Lectures 10 (linked to 12) Cytokines and Immune Response September 17 & 24, 2004 Chris Schindler

1. Lectures 10 (linked to 12) Cytokines and Immune Response September 17 & 24, 2004 Chris Schindler cws4@columbia.edu Reading: Janeway - as indicated Abbas - Chapter 11

2. Blood: 4-10,000 WBC per 1 mL Lymphocytes - 10-15 % Granulocytes - 35-80 % (T-, B- & NK cells) PMNs 35-80 % Eos 0-8 % Basos 0-2 % How did they get there? Where are they going? What regulates them? Think Cytokines, Growth Factors & Chemokines!!!! Monocytes - 0-15 % (Macs & DCs)

3. What are cytokines and chemokines? • Small (10-30 kDa) secreted peptides (usually glycosylated). • They bind to specific receptors on target cells to elicit a specific biological response. • Expression of cytokines and their receptors is usually tightly regulated. • Other more anachronistic terms include monokines and lymphokines.

4. What do cytokines, chemokines and growth factors do? • They direct the development, maturation, localization, interactions, activation and life span of immune cells. • Thus they play an essential role in regulating immunity (adaptive and innate).

5. How many flavors regulate immunity? • Growth Factors (e.g., CSF-1, SCF) • IL-1 Family (e.g., IL-1, IL-18 & “Toll-like”) • TNF Family (e.g., TNF-a, CD40L, FasL, LT-b) • TGF-b Family (e.g., TGF-b ) • Chemokines (e.g., CC and CXC families) • Hematopoietins / a.k.a. Four Helix Bundle (e.g., IL-2, IL-4, IL-6, IL-10, IL-12, IL-13, GM-CSF, IFN-g, IFN-a/b) • Also steroid hormones and prostaglandins

6. Other important facts about Cytokines, Chemokines & Growth Factors • There are functional similarities within ligand families (see summary). • There are important functional differences between ligand familes (see summary). • These functional characteristics are determined by the class of receptors these ligands bind. • These ligands function at three distinct ranges: • Autocrine* • Paracrine* • Endocrine* *Make sure you have an example of each

7. Additional important concepts • Properties of cytokines and chemokines. Pleiotropism - activate numerous types of responses, e.g., differentiation, growth, activation and chemotaxis. Redundancy - i.e., functional overlap. Synergy - between cytokines to maximize a response. *Antagonism - to regulate duration and potency of response. It is critical to maintain a delicate balance to avoid autoimmunity. • Innate vs. Adpative Immunity Innate Immunity Per-wired first line of defense (more primitive) Recognizes ~103 pathogen derived molecules (analogous to antigens) Most important during initial minutes and hours of infection Macrophages, Granulocytes and NK cells Adaptive Immunity Second, but very potent line of defense Antigen specific response - recognizes ~107 antigens Constitutes immunological memory for specific antigens T-cells and B-cells

8. Cytokines and the innate response to a viral infection • The innate response is often quite effective • The subsequent adaptive immune response is important for many viral pathogens and very important for immunization strategies

9. X Innate Viral Interfering Activity is Discovered in Cultured Cells (1950s)

10. Fractionating Viral Interfering Activity Leads to the Discovery of Interferons (IFNs) Immune IFN Fibroblast IFN Leukocyte IFNs • a.k.a IFN-g • critical for adaptive Immune • made by T-cells & NK cells • only one member • a.k.a IFN-b • very potent • made by all cells • only one member • a.k.a IFN-a’s • most prevalent • made by all cells • > 10 members Type II IFN Type I IFN

11. P P P P P P P Type II IFN Signaling Paradigm STAT1 STAT1 inflammation* macrophage act.* chemokines* IRF1 (antiviral transcription factor) MIG (a chemokine) GBP (anti-viral protein) iNOS (nitric oxide synthase) CIITA (transcription factor that induces MHC) Gamma-activated sequence

12. Figure 6-23

13. Figure 2-48

14. Figure 2-49

15. Identification of “High IFN Producing Cells” (HIPCs) in vivo A small subset of WBCs produce most of the circulating IFN-Is

16. Cytokines and the innate response to a skin infection

17. Figure 2-3 Wound Infection: Innate  Adaptive

18. Figure 2-5 part 1 of 2

19. Figure 2-8 part 1 of 2

20. Figure 2-39

21. Figure 2-15

23. Cytokines and the response to sepsis • Injection of LPS (a molecular pattern molecule found on G- bacteria) is a model system for sepsis. • The host response to sepsis is often referred to as the Acute Phase Response (APR).

24. Local vs. systemic infection

25. TLR-4 and company enable macrophages to sense and respond to LPS (to be covered in detail in a later lecture)

26. Figure 2-39

27. Serum cytokine production (from Macrophages) during Septic Shock TNF-a IL-1 IL-12 Serum Cytokine Level o 1 3 6 Hours after LPS injection Note, this is one of the few times you can meaningfully measure serum cytokine levels!!

28. Figure 2-46

29. IL-4 & TNF-a, and their corresponding receptors, are in two different families and have two distinct types of structures. IL-4 TNF-a Trimer TNFa Monmer/ Receptor Monomer IL4/IL4 Receptor Fig. 2-38

30. Top half of Fig. 2-47

31. Type I & II Cytokine Receptors (Hematopoietin R.) Toll (TLR) /IL-1 Receptors TNF Related Receptors TGF-b Receptors Chemokine Receptors V. Cytokines you need to know • IL-2 (big family e.g. IL-7 & IL-15) • IL-4 (small family inc. IL-13) • IL-6 (large family inc. G-CSF) • IL-10 (growing family) • IL-12 (small family inc. IL-23) • IFN-g • IFN-a (large family) • IL-1 • IL-18 • LT-a • TNF-a • CD40L • FasL • TGF-b (very large family) • Chemokines (see Fig. 11.6) • Inflammatory • Non-inflammatory • Innate Adaptive • √√ • √√ • √√ √ • √√ √√ • √√ √ • √√ √√ • √√ • √√ • √√ √ • √ √√ • √√ • √ √√ • √√ √√ • √√ √√ • √√ √√ • √√ √√ See Figs. 11.1 (p244), 11.2 (p245), 11.3 (p248) Tables 11-3 (p249), 11.4 (p264) in Abbas