Cell Metabolism Remembers Cheolho Cheong

Abstract

On April 25th, I received an email from Tae Jin Yun informing me that her PI, Cheolho Cheong, had passed away. This was not the first time that I had received such sad news, but this one felt very raw and painful. I did not know Cheolho personally but had been working closely with him for the previous few months on his Cell Metabolism paper (Yun et al., 2016, Cell Metabolism 23, 852–866). Despite the fact that I correspond with dozens of scientists every day, Cheolho stood out by his passion and enthusiasm for science. We talked extensively about his paper and his revision plans, experiments he was planning for the dendritic cell project, even those beyond the paper, and how he saw the field of atherosclerosis. He took the comments of the editors and reviewers to heart and worked hard at improving his paper. I was impressed by his reliability and his strong work ethics—he did not shy away from the hard path; in his own words, he liked “clear-cut evidences.” If he told me that he would get back to me about a specific piece of data within an hour, he actually would! In a world of chronic lateness, I appreciated that he was a man of his word. We also discussed science more broadly and his other projects, which intersected at least three different fields. It was obvious that he had a deep commitment to carrying on Ralph Steinman’s legacy and had an infectious passion for dendritic cells. I did not realize that anyone could love an immune cell type so much! Corresponding with Cheolho was inspiring, thought-provoking, and fun. When Tae Jin’s email came, I felt a tremendous sense of loss, and still do. I feel I was in the middle of several conversations with Cheolho that I will never finish. After his passing, I found out more about him from his colleagues and came to realize just how exceptional he was and what a tremendous loss this is for his friends, family, colleagues, and science.Among the many conversations my team and I had with Cheolho were his plans for a cover design. The authors of every accepted paper scheduled for an issue are invited to submit a cover design related to their paper. Cheolho was thinking of a play on the name of the enzyme he was investigating, Indoleamine 2,3-dioxygenase, IDO, and wanted to convey the synergy between plasmacytoid DCs (pDCs) and regulatory T cells (Tregs) to prevent atherosclerosis. He suggested a wedding ceremony between pDC and Treg as bride and groom exchanging their vows, standing on a heart-shaped floor to symbolize atherosclerosis and cardiovascular disease (Figure 1Figure 1).Figure 1Cheolho’s Initial Cover DraftView Large Image | View Hi-Res Image | Download PowerPoint SlideCheolho’s paper was scheduled to be published in the May issue, which had a gender focus. With his usual energy, he “proposed” two variations on the wedding theme. In the first one, Treg became a muscular super-heroine, akin to “Wonder Woman or She-Ra,” marrying an “ordinary man” (pDC) while “bad lipids run away” in fear (Figure 2Figure 2).Figure 2Cheolho’s Cover Image, Proposal OneArtwork by Yves Dumont.View Large Image | View Hi-Res Image | Download PowerPoint SlideFor the second cover proposal, he envisioned pDC still as an “ordinary man” in a tuxedo, saying “yes, IDO” while Treg, a “muscular firefighter woman,” extinguishes a fire, representing the lipid plaque (Figure 3Figure 3).Figure 3Cheolho’s Cover Image, Proposal TwoArtwork by Yves Dumont.View Large Image | View Hi-Res Image | Download PowerPoint SlideDespite a relatively short notice, he sent the final cover images to the journal office to be considered by the deadline. Again, with his distinctive attention to detail, he highlighted specific components of the images, such as which finger the wedding ring of Treg was placed on. Working with Cheolho on this cover image highlighted a different side of him to us—his sense of humor and his love for superheroes, to which his colleagues refer in the accompanying Obituary in this issue of Cell Metabolism. While writing this memoriam, I asked Gwen Randolph why Cheolho cast the pDC, his hero, as “an ordinary man,” and we shared some interesting speculations. “The funny thing,” she said, “is that his definition of an ordinary man is probably a superhero to us.” I thought it was a poignant metaphor for how Cheolho came across.Cell Metabolism would like to pay tribute to Cheolho’s dedication, passion, and enthusiasm; it was a privilege to work with him, and we feel his loss deeply. Our thoughts are with his family and friends.