biophysical immunology laboratory thomas vorup-jensen institute for medical microbiology and...

Biophysical Immunology Laboratory

Thomas Vorup-JensenInstitute for Medical Microbiology and

ImmunologyUniversity of Aarhus

Denmarkvorup-jensen@microbiology.au.dk

Innate ImmunityJaneway’s Immunobiology Chapter 2&3

Lecture II:(mainly) Soluble (humoral) factors

Important messages:

Important soluble molecules supporting innate immunity effectorfunctions

Connection between molecular structure and function in the immuneSystem

Connection between cellular and humoral innate immunity

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The (very) basic order of events in complement activation:three steps to inflammation

Complement factors insolution (plasma) Surface bound

complement factors

Pathogen

Cascade deposition:positive amplificationloop

Conformationalchange?

Recruitment of inflammatory cells

EnhancedPhagocytosis

(faster clearing!)

Direct killingby lysis

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”Target-binding” complement proteins are larger than the rest….

Vorup-Jensen & Boesen (2011) Adv. Drug Discov. Rev. 63:1008-19

35 nm

…but why?

Tanaka et al. (2010)

J Infect Chemother 16:383–387

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Innate ImmunityJaneway’s Immunobiology Chapter 2&3

Lecture II:(mainly) Soluble (humoral) factors

Important messages:

The classical pathway is activated through antibodies:Major molecular species involved are C1, C2 and C4 supportingto C3 activation

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Innate ImmunityJaneway’s Immunobiology Chapter 2&3

Lecture II:(mainly) Soluble (humoral) factors

Important messages:

The alternative pathway is activated spontaneous depostion of C3on cell surface. Failure to down-regulate C3 activation leads toopsonization of microbes.

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Dong et al. J. Immunol. (2007) 178:3016-22

SAXS solution structure of MBL

Trimer of carbohydrate-recognitiondomains

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Atomic Force Microscopy

Mingdong Dong, Sailong Xu & Flemming BesenbacheriNANO, University of Aarhus

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Constructing a MBL ligand-coated surface suitable for AFM

Mannose-amine immobilized on mica through coordination bonds

NH3

O

NH3

O

NH3

O

SiO3-

Min

eral

(m

ica)

str

uctu

re

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AFM imaging of rhMBL(I) on a mannosamine-coated surfacein liquid

Dong et al. J. Immunol. (2007) 178:3016-2226

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BSA BSA BSA

BSA BSA BSA

BSA

BSA

BSASI = 600 RU

SI = 1600 RU

SI = 4000 RU

1,000 RU 1 ng protein/mm2

0.005 mcBSA molecules/mm2

0.013 mcBSA molecules/mm2

0.033 mcBSA molecules/mm2

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Surface density of ligandschange MBL bindingkinetics

60 nm

KD 10-10 M and kd 10-6 s-1

d ~ 14 nm

d ~ 9 nm

d ~ 6 nm

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Organization of the cell wall of S. aureus: a nm-scaled pattern?

Touhami A et al. (2004) J. Bacteriol. 186: 3286–3295.

50 nm

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Primary immunodeficiencyin the innate immune system

Induced deficiencyin neutrophils

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Innate ImmunityJaneway’s Immunobiology Chapter 2&3

Lecture II:(mainly) Soluble (humoral) factors

Important messages:

The lytic pathway may serve to from pores in target membranes. Thepore formation will eventually leads to cellular lysis.

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Time

(adaptive immunity)39

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Innate ImmunityJaneway’s Immunobiology Chapter 2&3

Lecture II:(mainly) Soluble (humoral) factors

Important messages:

The complement system is an important mediator of cross-talk betweeninnate and adaptive immunity by mediating antigen uptake.

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iC3b is ”inactive” with regard to C3 conversion but may bindComplement receptors 3 & 4

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Hereditary angioedema: lack of C1INH

Treatment: blood transfusion or C1INH protein

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Systemic Lupus Erythematosus (SLE)

trialx.com

Innate ImmunityJaneway’s Immunobiology Chapter 2&3

Lecture II:(mainly) Soluble (humoral) factors

Important messages:

Failure to control complement activation leads to significanthealth problems

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Innate ImmunityJaneway’s Immunobiology Chapter 2&3

Lectures I & II

Important messages:

Important soluble molecules supporting innate immunity effectorFunctions

Cytokines & complement

Connection between molecular structure and function in the immunesystem

Pattern recognition, conformational changes in MBL

Connection between cellular and humoral innate immunityOpsonization facilitates antigen presentation to lymphocytes

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