Anti-M. tuberculosis Proteinderivative Monoclonal antibody, Clone CDI558

Tuberculosis, an ailment caused by the bacterium Mycobacterium tuberculosis (Mtb) complex, is one of the catastrophic transmittable diseases that affect human. Reports published by WHO indicate that in 2017 about 6.3 million people progressed to TB and 53 million TB patients died from 2000 to 2016. Therefore, early diagnosis of the disease is of great importance for global health care programs. Common diagnostics like the traditional PPD test and antibody-assisted assays suffer the lack of sensitivity, long processing time and cumbersome post-test proceedings. These shortcomings restrict their use and encourage innovations in TB diagnostics. In recent years, the biosensor concept opened up new horizons in sensitive and fast detection of the disease, reducing the interval time between sampling and diagnostic result. Among new diagnostics, label-free nano-biosensors are highly promising for sensitive and accessible detection of tuberculosis. Various specific label-free nano-biosensors have been recently reported detecting the whole cell of M. tuberculosis, mycobacterial proteins and IFN-gamma as crucial markers in early diagnosis of TB. This article provides a focused overview on nanomaterial-based label-free biosensors for tuberculosis detection.

Accumulating evidence suggests that gamma delta T cells play a critical role in the early response to Mycobacterium bovis and may be key in bridging innate and adaptive immunity following infection. In vitro, gamma delta T cells proliferate and produce robust amounts of IFN gamma in response to complex, protein and non-protein mycobacterial antigens including M. bovis purified protein derivative (PPD), heat shock proteins and cell wall components such as mycolylarabinogalactan peptidoglycan (mAGP). Vaccination with Bacille Calumette-Guerin (BCG), as well as infection with virulent M. bovis, induces an increase in the frequency and activation of WC1(+) gamma delta T cells circulating in the blood. Gamma delta T cells are rapidly recruited to the lungs and draining lymph nodes following BCG vaccination, and accumulate in developing lesions early following M. bovis infection. In Severe Combined Immuno-deficient (SCID)-bo mice, depletion of gamma delta T cells prior to M. bovis infection results in impaired granuloma formation, suggesting a role for gamma delta T cells in immune cell recruitment and lesion development. In vivo depletion of WC1(+) gamma delta T cells from calves prior to M. bovis infection results in significantly reduced levels of M. bovis specific IgG2 and IFN gamma, and increased IL-4 production compared to non-depleted control animals, suggesting that gamma delta T cells may also play a role in shaping the character of the adaptive M. bovis specific immune response. Whereas it is clear that gamma delta T cells are responding during M. bovis infection, much remains to be understood about their function in vivo and their ability to shape the innate and adaptive immune responses. This review focuses on recent advances in our understanding of gamma delta T cell biology with a particular emphasis on the immune response of gamma delta T cells in cattle during M. bovis infection. Published by Elsevier B.V.