Bruce Walker, MD
Principal Investigator: Bruce Walker, MD
Office/Location: 400TS 870
Phone: (857) 268-7073
Email: firstname.lastname@example.org | Assistant: Kylerose Delaney email@example.com
The Walker laboratory focuses on mechanisms of immune control in HIV infection, focusing in particular on persons who control HIV infection spontaneously without the need for medication. Through an international collaboration now funded by the Gates Foundation, more than 1500 persons who control HIV infection to less than 2000 RNA Copies/ml without the need for antiviral medications have been recruited, and immunologic, virologic and host genetic mechanisms accounting for this remarkable phenotype are being investigated. Our results, published in Science, indicate that the major genetic determinants of HIV control affect the nature of the peptide-HLA binding. We are currently focusing our research efforts on this interaction and how it impacts the inductive and effector phases of the CD8 T cell response.
Other projects currently underway are building on a observation that the antiviral efficacy of CTL varies dramatically among different epitopes and different restricting HLA alleles, in an attempt to define the major antiviral effector functions and apply these to vaccine development. At the same time, efforts are underway to define the subset of CD8 T cell responses that exert the strongest antiviral effect, and to define those responses that are simply passengers and fail to contribute to immune control.
In addition to these efforts in Boston, a major effort is underway at our laboratory at the Nelson Mandela School of Medicine at the University of KwaZulu-Natal, South Africa, where a major population based effort is underway to define evolution of clade C virus infection under immune selection pressure, and to define predictable pathways to immune escape. We have established a mechanism for recruitment of persons with acute HIV infection by screening persons who test antibody negative at VCT (now HCT) sites in KZN. We anticipate an expanding collaboration with persons at the Ithembalebantu Clinic in Umlazi to accelerate these studies, which will include examination of tissue biopsies.
Persons interested in joining this lab should have a strong background in immunology and/or molecular biology, a strong interest in working on immune responses in humans, and an ability to work relatively independently. The lab is highly collaborative with other labs within the Ragon Institute and outside, and thus seeks people who are committed to scientific collaboration. Please visit the Training Programs page for information about how to apply.
- Identification of strong circulating HIV-specific cytotoxic T lymphocytes in infected persons.
- Identification of HIV-specific CD4 T cells and their association with immune control of HIV.
- Identification of immunoregulatory pathways that turn HIV-specific immune responses off in vivo.
- Demonstration of the superior antiviral efficacy of Gag-specific CD8 T cell responses.
- Define the relative antiviral efficacy of epitope-specific CTL responses in infected persons
- Define the predicatable pathways to immune escape in infected persons
- Define the mechanisms that underlie effective cell killing
- Define the mechanisms of spontaneous control of HIV infection using a genome wide association scan.
1. Day CL, Kaufmann DE, Kiepiela P, Brown JA, Moodley ES, Reddy S, Mackey EW, Miller JD, Leslie AJ, DePierres C, Mncube Z, Duraiswamy J, Zhu B, Eichbaum Q, Altfeld M, Wherry EJ, Coovadia HM, Goulder PJ, Klenerman P, Ahmed R, Freeman GJ, Walker BD. 2006. PD-1 expression on HIV-specific T cells is associated with T-cell exhaustion and disease progression. Nature 443: 350-4
2. Kaufmann DE, Kavanagh DG, Pereyra F, Zaunders JJ, Mackey EW, Miura T, Palmer S, Brockman M, Rathod A, Piechocka-Trocha A, Baker B, Zhu B, Le Gall S, Waring MT, Ahern R, Moss K, Kelleher AD, Coffin JM, Freeman GJ, Rosenberg ES, Walker BD. 2007. Upregulation of CTLA-4 by HIV-specific CD4+ T cells correlates with disease progression and defines a reversible immune dysfunction. Nat Immunol 8: 1246-54
3. Chen H, Piechocka-Trocha A, Miura T, Brockman MA, Julg BD, Baker BM, Rothchild AC, Block BL, Schneidewind A, Koibuchi T, Pereyra F, Allen TM, Walker BD. 2009. Differential neutralization of human immunodeficiency virus (HIV) replication in autologous CD4 T cells by HIV-specific cytotoxic T lymphocytes. J Virol 83: 3138-49
4. Miura T, Brockman MA, Brumme ZL, Brumme CJ, Pereyra F, Trocha A, Block BL, Schneidewind A, Allen TM, Heckerman D, Walker BD. 2009. HLA-associated alterations in replication capacity of chimeric NL4-3 viruses carrying gag-protease from elite controllers of human immunodeficiency virus type 1. J Virol 83: 140-9
5. Kosmrlj A, Read EL, Qi Y, Allen TM, Altfeld M, Deeks SG, Pereyra F, Carrington M, Walker BD, Chakraborty AK. 2010. Effects of thymic selection of the T-cell repertoire on HLA class[thinsp]I-associated control of HIV infection. Nature 465: 350-4
6. The International HIV Controller Study. 2010. The major genetic determinants of HIV control affect HLA class I peptide binding. Science in press
Kiera Clayton | firstname.lastname@example.org
Kiera Clayton is a Postdoctoral Fellow who joined the Walker Lab in December of 2014. Her work focuses on understanding how co-inhibitory pathways play a role in modulating HIV-specific responses and their impact on protective T cell memory formation during HIV infection. She obtained an Honors BS in Biochemistry followed by her PhD in Immunology, both from the University of Toronto in Canada. During her PhD, she studied the co-inhibitory molecule, Tim-3, and characterized its function and regulation in human CD8+ T cells. In her free time, she enjoys running, skiing, wine tasting, and jazz.
