Related Experiment Videos
Potentiation of lymphocyte proliferative responses by nickel sulfide
1Department of Microbiology and Immunology, School of Medicine, University of Louisville, KY 40292.
Insights
Crystalline nickel sulfide (NiS) enhances spleen cell proliferation via cell interactions, inducing interleukins (IL-1, IL-2). Magnesium modulates these immune responses, suggesting nickel ions interact with intracellular targets.
Area of Science:
- Immunology
- Toxicology
- Cell Biology
Background:
- Crystalline nickel sulfide (NiS) is known to interact with biological systems.
- Understanding the immunomodulatory effects of NiS is crucial for assessing its toxicological profile.
- T-lymphocyte responses are central to adaptive immunity and can be modulated by environmental factors.
Purpose of the Study:
- To investigate the in vitro immunomodulatory effects of crystalline nickel sulfide (NiS) on spleen cells.
- To elucidate the role of cell-cell interactions, cytokine induction, and specific lymphocyte subpopulations in NiS-induced responses.
- To examine the modulatory effect of magnesium on NiS-driven immune cell proliferation.
Main Methods:
- Spleen cell proliferation assays were performed using crystalline NiS as a stimulant.
- Mixed lymphocyte reactions (MLR), concanavalin A (Con A), and lipopolysaccharide (LPS) were used to assess antigenic and mitogenic responses.
- Interleukin-1 (IL-1) and Interleukin-2 (IL-2) levels were measured.
- Flow cytometry was used to identify responding cell subpopulations (e.g., CD4+ T lymphocytes).
- Dose-dependent effects of magnesium were evaluated.
Main Results:
- Crystalline NiS induced spleen cell proliferation resembling MLR, dependent on cell-cell contact and involving CD4+ T lymphocytes.
- NiS stimulated the production of IL-1 and IL-2.
- Magnesium inhibited NiS-induced proliferation in a dose-dependent manner.
- NiS significantly enhanced spleen cell responses to Con A and LPS, with magnesium potentiating these combined effects.
- NiS did not affect Con A-induced IL-2 induction.
Conclusions:
- Crystalline NiS potentiates both antigenic (MLR) and mitogenic (Con A, LPS) spleen cell proliferative responses in vitro.
- NiS likely exerts its effects via ionic nickel acting on intracellular targets, with magnesium exhibiting noncompetitive interactions.
- Magnesium's modulatory effects on NiS action differ based on the type of proliferative stimulus (antigenic vs. mitogenic).
Abstract:
Crystalline nickel sulfide (NiS) induced a spleen cell proliferation that resembles a mixed lymphocyte reaction (MLR). It depended on cell-cell interaction, induced high levels of interleukin-1 (IL-1) and interleukin-2 (IL-2) and the responding cell subpopulation was composed of CD4+ T lymphocytes. Furthermore, the proliferation was inhibited in a dose-dependent manner by magnesium. Crystalline NiS also increased significantly the spleen cell proliferative response to concanavalin A (Con A) and lipopolysaccharide (LPS) with magnesium potentiating the combined effects of crystalline NiS and mitogens. Interestingly, crystalline NiS did not show any effect on the induction of IL-2 by Con A. The results described herein suggest that crystalline NiS can potentiate both antigenic (MLR) and mitogenic (Con A and LPS) proliferative responses in vitro. Crystalline NiS appears to potentiate these responses by acting in the form of ionic nickel on several intracellular targets for which magnesium ions have different noncompetitive interactions. The effects of magnesium on the potentiating action of crystalline NiS are different depending upon the type of primary stimulatory signal for proliferation (mitogenic or antigenic).