Vaccination Under Stress: Revealing the Molecular Basis of B-cell Responses under Stress in Mice

B cells produce antibodies which are the cornerstone of successful immune response to all approved vaccines. It has been shown that B cells express high levels of Beta2-adrenergic receptors that bind catecholamines, which are secreted during stress. We therefore aim to test the effect of stress on B cells differentiation and antibody responses following immunization. For this, we employed an established model to induce continuous mild stress in mice, and Ovalbomin (Ova) as the model immunogen. C57bl/6j mice were immunized at day 0 and randomly assigned into three groups: Group 1 was subjected to stress during innate immune response phase (days -1 to 2 post immunization), Group 2 was subjected to stress during Germinal Center (GC) reaction (days 9 to 12 post immunization), while the third group was a No-stress control group. Four weeks following immunization, all mice were sacrificed and three different compartments were analyzed: serum, spleen and inguinal lymph nodes. While the difference in anti-Ova serum IgG was not significant among the different groups, the IgG expression levels of anti-Ova B cells were significantly lower (p=0.004) in the spleens and the lymph nodes of mice from Group 2, and not Group 1, compared to the control group. Moreover, there was a dramatic 58% decrease in the percent of plasma cells in the lymph nodes of mice from Group 2 compared to the control group. We conclude that in mice both B cell and plasma cell compartments are affected by stress.