David Collins | email@example.com
David joined the Walker lab as a postdoctoral fellow in August 2015. His research aims to better define the hallmarks of effective memory CTL responses and to identify mechanisms of immune failure in a cohort of progressors who previously maintained durable HIV control. David is originally from upstate New York and holds a B.S. in microbiology from University of Rochester and a Ph.D. in microbiology and immunology from University of Michigan, where his thesis research elucidated the roles of Vpr and macrophage infection in HIV pathogenesis. Outside of lab David enjoys volunteering at animal shelters, playing tennis, and occasionally sleeping.
I am originally from Chicago, IL. I completed by BS in Biochemistry and BA in Economics from the University of Illinois in 2003. I subsequently obtained a PhD in Biochemistry with a focus in HIV immunology at Oxford University working in the MRC Immunochemistry Unit and in collaboration with the MRC Human Immunology Unit. After Oxford, I moved onto the Health Sciences and Technology (HST) program at Harvard Medical School to complete my MD, which I completed with Magna Cum Laude honors based on work I completed at the Ragon Institute of MGH, MIT and Harvard in the lab of Prof. Bruce Walker. I am now a 2nd-year Internal Medicine Resident at Massachusetts General Hospital and continue to pursue active projects in the lab.My research interests are focused on understanding the properties that define successful and dysfunctional HIV-specific CD8+ T cell responses in patients with divergent clinical outcomes using transcriptional profiling and shRNA knockdown technology. I am also working on a novel network analysis platform to identify critical areas of mutational constraint within the HIV proteome and ultimately hope to parlay this work into novel T-cell based vaccine designs.”
Itai Muzhingi | firstname.lastname@example.org
Itai Muzhingi is a rising junior at Amherst College, majoring in Biochemistry and Biophysics. A science enthusiast, he is highly interested in infectious disease research and hopes to pursue an MD/PhD in the near future. He is passionate about discovering affordable, accessible and easily administered methods of boosting the immune system in response to HIV infection. Under the mentorship of Dr. Gaurav Gaiha, Itai is currently performing a genome-wide CRISPR Screen of the pathways and molecules involved in the HLA Class I expression of an HIV epitope on Dendritic Cells. Before joining the Walker lab, Itai worked on developing a method of quantifying molecular Near Attack Conformations using computational chemistry techniques. In the long run, he hopes to use the research skills that he acquires to promote research and STEM education in his home country, Zimbabwe. Outside of work, Itai enjoys listening to music, hiking and exploring his artistic side with the aid of 3D modeling and animation platforms.
Priya Jani | email@example.com
Dylan Koundakjian | firstname.lastname@example.org
Dylan joined the Ragon Institute in December 2014 as a research technician working under Ryan Park. A native of Bedford, MA, he received his B.S. from Duke University with a double major in Biology and French. For his senior thesis, Dylan developed a protocol for extracting high quality genomic DNA from chimpanzee hair follicles to facilitate whole genome sequencing of primate study individuals living in the wild. At the Ragon, he has turned his attention towards studying the genetic factors which make CD4+ T-cells susceptible to HIV infection. When he’s not in lab, Dylan enjoys playing ice hockey, attending rock concerts, traveling, and kicking back with good film.
Katja Kleinsteuber | email@example.com
Katja is a postdoctoral fellow in the Walker lab working on CD8+ T cell responsesduring HIV infection. She joined the lab in February 2013 and is interested in human immune responses to infectious diseases. She is a passionate user of the CyTOF at the Ragon Institute. She received her Masters degree in Biochemistry and Molecular Biology from the University of Hamburg (Germany) and worked at the Bernhard-Nocht-Institute for Tropical Medicine in Hamburg for her PhD studies about human CD4+ T cell regulation in the context of tuberculosis.
