The overall objective of the proposed Mentored Quantitative Research Career Development Award (K25) is to provide a period of mentored didactic and research training that will allow Dr. Krishanu Ray with his physics background to make a career transition into an independent biomedical researcher. The immediate goal is for Dr. Ray to expand his current research program in applying advanced fluorescence spectroscopy techniques to interrogate virus-host interactions in early stages of HIV infection. Specifically, Dr. Ray will employ novel fluorescence based approaches not previously described for viral entry process. The four-year training plan involves a structured curriculum of coursework and seminars focusing on HIV related research. This program will be heavily weighted toward gaining expertise regarding the HIV biology, particularly using optical imaging and spectroscopy based approaches to HIV research under the mentorship of two exceptional scientists, Dr. Joseph R. Lakowicz and Dr. Anthony L. DeVico at the University of Maryland School of Medicine (UMSM). Because of Dr. Ray's location in the Center for Fluorescence Spectroscopy (CFS) and adjacent to the Institute of Human Virology (IHV) at the UMSM, it is possible to study the biophysical properties of HIV proteins and neutralizing antibody binding against HIV-1 envelope. The long-term goal is for Dr. Ray to acquire advanced biomedical research skills and knowledge that complement his skills as a spectroscopist. The ultimate goal is for him to develop into an independent, interdisciplinary biomedical researcher. This K25 award will enable Dr. Ray to take advantage of the outstanding resources available at CFS and IHV and expand his expertise and experience in this unique multidisciplinary setting. Dr. Ray will develop methods applying fluorescence correlation spectroscopy (FCS) and single molecule detection (SMD) to directly probe the nature of HIV-1 envelope interactions with cell surface receptors and/or anti-envelope antibodies at the molecular level. It is hypothesized that a detailed understanding of the conformational dynamics that impact the HIV envelope before and during receptor engagement will explain the observed susceptibility to various inhibitors. Accordingly, Dr. Ray will focus on the following aims: 1) To develop methods for examining HIV-1 gp120-CD4 interactions at the single molecule level. 2) To characterize HIV-1 Env trimer conformational dynamics using single molecule spectroscopy. 3) To compare the binding of human monoclonal antibodies with different neutralizing potencies to HIV-1 envelope trimers by FCS and SMD. Successful completion of the Aims will provide new quantitative approaches at the individual molecular level towards understanding early steps in viral entry. This program will provide an excellent milieu in which the applicant - under close mentorship - can become deeply involved in applying advanced fluorescence spectroscopic and imaging approaches to HIV research. Mentorship will be geared more toward biological issues to provide a well-rounded portfolio as the candidate progresses toward independence in biomedical spectroscopic and imaging research. Human-immunodeficiency virus type 1 (HIV-1) has been the subject of intensive research. The majority of antiretroviral drugs acts at a post-infection step and cannot cure HIV-1 infection. Consequently, there is a continued emphasis on developing either drugs or vaccines that block pre-entry events by targeting the HIV-1 surface trimers which enable binding to cell surface coreceptors. In this application, the nature of HIV-1 envelope interactions with cell surface receptors and/or anti-envelope antibodies will be determined at the single molecule level. This novel application of single molecule fluorescence based approaches is expected to provide unique information relevant to vaccine and drug development.

Public Health Relevance

Human-immunodeficiency virus type 1 (HIV-1) has been the subject of intensive research. The majority of antiretroviral drugs acts at a post-infection step and cannot cure HIV-1 infection. Consequently, there is a continued emphasis on developing either drugs or vaccines that block pre-entry events by targeting the HIV-1 surface trimers which enable binding to cell surface coreceptors. In this application, the nature of HIV-1 envelope interactions with cell surface receptors and/or anti-envelope antibodies will be determined at the single molecule level. This novel application of single molecule fluorescence based approaches is expected to provide unique information relevant to vaccine and drug development.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Mentored Quantitative Research Career Development Award (K25)
Project #
5K25AI087968-02
Application #
8232033
Study Section
Acquired Immunodeficiency Syndrome Research Review Committee (AIDS)
Program Officer
Sharma, Opendra K
Project Start
2011-03-01
Project End
2015-02-28
Budget Start
2012-03-01
Budget End
2013-02-28
Support Year
2
Fiscal Year
2012
Total Cost
$111,186
Indirect Cost
$8,236
Name
University of Maryland Baltimore
Department
Biochemistry
Type
Schools of Medicine
DUNS #
188435911
City
Baltimore
State
MD
Country
United States
Zip Code
21201
Barnoy, Eran A; Fixler, Dror; Popovtzer, Rachela et al. (2016) Extremely sensitive dual imaging system in solid phantoms. Proc SPIE Int Soc Opt Eng 9721:
Barnoy, Eran A; Fixler, Dror; Popovtzer, Rachela et al. (2015) An ultra-sensitive dual-mode imaging system using metal-enhanced fluorescence in solid phantoms. Nano Res 8:3912-3921
Ray, Krishanu; Badugu, Ramachandram; Lakowicz, Joseph R (2015) Bloch Surface Wave-Coupled Emission from Quantum Dots by Ensemble and Single Molecule Spectroscopy. RSC Adv 5:54403-54411
Gohain, Neelakshi; Tolbert, William D; Acharya, Priyamvada et al. (2015) Cocrystal Structures of Antibody N60-i3 and Antibody JR4 in Complex with gp120 Define More Cluster A Epitopes Involved in Effective Antibody-Dependent Effector Function against HIV-1. J Virol 89:8840-54
Choudhury, Sharmistha Dutta; Badugu, Ramachandram; Ray, Krishanu et al. (2015) Directional Emission from Metal-Dielectric-Metal Structures: Effect of Mixed Metal Layers, Dye Location and Dielectric Thickness. J Phys Chem C Nanomater Interfaces 119:3302-3311
Ray, Krishanu; Badugu, Ramachandram; Szmacinski, Henryk et al. (2015) Several hundred-fold enhanced fluorescence from single fluorophores assembled on silver nanoparticle-dielectric-metal substrate. Chem Commun (Camb) 51:15023-6
Fixler, Dror; Nayhoz, Tsviya; Ray, Krishanu (2014) Diffusion Reflection and Fluorescence Lifetime Imaging Microscopy Study of Fluorophore-Conjugated Gold Nanoparticles or Nanorods in Solid Phantoms. ACS Photonics 1:900-905
Zhang, Jian; Ray, Krishanu; Fu, Yi et al. (2014) First observation of enhanced luminescence from single lanthanide chelates on silver nanorods. Chem Commun (Camb) 50:9383-6
Dutta Choudhury, Sharmistha; Badugu, Ramachandram; Ray, Krishanu et al. (2014) Surface-plasmon induced polarized emission from Eu(III)--a class of luminescent lanthanide ions. Chem Commun (Camb) 50:9010-3
Ray, Krishanu; Mengistu, Meron; Yu, Lei et al. (2014) Antigenic properties of the HIV envelope on virions in solution. J Virol 88:1795-808

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