Human heart mast cells. Isolation, purification, ultrastructure, and immunologic characterization

Area of Science:

• Immunology
• Cardiology
• Cell Biology

Background:

• Mast cells play a crucial role in allergic reactions and inflammation.
• The specific role and characteristics of mast cells in human cardiac tissue are not fully understood.
• Understanding cardiac mast cells is vital for investigating cardiovascular diseases and anaphylaxis.

Purpose of the Study:

• To isolate, purify, and characterize mast cells from human heart tissue.
• To investigate the release of mediators from human cardiac mast cells in response to various stimuli.
• To establish a model for studying the involvement of mast cells in cardiac conditions.

Main Methods:

• Isolation and partial purification of mast cells from human heart tissue using collagenase digestion.
• Purification employing low-speed centrifugation and Percoll gradient.
• Characterization via ultrastructural studies, histamine and tryptase content analysis, cell culture, and mediator release assays (immunologic and non-immunologic stimuli).

Main Results:

• Human cardiac mast cells were successfully isolated and purified with >90% viability.
• These cells contain histamine, tryptase, and chymase, and release histamine in response to immunologic (anti-IgE, anti-FcεRI, C5a) and non-immunologic stimuli (rhSCF, A23187, compound 48/80).
• Stimulation induced tryptase release, and de novo synthesis of PGD2 and LTC4, with significant correlations between histamine secretion and mediator release.

Conclusions:

• Human heart mast cells can be isolated and purified, serving as a viable model system.
• Cardiac mast cells are capable of releasing key inflammatory mediators.
• These findings support the utility of human cardiac mast cells for studying cardiac anaphylaxis and associated cardiovascular diseases.