Pedro Lamothe Molina | firstname.lastname@example.org
Pedro is a Ph.D. student in Biological Sciences in Public Health from Harvard University. He joined the Walker Lab in February 2013 to study the CD8+ T cells immune responses against HIV infection. Pedro is originally from Mexico City where he did his undergraduate studies in Electronic Engineering and where he later received his Medical degree. He wanted to do more basic science research, so he did his M.S. in Biotechnology at Johns Hopkins University. He spends the time he is outside the lab, cycling and training for Ironman triathlons. He loves his Fox Terrier dog named Simon but the winter in Massachusetts… well, not so much.
Nzuekoh Nchinda | email@example.comNzuekoh Nchinda joined the Walker lab in August 2014 as a research technician working under Katja Kleinsteuber. Nzuekoh graduated from Harvard University with an A.B in Chemistry and a Secondary Field in Global Health and Health Policy in May 2014. She first became fascinated with infectious disease research while at the Fortune lab at the Harvard School of Public Health, where she was able to complete her senior thesis on chemical stress and population heterogeneity of mycobacteria. While studying CD8+ T cell responses with Katja in the Walker lab, Nzuekoh also looks forward to learning from the many exciting research projects at the Ragon Institute and learning about how biomedical research and medicine intersect. Nzuekoh is originally from Cameroon and was raised in Wisconsin. Outside of lab, she enjoys reading, writing, music, fine arts, and discussion of current events in the world.
Chioma Anthonia Nwonu | firstname.lastname@example.org
Chioma joined the Walker laboratory in September 2015 as a research technician under the direction of Srinika Ranasinghe. She attended Smith College where she majored in Biochemistry with a strong background in molecular biology. She previously worked in a laboratory at Smith College that studies the molecular biology of lymphatic filariasis, a neglected tropical disease. She hopes to pursue a career in medicine and clinical research. Chioma is from Nigeria and enjoys cooking traditional Nigerian dishes.
Ryan Park | email@example.com
Ryan is an MD student at Harvard Medical School. He received a B.S. and an M.S. in Molecular Biophysics and Biochemistry from Yale University in 2012. He is in the Harvard-MIT Health Sciences & Technology (HST) program and joined the Walker lab in January 2013 for his thesis project. He’s originally from Los Angeles but has also lived in Chicago, Fort Worth, and Seoul. In the lab, he is trying to understand the mechanism for the differential function of CD8+ T cell clones from Elite Controllers and Chronic Progressors. In his dwindling time outside of the lab and classroom, he enjoys cooking, playing the saxophone, and reading and dreaming about fast cars.
Alicja Piechocka-Trocha | firstname.lastname@example.org
Alicja is a Senior Laboratory Manager for the Ragon Institute and has been working for Dr. Bruce Walker for the last 24 years. Trained as a veterinarian from Polish Agriculture University in Olsztyn, she began to perform research, and despite all odds, she truly learned to love it. The aspect of teaching and educating future aspiring scientist as well as cultivating all habits of safe and meticulous lab work in young students and fellows has become a professional journey for her. What they learn with Alicja they will apply in their new endeavors. When not at work she enjoys reading books, long nature walks and skiing.
Srinika Ranasinghe | email@example.com
Srinika is a Research Scientist at the Ragon Institute working on HIV-specific CD4 T cell responses in natural HIV infection and vaccination strategies. She received her B.A/M.Ain Biological Sciences, and obtained her PhD in HIV immunology under the mentorship of Prof. Sir Andrew McMichael, at the University of Oxford. In 2010, she was delighted to join the Ragon Institute, where her research has focused on identifying epitope-specific CD4 T cell responses and their HLA class II restriction. She is also a young investigator in the Walker and Kaufmann research foci of CHAVI-ID, which seeks to understand the pivotal role of CD4 T follicular helper cells in generating broadly neutralizing antibodies against HIV. Srinika loves exploring the restaurants of Boston and kayaking on the Charles River.
Adrienne Yanez | firstname.lastname@example.org
Adrienne joined the Porichis lab as a research fellow in March 2015. She is working to identify and manipulate gene regulatory networks that improve HIV-specific CD4 T-cell responses to HIV infection. She received her Ph.D. from Harvard University, where she studied global regulation of miRNA activity by translation initiation factors in melanoma. In her spare time, she enjoys playing outside, exploring her surroundings, and gazing into empty centrifuges (see picture above).
Former Laboratory Members