With the modified CyTOF, which they named CyTOF-Lec, the scientists analyzed immune cells from the blood and tissues of human donors. вЂњBut we know of several lectins that can distinguish between a variety of sugars with different shapes and molecular compositions, and we plan to expand our work by using new lectins in the future.вЂќ вЂњWe donвЂ™t have as many lectins as we have antibodies,вЂќ says Abdel-Mohsen. вЂњWe now have a good toolkit to analyze in great detail the combination of proteins and sugars present on single cells.вЂќ In this study, the team replaced five of the CyTOF antibodies with five different lectins, molecules that can recognize various types of sugars. CyTOF relies on antibodies to identify specific proteins, and can record the presence, absence, and amount of nearly 40 different proteins at once. To answer this question, RoanвЂ™s team adapted a technique called CyTOF, which they previously used to study the protein profile of individual immune cells.

вЂњWe wondered to what extent cell-surface sugars might help us tell apart different types of cells within a population of immune cells,вЂќ says Tongcui Ma, PhD, the studyвЂ™s first author and a scientist at Gladstone. The chains differ in length, branching patterns, and the type of sugars they contain, and are known to affect a number of cell properties. The researchers studied various chains of simple sugar molecules. By sorting large populations of cells based on both their sugar and protein profiles, we may uncover new classes of cells that have eluded earlier studies and could hold the key to solving important biological problems.вЂќ Surveying the Sugars Coating Individual Cells вЂњBut they have been understudied, in part because they are harder to track than proteins. вЂњThere is a tremendous diversity of cell-surface sugars,вЂќ says Abdel-Mohsen, co-senior author of the study. The work also showcases a new technique for studying individual cells from large populations that could lead to a more detailed picture of cellular diversity. вЂњOne of the most striking findings from our study is that the amount of a single type of surface sugar can distinguish between memory CD4 T cells with vastly different biological features and susceptibility to HIV infection,вЂќ says Roan, who is also a professor of urology at UC San Francisco and the studyвЂ™s co-senior author. The scientists analyzed sugars on the surface of individual immune cells to help identify cells that HIV prefers to infect. They report their findings in the journal eLife. Together, the scientists uncovered surprisingly different sugar patterns on different immune cells, and an intriguing interplay between HIV and the sugars coating CD4 T cells.

Roan teamed up with Mohamed Abdel-Mohsen, PhD, an associate professor at The Wistar Institute and a specialist in the cellular machinery that synthesizes sugars.

Recently, they set their sight on another type of molecule at the cellвЂ™s surface: sugars. But these cells come in many flavors, and it has been difficult to ascertain exactly what makes one type of memory CD4 T cell more attractive to HIV than another.ДЇor years, Gladstone Associate Investigator Nadia Roan, PhD, and her team have tackled this question by analyzing CD4 T cells based on the collection of proteins they bear on their surface. They know that HIV favors a special type of immune cells called memory CD4 T cells. HIV researchers have long been trying to identify the specific cells that the virus prefers to infect and hide in.

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