Therapeutic HIV vaccine was considered as a hopeful curative method for AIDS patients. However, there is still no suitable HIV animal model for vaccine study since the difference in the immune system between human and animals. To evaluate the therapeutic effect of combined immunization strategy with multiple vector vaccines in macaque models. Plasmid DNA, recombinant Ad5 and MVA vaccines which expressing SIV gag and env genes were constructed. Sequential and repeated immune strategy were applied to immunize mice with these three vaccines. Cellular immune responses in mice immunized with these three vaccines were measured by ELISPOT test in vitro and CTL assay in vivo. The results were analyzed and compared with different antigen combination, order of vaccines and intervals to choose a suitable immunization strategy for macaque immunization in future. It indicated that strong SIV-Gag/Env-specific cellular immune responses were induced by these three vector vaccines. It laid a foundation for evaluating the therapeutic effect of combined immunization strategy with multiple vector vaccines in SIV infected macaque models.
AIDS Vaccines ; administration & dosage ; genetics ; immunology ; Adenoviridae ; genetics ; metabolism ; Animals ; Antibodies, Viral ; immunology ; Female ; Gene Products, env ; administration & dosage ; genetics ; immunology ; Gene Products, gag ; administration & dosage ; genetics ; immunology ; Genetic Vectors ; genetics ; metabolism ; HIV Infections ; immunology ; prevention & control ; virology ; Humans ; Immunization ; Mice ; Mice, Inbred BALB C ; Simian Immunodeficiency Virus ; genetics ; immunology ; Vaccines, DNA ; administration & dosage ; genetics ; immunology

A safe and effective vaccine against the human immunodeficiency virus type 1 (HIV-1) is expected to have a considerable impact on elimination of acquired immune deficiency syndrome. Despite decades of effort, an effective vaccine against HIV-1 remains elusive. In recent years, the Thai HIV Vaccine Efficacy Trial (known as RV144) showed a reduction in HIV-1 acquisition by 31%, but this agent could not delay disease progression in vaccinated individuals. Clinical analyses of experimental data and experiments in vitro have revealed two main types of immunogen design: induction of broad-spectrum neutralizing antibody (bNAb) and cytotoxic T lymphocyte (CTL) responses. bNAb can prevent or reduce acquisition of infection, and its main immunogens are virus-like particles, natural envelope trimers and stable bNAb epitopes. An effective CTL response can slow-down viral infection, and its main immunogens are "mosaic" vaccines, "conserved immunogens", and the "fitness landscape" of HIV-1 proteins. This review summarizes the strategies as well as progress in the design and testing of HIV-1 immunogens to elicit bNAb and CTL responses.
AIDS Vaccines ; genetics ; immunology ; Animals ; Drug Design ; HIV Antibodies ; immunology ; HIV Infections ; immunology ; prevention & control ; virology ; HIV-1 ; genetics ; immunology ; Humans

To optimize the immunization strategy against HIV-1, a DNA vaccine was combined with a recombinant vaccinia virus (rTV) vaccine and a protein vaccine. Immune responses against HIV-1 were detected in 30 female guinea pigs divided into six groups. Three groups of guinea pigs were primed with HIV-1 DNA vaccine three times, boosted with rTV at week 14, and then boosted with gp140 protein at intervals of 4, 8 or 12 weeks. Simultaneously, the other three groups of animals were primed with rTV vaccine once, and then boosted with gp140 after 4, 8 or 12 weeks. The HIV-1 specific binding antibody and neutralizing antibody, in addition to the relative affinity of these antibodies, were detected at different time points after the final administration of vaccine in each group. The DNA-rTV-gp140 immune regimen induced higher titers and affinity levels of HIV-1 gp120/gp140 antibodies and stronger V1V2-gp70 antibodies than the rTV-gp140 regimen. In the guinea pigs that underwent the DNA-rTV-gp140 regimen, the highest V1V2-gp70 antibody was induced in the 12-week-interval group. However, the avidity of antibodies was improved in the 4-week-interval group. Using the rTV-gp140 immunization strategy, guinea pigs boosted at 8 or 12 weeks after rTV priming elicited stronger humoral responses than those boosted at 4 weeks after priming. In conclusion, this study shows that the immunization strategy of HIV-1 DNA vaccine priming, followed by rTV and protein vaccine boosting, could strengthen the humoral response against HIV-1. Longer intervals were better to induce V1V2-gp70-specific antibodies, while shorter intervals were more beneficial to enhance the avidity of antibodies.
AIDS Vaccines ; administration & dosage ; genetics ; immunology ; Animals ; DNA, Viral ; administration & dosage ; genetics ; immunology ; Female ; Guinea Pigs ; HIV Infections ; immunology ; prevention & control ; virology ; HIV-1 ; genetics ; immunology ; Humans ; Immunization ; methods ; Vaccines, DNA ; administration & dosage ; genetics ; immunology ; Vaccinia virus ; genetics ; immunology ; env Gene Products, Human Immunodeficiency Virus ; administration & dosage ; genetics ; immunology

