Chapter 3 Definitions and Learning Objectives Define the following terms Leukocyte homing Leukocyte migration Recirculation Epithelium Endothelium Connective tissue Stroma Adhesion molecule Integrin Selectin P selectin E selectin L selectin ICAM VCAM LFA 1 VLA 4 Chemokine Chemokine receptor GPCRs Affinity Receptor ligand interaction Margination Leukocyte spreading Extravasation Inflammation Vaso dilation Septic shock HEV Afferent lymphatic vessel Efferent lymphatic vessel S1P S1PR1 Learning Objectives Important concepts to know At the end of this chapter you should be able to 1 Describe three important functions served by leukocyte migration from blood into tissues and explain the difference between the innate immune system and the adaptive immune system with respect to how their cells travel through circulation and move into infected tissue Fig 3 1 2 Describe the key molecules the major players involved in leukocyte recruitment including what the key molecule interacts with and where this other molecule is the location cell the key molecule is found on the function of the key molecule located what cell it is found on if and how the expression of the molecule is can be regulated additional important characteristics of the molecule Note It may be useful to create a chart with headings such as key player who produces it where is it found what does it interact with function and important characteristics 3 Explain the nomenclature used to describe chemokines and chemokine receptors and give examples of each 4 Describe the process of leukocyte extravasation i e Figure 3 3 beginning with an infection and ending when the infection is cleared 5 List examples of locations where extravasation can occur including the cell s that use this process naive or effector the molecules involved in facilitating leukocyte extravasation how some cells can be preferentially selected to extravasate out of blood vessels into tissue hint chemokines chemokine receptors selectins and integrins who has who It may be useful to create a chart for each cell in each of the different locations that use extravasation with headings such as location cell chemokine chemokine receptor selectin integrin 6 Using your knowledge about leukocyte extravasation describe what would occur if this process were defective What condition could arise 7 Identify the major proinflammatory cytokines and discuss their local and systemic effects on the body Be sure to include how these cytokines are produced who produces them and what roles they play in inflammation 8 Trace the pathway of the following through the lymph node beginning with the point of entry into the lymphatic node and ending with an efferent lymphatic vessel lymph naive lymphocytes effector lymphocytes antigen dendritic cells 9 Explain how naive lymphocytes and dendritic cells migrate to their appropriate locations within a lymph node Please be sure to discuss their regulation by the various chemokines and chemokine receptors using specific examples 10 Describe the pathways of T cell recirculation and compare and contrast the difference in events that occur if a naive T cell does not recognize an antigen in the lymph node versus if there is antigen recognition and the T cell becomes activated to an effector T cell 11 Compare and contrast the molecules involved in naive and effector T cell migration 12 Describe the role of S1P and S1P1R in facilitating exit of lymphocytes from the lymph node and discuss the role of S1PR1 expression in stimulating an immune response 13 Describe how chemokines and chemokine receptors regulate the movement of B cells through the spleen lymph node and peripheral tissue In your description you should use specific chemokines and chemokine receptors to illustrate your answer Additional questions to answer on your own 1 Please read the section on Adhesion molecules on leukocytes and endothelial cells involved in leukocyte recruitment on p 37 39 as well as Figure 3 2 What is the difference between low affinity and high affinity integrins What role do chemokines and chemokine receptors play in this process