Open Access Research article

Interleukin 32γ (IL-32γ) is highly expressed in cutaneous and mucosal lesions of American Tegumentary Leishmaniasis patients: association with tumor necrosis factor (TNF) and IL-10

Hélio Galdino1, Anetícia Eduarda Maldaner1, Lívia Lara Pessoni1, Frederico M Soriani2, Ledice Inácia de Araújo Pereira1, Sebastião Alves Pinto3, Fernanda Bugalho Duarte4, Clayson Moura Gomes1, Anna Karoline Aguiar Fleuri1, Miriam Leandro Dorta1, Milton Adriano Pelli de Oliveira1, Mauro Martins Teixeira2, Aline Carvalho Batista5, Leo A B Joosten6, Leda Quercia Vieira2 and Fátima Ribeiro-Dias1*

Author Affiliations

1 Institute of Tropical Pathology and Public Healthy, Universidade Federal de Goiás, Rua 235 S/N – Setor Universitário, Goiânia 74605-050, Goiás, Brazil

2 Department of Biochemistry and Immunology, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil

3 Department of Pathology, Faculty of Medicine, Universidade Federal de Goiás, and Instituto Goiano de Oncologia e Hematologia (INGOH), Goiânia, Goiás, Brazil

4 Otorhinolaryngology, Hospital Unique, Goiânia, Goiás, Brazil

5 Department of Pathology, Faculty of Odontology, Universidade Federal de Goiás, Goiânia, Goiás, Brazil

6 Department of Internal Medicine, Radboud University Nijmegen Medical Centre, Nijmegen, The Netherlands

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BMC Infectious Diseases 2014, 14:249  doi:10.1186/1471-2334-14-249

Published: 9 May 2014

Abstract

Background

The interleukin 32 (IL-32) is a proinflammatory cytokine produced by immune and non-immune cells. It can be induced during bacterial and viral infections, but its production was never investigated in protozoan infections. American Tegumentary Leishmaniasis (ATL) is caused by Leishmania protozoan leading to cutaneous, nasal or oral lesions. The aim of this study was to evaluate the expression of IL-32 in cutaneous and mucosal lesions as well as in peripheral blood mononuclear cells (PBMC) exposed to Leishmania (Viannia) braziliensis.

Methods

IL-32, tumour necrosis factor (TNF) and IL-10 protein expression was evaluated by immunohistochemistry in cutaneous, mucosal lesions and compared to healthy specimens. The isoforms of IL-32α, β, δ, γ mRNA, TNF mRNA and IL-10 mRNA were assessed by qPCR in tissue biopsies of lesions and healthy skin and mucosa. In addition, PBMC from healthy donors were cultured with amastigotes of L. (V.) braziliensis. In lesions, the parasite subgenus was identified by PCR-RFLP.

Results

We showed that the mRNA expression of IL-32, in particular IL-32γ was similarly up-regulated in lesions of cutaneous (CL) or mucosal (ML) leishmaniasis patients. IL-32 protein was produced by epithelial, endothelial, mononuclear cells and giant cells. The IL-32 protein expression was associated with TNF in ML but not in CL. IL-32 was not associated with IL-10 in both CL and ML. Expression of TNF mRNA was higher in ML than in CL lesions, however levels of IL-10 mRNA were similar in both clinical forms. In all lesions in which the parasite was detected, L. (Viannia) subgenus was identified. Interestingly, L. (V.) braziliensis induced only IL-32γ mRNA expression in PBMC from healthy individuals.

Conclusions

These data suggest that IL-32 plays a major role in the inflammatory process caused by L. (Viannia) sp or that IL-32 is crucial for controlling the L. (Viannia) sp infection.

Keywords:
IL-32; Leishmaniasis; TNF; IL-10; Leishmania (Viannia) sp