Longitudinal single-cell analysis of SARS-CoV-2-reactive B cells uncovers persistence of early-formed, antigen-specific clones

When the body encounters a pathogen, such as a virus, the immune system develops an adaptive immune response through B-cell and T-cell responses to clear the infection and develop memory to this pathogen. This memory, often referred to as “immunological memory,” allows the body to respond more rapidly and specifically if it faces the same pathogen a second time. Interestingly, the immune response continues to evolve long after initial pathogen exposure, with memory B-cells making better and more specific antibodies and undergoing molecular processes that tailor the immune response to the specific pathogen. Immunologists have been interested in the details of this evolution and memory, since understanding how the immune system remembers what it sees is vital for the development of vaccines and therapies. However, since these processes occur over extended periods of time, it has proven challenging to characterize how the immune response changes over time after exposure to a pathogen within the same person.  

An exciting study from Davide Angeletti’s team at the University of Gothenburg in Sweden employs a longitudinal approach to overcome this challenge. The study, conducted on patients with severe COVID-19, follows the trajectory of the immune response in six patients from hospital admission, recovery, up to a year after initial admission and profiled their adaptive immune cells. Specifically, the team employed single-cell sequencing technologies to profile the B cells of these patients and how their molecular repertoire changed over time following recovery and, in some cases, vaccination after recovery. The study found that the B cells in these patients continued to evolve after initial infection, hospitalization, and that these B cells increased their ability to bind and neutralize antigen long after the pathogen was cleared. Often, isolating and characterizing specific primary cell populations from patients is particularly challenging due to low cell number and resolution, but this study also overcame this challenge by employing Curiox Laminar Wash Technology, which allows a gentle alternative to traditional centrifugation methods.  

Download this article to learn more about:  

• The B cell response in patients hospitalized with severe COVID-19.  
• Transcriptomic, cell-surface marker characteristics, and B cell receptor (BCR) repertoire of B cell populations that evolved following infection and recovery from COVID-19.  

• High resolution data from rare primary cell populations was made possible through Laminar Wash Technology.