Human IgG Fc promotes expression, secretion and immunogenicity of enterovirus 71 VP1 protein

Enterovirus （EV71） can cause severe neurological diseases, but the underlying pathogenesis remains unclear. The capsid protein, viral protein 1 （VP1）, plays a critical role in the pathogenicity of EVT1. High level expression and secretion ofVP 1 protein are necessary for structure, function and immunogenicity in its natural conformation. In our previous studies, 5 codon-optimized VP 1 DNA vaccines, including wt-VP 1, tPA-VP 1, VP l-d, VP 1-hFc and VP 1 - mFc, were constructed and analyzed. They expressed VP1 protein, but the levels of secretion and immunogenicity of these VP1 constructs were significantly different （P〈0.05）. In this study, we further investigated the protein lev- els of these constructs and determined that all of these constructs expressed VP1 protein. The secretion level was increased by including a tPA leader sequence, which was further increased by fusing human IgG Fc （hFc） to VP1. VP 1-hFc demonstrated the most potent immunogenicity in mice. Furthermore, hFc domain could be used to purify VPI-hFc protein for additional studies.

Immunogenicity and protective role of antigenic regions from five outer membrane proteins of Flavobacterium columnare in grass carp Ctenopharyngodon idella

Flavobacterium columnare causes columnaris disease in freshwater fi sh. In the present study, the antigenic regions of fi ve outer membrane proteins(OMPs), including zinc metalloprotease, prolyl oligopeptidase, thermolysin, collagenase and chondroitin AC lyase, were bioinformatically analyzed, fused together, and then expressed as a recombinant fusion protein in Escherichia coli. The expressed protein of 95.6 k Da, as estimated by 10% sodium dodecyl sulfate-polyacrylamide gel electrophoresis, was consistent with the molecular weight deduced from the amino acid sequence. The purifi ed recombinant protein was used to vaccinate the grass carp, C tenopharyngodon idella. Following vaccination of the fi sh their Ig M antibody levels were examined, as was the expression of I g M, Ig D and Ig Z immunoglobulin genes and other genes such as MHC Iα and MHC I I β, which are also involved in adaptive immunity. Interleukin genes( IL), including I L- 1β, IL- 8 and I L- 10, and type I and type II interferon(I FN) genes were also examined. At 3 and 4 weeks post-vaccination(wpv), signifi cant increases in Ig M antibody levels were observed in the fi sh vaccinated with the recombinant fusion protein, and an increase in the expression levels of I g M, Ig D and Ig Z genes was also detected following the vaccinations, thus indicating that an adaptive immune response was induced by the vaccinations. Early increases in the expression levels of IL and IFN genes were also observed in the vaccinated fi sh. At four wpv, the fi sh were challenged with F. column a re, and the vaccinated fi sh showed a good level of protection against this pathogen, with 39% relative percent survival(RPS) compared with the control group. It can be concluded, therefore, that the fi ve OMPs, in the form of a recombinant fusion protein vaccine, induced an immune response in fi sh and protection against F. columnare.

Immunogenicity of recombinant attenuated Salmonella typhimurium expressing a 45-peptide hybrid antigen gene of Plasmodium falciparum

A synthetic hybrid 45-peptide gene of Plasmodium falciparum (Pf), which encoded two CSP repeated peptides NANP and three merozoite peptides SPf83. 1, SPf55. 1 and SPf35. 1, was cloned in an expression vector pWR450-1, then the recombinant plasmid pWRA was introduced into the attenuated Salmonella typhimurium SL3261. When used as a live vaccine and administered orally (po), intravenously (iv) or intraperitoneally (ip),the recombinant strain was able to live in vivo and elicit specific humoral and cellular immunity in BALB/c mice and rabbits. As oral immunization is safe and effective, it is thought that the live recombinant Salmonella tyPhimurium vaccine may bring the Pf oral live vaccine a step nearer.

