M2-Polarized Macrophages Determine Human Cutaneous Lesions in Lacaziosis.

Lacaziosis is a cutaneous chronic mycosis caused by Lacazia loboi. Macrophages are important cells in the host immune response in fungal infections. The macrophage population exhibits strong plasticity that varies according to the stimuli in the microenvironment of lesions M1 profile promotes a Th1 pattern of cytokines and a microbicidal function and M2 is related to Th2 cytokines and immunomodulatory response. We investigated the population of M1 and M2 polarized macrophages in human cutaneous lesions. A total of 27 biopsies from human lesions were submitted to an immunohistochemistry protocol using antibodies to detect M1 and M2 macrophages (Arginase-1, CD163, iNOS, RBP-J and cMAF). We could observe high number of cells expressing Arginase1, CD163 and c-MAF that correspond to elements of the M2 profile of macrophage, over iNOS and RBP-J (elements of the M1 profile). The results suggest a predominant phenotype of M2 macrophages, which have an immunomodulatory role and probably contributing to chronicity of Lacaziosis.

The cytotoxic T cells may contribute to the in situ immune response in Jorge Lobo's Disease human lesions.

Jorge Lobo's Disease (JLD) is a cutaneous chronic granulomatous disease caused by the pathogenic fungus Lacazia loboi. It is characterized by a granulomatous reaction with multinucleated giant cells and high number of fungal cells. In order to contribute to the comprehension of immune mechanisms in JLD human lesions, we studied the cytotoxic immune response, focusing on TCD8+ and NK cells, and granzyme B. Forty skin biopsies of lower limbs were selected and an immunohistochemistry protocol was developed to detect CD8+ T cells, NK cells and Granzyme B. In order to compare the cellular populations, we also performed a protocol to visualize TCD4+ cells. Immunolabeled cells were quantified in nine randomized fields in the dermis. Lesions were characterized by inflammatory infiltrate of macrophages, lymphocytes, epithelioid and multinucleated giant cells with intense number of fungal forms. There was a prevalence of CD8 over CD4 cells, followed by NK cells. Our results suggest that in JLD the cytotoxic immune response could represent another important mechanism to control Lacazia loboi infection. We may suggest that, although CD4+ T cells are essential for host defense in JLD, CD8+ T cells could play a role in the elimination of the fungus.

Nutritional status and immune response in murine experimental Jorge Lobo's disease.

There are no studies investigating the role of nutritional status and immunity associated with Jorge Lobo's disease. The objective of this study was to evaluate the effects of protein-calorie malnutrition on the immune response of BALB/c mice inoculated with Lacazia loboi. In this study,the animals were divided into four groups: G1: inoculated with restricted diet, G2: not inoculated with restricted diet, G3: inoculated with regular diet, G4: not inoculated with regular diet. The animals of groups G1 and G2 were submitted to malnutrition for 20 days and once installed the animals were inoculated intradermally into the footpad. After 4 months, they were euthanised for the isolation of peritoneal lavage cells and removal of the footpad. The production of IL-2, IL-4, IL-10, IL-12, IFN-γ, TNF-α, H2 O2 and nitric oxide (NO) was evaluated in the peritoneal lavage cells. The footpad was evaluated regarding the size of macroscopic lesions, number of fungi and viability index. The results showed that the infection did not exert great influence on the body weight of the mice and previous malnutrition was an unfavourable factor for viability index, number of fungi, macroscopic lesion size in the footpad and production of H2 O2 , NO, IL-12, IL-10 and IFN-γ, suggesting that malnutrition significantly altered fungal activity and peritoneal cells. The results suggest considerable interaction between nutrition and immunity in Jorge Lobo's disease.

Disseminated infection with Lacazia loboi and immunopathology of the lesional spectrum.