Recent studies show that the vector of recombinant Bacillus Calmette-Guérin (rBCG) has a series of advantages. With exogenous gene and vaccine in one inoculation, it can obtain strong and persistent immune response at one time so that BCG is considered as a kind of ideal vector for live recombinant vaccine. This review outlines the application of rBCG vaccine and its vector in infectious diseases caused by bacteria, viruses, other microorganisms and parasites.
AIDS Vaccines ; genetics ; immunology ; Antigens, Bacterial ; genetics ; immunology ; BCG Vaccine ; genetics ; immunology ; metabolism ; Communicable Disease Control ; methods ; Genetic Vectors ; genetics ; HIV Infections ; prevention & control ; HIV-1 ; Mycobacterium tuberculosis ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; Tuberculosis ; prevention & control ; Vaccines, Synthetic ; immunology

OBJECTIVETo construct and compare the immunogenicities of DNA vaccines expressing pol genes derived from B`/C and A/E recombinant subtypes of HIV-1 in China.

METHODSTwo DNA vaccines were constructed by inserting the codon optimized pol genes derived from B'/C and A/E subtypes of HIV-1 into mammalian expression vector pSV1.0. In vitro expression efficiencies of the two DNA vaccines were determined by Western blotting and their immunogenicities were compared by i.m. immunizing female BALB/c mice. After immunization, mice splenocytes were isolated sterilely and IFN-γ based enzyme linked immunospot assay (ELISPOT) was employed to read out the specific T cell immunity.

RESULTSThe constructed DNA vaccines were validated by restriction enzyme digestion and DNA sequencing. Western blotting result showed both of the two DNA vaccines could be expressed at appreciable levels in vitro. Under the stimulation of Consensus B Pol peptide pools, specific T cell frequency elicited by pSVAE-Pol was (636±178) SFCs/10(6) splenocytes; specific T cell frequency elicited by pSVCN-Pol was (468±265)SFCs/10(6) splenocytes (P=0.412). Under the stimulation of HIV-1 AE2f Pol peptide pools, specific T cell frequency elicited by pSVAE-Pol was (1378±611) SFCs/10(6) splenocytes; specific T cell frequency elicited by pSVCN-Pol was (713±61) SFCs/10(6) splenocytes (P=0.134). Further analysis suggested pSVAE-Pol induced specific T cell responses mainly focused on Pol 1 peptide pool, while, in addition to induce Pol 1 specific T cell responses, pSVCN-Pol could also elicit T cell responses against consensus B Pol 2 peptide pool.

CONCLUSIONAlthough pSVAE-Pol was more immunogenic, pSVCN-Pol could induce T cell responses against broader epitope spectrum. Rational vaccine design may need combine them together.

AIDS Vaccines ; genetics ; immunology ; Animals ; Female ; Genes, pol ; immunology ; HIV-1 ; genetics ; immunology ; Immunity, Cellular ; Immunization ; Mice ; Mice, Inbred BALB C ; T-Lymphocytes ; immunology ; Vaccines, DNA ; genetics ; immunology

New strategies to improve vaccine efficacy against human immunodeficiency virus type 1 (HIV-1) are still required. DNA vaccines, exhibiting potential advantages over conventional vaccines for their simplicity and versatility, can induce specific humoral and cellular immune responses. We developed a recombinant pVAX1 DNA vector carrying p24 gene of HIV-1. The results showed that pVAX1 mediated gene possessed the ability of effective expression in both transfected 293T cells and BALB/c mice. And pVAX1-p24 DNA prime and boost immunization can induce significant P24-specific humoral immune responses and cellular immune responses in BALB/c mice. Furthermore, immunization with pVAX1-p24 DNA prime and protein boost induced 7.3 to 8.0-fold greater p24-specific humoral responses than pVAX1-p24 DNA prime and boost, while the cellular immune responses induced by combined immunization was lower. The results suggested that pVAX1-p24 DNA and P24 protein vaccine is a promising HIV-1 vaccine, and the selections of the immunization strategies are important for the immunization results.
AIDS Vaccines ; genetics ; immunology ; Animals ; DNA ; genetics ; immunology ; HEK293 Cells ; HIV Core Protein p24 ; genetics ; immunology ; Humans ; Immunization ; Mice ; Mice, Inbred BALB C ; Vaccines, DNA ; genetics ; immunology

