The immune interplay between the host and the pathogen in Aspergillus fumigatus lung infection.

The interplay between Aspergillus fumigatus and the host immune response in lung infection has been subject of studies over the last years due to its importance in immunocompromised patients. The multifactorial virulence factors of A. fumigatus are related to the fungus biological characteristics, for example, structure, ability to grow and adapt to high temperatures and stress conditions, besides capability of evading the immune system and causing damage to the host. In this context, the fungus recognition by the host innate immunity occurs when the pathogen disrupts the natural and chemical barriers followed by the activation of acquired immunity. It seems clear that a Th1 response has a protective role, whereas Th2 reactions are often associated with higher fungal burden, and Th17 response is still controversial. Furthermore, a fine regulation of the effector immunity is required to avoid excessive tissue damage associated with fungal clearance, and this role could be attributed to regulatory T cells. Finally, in this work we reviewed the aspects involved in the complex interplay between the host immune response and the pathogen virulence factors, highlighting the immunological issues and the importance of its better understanding to the development of novel therapeutic approaches for invasive lung aspergillosis.

T helper 1-inducing adjuvant protects against experimental paracoccidioidomycosis.

Immunostimulatory therapy is a promising approach to improving the treatment of systemic fungal infections such as paracoccidioidomycosis (PCM), whose drug therapy is usually prolonged and associated with toxic side effects and relapses. The current study was undertaken to determine if the injection of a T helper (Th) 1-stimulating adjuvant in P. brasiliensis-infected mice could have a beneficial effect on the course of experimental PCM. For this purpose, mice were infected and treated with complete Freund's adjuvant (CFA), a well-established Th1 experimental inductor, or incomplete Freund's adjuvant (IFA - control group) on day 20 postinfection. Four weeks after treatment, the CFA-treated mice presented a mild infection in the lungs characterized by absence of epithelioid cell granulomas and yeast cells, whereas the control mice presented multiple sites of focal epithelioid granulomas with lymphomonocytic halos circumscribing a high number of viable and nonviable yeast cells. In addition, CFA administration induced a 2.4 log reduction (>99%) in the fungal burden when compared to the control group, and led to an improvement of immune response, reversing the immunosuppression observed in the control group. The immunotherapy with Th1-inducing adjuvant, approved to be used in humans, might be a valuable tool in the treatment of PCM and potentially useful to improve the clinical cure rate in humans.

Isolation and partial characterization of a D-galactose-binding lectin from the latex of Synadenium carinatum

No presente trabalho, foi purificada por cromatografia de afinidade em D-galactose imobilizada em agarose, uma lectina do latex de Synadenium carinatum (ScLL). Essa lectina é uma potente aglutinina para eritrócitos humanos, cuja atividade hemaglutinante foi inibida com 3,0 mM de N acetil-D-galactopiranosidio, 6,3 mM de metil-b-D-galactopiranosidio ou 50 mM metil-a-D-pironosidio ou D-fucose, porém, nenhuma inibição foi evidenciada por L-fucose, revelando uma especificidade anomérica e conformacional da lectina. A análise por SDS-PAGE dessa lectina pareceu ser uma glicoproteína composta por duas cadeias polipeptídicas de aproximadamente 28 e 30 kDa, porém, em cromatografia de exclusão por tamanho sobre Sephadex G100 e em gel nativo apresentou um peso molecular aparente de 120-130 kDa, a qual mostrou ser composta de uma mistura de subunidades de peptídeos de 28 e 30 kDa. Essa lectina manteve-se estável em pH de 6 a 9 e temperatura de 4 a 56ºC. A seqüência N-terninal contem uma região conservada GPN a qual também é observada em outras lectinas de látex de outras Euphorbiaceas ligante de D-galactose.

Influence of topical administration of n-3 and n-6 essential and n-9 nonessential fatty acids on the healing of cutaneous wounds.

Injury triggers a series of physiological events at the wound site. These include an inflammatory response that is established shortly after the injury, which is then followed by an intense formation of tissue over a period of days. Poly- and monounsaturated fatty acids exert major functions on the inflammatory responses, either in the form of phospholipids anchored in the cell membrane or as soluble lipoic mediators. We present evidence that linolenic (n-3), linoleic (n-6), and oleic (n-9) fatty acids can modulate the closure of surgically induced skin wounds. We found that n-9 fatty acids induced faster wound closure when compared to n-3, n-6, and control. In addition, n-9 fatty acids strongly inhibited the production of nitric oxide at the wound site. A mild improvement on wound closure was observed in the n-6 fatty acid-treated animals concurrent with a peak in nitric oxide production at 48 hours postsurgery. N-3 fatty acid treatment significantly delayed wound closure. Furthermore, we showed that n-3 fatty acid induced a peak in nitric oxide at 3 hours postsurgery and an intense deposition of extracellular matrix after 5 days of treatment. Thus, our results suggest a relevant role and potential therapeutic implication for fatty acids on skin wound healing.