David R. Martinez, Youyi Fong, Shuk Hang Li, Fang Yang, Madeleine F. Jennewein, Joshua A. Weiner, Erin A. Harrell, Jesse F. Mangold, Ria Goswami, George Seage, Galit Alter, Margaret E. Ackerman, Xinxia Peng, Genevieve G. Fouda, and Sallie R. Premar. 6/27/2019. “Fc characteristics mediate selective placental transfer of IgG in HIV-infected women.” Cell Press, 178. Publisher's VersionAbstract

The placental transfer of maternal IgG is critical for infant protection against infectious pathogens. However, factors that modulate the placental transfer of IgG remain largely undefined. HIV-infected women have impaired placental IgG transfer, presenting a unique ‘disruption model’ to define factors that modulate placental IgG transfer. We measured the placental transfer efficiency of maternal HIV and pathogen-specific IgG in U.S. (n=120) and Malawian (n=47) HIV-infected mothers and their HIV-exposed uninfected and infected infants. We examined the role of maternal HIV disease progression, infant factors, placental Fc receptor expression, IgG subclass, and glycan signatures and their association with placental IgG transfer efficiency. Maternal IgG characteristics, such as binding to placentally expressed Fc receptors FcgRIIa and FcgRIIIa, and Fc region glycan profiles were associated with placental IgG transfer efficiency. Our findings suggest that Fc region characteristics modulate the selective placental transfer of IgG, with implications for maternal vaccine design and infant health.

Madeleine F. Jennewein, Ilona Goldfarb, Sepideh Dolatshahi, Cormac Cosgrove, Francesca J. Noelette, Marina Krykbaeva, Jishnu Das, Aniruddh Sarkar, Matthew J. Gorman, Stephanie Fischinger, Carolyn M. Boudreau, Joelle Brown, Jennifer H. Cooperrider, Jasneet Aneja, Todd. J. Suscovich, Barney S. Graham, Georg M. Lauer, Tessa Goetghebuer, Arnaud Marchant, Douglas Lauffenburger, Arthur Y. Kim, Laura E. Riley, and Galit Alter. 6/27/2019. “Fc glycan-mediated regulation of placental antibody transfer.” Cell Press, 178. Publisher's VersionAbstract

Despite the worldwide success of vaccination, newborns remain vulnerable to infections. While neonatal vaccination has been hampered by maternal antibody-mediated dampening of immune responses, enhanced regulatory and toleragenic mechanisms, and immune system immaturity, maternal pre-natal immunization aims to boost neonatal immunity via antibody transfer to the fetus. However, emerging data suggest that antibodies are not transferred equally across the placenta. To understand this, we used systems serology to define Fc features associated with antibody transfer. The Fc-profile of neonatal and maternal antibodies differed, skewed towards NK cell-activating antibodies. This selective transfer was linked to di-galactosylated Fc-glycans that selectively bind FcRn and FCGR3A, resulting in transfer of antibodies able to efficiently leverage innate immune cells present at birth. Given emerging data that vaccination may direct antibody glycosylation, our study provides insights for the development of next- generation maternal vaccines designed to elicit antibodies that will most effectively aid neonates.

