Intravenous Immunoglobulins (IVIG) Enhance In vitro Activation of Neutrophils in C57BL/6 but not in CBA Mice

Intravenous immunoglobulins (IVIG) are used in the treatment of inflammatory, autoimmune conditions and cancer. However, the precise mechanism of their action and the mechanisms that underlie responsiveness and resistance of some patients to the IVIG therapy remain unknown. The anti-cancer effect of IVIg might be mediated by neutrophils, which regulate tumor development. We studied in vitro effects of IVIG on neutrophils from two immunologically contrasting mouse strains, CBA and C57BL/6. Results We examined total and differential WBC count, platelets count and the activity of normal neutrophils in intact CBA and C57BL/6 mice by method of luminol-dependent chemiluminescence (CL) of whole blood, and found significant difference in neutrophils, lymphocytes and platelets counts. Upon in vitro activation with opsonized zymozan (OZ), the C57BL/6 blood neutrophils showed no CL response at the absence of extracellular calcium while in the presence of calcium the CL responses of CBA and C57b blood were very similar. In the presence of IVIG, the calcium-dependent raise in OZ-activated CL response was registered only in C57BL/6 blood samples. Conclusions For the first time we demonstrate that IVIG cause the calcium-dependent neutrophils priming in vitro in whole blood of C57BL/6 but not in CBA mice.