New gene-based approaches for an AIDS vaccine

Area of Science:

• Immunology
• Vaccinology
• Virology

Background:

• Cellular immune responses, particularly T cell responses, are crucial for controlling human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV) infections.
• The rhesus macaque model using SIV or chimeric SHIV is a standard for studying AIDS pathogenesis and vaccine efficacy.
• DNA immunization is a key method for inducing specific T cell responses in preclinical models.

Purpose of the Study:

• To evaluate the efficacy of DNA immunization strategies in eliciting T cell responses against SIV/SHIV.
• To explore parameters influencing DNA immunogenicity in primates for AIDS vaccine development.
• To assess the potential of combined DNA and viral vector vaccination for protection against pathogenic challenge.

Main Methods:

• Utilizing DNA immunization in rhesus macaques to elicit T cell responses against SIV/SHIV antigens.
• Investigating factors affecting DNA immunogenicity, including antigen expression, protein choice, immunization route, and adjuvants.
• Employing a prime-boost strategy combining DNA immunization with attenuated recombinant viral vectors expressing SIV antigens.

Main Results:

• Optimizing DNA immunization parameters enhances immunogenicity in primates.
• Prime-boost regimens using DNA followed by viral vectors lead to improved specific immunity.
• Some prime-boost strategies have demonstrated protection against pathogenic SIV/SHIV challenge in preclinical models.

Conclusions:

• DNA immunization is a viable tool for generating T cell responses relevant to AIDS vaccine development.
• Combined DNA and viral vector prime-boost strategies represent a promising approach for enhancing vaccine efficacy.
• Gene-based AIDS vaccines, including DNA-based approaches, have progressed to clinical trials based on preclinical findings.