Hugh C. Welles, Madeleine F. Jennewein, Rosemarie D. Mason, Sandeep Narpala, Lingshu Wang, Cheng Cheng, Yi Zhang, John-Paul Todd, Jeffrey D. Lifson, Alejandro B. Balazs, Galit Alter, Adrian B. McDermott, John R. Mascola, and Mario Roederer. 12/5/2018. “Vectored delivery of anti-SIV envelope targeting mAb via AAV8 protects rhesus macaques from repeated limiting dose intrarectal swarm SIVsmE660 challenge.” PloS Pathogens. Publisher's VersionAbstract
Gene based delivery of immunoglobulins promises to safely and durably provide protective immunity to individuals at risk of acquiring infectious diseases such as HIV. We used a rhesus macaque animal model to optimize delivery of naturally-arising, autologous anti-SIV neutralizing antibodies expressed by Adeno-Associated Virus 8 (AAV8) vectors. Vectored transgene expression was confirmed by quantitation of target antibody abundance in serum and mucosal surfaces. We tested the expression achieved at varying doses and numbers of injections. Expression of the transgene reached a saturation at about 2 x 1012 AAV8 genome copies (gc) per needle-injection, a physical limitation that may not scale clinically into human trials. In contrast, expression increased proportionately with the number of injections. In terms of anti-drug immunity, anti-vector antibody responses were universally strong, while those directed against the natural transgene mAb were detected in only 20% of animals. An anti-transgene antibody response was invariably associated with loss of detectable plasma expression of the antibody. Despite having atypical glycosylation profiles, transgenes derived from AAV-directed muscle cell expression retained full functional activity, including mucosal accumulation, in vitroneutralization, and protection against repeated limiting dose SIVsmE660 swarm challenge. Our findings demonstrate feasibility of a gene therapy-based passive immunization strategy against infectious disease, and illustrate the potential for the nonhuman primate model to inform clinical AAV-based approaches to passive immunization.
Madeleine F. Jennewein, Audrey Butler, and Galit Alter. 8/23/2018. “ Neonate-OMICs: charting the unknown immune response in early life.” Cell Press, 174, 5, Pp. 1051-1053.Abstract
The study of neonatal immunology has been hampered by lack of access to infant samples. Novel sample sparing methods and systems-wide approaches have uniquely expanded this field, demonstrating that newborn immunity varies widely but converges over the first 3 months of life. During this important time window, environmental and genetic factors impact the infant immune system and can influence lifelong immunity.
Transfer of maternal immunity and programming of the newborn immune system.
Madeleine Jennewein, Abu-Raya Bahaa, Yiwei Jiang, Galit Alter, and Arnaud Marchant. 10/3/2017. “Transfer of maternal immunity and programming of the newborn immune system.” Seminars in Immunopathology. Publisher's VersionAbstract
As placental mammals, the pregnant women and the fetus have intense and prolonged interactions during gestation. There is increasing evidence that multiple molecular as well as cellular components originating in pregnant women are transferred to the fetus. The transfer of maternal antibodies has long been recognized as a central component of newborn immunity against pathogens. More recent studies indicate that inflammatory mediators, micronutrients, microbial products and maternal cells are transferred in utero and influence the fetal immune system. Together, these multiple signals are likely to form a complex network of interactions that program the neonatal immune system and tune its homeostatic regulation. Maternal disorders, in particular infectious diseases, modify these signals and may thereby alter immunity in early life. Understanding maternal programming of the newborn immune system could provide a basis for interventions promoting child health. 
The Immunoregulatory Roles of Antibody Glycosylation
Madeleine Jennewein and Galit Alter. 4/3/2017. “The Immunoregulatory Roles of Antibody Glycosylation.” Trends in Immunology, 38, 5, Pp. 358-372. Publisher's VersionAbstract
Alison E. Mahan, Madeleine F. Jennewein, Todd Suscovich, Kendall Dionne, Jacquelynne Tedesco, Amy W. Chung, Hendrik Streeck, Maria Pau, Hanneke Schuitemaker, Don Francis, Patricia Fast, Dagna Laufer, Bruce Walker, Lindsey Baden, Dan H. Barouch, and Galit Alter. 3/16/2016. “Antigen-Specific Antibody Glycosylation Is Regulated via Vaccination.” PloS Pathogens. Publisher's VersionAbstract


2 Jun 2016: Mahan AE, Jennewein MF, Suscovich T, Dionne K, Tedesco J, et al. (2016)Correction: Antigen-Specific Antibody Glycosylation Is Regulated via Vaccination. PLOS Pathogens 12(6): e1005694. View correction


Antibody effector functions, such as antibody-dependent cellular cytotoxicity, complement deposition, and antibody-dependent phagocytosis, play a critical role in immunity against multiple pathogens, particularly in the absence of neutralizing activity. Two modifications to the IgG constant domain (Fc domain) regulate antibody functionality: changes in antibody subclass and changes in a single N-linked glycan located in the CH2 domain of the IgG Fc. Together, these modifications provide a specific set of instructions to the innate immune system to direct the elimination of antibody-bound antigens. While it is clear that subclass selection is actively regulated during the course of natural infection, it is unclear whether antibody glycosylation can be tuned, in a signal-specific or pathogen-specific manner. Here, we show that antibody glycosylation is determined in an antigen- and pathogen-specific manner during HIV infection. Moreover, while dramatic differences exist in bulk IgG glycosylation among individuals in distinct geographical locations, immunization is able to overcome these differences and elicit antigen-specific antibodies with similar antibody glycosylation patterns. Additionally, distinct vaccine regimens induced different antigen-specific IgG glycosylation profiles, suggesting that antibody glycosylation is not only programmable but can be manipulated via the delivery of distinct inflammatory signals during B cell priming. These data strongly suggest that the immune system naturally drives antibody glycosylation in an antigen-specific manner and highlights a promising means by which next-generation therapeutics and vaccines can harness the antiviral activity of the innate immune system via directed alterations in antibody glycosylation in vivo. 

Gira Bhabha, Damien C. Ekiert, Madeleine F. Jennewein, CM Zmasek, Lisa M. Tuttle, G Kroon, HJ Dyson, A Godzik, Ian A. Wilson, and Peter E. Wright. 11/2013. “Divergent evolution of protein conformational dynamics in dihydrofolate reductase.” Nature Structure and Molecular Biology, 20, 11, Pp. 1243-1249. Publisher's VersionAbstract
Molecular evolution is driven by mutations, which may affect the fitness of an organism and are then subject to natural selection or genetic drift. Analysis of primary protein sequences and tertiary structures has yielded valuable insights into the evolution of protein function, but little is known about the evolution of functional mechanisms, protein dynamics and conformational plasticity essential for activity. We characterized the atomic-level motions across divergent members of the dihydrofolate reductase (DHFR) family. Despite structural similarity, Escherichia coli and human DHFRs use different dynamic mechanisms to perform the same function, and human DHFR cannot complement DHFR-deficient E. coli cells. Identification of the primary-sequence determinants of flexibility in DHFRs from several species allowed us to propose a likely scenario for the evolution of functionally important DHFR dynamics following a pattern of divergent evolution that is tuned by cellular environment