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Nina Papavasiliou is an immunologist and Helmholtz Professor in the Division of Immune Diversity at the
German Cancer Research Center The German Cancer Research Center (known as the Deutsches Krebsforschungszentrum or simply DKFZ in German) is a national cancer research center based in Heidelberg, Germany. It is a member of the Helmholtz Association of German Research Centres ...
in Heidelberg, Germany. She is also an adjunct professor at the Rockefeller University, where she was previously associate professor and head of the Laboratory of Lymphocyte Biology. She is best known for her work in the fields of DNA and
RNA editing RNA editing (also RNA modification) is a molecular process through which some cells can make discrete changes to specific nucleotide sequences within an RNA molecule after it has been generated by RNA polymerase. It occurs in all living organism ...
.


Education and early career

Papavasiliou received her Bachelors of Science from Oberlin College in biology in 1992. She then completed her PhD at the Rockefeller University in Michel C. Nussenzweig's Laboratory of Molecular Immunology. There, she began studying how B cell antigen receptors—or antibodies anchored to the cell membrane—undergo mutation so they can specifically recognize a particular
antigen In immunology, an antigen (Ag) is a molecule or molecular structure or any foreign particulate matter or a pollen grain that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune respons ...
and elicit an immune response. She followed that interest to the
Yale School of Medicine The Yale School of Medicine is the graduate medical school at Yale University, a private research university in New Haven, Connecticut. It was founded in 1810 as the Medical Institution of Yale College and formally opened in 1813. The primary te ...
, where she worked as a postdoctoral fellow in the lab of David G. Schatz.


