NK Cells Use Perforin Rather than Granulysin for Anticryptococcal Activity

Granulysin for Anticryptococcal Activity NK Cells Use Perforin Rather than

NK cells kill mycobacteria directly by releasing perforin and granulysin.

Although the mechanisms underlying the cytotoxic effect of NK cells on tumor cells and intracellular bacteria have been studied extensively, it remains unclear how these cells kill extracellular bacterial pathogens. In this study, we examine how human NK cells kill Mycobacterium kansasii and M.tb. The underlying mechanism is contact dependent and requires two cytolytic proteins: perforin and gr...

Cryptococcus neoformans directly stimulates perforin production and rearms NK cells for enhanced anticryptococcal microbicidal activity.

NK cells, in addition to possessing antitumor and antiviral activity, exhibit perforin-dependent microbicidal activity against the opportunistic pathogen Cryptococcus neoformans. However, the factors controlling this response, particularly whether the pathogen itself provides an activation or rearming signal, are largely unknown. The current studies were performed to determine whether exposure ...

Cytotoxic CD4+ T cells use granulysin to kill Cryptococcus neoformans, and activation of this pathway is defective in HIV patients.

An important mechanism of host defense to Cryptococcus neoformans involves the direct microbicidal activity of lymphocytes. The importance of CD4+ T cells is illustrated by the incidence of this infection in the acquired immunodeficiency syndrome (AIDS) patients; however, the relative activity of microbicidal CD4+ T cells compared with CD8+ T cells and natural killer (NK) cells has not been est...

Inhibitory Receptors in NK Cells Degranulation, Is the Preferred Target of Lytic Granule Polarization, Rather than