CD8+ T cells in situ in different clinical forms of human cutaneous leishmaniasis.
BACKGROUND
Leishmania braziliensis infection induces a large spectrum of lesions that clinically manifest as nodules or papules that progress to ulcers. Although it is already known that T helper cells predominate in the lesions, cytotoxic T cells have also been reported to be present, and their role in leishmaniasis immunopathogenesis is not well known. This study investigated the amounts of CD8+ and granzyme B+ cells in different clinical forms of human cutaneous leishmaniasis (CL).


METHODS
Forty tissue fragments from early (E-CL) and late CL (L-CL) lesions and from disseminated leishmaniasis (DL) - papules and ulcers - were characterized. The inflamed area per fragment was calculated, and the CD8 and granzyme B expression levels in the infiltrates were quantified by counting positive cells in 15 fields. The localization of CD8 and granzyme B was graded subjectively.


RESULTS
Inflammation was higher in L-CL and DL ulcers. CD8 expression was increased in late ulcerated lesions compared to recent lesions. The increase in CD8+ cells also correlated with the duration of the lesion. Papules had a higher frequency of granzyme B+ cells than E-CL lesions, although the frequency was similar to those for late and DL ulcers. CD8+ cells were mostly found in the papillary dermis.


CONCLUSIONS
CD8+ T and granzyme B+ cells are present in the inflammatory infiltrates of CL and DL and may participate in the immunopathogenesis of Leishmania infection.
Laboratório Avançado de Saúde Pública, Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, SalvadorBA.
Marina Loyola
ML
Dantas
Laboratório Avançado de Saúde Pública, Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, SalvadorBA.
Juliana Cabral de
JC
Oliveira
Serviço de Imunologia, Hospital Universitário Professor Edgard Santos, Universidade Federal da Bahia, SalvadorBA.
Lucas
L
Carvalho
Serviço de Imunologia, Hospital Universitário Professor Edgard Santos, Universidade Federal da Bahia, SalvadorBA.
Sara Timóteo
ST
Passos
Serviço de Imunologia, Hospital Universitário Professor Edgard Santos, Universidade Federal da Bahia, SalvadorBA.
Adriano
A
Queiroz
Serviço de Imunologia, Hospital Universitário Professor Edgard Santos, Universidade Federal da Bahia, SalvadorBA.
Paulo
P
Machado
Serviço de Imunologia, Hospital Universitário Professor Edgard Santos, Universidade Federal da Bahia, SalvadorBA.
Edgar
E
Carvalho
Laboratório Avançado de Saúde Pública, Centro de Pesquisas Gonçalo Moniz, Fundação Oswaldo Cruz, SalvadorBA.
Sérgio
S
Arruda
D000293:Adolescent; D000328:Adult; D018414:CD8-Positive T-Lymphocytes / Q000201:enzymology / Q000276:immunology*; D002648:Child; D005260:Female; D053804:Granzymes / Q000276:immunology*; D006801:Humans; D007150:Immunohistochemistry; D016773:Leishmaniasis, Cutaneous / Q000276:immunology* / Q000473:pathology; D008297:Male; D008875:Middle Aged; D055815:Young Adult
D053804:Granzymes