Deficiency of the macrophage migration inhibitory factor gene has no significant effect on endotoxaemia

By targeted disruption of the MIF gene, we have established a mouse strain deficient in macrophage (Mφ) migration inhibitory factor (MIF). Despite previous reports indicating an essential role of MIF in endotoxaemia, an injection of lipopolysaccharide (LPS) into the MIF-deficient mice (maintained under specific pathogen-free conditions) caused shock. No significant difference was detected between the MIF-deficient mutant and normal mice in susceptibility to LPS for endotoxaemia or tumour necrosis factor-α (TNF-α) formation upon LPS injection. Peritoneal Mφ from the two strains produced TNF-α in response to LPS with similar dose responses. Dexamethasone suppressed the LPS-induced TNF-α response of Mφ, but no difference was detected between the Mφ from the two strains. These results suggest that endogenous MIF has no significant effect on the LPS-induced TNF-α production and no effect on suppression of the response by glucocorticoids. Thus, MIF is not crucial for LPS-induced immune responses leading to shock

Immunoexpression of Survivin in non-neoplastic lymphoid tissues and malignant lymphomas using a new monoclonal antibody reactive on paraffin sections

Survivin is a member of the inhibitor of apoptosis gene family, which is also implicated in mitosis regulation. Most reports in the literature impute poor prognosis to neoplasms with overexpression of this protein. The purpose of the present study is to validate and compare the immunohistochemical reactivity of malignant lymphomas and reactive lymphoid tissue using a new mouse monoclonal antibody to Survivin produced in our laboratory, 6-78. Survivin was detected by immunohistochemistry on tissue microarrays. It was shown that the antibody anti-Survivin 6-78 reliably stains formalin-fixed, paraffin-embedded reactive and neoplastic lymphoid tissues, mostly in a nuclear pattern. We confirmed using this novel antibody that Survivin immunostaining has a tendency to be lower in reactive lymphoid tissues and low-grade B cell lymphomas than in aggressive lymphomas. This antibody may represent a useful tool for standardizing the study of the immunoexpression of Survivin in neoplasms