Maternal nutrient restriction: Effects on offspring immune function

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DESCRIPTION (provided by applicant): Poor maternal nutrition during pregnancy has been associated with increased neonatal mortality and susceptibility to infection and a higher incidence of chronic diseases including cardiovascular disorders, childhood asthma and diabetes. Many of these complications could be due to common underlying immune deficits elicited in utero by the lack of appropriate nutrition. To address the effects of MNR (maternal nutrient restriction) on developmental programming in non-human primates (NHP), the Center for Pregnancy and Newborn Research has developed a cohort of baboon offspring whose mothers received a diet restricted to 70% of the caloric value eaten by the ad lib fed controls (R24 RR0213667). This NHP MNR model offers a unique opportunity to examine the consequences of decreased nutrient availability during pregnancy on immunity in young adult offspring. It has been demonstrated that these MNR offspring have lower birth weights and exhibit physiological changes, most notably increased insulin resistance that persist into childhood. The immune health of these NHP offspring will be tested when they are 5-6 years old, equivalent to post-pubertal 15-16 year old humans. This will allow us to use assays that have been optimized for young adults for an ongoing aging study (R01AG030119). We hypothesize that the offspring of MNR pregnancies will have altered immune developmental programming, resulting in defects in the regulation of innate and adaptive immunity. To address this hypothesis, the baboons will be challenged with a protein vaccine to assess the functional capability of their antigen-specific adaptive immune responses (Aim I). Parameters of both B cell and T cell immunity will be measured in response to primary (naive) and secondary (memory or boost) immunizations. The functional capacity will then be correlated with parameters of immune health to be assessed in Aim II in the absence of an immune challenge. These will include: serum cytokine levels, blood cell populations, T cell repertoire, thymic function, and cel population- specific expression profiling to identify genes regulated in lymphocytes by MNR relative to control. In summary, use of this valuable NHP cohort will provide a unique opportunity to dissect the effects of MNR during pregnancy and lactation on immune system development in a well-controlled primate model. The project is innovative and timely as it incorporates both an immune challenge (vaccine) to test functional capacity coupled with assessments of general immune health. Moreover, expression profiling of T and B cells will provide the first insights into specific mechanisms that effect long-term immune consequences of malnutrition during pregnancy. These approaches may also reveal potential candidate biomarkers of immune health that could then facilitate the identification of immunologically "at risk" children leading o vaccine compositions/protocols that are likely to have greater efficacy. PUBLIC HEALTH RELEVANCE: Poor maternal nutrition during pregnancy has been associated with low birth weight, neonatal mortality, susceptibility to infectious diseases and other long-term complications; many of these effects could be due to common underlying immune deficits that result from the lack of vital nutrients during this critical window of immune development. We have the unique opportunity to measure immune function in a cohort of young baboons whose mothers were given a moderately restricted diet during pregnancy and lactation. These studies will have direct relevance to humans and should provide novel insights into the management of potential health complications, like infection and inflammatory disorders, which might arise as these at-risk offspring mature into adulthood and then age.