Generation and Immunogenicity of a Recombinant Adenovirus Co-Expressing the E2 Protein of Classical Swine Fever Virus and the GP5 Protein of Porcine Reproduction and Respiratory Syndrome Virus

Classical swine fever （CSF） and porcine reproduction and respiratory syndrome （PRRS） are both economically important, highly contagious diseases of swine worldwide. To develop an effective vaccine to control these two diseases, we constructed a recombinant adenovirus rAdV-GP52AE2, using a replication-defective human adenovirus serotype 5 as a delivery vector, to co-express the GP5 protein of highly pathogenic porcine reproduction and respiratory syndrome virus （PRRSV） and the E2 protein of classical swine fever virus （CSFV）. Foot-and-mouth disease virus （FMDV） 2A peptide was used as a linker between the GP5 and E2 proteins to allow automatic self-cleavage of the polyprotein. The GP5 and E2 genes were expressed as demonstrated by immunofluorescence assay and Western blotting. Immunization of mice resulted in a CSFV-neutralizing antibody titer of 1：128 and a PRRSV-neutralizing antibody titer of 1：16. The lymphoproliferative responses were detected by Cell Counting Kit-8 assay and the stimulation index of CFSV-specific and PRRSV-specific lymphocytes in the rAdV-GP52AE2 group was significantly higher than that in the negative control group. The results show that rAdV-GP52AE2 can induce both effective humoral and cell-mediated immune responses in mice. The protective efficacy of the recombinant virus against CSF was evaluated in immunized rabbits, which were protected from fever induced by challenge with C-strain. Our study provides supporting evidence for the use of FMDV 2A to develop a bivalent genetically-engineered vaccine.

Immunogenicity of Lyophilized MVA Vaccine for HIV-1 in Mice Model

Highly attenuated modified vaccinia Ankara（MVA） is sensitive to repeat freeze-thaw cycle and easy to lose activity. In order to make the activity of MVA vaccine remain stable during its manufacturing, storage, and administration, the lyophilization as a good option could be resorted to; through screening, the right stabilizer composition and its production procedure were obtained. The final moisture content of freezing-dried recombinant MVA-HIV vaccine was lower than 3%. It can be reconstituted quickly and shows regular physical appearance and stable potency. In vivo functional experiment, mice were divided randomly into the liquid vaccination group, the lyophilized vaccination group, and the control group. Having been DNA vaccine priming, the mice were boosted with a dose of 10^7 pfu MVA- HIV vaccine, which produced indistinguishable antibody titer and cytotoxic T-lymphocyte（CTL） level compared with those of liquid vaccination group （ P 〉 0.05 ）. These results demonstrate that lyophilized MVA vaccine can induce high immunogenicity in mice.

Investigation of bone reconstruction using an attenuated immunogenicity xenogenic composite scaffold fabricated by 3D printing

Bone is known to have a natural function to heal itself.However,if the bone damage is beyond a critical degree,intervention such as bone grafting may be imperative.In this work,the fabrication of a novel bone scaffold composed of natural bone components and polycaprolactone(PCL)using 3D printing is put forward.α1,3-galactosyltransferase deficient pigs were used as the donor source of a xenograft.Decellularized porcine bone(DCB)with attenuated immunogenicity was used as the natural component of the scaffold with the aim to promote bone regeneration.The 3D printed DCB-PCL scaffolds combined essential advantages such as uniformity of the interconnected macropores and high porosity and enhanced compressive strength.The biological properties of the DCB-PCL scaffolds were evaluated by studying cell adhesion,viability,alkaline phosphatase activity and osteogenic gene expression of human bone marrow-derived mesenchymal stem cells.The in vitro results demonstrated that the DCB-PCL scaffolds exhibit an enhanced performance in promoting bone differentiation,which is correlated to the DCB content.Furthermore,critical-sized cranial rat defects were used to assess the effect of DCB-PCL scaffolds on bone regeneration in vivo.The results confirm that in comparison with PCL scaffolds,the DCB-PCL scaffolds can significantly improve new bone formation in cranial defects.Thus,the proposed 3D printed DCB-PCL scaffolds emerge as a promising regeneration alternative in the clinical treatment of large bone defects.

Comparative Study on the Immunogenicity between Hsp70 DNA Vaccine and Hsp65 DNA Vaccine in Human Mycobacterium Tuberculosis

