The immune response to respiratory pathogens is highly complex and is orchestrated by many cell types, through a series of discreet cellular interactions and over an extended period of time. The nature of the response displays considerable heterogeneity, and can be either protective or pathogenic. The characteristics of the immune response are dictated by many factors in both the host and pathogen. Characteristics of the pathogen, including its cellular tropism, the sites and regulation of pathogen infection, its replication and persistence in vivo influence the responses of the host, as do host genetics and prior immune experience with each pathogen, either through prior vaccination or infection.

The goal of this Topic is to explore the different phases and levels of control for lymphocyte priming in the lymph node, homing and finally delivery of effector function in the lung in response to respiratory pathogens, with a special focus on influenza, RSV and tuberculosis. This Research Topic of Frontiers in Immunology will cover the discreet phases of pathogen infection and replication and the development of the adaptive immune response. These events include invasion and pathogen replication within the complex cellular microenvironment in the lung, antigen handling by lung resident or infiltrating cells, delivery of antigen to the draining lymph node and the events that follow including programming of T cells and B cells to access the lung vasculature and parenchyma, delivery of effector function and finally establishment of memory cells that can protect the host during a subsequent respiratory infection. The areas of focus will include the control of lymphocyte trafficking and differentiation within the lymph node and the licensing events that promote development of the discreet effector functions required for protective immunity. Related topics that are anticipated to be covered, depending on the contributors, would be chemokine and integrin-mediated trafficking and localization and in vivo imaging techniques to visualize key interactions among different cell types in the lymph node and lung.

Keywords: Virus, respiratory tract, immune response, lymphocyte homing, T cells

Important Note: All contributions to this Research Topic must be within the scope of the section and journal to which they are submitted, as defined in their mission statements. Frontiers reserves the right to guide an out-of-scope manuscript to a more suitable section or journal at any stage of peer review.