Elias K. Haddad, Ph.D.
Principal Investigator
Viral Pathogenesis & Therapeutics


Elias K. Haddad, Ph.D., is a principal investigator of the Vaccine & Gene Therapy Institute of Florida (VGTI Florida®). Dr. Haddad also holds adjunct affiliations at University of Miami in the Department of Microbiology and Immunology and at Florida Atlantic University in the Department of Integrative Biology. He’s an expert in viral disease pathogenesis, and studies the immune responses to chronic and emerging infectious diseases. He is recognized as a pioneer in the systems biology field, which focuses on the complex interactions in biological systems using an inter-disciplinary approach (genomics, proteomics, molecular immunology, signal transduction, and virology). His work has resulted in more than 50 articles published in major scientific journals.

Dr. Haddad’s work has led to discoveries regarding how the immune response to infectious diseases is regulated and how the immune system combats foreign invaders, including work on identifying a protein that shields the body’s immune system from HIV infection. This tactic led to identifying unique features, or a signature, of the protective immune response provoked by the yellow fever vaccine -- one of the most potent vaccines ever made. Scientists now use this finding as a benchmark to design and monitor the development of other vaccines across many diseases. 

Dr. Haddad has been the recipient of a number of prestigious fellowships, including the Fogarty Fellowship awarded by the National Institutes of Health, and a research fellowship awarded by the National Cancer Institute. He also was the recipient of FRSQ Ph.D. fellowship while studying at McGill. Prior to joining VGTI Florida, Dr. Haddad was a senior research scientist at the University of Montreal.

Dr. Haddad earned his bachelor’s degree in biological sciences and master’s degree in immunology from American University of Beirut. He earned his doctorate in immunology at McGill University, and conducted post-doctoral work at the National Cancer Institute and National Institutes of Health.



Laboratory of Elias K. Haddad 
Dr. Haddad’s laboratory studies humoral and cellular immunity in chronic viral infections. Dr. Haddad’s research is focused on three main research interests. 
  1. Mechanisms driving memory B cell survival and persistence in HIV infection. As in chronic viral infections and cancers, virally infected cells interfere and deregulate memory B cell functions. This will lead to aberrant and dysfunctional immune responses. Dr. Haddad’s research is focusing on identifying the mechanisms leading to this aberrant (exhaustion or apoptosis) memory B cell responses in HIV infection. 
  2. Study the molecular interaction between follicular helper T cells (TFH) and B cells in homeostatic and pathophysiological conditions. Dr. Haddad’s research led to the identification of the transcription factor FOXO3a which was found to be responsible for the memory B cell survival. Currently, Dr. Haddad’s research is focusing on identifying molecular signals originating from TFH that are capable of regulating FOXO3a pathway in memory B cells. In addition, Dr. Haddad is also focused on identifying whether TFH cells are dysfunctional during HIV infection and whether this defect would have major implications on antibody production. 
  3. Analysis of age-related changes in human dendritic cell and monocytes subsets in response to pathogens. Immunosenescence due to ageing has been shown to be associated with immune defects. Thus aged individuals have lost their capacity to mount efficient immune responses to vaccines or infections. Currently, Dr. Haddad’s focus will be to perform systems analyses of the key innate immune players, Dendritic cells (DCs) and Monocytes (Mo), which have been shown to be central to communication between the innate and adaptive compartments of the immune system and to potentially harbor defects with aging.  

Contact Information
Elias K. Haddad, Ph.D.
Principal Investigator
Vaccine & Gene Therapy Institute of Florida
9801 SW Discovery Way
Port St. Lucie, FL 34987
Tel: (772) 345-5689
Fax: (772) 345-0625
Lab Members
Rafael Cubas, Ph.D. -  
Talibah Metcalf, Ph.D. - 
Virginie Tardiff, Ph.D.
Rochelle Muir, Ph.D.


The ultimate objective of Dr. Haddad’s research is to identify molecular targets associated with aberrant memory T cell responses that can be used in the design of therapeutic and preventative vaccines for chronic infections and cancers.

