Medina RA & García-Sastre A (2011) Influenza A viruses: new research developments. Nat. Rev. Microbiol. 9, 590–603.
Mengaud J, Ohayon H, Gounon P et al. (1996) E-cadherin is the receptor for internalin, a surface protein required for entry of
L. monocytogenes into epithelial cells. Cell 84, 923–932. Mercer J, Schelhaas M & Helenius A (2010) Virus entry by endocytosis. Annu. Rev. Biochem. 79, 803–833. Miller S & Krijnse-Locker J (2008) Modification of intracellular membrane structures for virus replication. Nat. Rev. Microbiol. 6, 363–374. Mullins JI & Jensen MA (2006) Evolutionary dynamics of HIV-1 and the control of AIDS. Curr. Top. Microbiol. Immunol. 299, 171–192. Parrish CR & Kawaoka Y (2005) The origins of new pandemic viruses: the acquisition of new host ranges by canine parvovirus and influenza A viruses. Annu. Rev. Microbiol. 59, 553–586. Pizarro-Cerdá J & Cossart P (2006) Bacterial adhesion and entry into host cells. Cell 124, 715–727. Ray K, Marteyn B, Sansonetti PJ & Tang CM (2009) Life on the inside: the intracellular lifestyle of cytosolic bacteria. Nat. Rev. Microbiol.  7, 333–340. Sibley LD (2011) Invasion and intracellular survival by protozoan parasites. Immunol. Rev. 240, 72–91. Tilney LG & Portnoy DA (1989) Actin filaments and the growth, movement, and spread of the intracellular bacterial parasite,  Listeria monocytogenes. J. Cell Biol. 109, 1597–1608. Vink C, Rudenko G & Seifert HS (2012) Microbial antigenic variation mediated by homologous DNA recombination. FEMS Microbiol. Rev. 36, 917–948. Walsh D & Mohr I (2011) Viral subversion of the host protein synthesis machinery. Nat. Rev. Microbiol. 9, 860–875.
Welch MD & Way M (2013) Arp2/3-mediated actin-based motility: a tail of pathogen abuse. Cell Host Microbe 14, 242–255.
The Innate and Adaptive Immune Systems 24
As we discussed in Chapter 23, all living organisms serve as hosts for other species, usually in relationships that are benign or even mutually helpful. But all organisms, and all cells in a multicellular organism, need to defend themselves against infection by harmful invaders, collectively called pathogens, which can be microbes (bacteria, viruses, or fungi), or larger parasites. Even bacteria defend themselves against viruses, using intracellular proteins called restriction factors, which block viral propagation. Invertebrates use a variety of defense strategies, including protective barriers, toxic molecules, restriction factors, and phagocytic cells that ingest and destroy invading pathogens. Vertebrates, too, depend on such innate immune responses, but they can also harness more sophisticated and specific mechanisms, called adaptive immune responses. The innate responses occur first, calling the adaptive immune responses into play if required, in which case, both types of responses work together to eliminate the pathogen (Figure 24–1).