Research

Papavasiliou's research centers on demystifying how cells and organisms diversify and expand the information encoded in their genomes, both at the DNA and RNA level. She opened her Laboratory of Lymphocyte Biology at Rockefeller University in 2001 as an assistant professor. Much of her group's early work was done in the context of the adaptive immune response, which is able to combat a wide array of pathogens seeking to invade the host by rapidly generating novel antibodies that are able to specifically recognize a given invader. Her group has worked to characterize the activity of an
enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...
known as
activation-induced cytidine deaminase Activation-induced cytidine deaminase, also known as AICDA, AID and single-stranded DNA cytosine deaminase, is a 24 kDa enzyme which in humans is encoded by the ''AICDA'' gene. It creates mutations in DNA by deamination of cytosine base, which t ...
(AID). AID changes
cytidine Cytidine (symbol C or Cyd) is a nucleoside molecule that is formed when cytosine is attached to a ribose ring (also known as a ribofuranose) via a β-N1- glycosidic bond. Cytidine is a component of RNA. It is a white water-soluble solid. which ...
(C) residues to
uracil Uracil () (symbol U or Ura) is one of the four nucleobases in the nucleic acid RNA. The others are adenine (A), cytosine (C), and guanine (G). In RNA, uracil binds to adenine via two hydrogen bonds. In DNA, the uracil nucleobase is replaced b ...
(U) in DNA, which is recognized as DNA damage and repaired in such a way that introduces
thymidine Thymidine (symbol dT or dThd), also known as deoxythymidine, deoxyribosylthymine, or thymine deoxyriboside, is a pyrimidine deoxynucleoside. Deoxythymidine is the DNA nucleoside T, which pairs with deoxyadenosine (A) in double-stranded DNA. ...
(T), effectively mutating Cs to Ts in DNA. The process is known as
somatic hypermutation Somatic hypermutation (or SHM) is a cellular mechanism by which the immune system adapts to the new foreign elements that confront it (e.g. microbes), as seen during class switching. A major component of the process of affinity maturation, SHM div ...
and is how B cells can rapidly introduce DNA mutations into receptors that recognize the invaders, known as
antigen In immunology, an antigen (Ag) is a molecule or molecular structure or any foreign particulate matter or a pollen grain that can bind to a specific antibody or T-cell receptor. The presence of antigens in the body may trigger an immune respons ...
s. Papavasiliou's lab has worked to understand how AID expression is regulated in the immune system and how AID targets certain genes for mutation. Papavasiliou also studies
RNA editing RNA editing (also RNA modification) is a molecular process through which some cells can make discrete changes to specific nucleotide sequences within an RNA molecule after it has been generated by RNA polymerase. It occurs in all living organism ...
in the context of the innate immune response using
next-generation sequencing Massive parallel sequencing or massively parallel sequencing is any of several high-throughput approaches to DNA sequencing using the concept of massively parallel processing; it is also called next-generation sequencing (NGS) or second-generation ...
and bioinformatics approaches to identify and characterize RNA editing targets. Her group first identified novel RNA editing targets of
APOBEC1 Apolipoprotein B mRNA editing enzyme, catalytic polypeptide 1 also known as C->U-editing enzyme APOBEC-1 is a protein that in humans is encoded by the ''APOBEC1'' gene. This gene encodes a member of the APOBEC protein family and the cytidine de ...
, which mutates a
cytosine Cytosine () ( symbol C or Cyt) is one of the four nucleobases found in DNA and RNA, along with adenine, guanine, and thymine (uracil in RNA). It is a pyrimidine derivative, with a heterocyclic aromatic ring and two substituents attached (an ...
to a
uracil Uracil () (symbol U or Ura) is one of the four nucleobases in the nucleic acid RNA. The others are adenine (A), cytosine (C), and guanine (G). In RNA, uracil binds to adenine via two hydrogen bonds. In DNA, the uracil nucleobase is replaced b ...
in an RNA transcript, and was previously thought to only edit
Apolipoprotein B Apolipoprotein B (ApoB) is a protein that in humans is encoded by the gene. Function Apolipoprotein B is the primary apolipoprotein of chylomicrons, VLDL, Lp(a), IDL, and LDL particles (LDL—commonly known as "bad cholesterol" when in ref ...
(apoB) in the small intestine. Her group has since moved on to attempt to characterize the potential role APOBEC1-editing may be playing outside of its function with apoB. Papavasiliou most recently branched out to studying mechanisms of
antigenic variation Antigenic variation or antigenic alteration refers to the mechanism by which an infectious agent such as a protozoan, bacterium or virus alters the proteins or carbohydrates on its surface and thus avoids a host immune response, making it one of ...
—or how pathogens vary their surface proteins to escape the immune response—using
Trypanosoma brucei ''Trypanosoma brucei'' is a species of parasitic kinetoplastid belonging to the genus '' Trypanosoma'' that is present in sub-Saharan Africa. Unlike other protozoan parasites that normally infect blood and tissue cells, it is exclusively extrace ...
, the parasite that causes African sleeping sickness, as a model organism. Her group has developed new tools to better understand the dynamics of protein coat switching in trypanosomes, and is working to better understand the mechanisms by which trypanosomes are able to diversify their coat proteins over the course of an infection. In 2016, Papavasiliou moved to the
German Cancer Research Center The German Cancer Research Center (known as the Deutsches Krebsforschungszentrum or simply DKFZ in German) is a national cancer research center based in Heidelberg, Germany. It is a member of the Helmholtz Association of German Research Centres ...
to begin her lab in the Division of Immune Diversity with additional support from a European Research Council Consolidator Grant.


Award & honors

* Keck Fellow, 2002 *
Searle Scholar The Searle Scholars Program is a career development award made annually to the 15 young US professionals in biomedical research and chemistry considered most promising. The award was established in 1980 by a donation from the Searle family, and is ...
, 2003 *Sinsheimer Fund Scholar, 2005 * Thorbecke Award, Society for Leukocyte Biology, 2006 *
The Vilcek Foundation The Vilcek Foundation raises awareness of immigrant contributions to the United States, and fosters appreciation of the arts and sciences. The foundation's flagship programs include the Vilcek Foundation Prizes, which recognize and support immigra ...
Prize Finalist for Creative Promise in Biomedical Science, 2009 *
National Institutes of Health The National Institutes of Health, commonly referred to as NIH (with each letter pronounced individually), is the primary agency of the United States government responsible for biomedical and public health research. It was founded in the late ...
Director’s Transformative Research Project Award, 2011


References

{{DEFAULTSORT:Papavasiliou, Nina Year of birth missing (living people) Living people Greek women scientists Rockefeller University alumni Oberlin College alumni Rockefeller University faculty Greek immunologists