Macrophage immunophenotypes in Jorge Lobo's disease and lepromatous leprosy - a comparative study

Jorge Lobo's disease (JLD) and lepromatous leprosy (LL) share several clinical, histological and immunological features, especially a deficiency in the cellular immune response. Macrophages participate in innate and adaptive inflammatory immune responses, as well as in tissue regeneration and repair. Macrophage function deficiency results in maintenance of diseases. M1 macrophages produce pro-inflammatory mediators and M2 produce anti-inflammatory cytokines. To better understand JLD and LL pathogenesis, we studied the immunophenotype profile of macrophage subtypes in 52 JLD skin lesions, in comparison with 16 LL samples, using a panmacrophage (CD68) antibody and selective immunohistochemical markers for M1 (iNOS) and M2 (CD163, CD204) responses, HAM56 (resident/fixed macrophage) and MAC 387 (recently infiltrating macrophage) antibodies. We found no differences between the groups regarding the density of the CD163, CD204, MAC387+ immunostained cells, including iNOS, considered a M1 marker. But HAM56+ cell density was higher in LL samples. By comparing the M2 and M1 immunomarkers in each disease separately, some other differences were found. Our results reinforce a higher M2 response in JLD and LL patients, depicting predominant production of anti-inflammatory cytokines, but also some distinction in degree of macrophage activation. Significant amounts of iNOS + macrophages take part in the immune milieu of both LL and JLD samples, displaying impaired microbicidal activity, like alternatively activated M2 cells

HLA-G expression in Merkel cell carcinoma and the correlation with Merkel cell polyomavirus infection.

Merkel cell carcinoma (MCC) is a rare aggressive neuroendocrine cutaneous carcinoma with a high mortality rate. The MCC etiology is not fully understood. Merkel cell-associated polyomavirus (MCPyV) was found in MCC patients, indicating a risk factor for the tumor. Caucasian, elderly, and immunocompromised individuals are more likely to develop this tumor. HLA-G consists of a non-classical class I (Ib) HLA molecule with an immunoregulatory function and was associated with tumor escape in different types of tumors, nonetheless, never been studied in MCC. The purpose of this study was to evaluate the HLA-G expression and also to detect the MCPyV in MCC patients and correlate it with the clinical course of the disease. Forty-five MCC patients were included in a retrospective study. Formalin-fixed paraffin-embedded cutaneous skin biopsies were used by immunohistochemistry and RT-PCR to verify the HLA-G expression and MCPyV infection. HLA-G expression was found in 7 (15.6%), while the presence of MCPyV was detected in 28 (62.2%) of the studied patients. No significant association was found between HLA-G expression and MCPyV infection (p = 0.250). The presence of MCPyV was associated with areas of low sunlight exposure (p = 0.042) and the HLA-G expression with progression to death (p = 0.038). HLA-G expression was detected in MCC patients, as well as the MCPyV presence was confirmed. These markers could represent factors with a possible impact on patient survival; however, further studies with a greater number of patients are needed, to better elucidate the possible role in disease progression.

HLA-G expression in Merkel cell carcinoma and the correlation with Merkel cell polyomavirus infection

Merkel cell carcinoma (MCC) is a rare aggressive neuroendocrine cutaneous carcinoma with a high mortality rate. The MCC etiology is not fully understood. Merkel cell-associated polyomavirus (MCPyV) was found in MCC patients, indicating a risk factor for the tumor. Caucasian, elderly, and immunocompromised individuals are more likely to develop this tumor. HLA-G consists of a non-classical class I (Ib) HLA molecule with an immunoregulatory function and was associated with tumor escape in different types of tumors, nonetheless, never been studied in MCC. The purpose of this study was to evaluate the HLA-G expression and also to detect the MCPyV in MCC patients and correlate it with the clinical course of the disease. Forty-five MCC patients were included in a retrospective study. Formalin-fixed paraffin-embedded cutaneous skin biopsies were used by immunohistochemistry and RT-PCR to verify the HLA-G expression and MCPyV infection. HLA-G expression was found in 7 (15.6%), while the presence of MCPyV was detected in 28 (62.2%) of the studied patients. No significant association was found between HLA-G expression and MCPyV infection (p = 0.250). The presence of MCPyV was associated with areas of low sunlight exposure (p = 0.042) and the HLA-G expression with progression to death (p = 0.038). HLA-G expression was detected in MCC patients, as well as the MCPyV presence was confirmed. These markers could represent factors with a possible impact on patient survival; however, further studies with a greater number of patients are needed, to better elucidate the possible role in disease progression.

Experimental reproduction of the Jorge Lobo's disease in BAlb/c mice inoculated with Lacazia loboi obtained from a previously infected mouse.

Long-term maintenance of Lacazia loboi in the laboratory has not been reported. We report here the use BALB/c mice to maintain the Lacazia loboi for extended period of time. Eight to ten week-old mice were inoculated intradermally in both hind footpads with a fungal suspension from a macerated footpad obtained from an original mouse previously infected with the fungi and sacrificed 8 months after inoculation. The inoculated animals were sacrificed at different time intervals, footpads were excised, the right one was submitted to histopathological examination and the left one was macerated in sterile saline for fungal count and viability index determination. The inoculated animals presented the histopathological picture identical to the mice previously inoculated with material from human lesion. Granulomatous infiltrates with predominance of macrophages and giant cells were observed. The granulomas evolved progressively as observed in the different times of sacrifice. After 7 months of inoculation, macroscopic lesions were observed, and the number of fungi obtained from macerated footpads was higher than the number of inoculated fungi. The pattern of lesion development was similar to what was observed in animals infected with a fungal suspension obtained from a human lesion. Considering the histopathological findings, the clinical manifestations, and the finding of a higher number of fungi obtained than the inoculated into footpads of each mice, we believe the BALB/c mice strain is as an excellent way to maintain L. loboi in laboratory. Moreover, even after serial passages of the fungi, the granulomatous lesions are reproduced consistently in laboratory conditions.

Experimental reproduction of the Jorge Lobos disease in BALB/c mice inoculated with Lacazia loboi obtained from a previously infected mouse

Long-term maintenance of Lacazia loboi in the laboratory has not been reported. We report here the use BALB/c mice to maintain the Lacazia loboi for extended period of time. Eight to ten week-old mice were inoculated intradermally in both hind footpads with a fungal suspension from a macerated footpad obtained from an original mouse previous infected with the fungi and sacrificed 8 months after inoculation. The inoculated animals were sacrificed at different time intervals, footpads were excised, the right one was submitted to histopathological examination and the left one was macerated in sterile saline for fungal count and viability index determination. The inoculated animals presented the histopathological picture identical to the mice previously inoculated with material from human lesion. Granulomatous infiltrates with predominance of macrophages and giant cells were observed. The granulomas evolved progressively as observed in the different times of sacrifice. After 7 months of inoculation, macroscopic lesions were observed, and the number of fungi obtained from macerated footpads was higher than the number of inoculated fungi. The pattern of lesion development was similar to what was observed in animals infected with a fungal suspension obtained from a human lesion. Considering the histopathological findings, the clinical manifestations, and the finding of a higher number of fungi obtained than the inoculated into footpads of each mice, we believe the BALB/c mice strain is as an excellent way to amintain L. loboi in laboratory. Moreover, even after serial passages of the funfi, the granulomatous lesions are reproduced consistently in laboratory conditions.