Role of PspC interaction with human polymeric immunoglobulin receptor and factor H in Streptococcus pneumoniae infections and host cell induced signalling [Elektronische Ressource] / vorgelegt von Vaibhav Agarwal

Vaibhav

Sujets

• Biologie

Informations

• Publié par: julius-maximilians-universitat_wurzburg
• Publié le: 01 janvier 2008
• Nombre de lectures: 23
• Langue: Deutsch
• Poids de l'ouvrage: 8 Mo

Extrait

Role of PspC interaction with human polymeric
immunoglobulin receptor and Factor H in
Streptococcus pneumoniae infections and host cell
induced signalling



Dissertation
zur Erlangung des naturwissenschaftlichen Doktorgrades der
Bayerischen Julius-Maximilians-Universität Würzburg

vorgelegt von

M.Sc.
Vaibhav Agarwal
aus Dehradun, Indien

November 2008






























„Gedruckt mit Unterstützung des Deutschen Akademischen Austauschdienstes“















Eingereicht am: .....................................................................................................................

Mitglieder der Promotionskommission:
Vorsitzender: .........................................................................................................................
1. Gutachter: Prof. Dr. Sven Hammerschmidt
2. Gutachter: Prof. Dr. Jürgen Kreft

Tag des Promotionskolloquiums: .........................................................................................

Doktorurkunde ausgehändigt am: ......................................................................................... Erklärung

Hiermit erkläre ich, dass ich die Dissertation
“Role of PspC interaction with human polymeric immunoglobulin receptor and Factor H in
Streptococcus pneumoniae infections and host cell induced signalling”

selbstständig und nur unter der Verwendung der angegebenen Quellen und Hilfsmittel
angefertigt wurde.

Ich erkläre außerdem, dass die Dissertation bisher weder in gleicher noch in ähnlicher Form in
einem anderen Prüfungsverfahren vorgelegen hat.

Ich habe bisher außer den mit dem Zulassungsgesuch urkundlich vorgelegten Graden keine
weiteren akademischen Grade erworben oder zu erwerben versucht.

Greifswald, November 2008


Vaibhav Agarwal

Contents
1. Zusammenfassung……………………………………………………………… 1
2. Summary……………………………………………………………………… 4
3. Introduction.......................................................................................................... 7
3.1. Streptococcus pneumoniae....................................................................... 7
3.2. Therapy and prevention of pneumococcal infection: history and
present...................................................................................................... 8
3.3. Cell wall structures and virulence factors of S. pneumoniae............... 11
113.3.1. The pneumococcal capsule.............................................................
133.3.2. Pneumococcal cell wall...................................................................
143.3.3. Pneumococcal virulence factors......................................................
223.4. PspC a multifunctional virulence factor of S. pneumoniae.................
243.5. The polymeric immunoglobulin receptor (pIgR).................................
263.6. Complement system................................................................................
273.6.1. The complement and immune regulator Factor H..........................
313.7. Bacterial strategies for interactions with eukaryotic cells...................
3.7.1. Interaction of bacterial pathogens with host cell cytoskeleton....... 31
3.7.2. Bacterial interaction with host cell signaling pathways………….. 33
383.8. Objectives of the project……………………………………………….
4. Results…………………………………………………………………………... 39
4.1. Interaction of the pneumococcal surface protein C (PspC) with
39human-pIgR............................................................................................
4.1.1. PspC-hpIgR mediated pneumococcal adherence to and 39
internalization into host epithelial cells.............................................
4.1.2. Inhibition of PspC-hpIgR mediated pneumococcal internalization
41into host epithelial cells.....................................................................
4.2. Role of host cell cytoskeleton dynamics on PspC-hpIgR mediated
42
ingestion of S. pneumoniae by epithelial cells.......................................
4.3. Identification of small GTPase Cdc42 as a key player in PspC-
44
hpIgR mediated internalization of S. pneumoniae by epithelial cells.
4.3.1. Inhibition of Rho family of small GTPases and its effect on 45
internalization process.......................................................................
4.3.2. Functionally active Cdc42 is essential for pneumococcal 49
internalization....................................................................................
 
I 
 4.3.3. Cdc42 and not RhoA and Rac1 are activated upon pneumococcal 50
ingestion by pIgR-expressing epithelial cells....................................
4.3.4. PspC-hpIgR mediated pneumococcal infections of host epithelial
51cells induces Cdc42 dependent microspike like structure.................
4.4. PspC-hpIgR mediated pneumococcal ingestion by pIgR expressing
54epithelial cells relies on PI3-kinase and Akt.........................................
4.4.1. PI3-kinase is important for pneumococcal uptake by host epithelial 54
cells....................................................................................................
4.4.2. The PI3-kinase/Akt pathway is activated upon PspC-hpIgR 56
mediated internalization of pneumococci into host cells...................
4.4.3. Akt activation is essential for PspC-hpIgR mediated pneumococcal
58internalization into host epithelial cells.............................................
4.5. Function of protein tyrosine kinases during PspC-hpIgR mediated
60internalization of S. pneumoniae by epithelial cells.............................
4.5.1. Activation of protein tyrosine kinases is essential during
60
pneumococcal internalization into host cells.....................................
4.5.2. Functionally active Src kinase is important for pneumococcal
63
ingestion by pIgR-expressing host epithelial cells............................
4.5.3. Role of Mitogen activated protein kinases in PspC-hpIgR mediated
65pneumococcal infection of host epithelial cells.................................
4.5.3.1. ERK and JNK MAPK pathways are activated during

PspC-hpIgR mediated pneumococcal infection of host 66
cells......................................................................................
4.5.3.2. Transcription factor c-Jun is activated during uptake of 67
pneumococci via PspC-hpIgR mechanism..........................
4.5.3.3. Mitogen Activated Protein Kinase activity is essential for 67
hpIgR-mediated pneumococcal invasion of host cells........
4.6. Cross-talk between signalling pathways induced during pIgR
70mediated pneumococcal infections of host cells....................................
4.6.1. Src kinase facilitates ERK activation during PspC-hpIgR mediated
70
pneumococcal infections...................................................................
4.6.2. Activation of JNK during pneumococcal invasion relies on Src 71
kinase.................................................................................................
4.6.3. PI3-kinase and Src kinase are activated separately during
73pneumococcal infection.....................................................................
4.7. Role of calcium during PspC-hpIgR mediated internalization of
74S. pneumoniae by epithelial cells............................................................
 
II 
 4.8. Identification of the host endocytic machinery involved in the
76PspC-hpIgR mediated pneumococcal uptake by epithelial cells........
4.8.1. Pneumococci co-opt clathrin and dynamin during invasion of 77
epithelial cells....................................................................................
4.8.2. Recruitment of clathrin during PspC-hpIgR mediated
81pneumococcal internalization of epithelial cells...............................
4.9. Interaction of PspC with complement regulator Factor H................. 83
4.9.1. Recruitment of Factor H by S. pneumoniae...................................... 83
4.9.2. Species-specific interaction of Factor H with S. pneumoniae........... 85
4.9.3. Association of purified Factor H with S. pneumoniae....................... 88
4.9.4. Recruitment of Factor H by pneumococci is independent of the
90PspC subtypes....................................................................................
4.10. The role of Factor H on host cellular adherence and invasion by 91S. pneumoniae..........................................................................................
4.10.1. Factor H facilitates adherence of S. pneumoniae to host cells…… 92
4.10.2. Factor H facilitates invasion by of host cells.......... 93
4.10.3. Interference of the capsular polysaccharide on Factor H-mediated
95adherence to host cells...............