Analyzing Mouse B Cell Responses Specific to LCMV Infection.

B cell responses play a central role in humoral immunity, which protects an individual from invading pathogens by antigen-specific antibodies. Understanding the basic principles of the B cell responses during viral infection is of substantial importance for anti-viral vaccine development. In inbred mice, lymphocytic choriomeningitis virus (LCMV) infection elicits robust and typical T cell-dependent B cell responses, including germinal center reaction, memory B cell formation, and a long-lived plasma cell pool in bone marrow. Therefore, this system represents an ideal model to investigate anti-viral B cell responses. In this protocol, we describe how to propagate and quantify LCMV and successfully establish an acute LCMV infection in mice. This protocol also provides three different techniques to analyze B cell responses specific to an acute LCMV infection: the identification of germinal center (GC) B cells and follicular helper CD4 T (TFH) cells from the spleens and lymph nodes via flow cytometry, titration of LCMV-specific IgG in the serum after LCMV infection using an enzyme-linked immunosorbent assay (ELISA) analysis, and detection of LCMV-IgG secreted plasma cells from bone marrow with an enzyme-linked immunospot (ELISPOT) assay.