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Faculty Spotlight: Nancie Jo MacIver, MD, PhD

Friday, March 15, 2019
Nancie Jo MacIver, MD, PhD

This week’s faculty spotlight shines on Nancie Jo MacIver, MD, PhD, associate professor of pediatrics in the Division of Endocrinology. MacIver talks to us about how she became interested in the field of endocrinology as a result of a last minute clerkship switch during her fourth year of medical school. She also shares her reflections on her most significant mentor, Jeff Rathmell, PhD, who welcomed her to his laboratory during her fellowship, and offers some insights into her research focused on how large changes in nutritional status alter immune cell metabolism, differentiation, and function in the context of health and disease. She also talks about her passions outside of work, including exercise, her husband, three children, and two dogs (one good and one bad).

How long have you been at Duke? How did you decide to come here?
I came to Duke in 2003 for my pediatric residency, and I never left.  I stayed for fellowship in pediatric endocrinology, and I have been on faculty since 2009. When I came to Duke for residency, I had just finished an 8-year combined MD-PhD program at Mayo Clinic in Minnesota, and my husband and I were looking for a change in geographic location. Durham was a fabulous fit. With over 2 million people in the Raleigh-Durham-Chapel Hill area and surrounding suburbs, there is always plenty to do, but without the lifestyle challenges or costs that can come with a larger city.

What are your responsibilities within the Division of Endocrinology? What does a typical day for you look like?
I am a physician scientist with a small amount of clinical duties split between outpatient clinic and hospital service and with the majority of my time spent running my laboratory. I supervise a group of two post-doctoral associates, one graduate student, one undergraduate student, and one lab technician. I participate in teaching in multiple ways--I give several didactic lectures to residents and fellows throughout the year, I supervise a fellow continuity clinic, and I have a small commitment to teaching in the graduate school for my secondary departments--the Department of Immunology and the Department of Pharmacology and Cancer Biology. In addition, I am the Director of the Duke Scholars in Molecular Medicine (DSMM), which is a program supported by the School of Medicine in which we take PhD trainees (PhD students and post-docs) and give them an exposure to clinical medicine. My job is, therefore, quite a mix of activities on any given day.  Today, for example, I am preparing a lecture to give to the residents next week, writing an IACUC (animal protocol) amendment, meeting with members of my lab about their projects, reviewing budgets and feedback for the Duke Scholars program, and taking a conference call about my upcoming role as camp physician at Diabetes Camp for the first time, along with other small tasks.

How did you first get interested in medicine? What made you decide to pursue pediatric endocrinology in particular?
I have always loved science and math, and at some point in high school, I decided to become a physician for the personal interactions. My interest in endocrinology is a funny story; I had to make a last minute clerkship switch during my fourth year of medical school, for family reasons. The only thing available to me was an outpatient rotation in adult endocrinology. I though it sounded horrible, but I did not really have any other option, so I took it. I ended up loving that month of endocrinology and requesting an elective in pediatric endocrinology during my first year of residency at Duke. I enjoy many things about this subspecialty. First, there is a lot of outpatient continuity, which I enjoy. Second, we are pretty much in the business of helping kids grow and develop normally and, in most cases, are able to offer treatment for the problems we see in our clinic to make that happen, which is extremely gratifying.

What are your specific interests in the field of pediatric endocrinology?
As an outpatient provider, I see any endocrine problem other than diabetes. I only take care of diabetes on an inpatient basis. That was a choice I made when I first came on faculty because I felt that my limited clinic availability would prevent good continuity for outpatient diabetes care.

Can you tell us about some of your current research?
My laboratory is broadly interested in how large changes in nutritional status (e.g. malnutrition or obesity) alter immune cell metabolism, differentiation, and function in the context of health and disease. We have several ongoing projects, many of which are collaborative, to study how undernutrition or overnutrition influences our ability to fight infection. One interesting example is with influenza infection. Patients with undernutrition or overnutrition/obesity have an increased risk of influenza mortality and are more likely to get influenza despite being vaccinated. Surprisingly, we have evidence in mouse studies that obesity-associated impaired influenza response does not improve following weight loss. Likewise, there is also a persistently impaired immune response to infection following correction of undernutrition; immunity can remain impaired for months to years after achieving a normal weight. We are exploring possible mechanisms for these prolonged immune deficiencies by examining the role of epigenetics and the microbiome. We are also working to identify molecular mechanisms by which nutritionally regulated hormones and cytokines (including insulin, insulin-like growth factor-1, leptin, and interleukin-6) communicate nutritional status to immune cells and thereby influence immune cell differentiation in under- and overnutrition and in inflammatory disease.

Who was your most significant mentor and what knowledge did you gain through this collaboration?
My fellowship mentor, Jeff Rathmell, was my most significant mentor. Jeff was a PhD researcher in the Department of Pharmacology and Cancer Biology at Duke when I approached him about a fellowship project. He welcomed me into his laboratory during my fellowship and allowed me to stay there during my first few years on faculty when I was a Medical Instructor. Jeff has provided me with critical advice, guidance, opportunities, and networking for the last 13 years. He has definitely been the most important influence on my research career. Although Jeff left Duke a few years ago, I continue to call him for advice and guidance as needed, and I deeply value our friendship. I also want to give a shout out to my Division Chief, Mike Freemark, who has also been a key mentor and advisor to me. Mike is a great boss, and I continue to be grateful for his generous mentoring and support which I have been fortunate to receive since my training started at Duke.

Since your completed your pediatric internship and residency as well as a pediatric endocrinology fellowship here at Duke, do you have any advice for trainees?
When you stay for a faculty position at the same institution where you trained, it does sometimes take a while for the older faculty to see you as something other than a trainee. I remember one instance when I rode in a garage elevator with a faculty colleague after I had been on faculty for about 3 years, and she asked me if I was almost done with my residency! On the other hand, there is a real advantage to the many relationships you make over time by staying in one place, as well as the institutional knowledge that you gain through longevity. One piece of advice that my research mentor gave me many years ago, and I will pass that along here, is that if you continue to work hard and try to do the right things, it will all work out. I think that has been true of my career so far.

What passions or hobbies do you have outside of work?
I love to read, which is my primary activity when I am not sitting in front of my computer doing work. As people who know me well can tell you, I have been an avid participant of Zumba for years, and I have recently fallen in love with Orangetheory Fitness as well. Unfortunately, balancing those good habits are a love of food and eating out. My husband Jeff (a different Jeff than the one mentioned above) and I have been together for almost 20 years, and we have three awesome kids who keep our lives messy and interesting: Wendy (age 17), Xander (age 15), and Dexter (age 10), and we currently have two dogs (one good one and one bad one).