The state of gene therapy research in Africa, its significance and implications for the future

Abstract

Gene therapy has made impressive recent progress and has potential for treating a wide range of diseases, many of which are important to Africa. However, as a result of lack of direct public funding and skilled personnel, direct research on gene therapy in Africa is currently limited and resources to support the endeavor are modest. A strength of the technology is that it is based on principles of rational design, and the tools of gene therapy are now highly versatile. For example gene silencing and gene editing may be used to disable viral genes for therapeutic purposes. Gene therapy may thus lead to cure from infections with HIV-1, hepatitis B virus and Ebola virus, which are of significant public health importance in Africa. Although enthusiasm for gene therapy is justified, significant challenges to implementing the technology remain. These include ensuring efficient delivery of therapeutic nucleic acids to target cells, limiting unintended effects, cost and complexity of treatment regimens. In addition, implementation of effective legislation that will govern gene therapy research will be a challenge. Nevertheless, it is an exciting prospect that gene therapy should soon reach the mainstream of medical management. Participation of African researchers in the exciting developments is currently limited, but their involvement is important to address health problems, develop capacity and enhance economic progress of the continent.

Figure 1

Modification of cells ex vivo. Cells are collected and expanded in culture following selection. Transduction with vectors is employed to introduce a therapeutic sequence which may, for example, confer resistance to HIV-1 or induce expression of a globin gene. The selected cells may be re-infused into the donor by autologous transplant. Use of hematopoietic stem cells enables formation of self-renewing precursor cells that generate progeny with the desired phenotype.

Figure 2

Delivering antiviral sequences using viral vectors or NVVs. Following systemic administration, viral vectors and NVVs target hepatocytes, where the therapeutic sequences are delivered. Typically NVVs enter the liver cells by endocytosis. The approach is useful to effect a therapeutic action against HBV or hemorrhagic fever viruses such as EBOV.