COVID-19 patients, and provide proposals for the usage of antibody test in clinical practice. Methods A multi-center cross-section study (285 patients) and a single-center follow-up study (63 patients) were performed to investigate the feature of acute antibody response to SARS-CoV-2. A cohort of 52 COVID-19 suspects and 64 close contacts were enrolled to evaluate the potentiality of the antibody test. Results The positive rate for IgG reached 100% around 20 days after symptoms onset. The median day of seroconversion for both lgG and IgM was 13 days after symptoms onset. Seroconversion of IgM occurred at the same time, or earlier, or later than that of IgG. IgG levels in 100% patients (19/19) entered a platform within 6 days after seroconversion. The criteria of ‘IgG seroconversion’ and ‘> 4-fold increase in the IgG titers in sequential samples’ together diagnosed 82.9% (34/41) of the patients. Antibody test aided to confirm 4 patients with COVID-19 from 52 suspects who failed to be confirmed by RT-PCR and 7 patients from 148 close contacts with negative RT-PCR. Conclusion IgM and IgG should be detected simultaneously at the early phase of infection. The serological diagnosis criterion of seroconversion or the ‘>; 4-fold increase in the IgG titer’ is suitable for a majority of COVID-19 patients. Serologic test is helpful for the diagnosis of SARS-CoV-2 infection in suspects and close contacts.

OBJECTIVE: To report outcomes of pregnancies that occurred during the fingolimod clinical development program. METHODS: Pregnancy outcomes from phase II, phase III, and phase IV clinical studies (with optional extensions) were reported by clinical trial investigators. Fingolimod exposure in utero was defined as fingolimod treatment at the time of conception or in the 6 weeks before conception. RESULTS: As of October 31, 2011, 89 pregnancies were reported in completed or ongoing clinical studies, with 74 in fingolimod treatment arms. Of 66 pregnancies with in utero exposure to fingolimod, there were 28 live births, 9 spontaneous abortions, 24 elective abortions, 4 ongoing pregnancies, and 1 pregnancy with an unknown outcome (patient lost to follow-up). Two infants were born with malformations: 1 with congenital unilateral posteromedial bowing of the tibia and 1 with acrania. Elective abortions were performed for 1 case each of tetralogy of Fallot, spontaneous intrauterine death, and failure of fetal development. There were 5 cases (7.6%; 95% confidence interval 3%-17%) of abnormal fetal development in the 66 pregnancies that had in utero exposure to fingolimod. In all 5 cases, fetal exposure to the drug took place in the first trimester of pregnancy. CONCLUSIONS: The number of patients becoming pregnant during fingolimod therapy remains small and does not permit firm conclusions to be drawn about fetal safety of fingolimod in humans. Given the known risks of teratogenicity in animals and the present data, women of childbearing potential should use effective contraception during fingolimod therapy and for 2 months after discontinuation.

Hydrophobic sol-gel derived methylsilsesquioxane (MSQ) was compared to wax and alkylketene dimer (AKD) as barrier materials defining channels in paper-based microfluidic devices. While all three of the barrier types performed well with water, only the MSQ barriers were not breached by aggressive cell lysing solutions and surfactant solutions (SDS, CTAB, Triton X-100). The MSQ barriers also withstood glycerol, toluene and DMSO whereas all three barrier types were breached by alcohols. MSQ based devices could be prepared either by direct inkjet printing of the barriers or by base etching of MSQ impregnated paper. The functionality of MSQ based devices was demonstrated by formatting a colormetric sensor for Escherichia coli.

Considerable functional heterogeneity within human natural killer (NK) cells has been revealed through the characterization of distinct NK-cell subsets. Accordingly, a small subset of CD56(+)NKp44(+)NK cells, termed NK-22 cells, was recently described within secondary lymphoid tissue (SLT) as IL-22(-) when resting, with a minor fraction of this population becoming IL-22(+) when activated. Here we discover that the vast majority of stage 3 immature NK (iNK) cells in SLT constitutively and selectively express IL-22, a T(H)17 cytokine important for mucosal immunity, whereas earlier and later stages of NK developmental intermediates do not express IL-22. These iNK cells have a surface phenotype of CD34(-)CD117(+)CD161(+)CD94(-), largely lack expression of NKp44 and CD56, and do not produce IFN-gamma or possess cytolytic activity. In summary, stage 3 iNK cells are highly enriched for IL-22 and IL-26 messenger RNA, and IL-22 protein production, but do not express IL-17A or IL-17F.