The BALB/c mice were immunized with Hsp70 DNA and Hsp65 DNA vaccines in human Mycobacterium tuberculosis. Eight weeks after immunization, the eyeballs were removed, blood and spleen taken, and intraperitoneal macrophages were harvested. The lymphocytic stimulating index (SI) was used to measure the cellular proliferating ability and NO release to measure the phagocytic activity of the macrophages. With ELISA kit, the levels of interleukin-2 (IL-2) and interferon-γ (IFN-γ) in serum and the splenic lymphocytic cultured supernatant were detected. The results showed that after the mice were immunized with 100 μg/mouse of Hsp70 DNA vaccine intramuscularly, the splenic lymphocytic proliferating ability in the mice was significantly increased as compared with that in the control group, vector group and Hsp65 DNA vaccine group (P<0.01); The contents of NO in the intraperitoneal macrophages of the mice were significantly lower than in the control group and Hsp65 DNA vaccine group (P<0.01); The levels of serum IL-2 in the mice were significantly higher than in the control group, but there was no statistical difference between Hsp65 DNA group and vector group (P>0.05); The contents of serum IFN-γ in the mice were significantly higher than in the control group, but significantly lower than in the Hsp65 DNA vaccine group (P<0.05). It was indicated that immunization with Hsp70 DNA vaccine could obviously enhance the immune response, but its intensity seemed inferior to Hsp65 DNA vaccine. The anti-infection mechanisms and clinical use in the future of the vaccines of Hsp70 DNA and Hsp65 DNA are worth further studying.

Prokaryotic Expression and Immunogenicity of Major Antigen Epitope of Rabbit Haemorrhagic Disease Virus VP60

[ Objective] To investigate the immunogenicity of main antigen epitope of RHDV （ Rabbit haemorrhagic disease virus） VP60 expressed in a prokaryotic system. [ Method] The major antigen epitope gene of RHDV VP60 was amplified by RT-PCR. It was cloned into pET-28b （ ＋ ） and expressed in E. coli Rosetta strain. The recombinant protein was detected by Western blot. The pudfied recombinant protein was used to immunize rabbits in order to observe its immunogenicity. [ Result] Western blot analysis revealed a clear band at approximately 24.0 kDa. The purified recom- binant protein reacted with the purified RHDV in ELISA. [ Conclusion] The prokaryotically expressed main antigen epitope of RHDV VP60 shows good immunogenicity.

Preparation and immunogenicity of tag-free recombinant human eppin

Human epididymal protease inhibitor （eppin） may be effective as a male contraceptive vaccine. In a number of studies, eppin with an engineered His6-tag has been produced using prokaryotic expression systems. For production of pharmaceutical-grade proteins for human use, however, the His6-tag must be removed. This study describes a method for producing recombinant human eppin without a His6-tag. We constructed plasmid pET28a （＋）-His6-tobacco etch virus （TEV）-eppin for expression in Escherichia coli. After purification and refolding, the fusion protein His6-TEV-eppin was digested with TEV protease to remove the His6-tag and was further purified by NTA-Ni2＋ affinity chromatography. Using this procedure, 2 mg of eppin without a His6-tag was isolated from 1 I of culture with a purity of 〉95%. The immunogenicity of the eppin was characterized using male Balb/c mice.

Efficacy,effectiveness,immunogenicity- are not the same in vaccinology

Manuscript of Carrera et al is devoted to immunization in inflammatory bowel disease(IBD)that is very important issue in gastroenterology.However,some specific definitions used in the article need clarification.Efficacy of vaccine is measured in a randomised,placebo-controlled studies,that are expensive and difficult to plan.Moreover,it is unethical to offer a placebo instead of vaccine.For all of these reasons,efficacy of vaccine is measured in IBD patients rarely.Effectiveness of vaccine is measured as an epidemiological affect from observational studies.These studies are also uncommon in IBD because it would be difficult to perform a study that assess the prevalence of one rare disease(vaccine-preventable)in patients with a chronic rare condition,such as IBD.Immunogenicity of vaccine refers to the ability of a vaccine to induce an immune response in a vaccinated individual that is,in fact,the matter of the article.

Rabies Virus Neutralizing Activity,Safety,and Immunogenicity of Recombinant Human Rabies Antibody Compared with Human Rabies Immunoglobulin in Healthy Adults

