Before any formal treatments such as antibiotics and chemotherapy were developed, vitamin D was used to treat tuberculosis (Martineau et al. 2007). Although the use of vitamin D to treat tuberculosis became uncommon with the development of antimycobacterial treatments, it has since come back into rotation due to its ability to enhance immune response (Martineau et al. 2007).
The active form of vitamin D, 1,25-dihydroxy-vitamin D, also called calcitriol, is what regulates the response to the bacteria infection (Martineau et al. 2007). To produce calcitriol, 1α-hydroxylase adds a hydroxyl group to 25-hydroxy-vitamin D (Martineau et al. 2007).
In the active form of the disease, Mycobacterium tuberculosis will be confined within macrophages, which become surrounded by T cells (Martineau et al. 2007). These specific macrophages that respond the infection contain a gene that encodes 1α-hydroxylase, and the T cells secrete interferon gamma (IFNg), which increases the upregulation of 1α-hydroxylase and inhibits the production of an enzyme that inactivates calcitriol (Martineau et al. 2007).
Calcitriol gives rise to respiratory bursts and increases phagolysosome fusion in macrophages containing M. tuberculosis (Martineau et al. 2007). These bolster the immune response by damaging, and ultimately killing, the bacteria (Martineau et al. 2007).
Antimycobacterial Latent Tuberculosis Treatments
Although patients with latent tuberculosis are not contagious, and do not exhibit any signs or symptoms of the disease, they still must undergo treatment to prevent the development of active tuberculosis (CDC Basic TB Facts). The medications used for treatment include isoniazid, rifampin, and rifapentine (CDC Basic TB Facts). These medications can be used individually, or in combination with each other (CDC Basic TB Facts). However, the length of treatment varies depending on the medication, and treatment can last anywhere between 3 and 9 months (Zumla et al. 2015).
Antimycobacterial Active Tuberculosis Treatments
Treatments for active tuberculosis can include the same medications used to treat latent tuberculosis (CDC Basic TB Facts). However, these medications can be supplemented with small molecules that enhance host immune response. One of these molecules, R207910, also known as bedaquiline, has been proven to be one of the most effective antimycobacterial supplements (Andries et al. 2005). It was determined that the atpE gene is the target for bedaquiline, and since this target is so specific, bedaquiline will not interfere with other tuberculosis treatments (Andries et al. 2005). Bedaquiline works by inhibiting ATP synthase, thus leading to a decrease in the amount of ATP available for the bacterium and a disruption in pH homeostasis necessary for survival (Adries et al. 2005).