We constructed a phage-displayed random mutation library of Tat38-61(51N/55N), for studying the molecular evolution screening of HIV-1 Tat38-61 epitope. We used primers containing the random nucleotide sequences, and introduced the random mutations at the sites of 51 and 55 amino acids coding sequences into full-length Tat sequences by overlapping PCR. With the randomly mutated full-length Tat as template, the Tat38-61(51N/55N) mutants which contained recognition sequences for the Xba I in both ends were amplified by PCR using the designed primers. The mutants were cloned into Xba I site in the phagemid vector pCANTAB5S, then the recombinants were transformed into E. coli TG1, a phage-displayed the random mutation library of Tat38-61(51N/55N) was constructed by the rescue of help virus M13KO7. The results showed that the library consisted of about 5.0 x 10(6) colonies and the phage library titer was 2.65 x 10(12) TU/mL. More than 56.50% colonies in the library were positive for insertion. Sequence analysis showed that the nucleotides encoding amino acids at the sites of 51 and 55 distributed randomly. The constructed mutation library could meet the requirements for the following molecular evolution screening, and might prepare the Tat mutants for the further study of new Tat vaccine candidates.
AIDS Vaccines ; immunology ; Escherichia coli ; genetics ; metabolism ; HIV-1 ; genetics ; Humans ; Mutation ; Peptide Fragments ; biosynthesis ; genetics ; immunology ; Peptide Library ; Recombinant Proteins ; biosynthesis ; genetics ; immunology ; tat Gene Products, Human Immunodeficiency Virus ; biosynthesis ; genetics ; immunology

PURPOSE: The third variable (V3) loop of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein has been intensively studied for AIDS vaccine development. Bacille Calmette-Guerin (BCG) is widely used to immunize against tuberculosis and has many advantages as a vaccine vehicle, such as low toxicity, adjuvant potential, low cost, and long-lasting immune-inducing capacity. This work was initiated to investigate the immunogenicity of recombinant BCG (rBCG-mV3) designed to express trimeric HIV-1 V3 loop (mV3) in rBCG-mV3-immunized animals. MATERIALS AND METHODS: HIV-1 V3-concatamer was cloned into pMV261, a BCG-expression vector, and then rBCG-mV3 was constructed by introducing the recombinant plasmid (pMV-V3). The recombinant BCG was examined with regard to its expression of V3-concatamer and the genetic stability in vivo and in vitro. The immune responses induced by recombinant BCG were tested in immunized mice and guinea pigs. RESULTS: The rBCG-mV3 expressed detectable amounts of V3-concatamer when induced by single heat-shock. The recombinant BCG was genetically stable and maintained the introduced mV3 gene for several weeks. V3-specific antibodies were clearly detected 6 weeks after inoculation. The antibody titer rapidly increased after immunization up to 10 weeks, and then maintained for over 4 weeks. IgG2a was prevalent in the V3-specific antiserum. The recombinant BCG was also effective in inducing delayed-type hypersensitivity responses in the immunized guinea pigs. rBCG-immunized mice retained substantial amounts of V3-specific T cells in the spleen, even 5 months after the first immunization. CONCLUSION: Recombinant BCG-mV3 is very efficient in inducing humoral and long-lasting cell-mediated immunity against HIV-1 V3 in the immunized animals.
AIDS Vaccines/genetics/*immunology ; Animals ; BCG Vaccine/genetics/*immunology ; Female ; Guinea Pigs ; HIV-1/*immunology ; Humans ; Immunity, Cellular/genetics/*immunology ; Immunity, Humoral/genetics/*immunology ; Mice ; Mice, Inbred BALB C ; env Gene Products, Human Immunodeficiency Virus/genetics/*immunology

