Immune responses to the expressed products of the CSP antigen gene of Plasmodi um falciparum southern China isolate FCC1/HN in Hela cell

Objective To construct a eukaryotic expression system with pcDNA3-PfCSP/Hela for the Circumsporozoite protein (CSP) gene of Plasmodium falciparum (P. falciparum), to observe the immune responses in BALB/c mice induced by the expressed proteins. Methods The recombinant plasmid pcDNA3-PfCSP was transformed into the Hela cell line. The expressed protein was isolated and analyzed by using SDS-PAGE and used for immunization of BALB/c mice by subcutaneous, intravenous, and intraperitoneal adminstration. Enzyme-linked immunosorbent assay(ELISA), Dot-ELISA, Western blot, T lymphocyte proliferation test, natural killer cell(NKC) activity assay, and CD4+ and CD8+ T cell detection were used for observation of humoral and cellular immune responses. Results Immune sera strongly reacted with the expressed protein, antibody titer was up to 1∶6400 as detected by ELISA. Western blot analysis revealed a specific band at 38.3?Kda. When the spleen cells of normal and immunized BALB/c mice were specifically stimulated with expressed protein, the optical densities were 0.12±0.03 and 0.34±0.04, respectively. The latter were significantly higher than the former (P<0.01). We used the MTT colorimetric assay to measure NKC activity of mice spleen. The results showed that the NKC activity of immunized BALB/c mice was remarkably higher than that of the controls (P<0.05). CD4+ and CD8+ T cells were detected by using monoclonal antibody immunofluorescence methods. The results showed that the percentage of CD4+ and CD8+ T cells of immunized group were significantly higher than that of control group (P<0.05).Conclusions The humoral and cell-mediated immune responses and elevated NKC activity to products made with a eukaryotic expression system could be specifically detected in BALB/c mice. These findings indicate that the expressed protein could enhance the immune function in mice.

JNK1 negatively controls antifungal innate immunity by suppressing CD23 expression

Subject Code:H10 With the support by the National Natural Science Foundation of China,a study by Dr.Lin Xin(林欣)’s groups from the Institute for Immunology,School of Medicine,Tsinghua University demonstrates that JNK1negatively regulates CD23,a novel C-type lectin receptor(CLR)with antifungal properties。

Recombinant Newcastle disease virus expressing African swine fever virus protein 72 is safe and immunogenic in mice

African swine fever(ASF) is a lethal hemorrhagic disease that affects wild and domestic swine. The etiological agent of ASF is African swine fever virus(ASFV). Since the first case was described in Kenya in 1921, the disease has spread to many other countries. No commercial vaccines are available to prevent ASF. In this study, we generated a recombinant Newcastle disease virus(r NDV) expressing ASFV protein 72(p72) by reverse genetics and evaluated its humoral and cellular immunogenicity in a mouse model. The recombinant virus, r NDV/p72, replicated well in embryonated chicken eggs and was safe to use in chicks and mice. The p72 gene in r NDV/p72 was stably maintained through ten passages. Mice immunized with r NDV/p72 developed high titers of ASFV p72 specific Ig G antibody, and had higher levels of Ig G1 than IgG2 a. Immunization also elicited T-cell proliferation and secretion of IFN-γ and IL-4. Taken together, these results indicate that r NDV expressing ASFV p72 might be a potential vaccine candidate for preventing ASF.

Recombinant canarypox virus expressing the VP2 protein of infectious bursal disease virus induces protection in vaccinated SPF chickens

Dear Editor,Infectious bursal disease virus（IBDV）causes infectious bursal disease,a highly contagious immunosuppressive disease that affects young chickens and causes economic losses in the poultry industry worldwide.IBDV replicates mainly in actively dividing B lymphocytes within the bursa of Fabricius（BF）,leading to immunosuppression in affected flocks（Mahgoub et al.,2012）.Viral protein 2（VP2）,