BackgroundTBM (Tuberculous meningitis) is severe form of tuberculosis causing death of one third of the affected individuals or leaving two-third of the survivors disabled. MMP-9 (Matrix metalloproteinase-9) is produced by the central nervous system in a variety of inflammatory conditions and has a role in the breakdown of extracellular matrix and blood–brain barrier.MethodsIn this study, the levels of MMP-9 and its inhibitor, TIMP-1 (tissue inhibitor of metalloproteinases-1), were screened using zymography and reverse zymography in cerebrospinal fluid and serum of tuberculous meningitis patients at different stages of the disease. Further, role of MMP-9 as therapeutic target was studied in C6 glioma cells infected with Mycobacterium tuberculosis H37Rv. Cells were treated with dexamethasone or SB-3CT (specific inhibitor of MMP-9) in combination with conventional antitubercular drugs.ResultsMMP-9 levels in patients were increased as the disease progressed to advanced stages. The infection led to increased MMP-9 levels in C6 glioma cells and specific inhibition of MMP-9 by SB-3CT augmented bacillary clearance when used along with antitubercular drugs.ConclusionMMP-9 plays a prominent role in progression of tuberculous meningitis from initial to advanced stages. Increased levels of MMP-9 during advancement of the disease leads to degeneration of nervous tissue and blood brain barrier disruption. Hence, MMP-9 can be considered as a therapeutic target for efficient management of TBM and can be explored to inhibit further progression of the disease if used at an early stage.

Tuberculous meningitis (TBM) is an outcome of neuroinflammatory degeneration caused due to Mycobacterium tuberculosis infection and leads to death or neurological disabilities in the affected individuals. It causes the highest morbidity and mortality amongst all forms of tuberculosis. Matrix metalloproteinase-9 levels increase and cause inflammatory destruction during progression of the disease. Although corticosteroids are usually given as an adjuvant therapy to overcome these complications, treatment outcome is contradictory. This study was designed to evaluate whether specific inhibition of MMP-9 can be beneficial in management of the disease. MMP-9 levels were inhibited using SB-3CT or dexamethasone along with conventional drugs for treatment of tuberculous meningitis. Both SB-3CT and dexamethasone decreased the elevated levels of MMP-9 in sera and tissues of the infected mice. However, dexamethasone administration had an inhibitory effect on bacillary clearance, while SB-3CT potentiated the bacillary clearance, suggesting that MMP-9, if specifically inhibited, can be beneficial in the management of TBM.

Tuberculosis still stands as the world’s leading infectious disease as 1/4th of the world’s population harbors Latent TB infection (LTBI) > 10 million develops active TB and ~ 1.5 million people die per year. Approximately 4,65,000 people fell ill with multidrug or rifampicin-resistant tuberculosis (MDR/RR-TB)/year. This deadly TB scenario demands new TB drug regimens to tackle global infection reservoir, and worldwide spread of drug resistance and DS TB. Successful entry of single new drug into market is much complicated mission owing to time, cost, efficacy, and safety issues. Therefore, drug repurposing seems one reliable hope to meet the challenges of modern TB drug discovery timely, as it starts with examining market acclaimed drugs against other diseases for their efficacies against tuberculosis avoiding several lengthy and costly steps required for new molecules. Several drugs have been identified, which show potential for TB treatment. There is need for careful consideration of various trial designs to ensure that TB phase III trials are initiated for fruitful development of new TB treatment regimens. TB drug repurposing will not only give fast track novel drugs but will also serve to identify new targets for future development in cost-effective manner.

The high death rate and progressive spread of tuberculosis emphasizes the need to address the complexities associated with the disease and its treatment. Complications associated with the disease are associated with the process of inflammation. Host defense system protects the body against pathogen by various inflammatory responses and the same are utilized by the pathogen as an offensive tool to progress inside the host. The genetic factors which determine the expression of inflammatory markers affect the onset of the disease and its treatment. The susceptibility to infection, progression to active or latent form and dissemination to the other sites are governed by the inflammatory responses generated by the host. The prognosis of tuberculosis is not the pathogenic infection but the outcome of the host-pathogen interactions, most of which are still not understood. In this review we discuss the major host inflammatory responses during Mycobacterium tuberculosis infection and their role in progression and/or containment of the infection. In addition the possible role of anti-inflammatory drugs as adjunct to the current anti-tuberculosis treatment will be reviewed.

Background: Dendritic cells (DC) are key regulators of immune response with the ability to affect both the innate and adaptive immune responses and are abundant in the gut mucosa. The severity of shigellosis varies with the serotype involved with S. dysenteriae (SD) producing the severest infections and complications with S. sonnei (SS) being at other end of spectrum usually causing mild self-limiting diarrhea. While shigellae are known to induce the apoptosis of mature DCs, there is no information in cytokine milieu of DCs incubated with different serotypes of Shigellae.