About Hansel M. Fletcher, PhD

Dr. Fletcher is currently the Assistant Dean for Graduate Student Affairs in the School of Medicine at Loma Linda University. As part of this portfolio he manages the graduate program including the curriculum.  Recently, he lead the faculty group and program directors in the development and implementation of three new graduate programs in the School of Medicine.  He is also Professor and Vice Chair for the Department of Basic Sciences, Division of Microbiology and Molecular Genetics. Since 2004, He has been serving as the Graduate Program Director for the Division of Microbiology and Molecular Genetics. Nationally, he currently serves on the Education Boards for the Association of Medical School Microbiology and Immunology Chairs and the American Society for Microbiology.  He serves on several study panels for the National Institutes of Health, including study sections that evaluate grants for the training and development of graduate students, postdoctoral fellows and faculty at the early stages of their career. He recently served for 2 years (March 2019- March 2021) as the chair for the Fellowship F08 study section panel. He serves on the editorial board of multiple scientific journals, is an Academic Editor for PLoS One and is the Editor-in-Chief for the Molecular Oral Microbiology journal.  Dr. Fletcher holds Adjunct professorships at Universities in the United States of America, India, China, South Korea and Jamaica. The 2015 Lifetime achievement award was conferred December 18, 2015, on Dr. Fletcher by the Indian Association of Applied Microbiologist. He received the President’s Medallion from Northern Caribbean University at their graduation commencement August 13, 2017.  He served as President for the International Association for Dental Research/American Association for Dental Research (IADR/AADR) Microbiology/Immunology scientific group from March 2017 – March 2020.  He currently serves as the Chair of the Committee for Diversity and Inclusion for IADR/AADR. 

As an experienced and well-trained scientist in the molecular genetics and biochemistry of microbial diseases, his research program has been focused on oral bacterial pathogens important to periodontal diseases and inflammatory systemic diseases including cardiovascular disease and rheumatoid arthritis. His pioneering work on genetic tool development for Porphyromonas lead to the first demonstration of the role of proteases in the virulence of P. gingivalis. Furthermore, the genetic tool (an ermF/ermAM antibiotic resistance cassette) is the most widely used in genetics studies in P. gingivalis. His research program has provided evidence for posttranslational regulation of proteolytic activity in P. gingivalis and the first report of the identification of a gingipain proenzyme from this organism.  He has also provided evidence of a new paradigm for DNA repair of 8-oxo-7,8-dihydroguanine lesions in P. gingivalis in addition to the first demonstration that gingipains from P. gingivalis can induce caspase-independent apoptosis in endothelial cells. His work with the P. gingivalis vimA (virulence modulation A) gene, identified in his laboratory, is emerging as a founding member of novel post-translational control mechanism in Gram-negatives. His group has begun other studies with Fillifactor alocis, a new emerging Gram-positive bacterium that is now proposed to be a diagnostic indicator of periodontal disease. They were the first to report on the virulence potential of this organism. Moreover, based on proteomic studies of the interaction of P. gingivalis and F. alocis with host epithelial cells raise questions on the ability of these bacteria to modulate host function via a post-translational mechanism involving acetylation and/or methylation.  Both these organisms, which have invasive abilities, can secrete proteins with putative acetyltransferase and methyltransferase functions which can have implications for host/virus epigenetic modulation.

In addition to his research program that has attracted more than 14 million dollars (US) in research funding resulting in 115 presentations and 156 publications including papers (74), abstracts (77) and book chapters, he also has a strong record in the training of graduate students. Twenty graduate students, including 10 candidates with M.S. degrees, have graduated from his research program. Of this number, 4 currently hold university faculty positions. Twelve postdoctoral fellows have been trained in his laboratory, with 6 currently holding university faculty positions while one serves as the Director of Research and Development at a biotechnology company and another University Vice President for Research.

As a scientist/educator/administrator from an underrepresented population, he has leveraged his experience to continue the development of a highly motivated people.  One of his goals and guiding principle is to continue working towards promoting diversity within the scientific arena by actively recruiting and training students from underrepresented and disadvantaged populations and by serving as a role model, mentor and advisor to these individuals.   He has been involved and will continue to be aggressively engaged in faculty development and capacity building at our Historically Black Colleges and Universities (HBCUs) and academic institutions throughout the Caribbean, Latin America, India, South Korea and Africa.