The cellular and humoral immune response against primary infection with Coxiella burnetii

Abstract

Coxiella burnetii infection in mice results in a limited febrile illness that can be measured by examining splenomegaly, bacterial burden, and histopathology. In humans, this disease is known as Q fever. Using the mouse model, we examined both the T cell and the B cell response to primary infection with virulent C. burnetii. We discovered that Major Histocompatibility Complex class I and CD8+ Cytotoxic T cell lysis are critical for defense against primary infection. During the vaccine response, Major Histocompatibility Complex class II is essential for protective immunity. We also found that B1a B cells are important for producing cytokines and antibodies during primary infection. In addition, we discovered that avirulent C. burnetii induces caspase-1 dependent pyroptosis in murine B1a B cells. These studies build the foundation for better understanding of the immune response to C. burnetii infection and will hopefully lead to the development of new and more effective strategies for treating and preventing Q fever.