title: Manipulation of costimulatory molecules by intracellular pathogens: veni, vidi, vici!! creator: Khan, Nargis creator: Gowthaman, Uthaman creator: Pahari, Susanta creator: Agrewala, J N subject: R Medicine (General) description: Some of the most successful pathogens of human, such as Mycobacterium tuberculosis (Mtb), HIV, and Leishmania donovani not only establish chronic infections but also remain a grave global threat. These pathogens have developed innovative strategies to evade immune responses such as antigenic shift and drift, interference with antigen processing/presentation, subversion of phagocytosis, induction of immune regulatory pathways, and manipulation of the costimulatory molecules. Costimulatory molecules expressed on the surface of various cells play a decisive role in the initiation and sustenance of immunity. Exploitation of the "code of conduct" of costimulation pathways provides evolutionary incentive to the pathogens and thereby abates the functioning of the immune system. Here we review how Mtb, HIV, Leishmania sp., and other pathogens manipulate costimulatory molecules to establish chronic infection. Impairment by pathogens in the signaling events delivered by costimulatory molecules may be responsible for defective T-cell responses; consequently organisms grow unhindered in the host cells. This review summarizes the convergent devices that pathogens employ to tune and tame the immune system using costimulatory molecules. Studying host-pathogen interaction in context with costimulatory signals may unveil the molecular mechanism that will help in understanding the survival/death of the pathogens. We emphasize that the very same pathways can potentially be exploited to develop immunotherapeutic strategies to eliminate intracellular pathogens. publisher: Public Library of Sciece date: 2012 type: Article type: PeerReviewed format: application/pdf identifier: http://crdd.osdd.net/open/1236/1/agrewala2012.pdf relation: http://www.plospathogens.org/article/info%3Adoi%2F10.1371%2Fjournal.ppat.1002676 identifier: Khan, Nargis and Gowthaman, Uthaman and Pahari, Susanta and Agrewala, J N (2012) Manipulation of costimulatory molecules by intracellular pathogens: veni, vidi, vici!! PLoS pathogens, 8 (6). e1002676. ISSN 1553-7374 relation: http://crdd.osdd.net/open/1236/