PURPOSE: The third variable (V3) loop of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein has been intensively studied for AIDS vaccine development. Bacille Calmette-Guerin (BCG) is widely used to immunize against tuberculosis and has many advantages as a vaccine vehicle, such as low toxicity, adjuvant potential, low cost, and long-lasting immune-inducing capacity. This work was initiated to investigate the immunogenicity of recombinant BCG (rBCG-mV3) designed to express trimeric HIV-1 V3 loop (mV3) in rBCG-mV3-immunized animals. MATERIALS AND METHODS: HIV-1 V3-concatamer was cloned into pMV261, a BCG-expression vector, and then rBCG-mV3 was constructed by introducing the recombinant plasmid (pMV-V3). The recombinant BCG was examined with regard to its expression of V3-concatamer and the genetic stability in vivo and in vitro. The immune responses induced by recombinant BCG were tested in immunized mice and guinea pigs. RESULTS: The rBCG-mV3 expressed detectable amounts of V3-concatamer when induced by single heat-shock. The recombinant BCG was genetically stable and maintained the introduced mV3 gene for several weeks. V3-specific antibodies were clearly detected 6 weeks after inoculation. The antibody titer rapidly increased after immunization up to 10 weeks, and then maintained for over 4 weeks. IgG2a was prevalent in the V3-specific antiserum. The recombinant BCG was also effective in inducing delayed-type hypersensitivity responses in the immunized guinea pigs. rBCG-immunized mice retained substantial amounts of V3-specific T cells in the spleen, even 5 months after the first immunization. CONCLUSION: Recombinant BCG-mV3 is very efficient in inducing humoral and long-lasting cell-mediated immunity against HIV-1 V3 in the immunized animals.
AIDS Vaccines/genetics/*immunology ; Animals ; BCG Vaccine/genetics/*immunology ; Female ; Guinea Pigs ; HIV-1/*immunology ; Humans ; Immunity, Cellular/genetics/*immunology ; Immunity, Humoral/genetics/*immunology ; Mice ; Mice, Inbred BALB C ; env Gene Products, Human Immunodeficiency Virus/genetics/*immunology

To study the immunogenicity of recombinant adeno-asscociated virus type 1 expressing HIV-1 gp120 gene (rAAV2/1-gp120) in BALB/c mice and Rhesus macaques. The gp120 gene derived from Chinese HIV-1 isolates was constructed into rAAV2/1 and rAd5 vectors. Firstly, the immunogenicity of rAAV2/1-gp120 was compared with rAd5-gp120 in BALB/c mice when used once or twice in 3 weeks interval. Then the monkeys were immunized with rAAV2/1-gp120 once. The HIV-1 specific IgG levels and neutralization activity to pseudotyped HIV-1 virus were tested using ELISA and neutralization assay, and the cellular immune responses were analyzed by IFN-gamma enzyme-linked immunospot (ELISPOT) and in vivo CTL assays. Compared with rAd5-gp120 immunized mice, mice immunized with rAAV2/1-gp120 once in duced stronger gp120-specific IgG and were sustained for at least 21 weeks. rAd5-gp120 immunized mice generated stronger cellular immune responses than rAAV2/1-gp120 in spleen and draining lymph node. But only moderate gp120-specific in vivo CTL activity was observed in both rAAV2/1-gp120 and rAd5-gp120 immunized mice. Four of five monkeys vaccinated with rAAV2/1-gp120 generated gp120 specific IgG, the titer ranged from 1:100 to 1:400 with end-point dilution. Gp120 specific IgG could be detected 4 weeks after immunization and reached the peak at 10 weeks after immunization. No neutralization activity against pseudotyped HIV-1 virus expressing NL4-3 Env antigen was detected. In Conclusion, rAAV2/1-gp120 induced high level of HIV-1 specific IgG antibody and moderate cellular immune responses. No neutralizing antibody was elicited. It indicates that the env gene and immunization strategy should be optimized to elicit neutralizing antibody against HIV-1 in further studies.
AIDS Vaccines ; administration & dosage ; immunology ; Adenoviridae ; genetics ; Animals ; COS Cells ; Cercopithecus aethiops ; Cytotoxicity, Immunologic ; immunology ; Dependovirus ; genetics ; Enzyme-Linked Immunosorbent Assay ; Genetic Vectors ; genetics ; HIV Antibodies ; immunology ; HIV Envelope Protein gp120 ; genetics ; immunology ; HIV-1 ; genetics ; immunology ; Immunization ; methods ; Immunoglobulin G ; immunology ; Macaca mulatta ; Mice ; Mice, Inbred BALB C ; Recombinant Fusion Proteins ; administration & dosage ; genetics ; immunology ; Time Factors