Mast Cells Are a Marked Source for Complement C3 Products That Associate with Increased CD11b-Positive Cells in Keratinocyte Skin Carcinomas

Abstract

By using immunohistochemistry and antibodies that identify complement C3c (in C3 and C3b) or CD11b receptor, we report that the proportion C3c⁺ mast cells and the number of CD11b⁺ cells are increased in basal cell carcinoma (BCC). Instead, only CD11b⁺ cells are increased in squamous cell carcinoma/Bowen’s disease, and only slightly so in actinic keratosis. Only C3c⁺ mast cells are increased in psoriasis. Furthermore, C3c⁺ mast cells correlated positively with CD11b⁺ cells, and iC3b immunoreactivity was detected around tryptase⁺ mast cells. Therefore, mast cells may convey immunoregulatory signals through C3, C3b, and iC3b to CD11b⁺ cells, especially in BCC.

Keywords:

• Basal cell carcinoma
• Squamous cell carcinoma
• Actinic keratosis
• Psoriasis
• Mast cell
• C3
• CD11b

Acknowledgments

The authors thank Ms Anne Koivisto and Ms Marjukka Aronen for expert technical assistance.

Declaration of interest

The authors report no conflicts of interest. The authors alone are responsible for the content and writing of the article.

Additional information

Funding

This work was supported by Cancer Center of Eastern Finland of the University of Eastern Finland, the Finnish Cancer Research Foundation, and the VTR-funding of Kuopio University Hospital.