Keratinocyte
Keratinocytes constitute 90% of the cells of the epidermis, the outermost layer of the skin. Basal cells in the basal layer (stratum basale) of the skin, are sometimes referred to as basal keratinocytes.
The primary function of keratinocytes is the formation of a barrier against environmental damage by heat, UV radiation, water loss, pathogenic bacteria, fungi, parasites, and viruses.
Pathogens invading the upper layers of the epidermis can cause keratinocytes to produce proinflammatory mediators, particularly chemokines such as CXCL10 and CCL2 (MCP-1) which attract monocytes, natural killer cells, T-lymphocytes, and dendritic cells to the site of pathogen invasion.