Objective:To establish a Zika virus-infected suckling SD rat model with type Ⅰ interferon receptor deficiency（SD-Ifnar1 -/-［cc］）and provide a novel animal model for investigating Zika virus pathogenesis and developing therapeutic strategies. Methods:Seventeen-day-old male SD-Ifnar1 -/-［cc］rat pups were randomly divided into experimental and control groups（ n=6）. The experimental group received an intraperitoneal injection of Zika virus strain SZ-wiv01（5×10 4 PFU/rat，200 μl），while the control group received an equal volume of phosphate-buffered saline（PBS）. Animals were euthanized via CO 2 asphyxiation on days 12 and 15 post-infection（dpi），and brain，spleen，liver，and testis tissues were harvested. Viral loads and cytokine expression levels were quantified using quantitative real-time PCR qRT-PCR），and histopathological evaluation was performed via HE staining. Results:qRT-PCR analysis revealed no detectable Zika virus RNA（Ct >35）in control tissues. In the experimental group，viral RNA（Ct <35）was detected in the brain，spleen，liver，and testis by day 12，with stable viral loads across tissues by day 15（ P>0.05）. Cytokine profiling demonstrated significant upregulation in the brain at day 12：IFN-β（5.58-fold， P<0.01），IL-6（7.11-fold， P<0.01），and CCL5（3.79-fold， P<0.01）. By day 15，these levels remained elevated（IFN-β：3.07-fold；IL-6：4.04-fold；CCL5：5.22-fold；all P<0.01）. In the liver，IFN-β mRNA decreased to 20% of the control level by day 15（ P<0.05），while IL-6 declined to 24% and CCL5 mRNA dropped to 38% by day 12. No significant cytokine changes were observed in the spleen（ P>0.05）. Testicular tissues exhibited reduced IFN-β mRNA levels（43% of control at day 12，31% at day 15； P<0.05）. Histopathological analysis revealed marked splenomegaly with disrupted splenic corpuscle architecture and lymphocyte depletion，significant inflammatory cell infiltration in hepatic portal areas，and testicular structural disorganization with inflammatory infiltration in Zika-infected rats. Conclusions:The SD-Ifnar1 -/-［cc］suckling rat model is successfully established and validated. This model recapitulates systemic Zika virus infection，tissue-specific pathology，and immune response dynamics，providing a robust platform for elucidating viral pathogenesis and advancing antiviral drug development.

Objective:To establish a Zika virus-infected suckling SD rat model with type Ⅰ interferon receptor deficiency（SD-Ifnar1 -/-［cc］）and provide a novel animal model for investigating Zika virus pathogenesis and developing therapeutic strategies. Methods:Seventeen-day-old male SD-Ifnar1 -/-［cc］rat pups were randomly divided into experimental and control groups（ n=6）. The experimental group received an intraperitoneal injection of Zika virus strain SZ-wiv01（5×10 4 PFU/rat，200 μl），while the control group received an equal volume of phosphate-buffered saline（PBS）. Animals were euthanized via CO 2 asphyxiation on days 12 and 15 post-infection（dpi），and brain，spleen，liver，and testis tissues were harvested. Viral loads and cytokine expression levels were quantified using quantitative real-time PCR qRT-PCR），and histopathological evaluation was performed via HE staining. Results:qRT-PCR analysis revealed no detectable Zika virus RNA（Ct >35）in control tissues. In the experimental group，viral RNA（Ct <35）was detected in the brain，spleen，liver，and testis by day 12，with stable viral loads across tissues by day 15（ P>0.05）. Cytokine profiling demonstrated significant upregulation in the brain at day 12：IFN-β（5.58-fold， P<0.01），IL-6（7.11-fold， P<0.01），and CCL5（3.79-fold， P<0.01）. By day 15，these levels remained elevated（IFN-β：3.07-fold；IL-6：4.04-fold；CCL5：5.22-fold；all P<0.01）. In the liver，IFN-β mRNA decreased to 20% of the control level by day 15（ P<0.05），while IL-6 declined to 24% and CCL5 mRNA dropped to 38% by day 12. No significant cytokine changes were observed in the spleen（ P>0.05）. Testicular tissues exhibited reduced IFN-β mRNA levels（43% of control at day 12，31% at day 15； P<0.05）. Histopathological analysis revealed marked splenomegaly with disrupted splenic corpuscle architecture and lymphocyte depletion，significant inflammatory cell infiltration in hepatic portal areas，and testicular structural disorganization with inflammatory infiltration in Zika-infected rats. Conclusions:The SD-Ifnar1 -/-［cc］suckling rat model is successfully established and validated. This model recapitulates systemic Zika virus infection，tissue-specific pathology，and immune response dynamics，providing a robust platform for elucidating viral pathogenesis and advancing antiviral drug development.

