A research team at the Texas Biomedical Research Institute is working on a four year study sponsored by the National Institutes of Health to develop an attenuated hybrid form of human papilloma and human immunodeficiency viruses. This could allow patients to mount an immune response with efficient antibodies to fight both viruses. The new research is being conducted in Rhesus macaques with a form of the rhesus (Rh)PV and Simian Immunodeficiency virus (SIV) or monkey HIV.
The study is led by Dr. Marie-Claire Gauduin, an associate scientist in the Virology and Immunology Department, and wants to create and test Human papillomavirus together with an HIV vaccine in simians using a recombinant rhesus papillomavirus (rRhPV) strategy to induce immune responses at mucosal genital sites to prevent the transmission of HIV and HPV .
“This strategy would represent the first attempt to immunize animals with a trans-complementing live attenuated RhPV-SIV vector virus replicating at the major port of entry of SIV/HIV and RhPV/HPV, which is the mucosa,” Gauduin said in a recent news release. “The study will also explore the feasibility of such vaccine delivery platforms to stimulate the mucosal (adaptive and/or innate) immune responses to restrict viral entry.”
The researchers will first create a hybrid virus that allows the expression of the SIV antigens in the long-term. Then they will examine the nature of the viral immune response, investigating the protective efficacy of the hybrid vaccine when faced with genuine SIV virus.
Approximately 80% of infections with HIV are spread through mucosa. As such, the team will utilize skin stem cells or the host’s epithelia for a mucosal delivery system that can carry the hybrid virus through the mucosal site of infection, while keeping an efficient immune response.
“What’s exciting about this is that if we can place the vector vaccine in just the right layer of the mucosa, it will promote antibody production and anti-SIV central memory CD8+ T cell expansion at the site of infection for a prolonged period of time, initiating the immune system, preventing HIV infection and/or propagation and generate immediate protection,” Dr. Gauduin said.
She added, “In addition, we will generate anti-SIV cell expansion within the vaginal and rectal mucosa. Remember, skin grows out and sheds creating new layers of skin. As it does this, we hope to create an antibody response memory in the mucosal layer so that as skin regenerates, future layers retain this immune response. In other words, this novel HIV vaccine strategy will use the host epithelial stem cells as mucosal ‘delivery systems’ to ‘carry’ viral antigen and keep the immune response in alert at site of viral infection.”
According to Gauduin, “The development of an effective vaccine that restricts viral replication at mucosal portals of entry remains our best hope for controlling the HIV pandemic.”