American
cutaneous leishmaniasis (ACL) presents distinct active clinical forms with different grades of severity, known as localised (LCL), intermediate (ICL) and diffuse (DCL)
cutaneous leishmaniasis. LCL and DCL are associated with a polarised T-helper (Th)1 and Th2
immune response, respectively, whereas ICL, or chronic
cutaneous leishmaniasis, is associated with an exacerbated
immune response and a mixed
cytokine expression profile.
Chemokines and
chemokine receptors are involved in cellular migration and are critical in the inflammatory response. Therefore, we evaluated the expression of the
chemokines CXCL10, CCL4, CCL8, CCL11 and CXCL8 and the
chemokine receptors CCR3, CXCR3, CCR5 and CCR7 in the lesions of
patients with different clinical forms of ACL using
immunohistochemistry. LCL
patients exhibited a high density of CXCL10+, CCL4+ and CCL8+
cells, indicating an important
role for these
chemokines in the local Th1
immune response and the migration of CXCR3+
cells. LCL
patients showed a higher density of CCR7+
cells than ICL or DCL
patients, suggesting major
dendritic cell (DC) migration to
lymph nodes. Furthermore, DCL was associated with low expression levels of Th1-associated
chemokines and CCL11+ epidermal DCs, which contribute to the recruitment of CCR3+
cells. Our findings also suggest an important
role for
epidermal cells in the induction of
skin immune responses through the
production of
chemokines, such as CXCL10, by
keratinocytes.