Objective Preliminary assessment of rabies virus neutralizing activity,safety and immunogenicity of a recombinant human rabies antibody(NM57)compared with human rabies immunoglobulin(HRIG)in Chinese healthy adults.Methods Subjects were randomly(1:1:1)allocated to Groups A(20 IU/kg NM57),B(40 IU/kg NM57),or C(20 IU/kg HRIG).One injection was given on the day of enrollment.Blood samples were collected on days-7 to 0(pre-injection),3,7,14,28,and 42.Adverse events(AEs)and serious AEs(SAEs)were recorded over a period of 42 days after injection.Results All 60 subjects developed detectable rabies virus neutralizing antibodies(RVNAs)(>0.05 IU/mL)on days 3,7,14,28,and 42.The RVNA levels peaked on day 3 in all three groups,with a geometric mean concentration(GMC)of 0.2139 IU/mL in Group A,0.3660 IU/mL in Group B,and0.1994 IU/mL in Group C.At each follow-up point,the GMC in Group B was significantly higher than that in Groups A and C.The areas under the antibody concentration curve over 0-14 days and 0-42 days in Group B were significantly larger than those in Groups A and C.Fifteen AEs were reported.Except for one grade 2 myalgia in Group C,the other 14 were all grade 1.No SAEs were observed.Conclusion The rabies virus neutralizing activity of 40 IU/kg NM57 was superior to that of 20 IU/kg NM57 and 20 IU/kg HRIG,and the rabies virus neutralizing activity of 20 IU/kg NM57 and 20 IU/kg HRIG were similar.Safety was comparable between NM57 and HRIG.

Investigation of immunogenicity of cryopreserved limbal stem cells

AIM: To investigate changes in immunogenicity of cryopreserved limbal stem cells. METHODS: Cryopreserved limbal stem cells, fresh primary limbal stem cells and blank controls were inoculated subcutaneously in C57BL-6 mice and the percentage of CD25 cells in limbal explants was determined by flow cytometry at day 21 post inoculation. Morphological studies were performed by light and electron microscopy of limbal explant sections. RESULTS: The number of regional and systemic lymphocytes derived from cryopreserved limbal stem cells was lower than that from fresh primary limbal stem cells. CONCLUSION: Lymphocytes derived from cryopreserved limbal stem cells showed changes in immunogenicity, but the significance is unknown. The cryopreservation and thawing methods await further study.

Effect of Aluminum Hydroxide Adjuvant on the Immunogenicity of the 2009 Pandemic Influenza A/H1N1 Vaccine:Multi-level Modeling of Data with Repeated Measures

Objective To evaluate the effect of the aluminum hydroxide （Al-OH） adjuvant on the 2009 pandemic influenza A/H1N1 （pH1N1） vaccine. Methods In a multicenter, double-blind, randomized, placebo-controlled trial, participants received two doses of split-virion formulation containing 15 ug hemagglutinin antigen, with or without aluminum hydroxide （N-OH）. We classified the participants into six age categories （〉61 years, 41-60 years, 19-40 years, 13-18 years, 8-12 years, and 3-7 years） and obtained four blood samples from each participant on days 0, 21, 35, and 42 following the first dose of immunization. We assessed vaccine immunogenicity by measuring the geometric mean titer （GMT） of hemagglutination inhibiting antibody. We used a two-level model to evaluate the fixed effect of aluminum Al-OH and other factors, accounting for repeated measures. Results The predictions of repeated measurement on GMTs of formulations with or without Al-OH, were 80.35 and 112.72, respectively. Al-OH significantly reduced immunogenicity after controlling for time post immunization, age-group and gender. Conclusion The Al-OH adjuvant does not increase but actually reduces the immunogenicity of the split-virion pH1N1 vaccine.

Comparative Study on the Immunogenicity between Recombinant MS-Sj26GST Vaccine and Recombinant BCG-Sj26GST Vaccine in Schistosoma japonicum

The BALB/c mice were immunized with rMS Sj26GST and rBCG Sj26GST vaccine in Schistosoma japonicum by subcutaneous injection After they were immunized for 8 weeks, the eyeballs were removed to get blood and macrophages of abdominal cavity and spleen cells were harvested The lymphocytic stimulating index (SI) was used to measure the cellular proliferating ability and NO release was used to measure the phagocytic activity of the macrophages By using ELISA kit, the levels of interleukin 2 (IL 2) and interferon γ (IFN γ) in serum and the splenic lymphocytic cultured supernatant were detected The results showed that after the mice were immunized with 10 6 CFU of rMS Sj26GST and rBCG Sj26GST vaccine separately by subcutaneous injection, proliferating ability of splenic lymphocytes in the mice showed no difference ( P >0 05), but both were significantly increased as compared with that in the control group( P <0 05); The contents of NO in the intraperitoneal macrophages of rMS Sj26GST vaccine group were significantly lower than in the control group ( P <0 001) and rBCG Sj26GST vaccine group ( P <0 01); The levels of serum IL 2 in the rMS Sj26GST vaccine group were significantly increased as compared with that in the control group ( P <0 001), vector group ( P <0 01) and rBCG Sj26GST vaccine group ( P <0 05); The contents of serum IFN γ in the rMS Sj26GST vaccine group were significantly increased as compared with that in the control group ( P <0 01) and rBCG Sj26GST vaccine group ( P <0 05) The contents of IFN γ in the cultured supernatant were significantly lower than those of rBCG Sj26GST vaccine group ( P <0 001), but were significantly increased as compared with that in the control group ( P <0 01) It was indicated that both vaccines could enhance the immune response of the mice, but rMS Sj26GST vaccine had stronger immunogenicity than rBCG Sj26GST vaccine

