B Cells and B Cell Blasts Withstand Cryopreservation While Retaining Their Functionality for Producing Antibody

• Main Authors: Philipp Fecher, Richard Caspell, Villian Naeem, Alexey Y. Karulin, Stefanie Kuerten, Paul V. Lehmann
• Format: Article
• Language: English
• Published: MDPI AG 2018-05-01
• Series: Cells
• Subjects: four color B cell ELISPOT; immune monitoring; freeze-thawing PBMC; plasma cells; antibody secretion; immunoglobulins; antibodies; immunoglobulin classes and subclasses; antibody-secreting cells; IgA; IgE; IgD; IgM; IgG1; IgG2; IgG3; IgG4; multiplex immune assay
• Online Access: http://www.mdpi.com/2073-4409/7/6/50

In individuals who have once developed humoral immunity to an infectious/foreign antigen, the antibodies present in their body can mediate instant protection when the antigen re-enters. Such antigen-specific antibodies can be readily detected in the serum. Long term humoral immunity is, however, also critically dependent on the ability of memory B cells to engage in a secondary antibody response upon re-exposure to the antigen. Antibody molecules in the body are short lived, having a half-life of weeks, while memory B cells have a life span of decades. Therefore, the presence of serum antibodies is not always a reliable indicator of B cell memory and comprehensive monitoring of humoral immunity requires that both serum antibodies and memory B cells be assessed. The prevailing view is that resting memory B cells and B cell blasts in peripheral blood mononuclear cells (PBMC) cannot be cryopreserved without losing their antibody secreting function, and regulated high throughput immune monitoring of B cell immunity is therefore confined to—and largely limited by—the need to test freshly isolated PBMC. Using optimized protocols for freezing and thawing of PBMC, and four color ImmunoSpot® analysis for the simultaneous detection of all immunoglobulin classes/subclasses we show here that both resting memory B cells and B cell blasts retain their ability to secrete antibody after thawing, and thus demonstrate the feasibility of B cell immune monitoring using cryopreserved PBMC.