Author Image

Athena Chen

Data Scientist, Biostatistician

I recently received my PhD from the Department of Biostatistics at the Johns Hopkins Bloomberg School of Public Health. For my dissertation work, I developed statistical methods to characterize antibody responses to various antigens using phage-immunoprecipitation sequencing technology (PhIP-Seq) with Dr. Ingo Ruczinski and Dr. H. Benjamin Larman. My research interests include Bayesian statistics, statistical genomics and proteomics, data analysis and data analysis teaching, and immunology.

Projects

BEER
BEER
Developer Apr 2020 - Present

Bayesian method for identifying enriched antibody responses from PhIP-Seq data.

PhIPData
Developer Feb 2021 - Present

Package defining an S4 class for PhIP-Seq experiments. PhIPData allows users to coordinate metadata with experimental data in analyses.

kTSP classifier for HIV cross-sectional incidence estimation
Research Assistant May 2018 - Feb 2020

Extension of the kTSP classifier to longitudinal data to identify recent infections for HIV cross-sectional incidence estimation.

Human phageome and toxome antigen library
Research Assistant Jun 2019 - Present

Annotated antigen library derived from metagenomic sequencing of stool samples and analyzed data with the new library.

Spatial Cell Modeling
Research Assistant Dec 2015 - Aug 2017

Analyzed and assessed challenges facing current single-particle modeling methods of biochemical systems.

Featured Publications

A list of all publications can be found here
Detecting Antibody Reactivities in Phage ImmunoPrecipitation Sequencing Data
Chen, A., Kammers, K., Larman, H. B., Scharpf R. B., Ruczinski, I.
bioRxiv | Jan 2021

Phage ImmunoPrecipitation Sequencing (PhIP-Seq) is a recently developed technology to assess antibody reactivity, quantifying antibody binding towards hundreds of thousands of candidate epitopes. The output from PhIP-Seq experiments are read count matrices, similar to RNA-Seq data; however some important differences do exist. In this manuscript we investigated whether the publicly available method edgeR for normalization and analysis of RNA-Seq data is also suitable for PhIP-Seq data. We find that edgeR is remarkably effective, but improvements can be made and introduce a Bayesian framework specifically tailored for data from PhIP-Seq experiments (Bayesian Enrichment Estimation in R, BEER).

Diagnosing Data Analytic Problems in the Classroom
Peng, R., Chen, A., Bridgeford, E., Leek, J. T. & Hicks, S. C.
Journal of Statistics and Data Science Education | Aug 2021

Teaching data analysis by providing students with real-world problems and datasets allows students to integrate a variety of skills in a situation that mirrors how data analysis actually works. However, whole data analyses may obscure the individual skills of data analytic practice that are generalizable across data analyses. One such skill is the ability to diagnose the cause of unexpected results in a data analysis. We describe an approach to teaching students skills in diagnosing data analytic problems.

HIV Antibody Profiles in HIV Controllers and Persons With Treatment-Induced Viral Suppression
Kammers, K., Chen, A., Monaco, D. R., Hudelson, S. E., Grant-McAuley, W., Moore, R. D., Alter, G., Deeks, S. G., Morrison, C. S., Eller, L. A., Blankson, J. N., Laeyendecker, O., Ruczinski, I., Eshleman, S. H. & Larman, H. B.
Frontiers in Immunology | Aug 2021

Low HIV viral load is associated with delayed disease progression and reduced HIV transmission. HIV controllers suppress viral load to low levels in the absence of antiretroviral treatment (ART). We used an antibody profiling system, VirScan, to compare antibody reactivity and specificity in HIV controllers, non-controllers with treatment-induced viral suppression, and viremic non-controllers.

A top scoring pairs classifier for recent HIV infections
Chen, A., Laeyendecker, O., Eshleman, S. H., Monaco, D. R., Kammers, K., Larman, H. B. & Ruczinski, I.
Statistics in Medicine | Mar 2021

As availability and use of antiretroviral treatment increase worldwide, algorithms that do not include HIV viral load and are not impacted by viral suppression are needed for cross-sectional HIV incidence estimation. Using a phage display system to quantify antibody binding to over 3300 HIV peptides, we present a classifier based on top scoring peptide pairs that identifies recent infections using HIV antibody responses alone.