  1. Pantel A, Teixeira A, Haddad E, Wood EG, Steinman RM, Longhi MP. Direct Type I IFN but Not MDA5/TLR3 Activation of Dendritic Cells Is Required for Maturation and Metabolic Shift to Glycolysis after Poly IC Stimulation. PLoS Biol. 2014 Jan;12(1):e1001759.
  2. Evans VA, Kumar N, Filali A, Procopio FA, Yegorov O, Goulet JP, Saleh S, Haddad EK, da Fonseca Pereira C, Ellenberg PC, Sekaly RP, Cameron PU, Lewin SR. Myeloid Dendritic Cells Induce HIV-1 Latency in Non-proliferating CD4(+) T Cells. PLoS Pathog. 2013 Dec;9(12):e1003799.
  3. Locci M, Havenar-Daughton C, Landais E, Wu J, Kroenke MA, Arlehamn CL, Su LF, Cubas R, Davis MM, Sette A, Haddad EK; International AIDS Vaccine Initiative Protocol C Principal Investigators, Poignard P, Crotty S. Human Circulating PD-1(+)CXCR3(-)CXCR5(+) Memory Tfh Cells Are Highly Functional and Correlate with Broadly Neutralizing HIV Antibody Responses. Immunity. 2013 Oct 17;39(4):758-69. 
  4. Samuel S, Beljanski V, Van Grevenynghe J, Richards S, Ben Yebdri F, He Z, Nichols C, Belgnaoui SM, Steel C, Goulet ML, Shamy A, Brown D, Abesada G, Haddad EK, Hiscott J BCL-2 Inhibitors Sensitize Therapy-resistant Chronic Lymphocytic Leukemia Cells to VSV Oncolysis. Mol Ther. 2013 May 21. doi: 10.1038.
  5. Goulet ML, Olagnier D, Xu Z, Paz S, Belgnaoui SM, Lafferty EI, Janelle V, Arguello M, Paquet M, Ghneim K, Richards S, Smith A, Wilkinson P, Cameron M, Kalinke U, Qureshi S, Lamarre A, Haddad EK, Sekaly RP, Peri S, Balachandran S, Lin R, Hiscott J. Systems Analysis of a RIG-I Agonist Inducing Broad Spectrum Inhibition of Virus Infectivity. PLoS Pathog. 2013 Apr;9(4):e1003298.
  6. Cubas RA, Mudd JC, Savoye AL, Perreau M, van Grevenynghe J, Metcalf T, Connick E, Meditz A, Freeman GJ, Abesada-Terk G Jr, Jacobson JM, Brooks AD, Crotty S, Estes JD, Pantaleo G, Lederman MM, and Haddad EK. Inadequate T follicular cell help impairs B cell immunity during HIV infection. Nat Med. 2013 Apr;19(4):494-9.
  7. Mudd JC, Murphy P, Manion M, Debernardo R, Hardacre J, Ammori J, Hardy GA, Harding CV, Mahabaleshwar GH, Jain MK, Jacobson JM, Brooks AD, Lewis S, Schacker TW, Anderson J, Haddad EK, Cubas RA, Rodriguez B, Sieg SF, Lederman MM. Impaired T-cell responses to sphingosine-1-phosphate in HIV-1 infected lymph nodes. Blood. 2013 Apr 11;121(15):2914-22.
  8. Klatt NR, Canary LA, Sun X, Vinton CL, Funderburg NT, Morcock DR, Quiñones M, Deming CB, Perkins M, Hazuda DJ, Miller MD, Lederman MM, Segre JA, Lifson JD, Haddad EK, Estes JD, Brenchley JM. Probiotic/prebiotic supplementation of antiretrovirals improves gastrointestinal immunity in SIV-infected macaques. J Clin Invest. 2013 Jan 16.
  9. Perreau M, Savoye AL, De Crignis E, Corpataux JM, Cubas R, Haddad EK, De Leval L, Graziosi C, Pantaleo G. Follicular helper T cells serve as the major CD4 T cell compartment for HIV-1 infection, replication, and production. J Exp Med. 2012 Dec 17.
  10. Petrovas C, Yamamoto T, Gerner MY, Boswell KL, Wloka K, Smith EC, Ambrozak DR, Sandler NG, Timmer KJ, Sun X, Pan L, Poholek A, Rao SS, Brenchley JM, Alam SM, Tomaras GD, Roederer M, Douek DC, Seder RA, Germain RN, Haddad EK, Koup RA. CD4 T follicular helper cell dynamics during SIV infection. J Clin Invest. 2012 Aug 27
  11. Peretz Y, He Z, Shi Y, Yassine-Diab B, Goulet JP, Bordi R, Filali-Mouhim A, Loubert JB, El-Far M, Dupuy FP, Boulassel MR, Tremblay C, Routy JP, Bernard N, Balderas R, *Haddad EK, Sékaly RP (Contributed equally). CD160 and PD-1 Co-Expression on HIV-Specific CD8 T Cells Defines a Subset with Advanced Dysfunction. PLoS Pathog. 2012 Aug;8(8)
