Construction of full-length human bladder cancer-specific antibody libraries based on mammalian display technology / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct full-length human bladder cancer-specific antibody libraries for efficient display of full-length antibodies on the surface of mammalian cells.</p><p><b>METHODS</b>The total RNA was isolated from peripheral blood mononuclear cells from patients with bladder cancer. The repertoires of IgG1 heavy chain variable region (VH) and Kappa light chain were amplified by RT-PCR using specific primers. The antibody genes were inserted into the vector pDGB-HC-TM to construct the bladder-cancer-specific antibody libraries of heavy chains and light chains. Ten clones from each library were randomly picked for gene sequencing and transient transfection into FCHO cells to analyze antibody display on mammalian cell surface by flow cytometry after staining with corresponding fluorescent labeled antibodies.</p><p><b>RESULTS</b>The libraries of bladder-cancer-specific antibody heavy chain (IgG1) and light chain (LCk) were successfully constructed. Seven out of the 10 clones randomly selected from the heavy chain library and 9 out of the 10 clones from the light chain library showed correct open reading frame, coding for 7 unique VH and 9 unique LCk. The combinatory library size reached 3.32×10(11).</p><p><b>CONCLUSION</b>We have successfully constructed a full-length human bladder-cancer-specific antibody library with a combinatory diversity of 3.32×10(11) based on mammalian display technology, which can be used for screening monoclonal antibodies against bladder-cancer-associated antigens.</p>

A meta-analysis of fish intake and the risk of renal cell cancer / 南方医科大学学报

<p><b>OBJECTIVE</b>To explore the association of fish intake with the risk of renal cancer.</p><p><b>METHODS</b>PubMed, Embase, CNKI and CA databases were searched for case-control studies or cohort studies examining the relationship between fish or fish products intake and renal cancer. Heterogeneity among the selected studies was assessed using I2 score, and the publication bias was assessed using funnel plots.</p><p><b>RESULTS</b>Seventeen articles were included in the analysis with a heterogeneity across the studies (P=0.003, I(2)=52.3%). A random-effects model was used to generate the pooled risk ratio (RR) and 95% confidence interval (CI), and no statistically significant association was found between the risk of renal cancer and fish intake (RR=0.90; 95% CI, 0.78-1.02). In subgroup analysis, no evidence was found that the study design, study region or publication date influenced the results; but in the gender subgroup analysis, fish intake we found to decrease the risk of renal cancer in men but not in women.</p><p><b>CONCLUSION</b>The results of meta-analysis do not support an association between fish intake and a lowered risk of renal cancer.</p>

Construction of dengue virus-specific full-length fully human antibody libraries by mammalian display technology / 南方医科大学学报

<p><b>OBJECTIVE</b>To construct dengue virus-specific full-length fully human antibody libraries using mammalian cell surface display technique.</p><p><b>METHODS</b>Total RNA was extracted from peripheral blood mononuclear cells (PBMCs) from convalescent patients with dengue fever. The reservoirs of the light chain and heavy chain variable regions (LCκ and VH) of the antibody genes were amplified by RT-PCR and inserted into the vector pDGB-HC-TM separately to construct the light chain and heavy chain libraries. The library DNAs were transfected into CHO cells and the expression of full-length fully human antibodies on the surface of CHO cells was analyzed by flow cytometry.</p><p><b>RESULTS</b>Using 1.2 µg of the total RNA isolated from the PBMCs as the template, the LCκ and VH were amplified and the full-length fully human antibody mammalian display libraries were constructed. The kappa light chain gene library had a size of 1.45×10(4) and the heavy chain gene library had a size of 1.8×10(5). Sequence analysis showed that 8 out of the 10 light chain clones and 7 out of the 10 heavy chain clones randomly picked up from the constructed libraries contained correct open reading frames. FACS analysis demonstrated that all the 15 clones with correct open reading frames expressed full-length antibodies, which could be detected on CHO cell surfaces. After co-transfection of the heavy chain and light chain gene libraries into CHO cells, the expression of full-length antibodies on CHO cell surfaces could be detected by FACS analysis with an expressible diversity of the antibody library reaching 1.46×10(9) [(1.45×10(4)×80%)×(1.8×10(5)×70%)].</p><p><b>CONCLUSION</b>Using 1.2 µg of total RNA as template, the LCκ and VH full-length fully human antibody libraries against dengue virus have been successfully constructed with an expressible diversity of 10(9).</p>

Interleukin-21 surface-modified MB49 cell vaccine for treatment of metastatic bladder in mice / 南方医科大学学报

<p><b>OBJECTIVE</b>To develop a novel vaccine by immobilizing interleukin-21 (IL-21) on the surface of MB49 cells and evaluate its effect in inducing specific cytotoxic T lymphocytes (CTLs) and antitumor immunity in a mouse model of subcutaneous metastatic bladder cancer.</p><p><b>METHODS</b>SA-IL-21 was immobilized on the surface of 30% ethanol-fixed MB49 cells to prepare the cell vaccine. C57BL/6 mice with subcutaneous implantation of MB49 bladder cancer cells were randomized into 5 groups to receive treatments with IL-21/MB49 vaccine, soluble IL-21, GFP surface-modified MB49 cells, ethanol-fixed MB49 cells, or PBS. The tumor growth and CTL were examined to assess the antitumor efficacy of the vaccine.</p><p><b>RESULTS</b>IL-21 surface-modified MB49 cell vaccine significantly inhibited the tumor growth and generated a long-lasting memory response (P<0.05). At the same effector-target (E:T) ratio, the specific CTLs induced by IL-21/MB49 vaccine showed the most potent cytotoxicity against MB49 cells (P<0.05).</p><p><b>CONCLUSION</b>With the protein-anchor technique, IL-21 can be efficiently immobilized on the surface of MB49 cells to prepare IL-21/MB49 cells vaccine. The novel vaccine can maintain its biological activity and significantly enhance the cytotoxicity of CTLs against bladder cancer cells.</p>