Exosomal Vaccine Loading T Cell Epitope Peptides of SARS-CoV-2 Induces Robust CD8+ T Cell Response in HLA-A Transgenic Mice.

Purpose: Current vaccines for the SARS-CoV-2 virus mainly induce neutralizing antibodies but overlook the T cell responses. This study aims to generate an exosomal vaccine carrying T cell epitope peptides of SARS-CoV-2 for the induction of CD8+ T cell response. Methods: Thirty-one peptides presented by HLA-A0201 molecule were conjugated to the DMPE-PEG-NHS molecules, and mixed with DSPE-PEG to form the peptide-PEG-lipid micelles, then fused with exosomes to generate the exosomal vaccine, followed by purification using size-exclusion chromatography and validation by Western blotting, liquid nuclear magnetic resonance (NMR) test and transmission electron microscopy. Furthermore, the exosomal vaccine was mixed with Poly (I:C) adjuvant and subcutaneously administered for three times into the hybrid mice of HLA-A0201/DR1 transgenic mice with wild-type mice. Then, the epitope-specific T cell responses were detected by ex vivo ELISPOT assay and intracellular cytokine staining. Results: The exosomal vaccine was purified from the Peak 2 fraction of FPLC and injected into the hybrid mice for three times. The IFN-γ spot forming units and the frequencies of IFN-γ+/CD8+ T cells were 10-82-fold and 13-65-fold, respectively, higher in the exosomal vaccine group compared to the Poly (I:C) control group, without visible organ toxicity. In comparison with the peptides cocktail vaccine generated in our recent work, the exosomal vaccine induced significantly stronger T cell response. Conclusion: Exosomal vaccine loading T cell epitope peptides of SARS-CoV-2 virus was initially generated without pre-modification for both peptides and exosomes, and elicited robust CD8+ T cell response in HLA-A transgenic mice.

The Relationship between the Hydrophilicity and Surface Chemical Composition Microphase Separation Structure of Multicomponent Silicone Hydrogels.

Three series of multicomponent silicone hydrogels were prepared by the copolymerization of two hydrophobic silicon monomers bis(trimethylsilyloxy) methylsilylpropyl glycerol methacrylate (SiMA) and tris(trimethylsiloxy) 3-methacryloxypropylsilane (TRIS) with three hydrophilic monomers. The surface hydrophilicity of the silicone hydrogels was characterized by contact angle measurements, and an interesting phenomenon was found that the silicone hydrogels made from less hydrophobic monomer SiMA possess more hydrophobic surfaces than those made from TRIS. The surface properties such as morphology and elemental composition of the silicone hydrogels were explored by scanning electron microscopy (SEM) imaging and energy dispersive spectrometry (EDS) analysis, and their relationships with the surface hydrophilicity were investigated in details. The results show neither the surface morphology nor the elemental composition has obvious impact on the surface hydrophilicity. Atomic force microscopy (AFM) imaging revealed that SiMA hydrogel had a more significant phase separation structure, which also made its surface uneven: a lot of tiny holes were observed on the surface. This surface phase separation structure made SiMA hydrogel more difficult to be wetted by water or PBS buffer, i.e., more hydrophobic than TRIS hydrogel. On the basis of these results, we propose that the phase separation structure as well as the nature of silicon monomers might be the fundamental reasons of surface hydrophilicity. These results could help to design a silicone hydrogel with better surface properties and wider application.

Cytotoxic cholestane-type and ergostane-type steroids from the aerial parts of Euphorbia altotibetic.

Phytochemical investigation of the ethanol extract obtained from the aerial parts of the Euphorbia altotibetic PAULS. Grown in China resulted in the isolation of three new cholestane-type and three new ergostane-type steroids (cholest-5-en-2ß, 4ß-diol; cholest-5-en-1ß, 4ß-diol; cholest-5-en-1α, 3ß, 4α -triol; (22E)-ergosta-7,9,22-trien- 3ß-ol ß-D-glucoside; 5α-methoxy-(22E)-ergosta-7,9,22-trien-3ß-ol ß-D-glucoside; 6ß- methoxy-(22E)-ergosta-7,9,22-trien-3ß-ol ß-D-glucoside), along with seven known compounds. Their structures were established by extensive one- and two-dimensional NMR spectroscopy, as well as other spectrum and chemical analysis. The isolated new steroids exhibited potent anti-tumor activity against the HeLa cell and Hep-G2 cell with the 50% inhibiting concentration values ranging from 1.9 to 9.2 µg/mL.

