Mycobacterium Tuberculosis (TB) Antibodies, Proteins & ELISA Kits

Mycobacterium tuberculosis (M. tb) is a rod shaped, obligate aerobic intracellular pathogen. This bacterium is transmitted via inhalation and thus, primarily affects the lungs. However, it can cause disease in any other organ of the body. TB can be latent, in which it is dormant, or active, in which it causes symptoms that can be contagious.

The pathogenesis of TB is dependent on the host immune response, therefore, viral infections such as, HIV infection, are a major risk factor for TB. Additional risk factors include: diabetes mellitus, immunosuppressive therapy and alcoholism, amongst many others.

There are two types of TB: primary TB which affects non-sensitized hosts, and post-primary (secondary) TB found in sensitized hosts. It is estimated that 2 billion people worldwide are infected with TB. 90-95% of patients are asymptomatic.

Diagnostic biomarkers and predictive markers for progression from latent to active TB are in high demand. Lipoarabinomannan or LAM is a major lipoglycan of the M. tuberculosis cell envelope, representing up to 15% of the bacterial mass. This complex lipoglycan has been identified in the urine of M. tuberculosis-infected individuals. LAM is considered a virulence factor associated with TB infection. During TB infections, LAM is present in the bodily fluids of patients, therefore representing a potential biomarker for the identification of TB-infected individuals. In addition, the immune response to LAM acts as a potential diagnostic tool.

Various studies in M. tuberculosis mouse models have demonstrated that tumour necrosis factor (TNF) is a vital component of both the inflammatory immune and the antibacterial protective response to TB. As previously mentioned, predictive biomarkers with the ability to distinguish between active TB and latent TB infection would be a major breakthrough in TB research. Mtb-specific tumour necrosis factor-alpha (TNF-alpha) has been described as a novel tool for the rapid diagnosis of active TB.

Interleukin-1 Beta (IL-1B) is a pro-inflammatory cytokine and a key mediator of inflammation. This cytokine plays a vital role in host resistance to TB infections. Clinical strains of TB stimulate IL-1B secretion from macrophages through employment of a unique caspase-1 independent pathway. TB mouse models have demonstrated the importance of IL-1B signalling in the host resistance to infection. IL-1B knock-out mice have a higher susceptibility to TB infection with high bacterial burden in the lungs and subsequently, increased mortality. In addition, negative regulation of IL-1B by type I interferons, which are induced by M. tuberculosis, mediates the control of gene expression.

Interleukin-6 (IL-6) is a major cytokine that has been shown to be elaborated by TB-infected mouse peritoneal macrophages in vitro. Therefore, IL-6 may function as a potent biomarker of TB infection, either on its own or along with other cytokines.

Interleukin-10 (IL-10) is a potent immunomodulatory cytokine affecting innate and acquired immune responses. IL-10 plays a crucial role in the regulation of host defence against TB infections. This cytokine can suppress antimycobacterial immunity and subsequently, promote the survival of pathogens. IL-10 has been implicated in the reactivation of TB in mouse models as well as in humans. Advancing our understanding of IL-10 can inform host directed therapies against TB.

Interleukin-12p40 (IL-12p40) is required for the protective IFN-γ responses to TB. It remains an important feature of resistance to TB infection in experimental animal models and human populations.

Interleukin-12p70 (IL-12p70) is a cytokine required to instruct an adaptive Th1 response for host defense against intracellular bacteria. M. tuberculosis tRNA induces IL-12p70.

The lymphokine, interferon gamma (IFN-gamma), plays a crucial role in resistance to intracellular pathogens. In M. tuberculosis, IFN-gamma is a key mediator of macrophage activation. Studies in mouse models of TB have demonstrated that mice deficient in IFN-gamma are highly susceptible to fatal TB. Humans deficient in the gene or receptor for IFN-gamma have also shown susceptibility to mycobacterial infections. Measurement of the IFN-gamma response to TB infection is consistently exploited in research to determine new tools for diagnosis, prevention and treatment of TB infection.

Interferon-gamma-induced protein 10 (IP-10) has been widely used to detect TB infection. However, its ability to differentiate between active and latent TB is currently unknown.

Macrophage migration inhibitory factor (MIF) is located in an important upstream position in the innate immune response to M. tuberculosis. This suggests that low expression of MIF alleles confers an increased risk of TB in various populations.

The most commonly used experimental animal models of tuberculosis are the mouse, rabbit, guinea pig and non-human primate. Assay Genie offers a wide range of animal model ELISA kits with the potential to support the advancing field of tuberculosis research.