man in lab coat

Dennis  J. O'Callaghan, PhD   


Former Chair of the Department of Microbiology and Immunology at LSU Health Shreveport, 1984-2018

Willis-Knighton Chair of Molecular Biology Emeritus, Shreveport, LA




External Research Funding


Graduate & Medical Students,
Postdocs & Residents


Center for Molecular & 
Tumor Virology



Bachelor's Degree: 1962 a native of New Orleans, he received the BS in Biology (Chemistry minor) from Loyola University, New Orleans, LA
PhD: 1968 awarded the PhD in Microbiology-Virology at the University of Mississippi Medical Center (UMMC), Jackson, MS and trained with Dr. Charles C. Randall, a pioneer in the elucidation of the structure of the genomes of both herpesviruses and poxviruses
Postdoctoral: 1971 completed postdoctoral studies at the University of Alberta Medical Center, Edmonton, Alberta, Canada with Dr. John Colter, who first discovered that the naked RNA genome of some human viruses is infectious per se.


Dr. O’Callaghan’s research program investigated the molecular biology of herpesviruses with emphasis on the mechanism by which viral regulatory protein determine whether the outcome of infection is a productive cytocidal infection or a persistent infection. His work employed a gallimaufry of molecular approaches and techniques to understand how viral proteins interact with cellular genes and proteins to determine the outcome of infection. Other aspects of his research investigated antiviral compounds and the role of cellular inflammatory proteins in herpesvirus pathogenesis. His laboratory has been funded continuously by grants from the National Institutes of Health, US Department of Agriculture, American Cancer Society, the Grayson Foundation and research contracts from the Pharmaceutical sector.

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While Dr. Dennis O’Callaghan officially retired from LSU Health Shreveport in 2018, he rarely misses a day coming to work because of his heartfelt affinity and dedication to LSUHS.  He continues to teach students in the School of Graduate Studies, keeps in touch with all alumnae in the Department of  Microbiology and Immunology tracking their professional growth and location and even assists with grad student recruitment.  For a man who was on the front lines of the US HIV pandemic in the 80’s, Dr. O’Callaghan is proof that keeping yourself active and in-service to others is a life well lived.
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Dr. O'Callaghan with the LSUHS Microbiology & Immunology Faculty

Dr. O'Callaghan with LSUHS Microbiology & Immunology Graduate Students

Dr. O'Callaghan's Research Lab Team

Dr. O'Callaghan's Research Lab Team

man seated with two boys standing

Dr. O'Callaghan with his Grandsons

man holding mallard ducks

Duck Hunting in Canada

group of people standing behind fish hanging from board

Dr. O'Callaghan's big catch in Alaska with Friends


five men in suits

2017 Investiture for Microbiology Endowed Chairs and Professorships. (L-R) LSUHS Chancellor G.E. Ghalli, Dr. Andrew Yurochko, Dr. Dennis O'Callaghan, Dr. Martin Sapp and LSUHS Foundation President Kevin Flood

Dr. O'Callaghan has been a member of numerous national and international scientific societies, including serving as President of the American Society for Virology (2000-2001), the American Society for Biochemistry and Molecular Biology, American Society for Investigative Pathology, the American Association for Cancer Research, Sigma Xi, Society for General Microbiology (British), the American Society for Experimental Biology and Medicine, and a member of the American Society for Microbiology.

He served as President of the South Central Branch of the America Society for Microbiology (ASM) and as Chair of the ASM Section on DNA Viruses. In 2008, he was selected to present the Distinguished Alumnus Lecture of the University of Mississippi Medical Center. He was elected as Fellow of both the American Association for the Advancement of Science and the Molecular Medicine Society. He served as editor of Virus Research and on the editorial boards of Virology, Journal of Virology, Recent Developments in Virology, and Pathogens and reviewed manuscripts as an ad hoc reviewer for many leading medical journals. He also served on the Advisory Panel of the NIH-supported Western Center of Excellence in Biodefense and Emerging Viral Diseases.

Over the years, Dr. O’Callaghan has chaired or served as a member of numerous scientific advisory boards and study sections for the NIH, US Department of Agriculture, the American Cancer Society, and the American Heart Association. He served on the Microbiology Committee of the National Board of Medical Examiners. He has well-developed skills in mentoring junior faculty, postdoctoral fellows, and graduate students, and many of his former trainees serve on faculties of medical centers, universities, and public and private research institutes. Some of these trainees hold leadership positions at the national level such as President, American Cancer Society; Director, BARDA (Biomedical Advanced Research and Development Authority); Provost and Interim President, Georgia Health System, and Executive Director, ARVO ( Association for Research in Vision and Ophthalmology).

Dr. O’Callaghan’s expertise in virology allowed him to establish the Center for Molecular and Tumor Virology at LSU Health Shreveport. This Center was funded for $22 million by an NIH COBRE Center grant for 15 years, the maximal time of support for COBRE grants.


Present - LSU Boyd Professor, Member of the Board of Directors for Louisiana State University Health Sciences Foundation in Shreveport, LA

2002 - Appointed as 63rd Boyd Professor, the highest academic in the LSU System

2000 - Elected as President of the American Society for Virology (ASV), the largest society devoted to virology

1995 - Selected as the Willis-Knighton Chair of Molecular Biology, the first endowed Chair on the Shreveport campus

1984-2018 Chair of the Department of Microbiology and Immunology at Louisiana State University Health Shreveport

1977-1984 Professor of Microbiology and Immunology at the University of Mississippi Medical Center, Jackson, MS

1974-1977 Associate Professor of Microbiology and Immunology at the University of Mississippi Medical Center, Jackson, MS

1971-1974 Assistant Professor of Microbiology and Immunology at the University of Mississippi Medical Center, Jackson, MS

1970-1971 Assistant Professor or Biochemistry at the University of Alberta School of Medicine, Edmonton, Alberta, Canada


In addition to his research, Dr. O’Callaghan’s love of teaching and interacting with students resulted in his being selected several times as the Basic Science Teacher of the Year by both medical and dental students. 


Dr. Dennis O'Callaghan Day - March 13, 2018

Dr. O'Callaghan and Senator Ryan Gatti

Dr. O'Callaghan and Members of His Family

(L to R) LSUHS Chancellor G.E. Ghali, Dr. Dennis O'Callaghan, Vice Chancellor of Research Dr. Chris Kevil, and Dr. John Sixbey