Wellcome Trust Research Career Development Fellowship:

A personal perspective

Samantha SampsonDepartment of Microbiology

Centre for Molecular Microbiology and Infection

Career History

Cape Town, South Africa:• BSc (Biochemistry & Chemistry)• BSc Hons, MSc & PhD (Medical Biochemistry)• Mycobacterium tuberculosis strain diversity

Career History

Boston, USA:• Post-doc• Novel TB vaccine efficacy studies

Career History

London, UK:• Research Fellow• Host-pathogen interactions: PE/PPE proteins

WT RCDF• Opportunity for postdoctoral scientists to become independent research scientists and to undertake research of high quality• Eligibility:

• 3-6 years research experience from date of PhD degree• intellectual contributions to published research• demonstrate potential to carry out independent research

WT RCDF• Application Procedure:

• Preliminary application form (25/9/08)• Full application (to appropriate funding committee)• Panel Interview

http://www.who.int/tdr/dw/tb_map.htm

My researchWorldwide TB incidence

TB: Disease Burden

• 1/3rd of world’s population infected with Mycobacterium tuberculosis• 8 million incident cases• 2 million deaths annually

PE/PPE proteins

PPE-MPTR subgroup (up to ~3720 aa)

(GGA/N GGA/N)n

PE-PGRS subgroup (up to >1500 aa)

PE

NXGXGNXG

PPE

PPE-SVP subgroup(up to ~470 aa)

GXXSVPXXWPPEPE

“PE-only” subgroup (~110 aa)

Subgroup with unique C-terminal region (up to ~560 aa)

Subgroup with unique C-terminal region (up to ~600 aa)

PE PPE

The proposal

• Title: The PE and PPE proteins of Mycobacterium tuberculosis and Mycobacterium bovis: exploring their potential as variable antigens

• Hypothesis: PE and PPE genes of M. tuberculosis and M. bovis encode variable antigens

The proposal

Aims: (i) Establish whether the PE and PPE genes are differentially expressed under different in vitro growth conditions and during host infection.

(ii) Determine whether PE and PPE epitopes are differentially recognised by the host immune system over the course of an infection.

(iii) Elucidate mechanisms of PE and PPE gene regulation.

Kinetics of PE/PPE immune responses>PE35MEKMSHDPIAADIGTQVSDNALHGVTAGSTALTSVTGLVPAGADEVSAQAATAFTSEGIQLLASNASA...MEKMSHDPIAADIGTQVSDN IAADIGTQVSDNALHGVTAG VSDNALHGVTAGSTALTSVT VTAGSTALTSVTGLVPAGAD TSVTGLVPAGADEVSAQAAT AGADEVSAQAATAFTSEGIQ QAATAFTSEGIQLLASNASA...

37 ºC, 5% CO2, 48 hours

Store plasma @ -80 ºC until use

PE/PPE regulation

Labeled probe (0.8 ng Rv1195 upstream region)

Unlabeled probe

Protein (100 ng, rRv0485-His6)

+

-

-

1

+

-

+

2

+

+

3

+

+

4

+

+

5

DNA-proteincomplex

Unbound, labelled DNA

Lung organ burden

0 25 50 75 100 125 150 175103

104

105

106

107

108

H37Rv

0485

Time (days)

Lo

g10

CF

U

Balb/cJ mouse survival

0 100 200 300 400 5000

102030405060708090

100 M. tuberculosis H37Rv

M. tuberculosis H37Rv:0485

Time (days)

Per

cen

t su

rviv

al

Why was my application successful?

• WT Remit: “… research across all biomedical science … to produce knowledge that can be used to protect and improve human and animal health.”• Preliminary data• Sponsor• Institution• Track record• Preparation• Right place at the right time!

Independent funding: Pros

• Independence• Limited teaching obligations (if you choose)• Technical assistance• Opportunity to develop own research interests• Develop management skills (time, budget, personnel)

Independent funding: Cons

• Independence• Finding a balance• Measurable outputs required

Advice

• Be flexible (personally and professionally)• Be pro-active• Have a Plan B• Research your options• DO WHAT YOU ENJOY!!

Acknowledgments

• Prof. Rob Warren (PhD Supervisor)

• Prof. Barry Bloom (Post-doc PI)

• Prof. Douglas Young (RCDF Sponsor)

• Rachael Goldstone (RA)