## 4 Discussion  
DEM-treated mice serve as models which allow us to study the effects of GSH diminishment (such as those induced by T2 DM or other causes) on TB patients. Furthermore, treating mice with the GSH-decreasing agent, DEM, while comparing them to untreated mice substantiates the positive effects of GSH supplementation observed in our previous studies. DEM has been known to reduce GSH levels for many years. A study by [PERSON] et al. suggests that DEM depletes cellular GSH to less than 5% of the GSH in untreated cells [26], deeming DEM a proper agent to study the effects of depleting GSH levels. The treatment of _M. tb_-infected C57 BL/6 (WT) mice with DEM (50 mM) led to effects similar to those seen in individuals with low GSH levels [8,13]. For example, the DEM-treated mice had significantly increased levels of proinflammatory cytokines, including IL-6, in the lung and plasma (Figure 2). We also observed increased TNF-\(\alpha\) levels in the lungs and plasma of mice (Figure 3). Furthermore, treatment with DEM led to an increase in reactive oxygen species (ROS) in the lung and plasma of the mice (Figure 4), confirming that rGSH levels have been depleted. In fact, our results show that rGSH and total GSH levels were downregulated by 50% in the plasma and in the lungs of mice treated with DEM for 2 and 4 weeks (Figure 1). Total GSH was also significantly diminished in the lung tissue of mice treated with DEM at 2 weeks post-infection. Such a significant decrease in rGSH levels was also observed by [PERSON] et al. in BAL/c mice treated with DEM [27]. This further demonstrates that the depletion of GSH leads to an increase in oxidative stress. This failed redox response and exacerbated inflammatory response induce an increased survival of _M. tb_. The significantly increased survival of _M. tb_ in both the lungs and the spleen of the DEM-treated mice suggests the importance of GSH in controlling _M. tb_ infection (Figure 5). GSH supplementation has been previously shown to significantly decrease _M. tb_ survival in the PBMCs of people infected with HIV and in human monocyte  
Figure 6: Morphometric analysis and hematoxylin and eosin staining of lung tissue sections of _M. tb_-infected mice that were sham-treated or treated with DEM. Morphometric analysis was performed in the mouse lung sections stained with hematoxylin and eosin at 4 weeks (**A**) and 8 weeks (**B**) post-_M. tb_ infection. 10\(\times\) (**C,E,G,J**) and 40\(\times\) (**D,F,H,J**) images of hematoxylin and eosin-stained lung sections of mice at 4 weeks (**C–F**) and 8 weeks (**G–J**) post-_M. tb_ infection are presented. The sample size (_n_) includes six mice each in the untreated and DEM-treated groups. derived macrophages of people with T2 DM [8; 13]. _M. tb_ survival in the mice samples also increased in a dose-dependent manner, with pathogen count increasing with an increase in DEM concentration (Figure 5). These observations suggest poor mycobacterial control in DEM-treated mice, which is typically controlled by the granuloma. Thus, it is important to elucidate granuloma formation in the lungs of DEM-treated mice. A granuloma is an organized aggregation of immune cells that forms in response to a repeated stimulus; it is also known as a small area of inflammation. Current literature acknowledges that _M. tb_ infection is the most common cause of granuloma formation [4]. The purpose of granuloma formation during _M. tb_ infection is to diminish the growth of the pathogen by forming aggregates of infected cells. Not surprisingly, the granulomas of DEM-treated mice were poorly formed, and the aggregates were relatively scattered, especially at 8 weeks post-infection (Figure 6). These mice had much larger areas of immune cell infiltration and more congestion of bronchial and vascular structures than the 4 weeks post-infection control group. Limitations of our study include using a mouse model of TB, which may lead to minor differences in results compared to humans. In further studies, our lab plans to treat diabetic mice (infected with _M.