CD11b+Gr-1low cells that accumulate in M.leprae-induced granulomas of the footpad skin of nude mice have the characteristics of monocytic-myeloid-derived suppressor cells.

CD11b+Gr-1low cells that are increased in the lungs of a Mycobacterium (M) tuberculosis-infection mouse model have the characteristics of monocytic (M)-myeloid-derived suppressor cells (MDSCs) and harbor M.tuberculosis. Interestingly, a high number of M-MDSCs have also been observed in skin lesions of patients with lepromatous leprosy. We hypothesized that CD11b+Gr-1low cells might be involved in the pathogenesis of leprosy, as they are in tuberculosis. In the current study, we investigated the issue of whether CD11b+Gr-1low cells accumulate in Mycobacterium (M) leprae-induced granulomas of the footpad skin of nude mice. Our results show that CD11b+Gr-1low cells began to accumulate in the 7-month-old M.leprae-induced granulomas and were replaced by other leukocytes, including CD11b+Gr-1high over time during M.leprae infections. CD11b + Gr-1low cells expressed the surface markers of M-MDSC, Ly6Chigh and Ly6Glow. In addition, CD11b+Gr-1low cells have the nuclei of a mononuclear cell type and expressed higher levels of arginase 1 (Arg1) and inducible NO synthetase (iNOS). Furthermore, they showed a higher infection rate by M.leprae. Taken together, our results indicate that the inoculation with M.leprae induced an accumulation of CD11b + Gr-1low at a relatively early stage, 7-month-old M.leprae-induced granulomas, and that CD11b+Gr-1low have the characteristics of M-MDSC and may act as a reservoir for M.leprae.

Granulomatous reaction following bacillus Calmette-Guérin vaccination: Successful response to clarithromycin.

We report a 3-year-old girl with a delayed nontuberculous granulomatous reaction on a bacillus Calmette-Guérin injection site with dissemination to distant sites who showed a favorable response to clarithromycin used for 12 weeks with no recurrence on a follow-up of more than 2 years.

Caracterização de modelo murino de granuloma não infeccioso em comparação à técnica de Shepard de infecção por M. leprae / Characterization of a murine model of non-infecious granuloma compared to the Shepard technique of M. leprae infection

Na hanseníase, o modelo de Shepard de inoculação por Mycobacterium leprae (M. leprae) em patas de camundongos vem sendo utilizado em diversos estudos sobre a resposta imune, avaliação de novas drogas e esquemas terapêuticos, além da dinâmica da infecção precoce e crônica. Para estudar o papel do microambiente granulomatoso na hanseníase, além de modelos animais convencionais ou imunocomprometidos, o desenvolvimento de modelos murinos de granuloma não infeccioso pode adicionar parâmetros patogênicos a serem comparados no desenvolvimento da doença. Preparações de nitrocelulose estão entre as formas de desenvolvimento de granulomas não imunogênicos em experimentação animal. O presente estudo investigou a formação de granulomas não infecciosos induzidos por partículas de nitrocelulose, em comparação a lesões induzidas por M. leprae. Grupos de camundongos nude e BALB/c, foram constituídos e inoculados, conforme a técnica de Shepard, com suspensão de M. leprae (ML), suspensão de nitrocelulose (NT), associação de M. leprae com nitrocelulose (ML/NT) e veículo controle (CTRL). Após 07, 14, 21 e 28 dias, amostras foram coletadas e analisadas histopatologicamente pelas colorações, HematoxilinaEosina e Fite-Faraco. Os grupos experimentais demonstraram a formação de granulomas em ambas os fenótipos murinos. Principalmente nos grupos NT e ML/NT, as lesões foram caracterizadas por infiltrado inflamatório mononuclear, predominantemente macrofágico, com presença de células epitelioides, eventuais macrófagos vacuolizados e ausência de células gigantes multinucleadas. As lesões induzidas exclusivamente por M. leprae pareceram menos exuberantes que àquelas observadas nos demais grupos, indicando que a nitrocelulose intensificou a resposta macrofágica nos espécimes avaliados e sugerindo que esse composto pode ser utilizado não só para o desenvolvimento de granulomas não imunogênicos, mas também na exacerbação da resposta imune em granulomas induzidos por agentes infecciosos, como M. leprae.