  12. Haddad EK, Hiscott J. Cytokine  networks during HIV infection: Shifting the balance. Cytokine Growth Factor Rev. 2012 Aug;23(4-5):139-41. (*Guest editor and corresponding author)
  13. van Grevenynghe J, Cubas RA, Dafonseca S, Metcalf T, Tremblay CL, Trautmann L, Sekaly RP, Schatzle J, Haddad EK. Foxo3a: An integrator of immune dysfunction during HIV infection. Cytokine Growth Factor Rev. 2012 Aug;23(4-5):215-21.
  14. Kroenke MA, Eto D, Locci M, Cho M, Davidson T, Haddad EK, Crotty S. Bcl6 and Maf cooperate to instruct human follicular helper CD4 T cell differentiation. J Immunol. 2012 Apr 15;188(8):3734-44.
  15. Haddad EK, Pantaleo G Systems biology in the development of HIV vaccines. Curr Opin HIV AIDS. 2012 Jan;7(1):44-9. Review.
  16. van Grevenynghe J, Cubas RA, Noto A, Da Fonseca S, He Z, Peretz Y, Filali-Mouhim A, Dupuy FP,. Procopio FA, Chomont N, Said EA, Boulassel MR, Tremblay CL, Balderas R, Routy JP, Sekaly RP, ? Haddad EK. Loss of polyclonal memory B-cells during chronic HIV infection is driven by FOXO3a- and TRAIL-mediated apoptosis. (Journal of Clinical Investigation, Journal of Clinical Investigation. 2011; 121: 3877-88.
  17. Said EA, Dupuy FP, Trautmann L, Zhang Y, Shi Y, El-Far M, Hill BJ, Noto A, Ancuta P, Peretz Y, Fonseca SG, Van Grevenynghe J, Boulasse MR, Bruneau J, Shoukry NH, Routy JP, Douek DC, Haddad EK, Sekaly RP. PD-1 Induced IL-10 Production by Monocytes Impairs CD4 T-Cell Activation during HIV Infection. Nat Med. 2010, 16(4):452-9.
  18. Nicolas Chomont, Mohamed El Far, Petronela Ancuta, Lydie Trautmann, Francesco A. Procopio, Bader Yassine-Diab, Genevieve Boucher, Mohamed-Rachid Boulassel, Georges Ghattas, Jason M. Brenchley, Timothy W. Schacker, Brenna J. Hill, Daniel C. Douek, Jean-Pierre Routy, Elias K. Haddad and Rafick-Pierre Sékaly. HIV-1 reservoir size and persistence are driven by T-cell survival and homeostatic proliferation. Nat Med. 2009 15(8):893-900.
  19. El-Far M, Halwani R, Said E, Trautmann L, Doroudchi M, Janbazian L, Fonseca S, van Grevenynghe J, Yassine-Diab B, Sékaly RP and Haddad EK. (2008). T cell exhaustion in HIV infection, Current Opinion in HIV and AIDS. 5(1):13-9.
  20. Denis Gaucher, René Therrien, Nadia Kettaf, Bastian R. Angermann, Geneviève Boucher, Abdelali Filali-Mouhim, Janice M. Moser, Riyaz S. Mehta, Donald R. Drake III, Erika Castro, Rama Akondy, Aline Rinfret, Bader Yassine-Diab, Elias A. Said, Younes Chouikh, Mark J. Cameron, Robert Clum, David Kelvin, Roland Somogyi, Larry D. Greller, Robert S. Balderas, Peter Wilkinson, Giuseppe Pantaleo, Jim Tartaglia, Elias K. Haddad, and Rafick-Pierre Sékaly Yellow fever vaccine induces integrated multilineage and polyfunctional immune responses. J Exp Med. 2008 ;205(13):3119-31.
  21. Julien van Grevenynghe, Francesco A Procopio, et al., Elias K Haddad ? Rafick-Pierre Sekaly. Transcriptional factor FOXO3a controls the persistence of memory CD4+ T cells during HIV infection. Nature Medicine, 2008 14(3):266-74.
  22. C. Riou, B. Yassine-Diab, J. Van grevenynghe, R. Somogyi, L. Greller, D. Gagnon, S. Gimmig, P. Wilkinson, Y. Shi, M. Cameron, R. Campos-Gonzalez, R.S Balderas, D. Kelvin, R.P. Sekaly and E.K. Haddad. Convergence of TCR and cytokines signaling leads to FOXO3a phosphorylation and drives the survival of Central Memory CD4+ T cells. J. Exp. Med. 2007; 204(1):79-91. 
  23. Trautmann, L, Janbazian, L, Chomont, N, Said, E, Gimmig, S, Bessette, B, Boulassel, M, Delwart, M, Sepulveda, H, Balderas, R, Routy, J.P,. Elias K. Haddad and Sekaly, R.P. 2006. Upregulation of PD-1 expression in HIV specific CD8 T cells leads to reversible immune dysfunction. Nature Medicine: 12(10):1198-1202.


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