The pathogenesis of lacaziosis continues to be obscure, and works have investigated the blood systemic immune response or the dermal immune response in restricted lesions in different body regions. Some authors describe that the inflammatory infiltrate in lacaziosis lesions showed a predominance of macrophages followed by CD45RO(+), CD4(+), and CD8(+) T cells; CD57(+) natural killer cells; S-100(+) cells; and CD20(+) B lymphocytes. A 54-year-old man and living in the State of Para, Amazon region, Brazil, was seen with a lesion on the left lower limb, which had started as a small nodular area 18 years ago. The lesion showed progressive growth and disseminated to other parts of the body. Our findings showed that dermal immune response differs depending on the type of lesions and clinical presentation, with presence of CD1a(+), FXIIIa(+), CD45(+), CD4(+), CD8(+), and S-100(+) cells and cytokine profile with expression of interleukin 1 ß, tumor necrosis factor α, transforming growth factor ß, IL-10, and interferon γ.

Nutritional status and immune response in murine experimental Jorge Lobo's disease

There are no studies investigating the role of nutritional status and immunity associated with Jorge Lobo's disease. The objective of this study was to evaluate the effects of protein-calorie malnutrition on the immune response of BALB/c mice inoculated with Lacazia loboi. In this study,the animals were divided into four groups: G1: inoculated with restricted diet, G2: not inoculated with restricted diet, G3: inoculated with regular diet, G4: not inoculated with regular diet. The animals of groups G1 and G2 were submitted to malnutrition for 20 days and once installed the animals were inoculated intradermally into the footpad. After 4 months, they were euthanised for the isolation of peritoneal lavage cells and removal of the footpad. The production of IL-2, IL-4, IL-10, IL-12, IFN-γ, TNF-α, H2 O2 and nitric oxide (NO) was evaluated in the peritoneal lavage cells. The footpad was evaluated regarding the size of macroscopic lesions, number of fungi and viability index. The results showed that the infection did not exert great influence on the body weight of the mice and previous malnutrition was an unfavourable factor for viability index, number of fungi, macroscopic lesion size in the footpad and production of H2 O2 , NO, IL-12, IL-10 and IFN-γ, suggesting that malnutrition significantly altered fungal activity and peritoneal cells. The results suggest considerable interaction between nutrition and immunity in Jorge Lobo's disease

Pesquisa de imunoglobulinas e complemento no granuloma da doença de Jorge Lobo / Immunoglobulin and complement research in the granuloma of Jorge Lobo's disease

A doença de Jorge Lobo é micose cutânea-subcutânea de evolução crônica causada pelo fungo Lacazia loboi. Esta micose é predominante na região Amazônica e afeta, principalmente, trabalhadores rurais que vivem em contato constante com a vegetação e o solo, como é o caso dos seringueiros dessa região. Os estudos abordando os aspectos imunopatológicos desta micose são ainda muito escassos, possivelmente devido ao não cultivo do seu agente etiológico. Considerando que existem estudos demonstrando a participação da resposta imune humoral na doença de Jorge Lobo, onde os pacientes exibem níveis séricos elevados de imunoglobulinas e complemento, e alterações no perfil de citocinas representadas por um predomínio do perfil Th2, o presente estudo foi realizado com a finalidade de avaliar a presença de anticorpos e components do sistema complemento no granuloma induzido pelo L.loboi. Participaram destte estudo 11 pacientes portadores da micose, provenientes do estado do Acre, dos quais foram coletados fragmentos de pele das lesões. O material foi avaliado quanto à presença de imunoglobulinas e complemento, através da técnica de imunofluorescência e submetido à coloração pela hematoxilina-eosina para serem avaliados histopatologicamente. Os resultados obtidos revelaram depósitos dessas proteínas envolvendo a parede celular dos fungos em todos os pacientes avaliados e presença de um infiltrado inflamatório constituído predominantemente por histiócitos, células gigantes multinucleadas e numerosos fungos. Os linfócitos estavam presentes em número discreto a moderado e os plasmócitos, embora em número inferior, sempre estiveram presentes. Os resultados obtidos neste estudo revelam a presença de anticorpos e complemento no granuloma da doença de Jorge Lobo e sugerem a participação dessas proteínas nos mecanismos de defesa contra o fungo L. loboi.