TY  - JOUR
AU  - Sakai, Tohru 
AU  - Nakamoto, Mariko 
AU  - Suto, Emi 
PY  - 2009
TI  - Hyper-Ag-specific Ab Production in NC/Nga Mice is not associated with Deletion Polymorphism in the Promotor Region of the FcγRIIB Gene
JF  - American Journal of Immunology
VL  - 5
IS  - 3
DO  - 10.3844/ajisp.2009.61.64
UR  - https://thescipub.com/abstract/ajisp.2009.61.64
AB  - Problem statement: NC/Nga (NC) mice produced high levels of ovalbumin (OVA)-specific IgG, IgG1 and IgG2a. We previously found deletion polymorphisms in the promoter region of fcgr2b in NC mice. To determine whether this mutation causes a hyper-humoral immune response, we generated congenic BALB/c mice carrying the NC-type fcgr2b allele (NC fcgr2b) and analyzed humoral immune response and FcγRIIB on germinal center (GC) B cells.  Approach: BALB/c, NC and BALB/c- NC fcgr2b congenic mice were immunized with OVA 2 times at a 2-week-interval. Levels of OVA-specific IgG, IgG1 and IgG2a in serum were determined by ELISA. Four-color (anti-B220, anti-IgD, 2.4G2 and PNA) flow cytometry analysis was performed on splenocytes obtained from OVA-immunized mice and levels of FcγRIIB in GC (IgD-PNAhigh) and  non-GC (IgD+PNAlow) B cells were analyzed. Results: Although perturbed up-regulation of FcγRIIB on GC B was observed in congenic mice, levels of OVA-specific Abs were comparable to those in BALB/c mice. Conclusion: NC fcgr2b affects the level of FcγRIIB in GC B cells but that the reduced FcγRIIB expression is not related to enhanced Ag-specific Ab responses in NC mice.