Theme Leader: Arsénio M. Fialho

Our research addresses the following topics:

i) – the study of trimeric autotransporter adhesins (TAAs) as novel and key virulence determinants in members of the Burkholderia cepacia complex (Bcc), a group of bacteria that can cause serious infections in patients suffering from Cystic Fibrosis (CF). To study the contribution of these genes/proteins to the pathogenesis of Bcc bacteria we take a multidisciplinary approach including bacterial genetics, molecular and cell biology, biochemistry and biophysics. We are particularly interested in defining the functions of TAAs during Bcc/host cell interactions. Increased knowledge of TAAs mode of action is crucial for the development of new drugs/vaccines to help the successful management the CF chronic infections.

ii) – in the context of Burkholderia cepacia complex (Bcc) infections, we also are interested in study new ways to tackle antimicrobial drug resistance. We have tested with success the use of a polyunsaturated omega-3 fatty acid (Docosahexaenoic acid; DHA) and fish oils as alternative antimicrobial agents against multiresistant Bcc bacteria. Studies are in progress to develop and test synthetic and natural products as novel antimicrobial agents. In particular our focus relies on study their efficacy and mode of action.

iii) – a third area of interest within the field of Microbial Pathogenesis is focused on the development of a non-mammalian animal model (the larvae of the greater wax moth Galleria mellonella) to dissect virulence caused by various microbes. We acquired experimental skills and made available an experimental facility at iBB including an insectarium for breeding and maintenance of larvae for in vivo studies of microbial infections. This animal model allowed us to assess the role of a number of virulence determinants of gram negative and positive bacteria.

iv) – apart from that, we also studied bacterial proteins/peptides as novel drug candidates for cancer therapy. Studies aiming to elucidate the cellular and molecular effects of treating cancer cell models with the bacterial protein azurin from aeruginosa, and its fragment, a cell penetrating peptide of 28 amino acids known as p28. The p28 peptide successfully completed two phase I clinical trials in US. Recently, we have paid a particular attention to the development of nano-carriers for anticancer drugs. In particular our focus relies on the design and fabrication of functionalized p28-nanoformulations capable of targeting cancer cells.

Our current projects within this subject include

  • Identification and characterization of trimeric autotransporter adhesins (TAA) in Bcc bacteria: mechanisms of action and their role in virulence

  • Microbial-based therapy of cancer: bacterial protein azurin and derived peptides as novel anticancer agents
  • Targeted azurin peptide-nanoparticles for cancer therapy

Selected Publications

Mil-Homens D, Pinto SN, Matos RG, Arraiano C, Fialho AM, “Burkholderia cenocepacia K56-2 trimeric autotransporter adhesin BcaA binds TNFR1 and contributes to induce airway inflammation", Cellular Microbiology, (2017) 19(4) doi: 10.1111/cmi.12677

Mil-Homens D., Leça M.I., Fernandes F., Pinto S.N., Fialho A.M. “Characterization of BCAM0224, a multifunctional trimeric autotransporter from the human pathogen Burkholderia cenocepacia” Journal of Bacteriology , 196(11):1968-79, 2014

El-Kirat-Chatel S., Mil-Homens D., Beaussart A., Fialho A.M., Dufrêne Y.F. “Single-molecule atomic force microscopy unravels the binding mechanism of a Burkholderia cenocepacia trimeric autotransporter adhesin” Molecular Microbiology, 89(4):649-659, 2013

N Bernardes, S Abreu, FA Carvalho, F Fernandes, NC Santos, AM Fialho “Modulation of membrane properties of lung cancer cells by azurin enhances the sensitivity to EGFR-targeted therapy and decreased β1 integrin-mediated adhesion” Cell Cycle, 15(11)1415-24 (2016) (DOI: 10.1080/15384101.2016.1172147, 2016

Bernardes N., Ribeiro A. S., Abreu S., Vieira A.F., Carreto L., Santos M., Seruca R., Paredes J., Fialho A.M. “High-throughput molecular profiling of a P-cadherin overexpressing breast cancer model reveals new targets for the anti-cancer bacterial protein azurin” International Journal of Biochemistry & Cell Biology, 50:1-9, 2014

Bernardes N., Ribeiro A.S., Abreu S., Mota B., Matos R.G., Arraiano C.M., Seruca R., Paredes J., Fialho A.M. “The bacterial protein azurin impairs invasion and FAK/Src signaling in P-cadherin-overexpressing breast cancer cell models”  PLoS One, 8 (7), e69023, 2013

External Collaborators:

Ananda M. Chakarbarty – Dept. Microbiology and Immunology, University of Illinois, Chicago, USA

Yves Duffrene – Université Catholique de Louvain, Institute of Life Sciences, Louvain-la-Neuve, Belgium

Catarina Barrias – i3S – Instituto de Investigação e Inovação em Saúde, University of Porto

Manuel Prieto – Molecular Biophysics Group, CQFM, IST

Nuno Santos –  Instituto de Medicina Molecular, IMM, University of Lisbon

Projects:

Virulence-associated Trimeric Autotransporter Adhesins from Burkholderia cenocepacia: functional, biophysical and structural characterization

(Fundação para a Ciência e a Tecnologia – PTDC/BIA-MIC/118386/2010 (Fev 2011 – Jan 2015)

Bacterial protein azurin as a new candidate drug to treat untreatable breast cancers

(Fundação para a Ciência e a Tecnologia – PTDC/EBB-BIO/100326/2008 (Jan 2010 – Dez 2012)