Antibody responses to endemic coronaviruses modulate COVID-19 convalescent plasma functionality
Morgenlander, W. M., Henson, S. N., Monaco, D. R., Chen, A., Littlefield, K., Bloch, E. M., Fujimura, E., Ruczinski, I., Crowley, A. R., Harini, N., Butler, S. E., Weiner, J. A., Li, M. Z., Bonny, T. S., Benner, S. E., Balagopal, A., Sullivan, D., Shoham, S., Quinn, T. C., Eshleman, S., Casadevall, A., Redd, A. D., Laeyendecker, O., Ackerman, M. E., Andrew, P., Elledge, S. J., Robinson, M. L., Tobian, A. A. R. & Larman, H. B.
The Journal of Clinical Investigation | Feb 2021

SARS-CoV-2 (CoV2) antibody therapies, including COVID-19 convalescent plasma (CCP), monoclonal antibodies, and hyperimmune globulin, are among the leading treatments for individuals with early COVID-19 infection. The functionality of convalescent plasma varies greatly, but the association of antibody epitope specificities with plasma functionality remains uncharacterized. We assessed antibody functionality and reactivities to peptides across the CoV2 and the 4 endemic human coronavirus (HCoV) genomes in 126 CCP donations.

Quantifying the roles of space and stochasticity in computer simulations for cell biology and cellular biochemistry
Johnson, M. E., Chen, A., Faeder, J. R., Henning, P., Moraru, I. I., Meier-Schellersheim, M., Murphy, R. F., Prustel, T., Theriot, J. A. & Uhrmacher, A. M.
Molecular Biology of the Cell | Jan 2021

Most of the fascinating phenomena studied in cell biology emerge from interactions among highly organized multimolecular structures embedded into complex and frequently dynamic cellular morphologies. For the exploration of such systems, computer simulation has proved to be an invaluable tool, and many researchers in this field have developed sophisticated computational models for application to specific cell biological questions. We have defined a series of computational test cases ranging from very simple to moderately complex, varying key features of dimensionality, reaction type, reaction speed, crowding, and cell size. We then quantified how explicit spatial and/or stochastic implementations alter outcomes, even when all methods use the same reaction network, rates, and concentrations.

Comprehensive profiling of HIV antibody evolution
Eshleman, S. H., Laeyendecker, O., Kammers, K., Chen, A., Sivay, M. V., Kottapalli, S., Sie, B. M., Yuan, T., Monaco, D. R., Mohan, D., Wansley, D., Kula, T., Morrison, C., Elledge, S. J., Brookmeyer, R., Ruczinski, I. & Larman, H. B.
Cell Reports | Apr 2019

This study evaluates HIV antibody responses and their evolution during the course of HIV infection. A phage display system is used to characterize antibody binding to >3,300 HIV peptides in 57 adults with early- to late-stage infection.

Recent & Upcoming Talks

Statistical Methods for Analyzing Phage-ImmunoPrecipitation Sequencing Data
Final Dissertation Defense | Feb 2022
Virtual

Antibody Profiling Identifies Antibody Targets Associated with Natural HIV Control

Introduction to workflowr

Introduction to JAGS and rJAGS

Top Scoring Pairs Classifier for Identifying Recent HIV Infection

Teaching

Graduate Teaching Assistant
Responsibilities
  • Guided students through lab exercises and discussions of course material.
  • Provided feedback on assignments to facilitate a better understanding of course concepts.
TermCourse NameInstructor(s)
Fall 2021Statistical ComputingStephanie Hicks, PhD
Spring 2021Bayesian Methods I and IIGary Rosner, PhD and Robert Scharpf, PhD
Fall 2019/2020Advanced Data ScienceJeff Leek, PhD; Stephanie Hicks, PhD; and Roger Peng, PhD
Summer 2020Data Wrangling with RAndrew Jaffe, PhD and John Muschelli, PhD
Summer 2020Introduction to R for Public Health ResearchersAndrew Jaffe, PhD and John Muschelli, PhD
Spring 2020Statistics for Laboratory Scientists I and IIIngo Ruczinski, PhD
Spring 2019Statistical Methods in Public Health III and IVMarie Diener-West, PhD; Leah Jager, PhD; and James Tonascia, PhD
Fall 2018Methods in Biostatistics I and IICiprian Crainiceanu, PhD
Undergraduate Teaching Assistant
Responsibilities
  • Developed computer lab exercises on bioinformatic techniques to analyze omic data sets.
  • Assisted students with homework and computing lab assignments.
  • Led review sessions to reinforce topics introduced in lecture
TermCourse NameInstructor(s)
Spring 2017Introduction to BioinformaticsPatrick Fleming, PhD
Fall 2016Biochemistry IPatrick Fleming, PhD
Summer 2016Discrete MathematicsFred Torcaso, PhD