Human Genetics and Infectious Disease
Prof L Bornman - Human Genetics and Disease Susceptibility, Tuberculosis
Associate Professor Liza Bornman presently heads a research group of three M.Sc. students. The group focuses on human genetic and epigenetic factors influencing susceptibility to infectious diseases, specifically tuberculosis (TB). According to statistics South Africa (SA), non-HIV TB is the leading natural cause of death in SA. Mycobacterium tuberculosis, the causative agent of TB, usually enters the body via inhalation into the lungs. The first line of defense against infection by this bacterium is the innate immune response. In this response, immune cells perceive the presence of the bacterium via receptors on their cell membranes, an event which ultimately leads to the activation of numerous defense genes. Activation of these defense genes relies heavily on the presence and functionality of a protein called the vitamin D receptor (VDR), as well as sufficient levels of active vitamin D3. The levels and functional abilities of the vitamin D receptor rely upon the genetic sequence of the gene, as well as the epigenetic regulation of this gene’s expression.
Currently, the group’s research involves determination of how the genetic and epigenetic variables of the VDR in individuals relate to TB status, and how these factors differ between Caucasian, Venda and ethnically diverse African populations. The study may also give insights into why the different populations show varying levels of susceptibility or predisposition to TB. Knowledge gained from the study can be shared with authorities involved in the management of the TB burden in South Africa, and may contribute to early identification and monitoring of individuals at risk for the development of TB. This is of utmost importance in the light of the synergy between HIV and TB in Southern Africa.