In terms of HIV cases, according to the U.S. Centers for Disease Control and Prevention (CDC) there were 38,500 diagnoses in 2015 (which represents the most recent verified data). With incidences remaining high, one research group have been working on a biological process to help to neutralize the virus.
Scientists based at Duke Human Vaccine Institute have been studying natural killer cells (and broadly neutralizing antibodies (bnAbs). It is hoped that this research will provide the basis for a vaccine: one that could offer a means of protection from HIV infection.
The basis of this is the observation that around half of the people who are infected with HIV experience the production of broadly neutralizing antibodies (and in contrast around 50 percent of those infected do not develop bnAbs). The reason why some people do not develop the beneficial antibodies is because HIV’s high mutation rate means that the antibodies no longer recognize the virus as a target.
The new research shows that bnAbs could assist with the development and efficacy of a vaccine. While this remains someway off, the researchers have recognized that if they can understand the molecular mechanisms of host control of bnAb induction, this will represent an important first step.
To achieve this, the researchers undertook transcriptome analysis of the blood from 50 HIV-1 bnAb producing patients and from 50 patients with HIV-1 that do not produce bnAbs. This involved analysis of the totality of RNA transcripts generated by the genome.
This assessment showed an upregulation of the RAB11FIP5 gene which encodes a Rab protein associated with endosomes. Furthermore, the study found that natural killer cells possess the highest expression of the gene, which is possibly linked to a dysfunction of the natural killer cells.
Natural killer cells are a type of cytotoxic lymphocyte of importance to the innate immune system. These cells provide rapid responses to viral-infected cells, acting at around three days after infection, and respond to tumor formation.
According to principal researcher Dr. Barton Haynes: “This type of immune cell wasn’t previously known to regulate bnAbs. We found a new natural killer cell pathway that appears to be important in regulating the bnAb production.” The results present an alternate pathway, for the future, to modulate during vaccination to generate a better HIV antibody response.
The new research has been published in the journal Cell. The research paper is titled “RAB11FIP5 Expression and Altered Natural Killer Cell Function Are Associated with Induction of HIV Broadly Neutralizing Antibody Responses.”