In leprosy, the Shepard model of inoculation by Mycobacterium leprae (M. leprae) in mouse footpad has been used in several studies on the immune response, evaluation of new drugs and therapeutic schemes, in addition to the dynamics of early and chronic infection. To study the role of the granulomatous microenvironment in leprosy, in addition to conventional or immunocompromised animal models, the development of murine models of non-infectious granuloma can add pathogenic parameters to be compared in the development of the disease. Nitrocellulose preparations are among the ways of developing non-immunogenic granulomas in animal experimentation. The present study investigated the formation of non-infectious granulomas induced by nitrocellulose particles, in comparison to lesions induced by M. leprae. Groups of athymic nude and BALB/c mice were set up and inoculated, according to Shepard technique, with M. leprae suspension (ML), nitrocellulose suspension (NT), M. leprae association with nitrocellulose (ML/NT) and control vehicle (CTRL). After 07, 14, 21 and 28 days, samples were collected and histopathologically analyzed by Hematoxylin-Eosin and FiteFaraco staining. The experimental groups demonstrated the formation of granulomas in both murine strains. Mainly in the NT and ML/NT groups, the lesions were characterized by mononuclear inflammatory infiltrate, predominantly macrophagic, with the presence of epithelioid cells, eventual vacuolated macrophages and absence of multinucleated giant cells. The lesions induced exclusively by M. leprae seemed less exuberant than those observed in the other groups, indicating that nitrocellulose intensified the macrophage response in the specimens evaluated, and suggesting that this compound can be used not only in the development of non-immunogenic granulomas, but also in exacerbation of the immune response in granulomas induced by infectious agents, such as M. leprae.

Immunohistochemical study of lepromin reaction in healthy adults.

Lepromin reaction was studied with immunoperoxidase techniques using monoclonal antibodies. The skin reactions were induced by injecting Mitsuda antigen into healthy adults without a family history of leprosy. Both early (48 hours) and late (3 weeks and 2 months) reactions were examined. In the late reaction, focal collections of epithelioid cells had formed, and not only T- but also B-lymphocytes were observed around the granuloma. CD1a+ cells were also confirmed to have increased in the late reaction.

Relationships between structure and biological activity of the mycolic acid-containing glycolipids from Nocardia asteroides "sensu stricto" and related species.

To reveal the taxonomical situation of Nocardia asteroides "sensu stricto", we compared the mycolic acid and mycolic acid-containing glycolipid composition and their granulomagenic activities in mice. The major glycolipids were glucose mono- and dimycolate, trehalose mono- and dimycolate and several unknown glycolipids, commonly, although the relative amount differed from strain to strains. On the other hand, molecular species composition of mycolic acids differed distinctively among the three closely related species: N. asteroides "sensu strico", N. farcinica and N. nova. GC/MS analysis showed the most abundant species of mycolic acids were C50(52) in N. asteroides, C54(52) in N. farcinica and C58(56) in N. nova, respectively with a different alpha-alkyl branch. Glucose mycolate and trehalose dimycolate possessing C50 mycolic acid showed a strong activity for granuloma formation in mice.

Formaçao do granuloma induzido pelo BCG no hamster: influência da hipersensibilidade tardia e da administração do "PPD" na evolução e no número de bactérias das lesões

No presente trabalho foi analisada a influência da hipersensibilidade do tipo tardio sobre a formaçao do granuloma induzido pelo BCG no hamster, bem como o efeito do PPD sobre a evoluçao e o número de bacilos das lesoes. Inicialmente, pode-se confirmar que o sub-epitelial da bolsa cervical do hamster é desprovido, induz a formaçao de lesao granulomatosa e nao sensibiliza o animal ap PPD. Por outro lado, a inoculaçao da bacteria no coxim plantar dos animais provocou lesao granulomatosa significantemente mais exuberante que aquela induzida na bolsa e determinou inequivoca reaçao de hipersensibilidade do tipo tardio ao PPD. Demonstrou-se ainda que a inoculaçao do PPD pelas vias sub-epitelial na bolsa, intravenosa ou intraperitoneal, determinou, em 48 horas, a reativaçao de lesoes induzidas pelo BCG na bolsa, caracterizada por necrose, infiltraçao celular e marcado aumento do número de bactérias na lesao. Demonstrou-se também que o efeito do PPD se dá por açao direta da droga sobre o granuloma, nao tendo o mesmo sido observado em lesoes induzidas na pata dos animais