Isolation,Identification and Immunogenicity of a Chicken-derived Strain of Fowl Avidenovirus Type 4

In order to obtain a fowl avidenovirus type 4 strain with good immunogenicity,chicken liver tissues suspected of adenovirus infection in a chicken farm in Binzhou were treated and then inoculated to chicken liver hepatocellular carcinoma cells(LMH).The cell cultures were extracted for DNA,which was subjected to PCR identification and sequencing analysis,and animal regression test and immunogenicity test were also carried out.The results showed that one fowl avidenovirus strain was successfully isolated.The isolated strain was inoculated to LMH cells,and the first generation showed obvious cytopathic changes.The PCR identification result of the 8^(th)generation cell culture of the isolated virus strain on LMH cells was positive.The sequencing result and NCBI sequence alignment analysis showed that the isolated virus strain had the highest nucleotide similarity with fowl avidenovirus type 4,reaching 100%,indicating that the isolated strain was of fowl avidenovirus type 4.The strain could cause the death of 21-day-old SPF chickens,with a mortality rate of 100%,and could completely replicate the same symptoms as clinically infected chickens after being challenged.The three batches of oil vaccine prepared with the isolated strain had a protection rate of 100%,and the geometric mean values of serum agar expansion titers were 1∶4.6,1∶4.9,and 1∶4.6,respectively.It can be seen that the isolated virus is of fowl avidenovirus type 4 in group I,and has good immunogenicity.

The Porcine Pulmonary Surfactant Protein A (pSP-A) Immunogenicity Evaluation in the Murine Model

This paper investigated the porcine surfactant protein A (pSP-A) immunogenicity in murine model. Many elegant stu-dies about SP-A therapeutic applications are available however specific studies about its exogenous immunogenicity were not easily assumed. Therefore, we investigated the immunogenicity of this porcine protein in mice. The mice re-ceived pSP-A subcutaneously on days 0 and 7. The animals were observed during 90 days and the blood was collected on days 30, 60 and 90 for assessment the immunogenic potential of pSP-A. Some animals showed circulating antibodies above the screening cut point, which was calculated based on control mice sera signals. However, those antibodies were considered false positive read-outs by the performed competitive inhibition assay. Also no neutralizing antibodies were detected able to avoid the porcine protein ability to promote lipid aggregation. So far in this model, porcine surfactant protein-A could be considered not immunogenic.

Immunogenicity of Rcombinant Type 1 Pilus Oil-emulsified Vaccine of Avian Escherichia coli in Chickens

[ Objective] To prepare recombinant type 1 pilus vaccine of avian Escherichia coil and to detect its immunogenicity in chickens. [Meth- od] The type 1 pilus was respectively isolated from the recombinant bacteria CZYR10 strain and wild avian Eschedchia co/i YR（ O18 ） strain and used to prepare oil-emulsified vaccine. The immunogenicity of the developed vaccine was detected in chickens using the challenge test. [ Result] The recombinant type 1 pilus protein had immunoprotective efficacy. The recombinant type 1 pilus protein had weaker protective efficacy than the isolated type 1 pilus protein, but the difference was not significant. [ Conclusion] The study provides a reference for immunization and control of chicken colibacillosis.