Triterpenoids of Euphorbia kansuensis Proch.

Phytochemical investigation of the ethanol extract of Euphorbia kansuensis Proch. led to the isolation of three new triterpenoids, along with ten known compounds. Their structures were established by extensive 1D and 2D NMR, as well as other spectrum analysis. Biological activities of the three new compounds against Hela cell, Hep-G2 cell, C. albicans ATCC10231 cell and SC5314 cell were evaluated. They showed strong anti-tumor and moderate anti-inflammatory activities with MIC values ranging from 13 to 25 µg/ml and from 30 to 128 µg/ml.

5-Chloro-1H-indole-3-carb-oxy-lic acid.

In the title compound, C(9)H(6)ClNO(2), the carboxyl group is twisted from the indole ring system by 9.00 (8)°. In the crystal, inversion dimers linked by pairs of O-H⋯O hydrogen bonds generate R(2) (2)(8) loops and N-H⋯O hydrogen bonds link the dimers into (001) sheets. Aromatic π-π stacking inter-actions [centroid-centroid distance = 3.7185 (12) A °] are also observed.

[Three dimensional finite element analysis of biomechanical distribution of dental implants with immediate loading].

OBJECTIVE: To analyze the stress distribution of bone around the dental implants with lateral immediate loading of different angles by three dimensional finite element. METHODS: An adult edentulous mandible was adopted for CT scanning. The CT image was imported to universal surgical integration system to establish a mandible three dimensional mesh model. The real shape of standard thread implant was simulated and the finite element model of mandible with dental implants for immediate loading was established. The models were immediately loaded with 150 N through the angle of 0 degrees, 10 degrees, 20 degrees, 30 degrees. The ANSYS 10.0 was used to analyze the Von Mises stress on the bone around dental implants. RESULTS: The accurate finite element model of mandible with dental implants for immediate loading was successfully established. The three dimensional finite element analytical results showed: Under axial load, the Von Mises stress of bone contact surface concentrated on the cortical bone of the implant cervix. The strain distribution was even, and centralized at the cortical bone of the implant cervix, cancellous bone of implant bottom and thread contact area. Under different lateral angle load, the Von Mises stress of bone contact surface also concentrated on the cortical bone of the implant cervix, but the maximum value was 4 times of the vertical loading, the strain distributed unevenly, mainly concentrated on the cortical bone of the implant cervix. With the load angle increased, the stress and the strain value also increased. CONCLUSION: When an axial force was immediately loaded, the stress value and the strain concentration value of bone interface around the dental implants are not apparently concentrated, the stress is distributed well. While a lateral force is loaded, the stress values and the strain concentration values of bone interface around the dental implants apparently increase and the strain are distributed unevenly.

[Withdrawal symptoms of ethanol are ameliorated by thymopentin in mice].

OBJECTIVE: To explore the effect of thymopentin (TP5) on the choice of ethanol and ameliorating withdrawal symptoms (anxiety) of ethanol in mice. METHODS: Mice were administered ethanol (v/v) in schedular fashion: 5% (1 week), 10% (1 week) and 15% (4 weeks), followed with the free choice between ethanol and water. Ethanol/(ethanol+water)x100% [E/(E+W)x100%] was measured as an index of ethanol selection. Light-dark box test and elevated plus maze test were chosen for the assessment of anxiety pre-drug and post-drug. After TP5 [0.2 mg/(kgxd), 0.4 mg/(kgxd)], i.p. or saline (vehicle control), i.p. for 14 days, the procedure was repeated. RESULT: (1) E/(E+W)x100%: the post-drug values of TP5 (0.2 mg/kg, 0.4 mg/kg) were lower significantly than the pre-drug values. (2) Light-dark box test: the post-drug values of number of entries and time spent in the light chamber of TP5 (0.2 mg/kg, 0.4 mg/kg) were more than the pre-drug values themselves and the post-drug value of saline. (3) Elevated plus maze test: the post-drug values of time spent on open arms of TP5 (0.2 mg/kg, 0.4 mg/kg) were more than the pre-drug values themselves and the post-drug value of salineìand the post-drug values of time spent on close arms of TP5 were less than the pre-drug values. CONCLUSION: TP5 could decrease the uptake of ethanol and ameliorate anxious behavior associated with ethanol withdrawal in mice.