Macrophage migration inhibition as a correlate of cell-mediated immunity to herpes simplex virus type 2 in mice

Expression Patterns of Macrophage Migration Inhibitory Factor and Its Gene Variants (MIF-173 G˃C) in Verruca Vulgaris

Introduction

Verruca vulgaris is a benign hyperkeratotic proliferation of the epidermis. Few studies look at the differences in serum and tissue macrophage migration inhibitory factor (MIF) levels in verruca vulgaris, as well as its gene polymorphisms that have yet to be explored. The current study provided in-depth evaluation of MIF in serum and tissues of patients with verruca vulgaris, and establishes for the first time the possible association of MIF gene polymorphisms with common warts.

Methods

This case-control study included 50 patients who were diagnosed clinically as common warts in comparison with 50 age and sex-matched controls. Clinical examination was done on all included cases. Serum MIF was measured using enzyme-linked immunosorbent assay (ELISA), while its tissue expression was analyzed using Western blotting and immunohistochemical techniques for the included participants. Analysis of MIF-173 G˃C single nucleotide polymorphism was performed by polymerase chain reaction (PCR) using restriction fragment length polymorphism (RFLP) technique.

Results

The overall results revealed significantly lower MIF tissue expression in lesional and perilesional skin biopsies from cases compared to the controls using Western blot and immunohistochemical analysis. Yet, the difference in the serum MIF levels between cases and controls was not significant (p ˃ 0.05). GC genotype of the studied MIF rs755622 G>C SNP could be considered as a protective genetic factor against the occurrence of verruca vulgaris among Egyptians with OR (95% CI) equal 0.444 (0.199-0.989).

Conclusion

MIF and its genetic variants are thought to play a pathogenic role in verruca vulgaris development and recurrence.

Comparison of the interaction of methyl mercury and mercuric chloride with murine macrophages

The toxicity of organic methyl mercury was studied on murine macrophages in cell culture and compared to that of inorganic mercuric chloride. Long-term treatment of macrophage cultures with methyl mercury resulted in decreased cell viability in a concentration-dependent fashion. Experiments showed that 20 microM methyl mercury was highly toxic, causing cell death within a few days, while cultures exposed to lower levels were less severely affected. Comparison of the toxicity of organic and inorganic mercury by cell viability showed no difference between equimolar concentrations of methyl mercury and mercuric chloride. Furthermore, protein synthesis (interferon-alpha/beta) was reduced in a concentration dependent manner and had the same reduced magnitude in cells treated with either methyl mercury or mercuric chloride. However, impairment of random migration and phagocytosis of macrophages appeared at lower concentrations in cells exposed to methyl mercury than in cells exposed to mercuric chloride. Electron microscopy of cells exposed to methyl mercury revealed mercury deposits in lysosomes and dispersed in the cytoplasm and nuclei. The present study shows that methyl mercury and mercuric chloride impair cell viability and protein production in cell cultures at equimolar concentrations, while methyl mercury inhibits macrophage functions such as migration and phagocytosis at lower concentrations than mercuric chloride.

Toxicity and ultrastructural localization of mercuric chloride in cultured murine macrophages

The effects of mercuric chloride on cell survival, phagocytosis and cell migration were examined in cultured mouse peritoneal macrophages, and the accumulation of mercuric chloride in the cells was visualized by autometallography and evaluated by light and electron microscopy. Macrophages exposed to mercury concentrations from 1.25 microM to 10 microM mercuric chloride showed a concentration- and time-dependent increase in mercuric chloride accumulation, while cells exposed to 20 microM and 40 microM mercury showed an inverse relationship between mercury concentration and the accumulation of mercury. Mercury concentrations above these levels caused cell necrosis. Electron microscopy revealed that mercury was located primarily within lysosomes but also in the nucleus and cytoplasm. Mercury increased the death rate of macrophages in a concentration-dependent manner when cells were treated with mercury concentrations not causing cell necrosis. Further, we found that mercury clearly impaired macrophage random migration and possibly the capability for phagocytosis.

Autointerference in silver accumulation in macrophages without affecting phagocytic, migratory or interferon-producing capacity

Silver accumulation and processing in mouse peritoneal macrophages was studied in vitro by autometallographic visualization of intracellular silver. During the first 24 h of incubation in a medium containing from 5 microM to 20 microM of silver lactate, an inverse relationship between silver concentration in the former and visualizable silver in macrophages was recorded. Later, however, the cells treated with higher silver concentrations accumulated most silver. Cells exposed to silver concentrations above these levels exhibited acute coagulation necrosis and disintegrated within the first 15 min of silver treatment. Macrophages treated with silver lactate concentrations not causing acute cytotoxicity showed no impairment of their phagocytic, migratory or interferon-producing capacities. The significance of autointerference in silver accumulation and processing in macrophages is discussed, and a functional defect in the lysosome/phagosome system is suggested as a basis for the phenomenon.

Production of lymphokines and interferon by immune cells involved in recovery of mice from herpes simplex virus type 2 hepatitis

Adoptive transfer of spleen cells from mice 4 days after infection with herpes simplex virus type 2 (HSV-2) reduced the virus titer in the liver of recipient mice infected 24 h before transfer. Macrophage chemotactic factor (CF) and macrophage migration inhibition factor (MIF) were produced by day 3 of infection in spleen cell cultures stimulated with HSV-2, but not with control antigen, i.e. 1 day before the cells are active in adoptive transfer. Interferon was produced in cultures established throughout the infection but not in normal spleen cells. From days 1 to 5 of infection interferon was produced irrespective of in vitro restimulation, although the highest amounts were always produced after stimulation with the specific antigen. Spleen cells from mice infected for 6 days produced interferon only when stimulated with HSV-2. The cells from 6-day-immune mice active in adoptive transfer and CF and MIF production were found to be Thy 1+, Ig- and Lyt2-. Both Thy 1+ and plastic adherent cells were necessary for interferon production, whereas Ig+ and Lyt2+ cells did not produce interferon. The interferon was acid stable and neutralized by antiserum against alpha/beta-interferon and thus has the characteristics of alpha-interferon. The data indicate that a delayed type hypersensitivity reaction with lymphokine-induced macrophage recruitment into infectious foci may be a central feature of the recovery process in HSV-2-induced hepatitis. A possible role of interferon produced by the accumulated cells needs further investigation.