Immunogenicity, Safety and Efficacy Comparison of Wockhardt’s Biosimilar Insulin Glargine—Glaritus®with Reference Product— Lantus®: Study Protocol &Early Data Trends

Objective: Present Phase IV Trial is aimed at evaluating the immunogenicity, safety, and efficacy of Wockhardt’s insulin glargine, Glaritus&reg;in comparison with reference insulin glargine, Lantus&reg;in subjects with type 2 diabetes mellitus (T2DM), inadequately controlled on oral hypoglycaemics. Setting: A head-to-head, prospective, open-label, parallel group, randomized, Phase IV, non-inferiority study over 6 months treatment conducted in 10 centres in India. Participants: Considering 20% drop-out rate, 180 subjects of either sex, age 18 - 55 years, diagnosed with T2DM with body mass index (BMI) 18 - 38 kg/m2 and HbA1c levels 8.0% - 10.0% inadequately controlled by 1 or more oral hypoglycaemics and according to investigator needed glargine treatment were enrolled in the study. Interventions: Subjects self-administered insulin glargine (Glaritus&reg;or Lantus&reg;) subcutaneously once daily for 6 months. Treatment in Glaritus&reg;arm was continued till 12 months. Percentage change in anti-insulin antibody (AIA) titre and HbA1C was ascertained at every 3 months interval. The tests were performed at accredited central laboratory. Treat-to-target dose titration: Starting doses of Glaritus&reg;and Lantus&reg;was 10 units (or 0.2 units/kg) once daily. The target fasting blood glucose was 70 to 130 mg/dL. Daily glargine dose was titrated by ±10% based on average of last 3 FBG values being out of target range and presence of nocturnal hypoglycemia. Early data trends: First interim analysis was planned once 100 subjects complete visit 8 (6 months treatment). By then, 119 subjects (78 males and 41 females) with mean age 46.3 years were enrolled, of which 90 (75.6%) subjects had evaluable data. The results of analysis indicated trend of comparability between Glaritus&reg;and Lantus&reg;at the end of 6 months in terms of immunogenicity (% change in AIA titre from baseline, &minus;10.52 ± 23.06 vs. 0.48 ± 63.95), glycemic control (change in HbA1c from baseline, &minus;1.09% ± 1.29% vs. 0.63% ± 1.19%) and hypoglycemic events (reported by 1 vs. 2 patients), respectively. Conclusion: The present study represents a robust design in line with international guidelines on biosimilar insulin development and the early data trends presents expected similarity of Glaritus&reg;in immunogenicity, efficacy and safety to that of Lantus&reg;in treatment of T2DM.

Maillard reaction and immunogenicity of protein therapeutics

The recombinant DNA technology enabled the production of a variety of human therapeutic proteins.Accumulated clinical experience,however,indicates that the formation of antibodies against such proteins is a general phenomenon rather than an exception.The immunogenicity of therapeutic proteins results in inefficient therapy and in the development of undesired,sometimes life-threatening,side reactions.The human proteins,designed for clinical application,usually have the same amino acid sequence as their native prototypes and it is not yet fully clear what the reasons for their immunogenicity are.In previous studies we have demonstrated for the first time that interferon-b(IFN-b)pharmaceuticals,used for treatment of patients with multiple sclerosis,do contain advanced glycation end products(AGEs)that contribute to IFN-b immunogenicity.AGEs are the final products of a chemical reaction known as the Maillard reaction or glycation,which implication in protein drugs' immunogenicity has been overlooked so far.Therefore,the aim of the present article is to provide a comprehensive overview on the Maillard reaction with emphasis on experimental data and theoretical consideration telling us why the Maillard reaction warrants special attention in the context of the welldocumented protein drugs' immunogenicity.

The truncated form of fagellin (tFlic) provides the 2dCap subunit vaccine with better immunogenicity and protective efects in mice

Porcine circovirus type 2(PCV2)is the main causative agent of porcine circovirus-associated diseases,and it causes substantial economic losses in the swine industry each year.It is crucial to develop an efective vaccine against the circulating strain PCV2d,which is prone to substantial degrees of mutation.In this study,a truncated form of fagellin(tFlic:85-111 aa)was inserted into the C-terminal sequence of 2dCap,and Western blotting results showed that recombinant Cap-tFlic VLPs were successfully expressed.Transmission electron microscopy(TEM)and dynamic light scattering(DLS)data indicated that purifed recombinant Cap-tFlic fusion proteins existed in the form of polymers and that tFlic could not afect the formation and internalization of VLPs.Integrated Cap-tFlic VLPs induced the expression of antigen presentation-related factors(MHC-II and CD86)by bone marrow-derived dendritic cells(BM-DCs),and the expression of TLR5-related factors(TNF-α)was dramatically elevated.Mice intramuscularly immunized with Cap-tFlic VLPs exhibited signifcantly higher levels of Cap-specifc antibodies and neutralizing antibodies than mice immunized with wild-type Cap VLPs.The data obtained in the current study indicate that Cap-tFlic may be a candidate for a subunit vaccine against PCV2 in the future.