Study On The Conservation Of Epitope In HIV-1 Multi-epitope Vaccine MEP1 And Comparative Study On Adjuvants

Acquired Immune Deficiency Syndrome(AIDS)has always been a major infectious disease that affects the safety of human life around the world.While highly active antiretroviral therapy(HARRT)has largely controlled the course of the disease in people with HIV,it has not stopped the spread and infection of HIV.Therapeutic vaccines of HIV can reduce HIV transmission rate and slow the progression of the AIDS.So far,there is still no effective vaccine against HIV in the world.To develop an effective vaccine of HIV in China,our research group developed a multi-epitope protein vaccine MEP1 which was targeted at the dominant MHC restriction of Chinese and the trend of HIV-1 epidemic characteristics.MEP1 contains 9 CTL epitopes and 1 Th-epitope-rich-region,which has obtained the national patent authorization.Previous studies have shown that MEP1 protein has good immunogenicity in BALB/c mouse model,the immune response induced by MEP1 was significantly correlated with MHC restriction in Chinese population.Now there is a new trend of HIV-1 epidemic strains in China,and the epitope conservation of Chinese HIV epidemic strains may have new change.We need to analyze the efrect of these changes on the MEP1 induced immune response.To optimize the vaccine regimen of MEP1,we need to explore the difference of immune response induced by MEP1 protein combined with different adjuvants.This thesis studies these two problems.1.The effect of the changing trend of HIV-1 epidemic strains on the immunization of HIV-1 Multi-epitope Vaccine MEP1 in China(1)Conservation analysis of CTL epitopes contained in MEP1 and its MHC restrictive evaluation.The data of China's HIV-1 epidemic strain from 2014 to 2017 were taken as the research object for data analysis.Conservation variation situations of 9 CTL epitopes contained in MEP1 were analyzed,and conservation in the different HIV-1 virus subtype of each epitope were analyzed.The MHC restriction and TAP affinity of mutant epitopes were analyzed by online software.The 9 CTL epitopes involved in MEP1 were conservative.Most of the amino acid residues were homotypic amino acid mutations,which did not affect the MHC restriction assessment of epitopes and TAP aff-inity.The conservatism of the epitopes is not affected by the changes of years from 2014 to 2417 P2,P3,P4,P6,P7 and P8 have subtype biased mutations,which show different trends of amino acid mutations in different HIV subtypes.All the 9 epitopes were stable in conservativeness(2)Immunological studies on transgenic A11/DR1 mice confirmed the effect of mutant epitopes on the immunization effect of MEP1.The results showed that the MHC restrictive evaluation of 9 CTL epitopes was more accurate.MEP1 induces the peptid-specific cellular immune response in response to HLA*11:01 mutant epitopes.The results also showed that MEP1 is applicable to the change of Chinese HIV epidemic strains.The multi-epitope protein MEP1 has some ability to respond to the epitope mutation of HIV-1 virus.2.Comparative study by MEP1 in combination with different adjuvants in BALB/c mice(1)Immune response characteristics of multi-epitope protein MEP1 combined with different adjuvants.MEP1 is mainly expressed as inclusion body.BALB/c mice were immunized by using the thrice immunization strategies identified in previous studiesHumoral and cellular immune responses were used to compare the differences in the immune responses induced by MEP1 among MF59 and aluminum adjuvants.MF59 and aluminum adjuvants enhanced the humoral and cellular immune responses induced by MEP1.MF59 promoted MEP1 to induce Thl/Th2 balanced cellular immune response,and aluminum adjuvant promoted MEP1 to induce Thl biased cellular immune response(2)Immune response characteristics of multi-epitope protein MEP1 combined with different adjuvants at the early stage.BALB/c mice were immunized by using the single immunization.Humoral and cellular immune responses were used to compare the differences in the immune responses induced by MEP1 among MF59 and aluminum adjuvants.MF59 and aluminum adjuvant can promote MEP1 to induce a stronger immune response.Aluminum adjuvant can promote MEP1 protein to produce higher level of immune response at the early stage.The immune strategy of MEP1 with aluminum adjuvant was determined3.ConclusionThe HIV-1 multi-epitope protein vaccine MEP1 has good immunogenicity.the 9 CTL epitopes of MEP1 were conservative.There are subtype biased mutations in P2,P3,P4,P6,P7 and P8,but most mutations do not affect the MHC restriction assessment of epitopes.MEP1 is applicable to the change of Chinese HIV epidemic strains.Aluminum adjuvant is more suitable for the selection of MEP1 immune strategy,which significantly enhanced the immune response induced by MEP1 and induce high level of humoral and cellular immune response in MEP1.