On Possible Indicators of Negative Selection in Germinal Centers
Event Details
- Type
- Center for Studies in Physics and Biology Seminars
- Speaker(s)
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Bertrand Ottino-Loffler, Ph.D., fellow, Center for Studies in Physics and Biology, The Rockefeller University
- Speaker bio(s)
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A central feature of vertebrate immune response is affinity maturation, wherein antibody-producing B cells undergo evolutionary selection in microanatomical structures called germinal centers, which form in secondary lymphoid organs upon antigen exposure. While it has been shown that the median B cell affinity dependably increases over the course of maturation, the exact logic behind this evolution remains vague. Three potential selection methods include encouraging the reproduction of high affinity cells (“birth/positive selection”), encouraging cell death in low affinity cells (“death/negative selection”), and adjusting the mutation rate based on cell affinity (“mutational selection”). While all three forms of selection would lead to a net increase in affinity, different selection methods may lead to distinct statistical dynamics. We present a tractable model of selection and analyze proposed signatures of negative selection. Given the simplicity of the model, such signatures should be stronger here than in real systems. However, we find a number of intuitively appealing metrics — such as preferential ancestry ratios, terminal node counts, and mutation count skewness — require nuance to properly interpret.
- Open to
- Public
- Contact
- Melanie Lee
- Phone
- (212) 327-8636
- Sponsor
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Melanie Lee
(212) 327-8636
leem@rockefeller.edu