Unravelling the networks dictating host resistance versus tolerance during pulmonary infections.
The appearance of single cell microorganisms on earth dates back to more than 3.5 billion years ago, ultimately leading to the development of multicellular organisms approximately 3 billion years later. The evolutionary burst of species diversity and the "struggle for existence", as proposed by Darwin, generated a complex host defense system. Host survival during infection in vital organs, such as the lung, requires a delicate balance between host defense, which is essential for the detection and elimination of pathogens and host tolerance, which is critical for minimizing collateral tissue damage. Whereas the cellular and molecular mechanisms of host defense against many invading pathogens have been extensively studied, our understanding of host tolerance as a key mechanism in maintaining host fitness is extremely limited. This may also explain why current therapeutic and preventive approaches targeting only host defense mechanisms have failed to provide full protection against severe infectious diseases, including pulmonary influenza virus and Mycobacterium tuberculosis infections. In this review, we aim to outline various host strategies of resistance and tolerance for effective protection against acute or chronic pulmonary infections.
Department of Medicine, Department of Microbiology & Immunology, and Department of Pathology, McGill University Health Centre, McGill International TB Centre, Meakins-Christie Laboratories, McGill University, 1001 Decarie Boulevard, Montreal, Quebec, H4A 3J1, Canada.
Isabelle
I
Meunier
Department of Medicine, Department of Microbiology & Immunology, and Department of Pathology, McGill University Health Centre, McGill International TB Centre, Meakins-Christie Laboratories, McGill University, 1001 Decarie Boulevard, Montreal, Quebec, H4A 3J1, Canada.
Eva
E
Kaufmann
Department of Medicine, Department of Microbiology & Immunology, and Department of Pathology, McGill University Health Centre, McGill International TB Centre, Meakins-Christie Laboratories, McGill University, 1001 Decarie Boulevard, Montreal, Quebec, H4A 3J1, Canada.
Jeffrey
J
Downey
Department of Medicine, Department of Microbiology & Immunology, and Department of Pathology, McGill University Health Centre, McGill International TB Centre, Meakins-Christie Laboratories, McGill University, 1001 Decarie Boulevard, Montreal, Quebec, H4A 3J1, Canada. maziar.divangahi@mcgill.ca.|RI-MUHC, Centre for Translational Biology, Meakins-Christie Laboratories, McGill University, 1001 Decarie Boulevard, Block E (EM3.2248), Montreal, Quebec, H4A 3J1, Canada. maziar.divangahi@mcgill.ca.
Maziar
M
Divangahi
D003141:Communicable Diseases / Q000276:immunology*; D060467:Disease Resistance / Q000276:immunology*; D054884:Host-Pathogen Interactions / Q000276:immunology*; D006801:Humans; D007108:Immune Tolerance; D008171:Lung Diseases / Q000276:immunology*
Host resistance; Host tolerance; Influenza virus; Pulmonary infections; Tuberculosis