Objective To analyze the mutation of PreS-S region in occult hepatitis B virus(OHBV) in HBV infected persons with positive HBsAb and investigate the biological mechanisms of the special infectious model.Methods A total of 38 HB-sAb positive OBI serum samples were amplified by Nested PCR and sequenced,HBV genotype and serotype were determined.The amino acid sequences of OHBV were compared to the corresponding sequence of wild-type strains of similar genotype obtained from the GenBank database.Results PreS-S segment of 11 samples were obtained and 8 samples were sequenced successfully.Among which,5 were genotype C and 3 were genotype B.Genotype B were all serotype adw,while genotype C were 1 adw and 4 adr.The mutation rates of PreS-S region,the immunoreactive area and the major hydrophilic region (MHR) were higher in OHBV than the wild-type strains (2.6％ vs 0.8％,x2 =40.23,3.2％ vs 0.3％,x2 =52.13,3.6％ vs 0.6％,x2 =13.25,all P＜0.01) and the substitutions of I126T,Q129R,M133T,F134I,D144E,G145K in α determinant were found in OBI samples.The mutation rate of amino acids in PreS-S region was higher in genotype C than genotype B (3.5％ vs 1.2％,x2--15.98,P＜0.01),meanwhile,the mutation rates in MHR,α determinant and immunoreactive region were higher in genotype C too,but no statistical significance was attained (4.7％ vs 1.7 ％,x2 =2.96,3.6 ％ vs 2.9％,x2 =0.25,4.1％ vs 2.3％,x2 =3.59,all P ＞0.05).Conclusion Mutations in PreS-S region,especially in immunoepitope,might change the virus'immunogenicity leading to escape from immune response and cause OBI with HBsAb positive.

Objective To analyze the differences of immune responses against Mycobacterium tu-berculosis antigens induced in two different nonhuman primates and to provide rationales for the selection of suitable animal models for vaccine efficacy evaluation.Methods Expression of functional surface markers including CD69 and HLA-DR, the activation markers on CD4+and CD8+T cells from in rhesus macaques and cynomolgus monkeys were measured by flow cytometry analysis.PBMCs were isolated from rhesus ma-caques and cynomolgus monkeys with Mycobacterium tuberculosis infection and stimulated with PPD and pep-tide pools ( ESAT-6/CFP-10) .Enzyme-linked imunospot ( ELISPOT) assay was performed to detect IFN-γproducing lymphocytes.Results The CD4+and CD8+T cells isolated from rhesus macaques without Myco-bacterium tuberculosis infection expressed higher levels of CD69 and HLA-DR than those from healthy cyno-molgus monkeys (P<0.01).The numbers of IFN-γspot forming cells/106 PBMCs in rhesus macaques with Mycobacterium tuberculosis infection for 10 and 11 months were respectively 3 and 3.5 times higher than that of cynomolgus monkeys upon after the stimulation of PBMCs with PPD.The levels of IFN-γproduction by the cells from rhesus macaque group were also higher than those from cynomolgus monkey group upon after the stimulation of PBMCs with ESAT-6 or CFP-10 peptide pools.Conclusion More IFN-γproducing cells were induced in rhesus macaques than that in cynimolgus monkeys after stimulation with Mycobacterium tu-berculosis antigens.Therefore, the rhesus macaques might be a better animal model for evaluating immune responses induced by Mycobacterium tuberculosis vaccines.

OBJECTIVETo screen for the inhibitor of vascular endothelial growth factor (VEGF) 165 from random peptide library.

METHODSPositive phage clones were rescued after two rounds of panning and competitive elution. Its affinity activity to KDR was monitored through ELISA, immunohistochemical method, Chicken CAM assay and MTT.

RESULTSFive specific binding positive target molecule phage clones were obtained which were able to bind to cells whose surface had high KDR, among which, clone 3 and 13 could effectively block the vascularization of the chorioallantoic membrane of chick embryo, but they were not inhibitive on the proliferation of high KDR expression cells.

CONCLUSIONThe peptides, being the inhibitors of VEGF, may be useful in the treatment of cancers.

Animals ; Binding Sites ; Endothelial Growth Factors ; antagonists & inhibitors ; metabolism ; Enzyme-Linked Immunosorbent Assay ; Humans ; Intercellular Signaling Peptides and Proteins ; metabolism ; Lymphokines ; antagonists & inhibitors ; metabolism ; Peptide Library ; Peptides ; pharmacology ; Vascular Endothelial Growth Factor A ; Vascular Endothelial Growth Factors

AIM: To investigate the effect of canstatin on cultured rabbit vascular smooth muscle cells(VSMC). METHODS: By means of cationic liposome mediated method, canstatin RNA was transferred into cultured VSMC. The proliferation quantity of VSMC were determined by the cell counting method and thymidine(-TdR) incorporation. RESULTS: Canstatin RNA could be effectively transferred into cultured primary rabbit aortic smooth muscle cells by the cationic liposome-Dosper and could markedly inhibit VSMC proliferation. CONCLUSION: Transfection of canstatin RNA could inhibit the growth of VSMC in vitro.