HemaCare reports 3 recent findings generating enthusiasm in the HIV research community
Enormous strides have been made against HIV ever since its discovery in the 1980s. A virus that was once synonymous with doom, HIV can now be managed with medical interventions and treated as a chronic condition. However, a cure remains ever elusive; an effective vaccine has been out of reach as well.
The difficulties have certainly not stopped the hundreds of thousands of researchers across the world who have worked hard to defeat HIV once and for all. HemaCare highlights three recent developments that are part of the cause for optimism that the needs of HIV treatment and prevention will be fully met.
1) Intriguing HIV insights from…llamas. One of the chief challenges in developing an HIV vaccine is that the different antibodies that arise in response sometimes interfere with each other and cancel their effects. Llama antibodies against HIV, on the other hand, are smaller than conventional human antibodies. Consequently, four llama antibodies target different regions of the virus’s CD4-binding site. When used in combination, the antibodies neutralized all of the 60 various HIV strains that were tested.
If further research pans out, a big step for medicine will be to “humanize” the antibodies so that the human immune system doesn’t recognize the llama antibodies as foreign invaders and go on the attack. There is hope that the llama antibodies could be genetically edited to reach this tolerability.
2) Using HIV’s docking strategy against itself. Typically, HIV uses cell receptors called CD4 and CCR5 to gain entry into the cells it infects. Now, scientists have developed a “fusion” that contains part of CD4 and CCR5, along with an antibody, which all together was positioned for optimal fit to target the part of HIV that seeks these receptors. In vitro tests showed that this construct, called eCD4-Ig, fared better than all the known HIV antibodies at blocking the virus from infecting cells. A harmless virus was then employed to deliver the gene for eCD4-Ig into monkey muscle cells; as a result, these monkeys expressed eCD4-Ig and successfully resisted attempts at infection.
3) Building on a vaccine’s modest effectiveness. You might remember when a vaccine trial in Thailand made waves for having some – but nowhere near complete – efficacy against HIV (31% effective after 3.5 years). Now, in a new study, the HVTN 100 trial, the vaccine regimen that was tested in Thailand has been altered in design and schedule in hopes of improving its performance. A few other changes have been made as well. If the experimental vaccine regimen passes the benchmarks of safety and immune response, it will be tested for effectiveness in a large trial in South Africa.
We at HemaCare are delighted to hear about these promising developments, and we are proud to offer blood components and cells from peripheral blood from IRB consented HIV volunteer patients. (Sorry, we have no llamas.)
1. McCoy LE, et al. Molecular evolution of broadly neutralizing llama antibodies to the CD4-binding site of HIV-1. PLoS Pathogens. 2014;10(12):e1004552.
2. Gardner MR, et al. AAV-expressed eCD4-Ig provides durable protection from multiple SHIV challenges. Nature. 2015;ahead of print