Immune homeostasis has been suggested to play an important role in the clinical evolution of chronic Chagas disease; however, the immunopathologic factors involved have not been fully elucidated. Therefore, our study aimed to analyse the frequency of CD4 CD25 FoxP3 cells, classic Th17 cells, alternative Th17 cells and IL-17 B cells from peripheral blood of chronic cardiac patients after in vitro stimulation with Trypanosoma cruzi soluble EPI antigen. Patients were selected and classified according to clinical evaluation of cardiac involvement: mild, B1 (CARD1) (n = 20) and severe, C (CARD2) (n = 11). Patients with the indeterminate form of CD were included as the control group A (IND) (n = 17). Blood samples were collected and cultured in the presence of EPI antigen. Cells frequency and median fluorescence intensity (MFI) were obtained by flow cytometry. Our results showed that only CD4 CD25 FoxP3 , CD4 CD25 FoxP3 , CD4 IL-17 IFN-γ and CD4 IL-17 IFN-γ cells are more frequent in patients with severe cardiac disease and correlate with worse global cardiac function. However, while indeterminate patients demonstrated a positive correlation between CD4 CD25 FoxP3 and CD4 IL-17 IFN-γ Th17 cells, this relationship was not observed in cardiac patients. IL-17 expression by Th17 cells and B cells correlated with disease progression. Altogether our results suggest that the clinical progression of Chagas cardiomyopathy involves worsening of inflammation and impairment of immunoregulatory mechanisms.

House dust mite (HDM) allergens are leading causes of allergic asthma characterized by Th2 responses. The lung-resident CD11b + dendritic cells (DCs) play a key role in Th2 cell development in HDM-induced allergic asthma. However, the regulatory mechanism of HDM-induced CD11b + DC activation remains incompletely understood. In this study, we demonstrate that mice deficient in an inhibitory immunoreceptor, Allergin-1, showed exacerbated HDM-induced airway eosinophilia and serum IgE elevation. By using bone marrow-chimeric mice that were sensitized with adoptively transferred HDM-stimulated wild-type or Allergin-1-deficient CD11b + bone marrow-derived cultured DCs (BMDCs), followed by challenge with HDM, we show that Allergin-1 on the BMDCs suppressed HDM-induced allergic airway inflammation. We also show that Allergin-1 suppressed HDM-induced PGE 2 production from CD11b + BMDCs by inhibiting Syk tyrosine kinase activation through recruitment of SHP-1, subsequently leading to negative regulation of Th2 responses. These results suggest that Allergin-1 plays an important role in regulation of HDM-induced allergic airway inflammation.

The migration of larval Schistosoma mansoni was tracked by means of autoradiographic analysis in naive rabbits percutaneously exposed to L-(75Se) selenomethionine-labeled cercariae on serial intervals of 1, 2, 4, 6, 8, 10, 15, 20, 25, 30, 40 and 50 days post-infection. Autoradiographic foci were detected from the 1st day in the skin, up to the 15th day in the liver. Adult and mature worms were recovered either paired or not 60 days after infection, by perfusion of hepatic and mesenteric veins. Morphometric analysis under optical microscopy, showed that worms were within regular dimention limits as compared to adult worms harboured by other host species. These observations extend previous informations on the S. mansoni-rabbit association and clearly demonstrate the post-liver phase of S. mansoni life-cycle in this host.

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After several decades of immunization against hepatitis B virus, the question still remains whether a new vaccine could avoid the limitations of the current vaccine similar to those associated with its injectable form or ineffectiveness on chronic hepatitis B disease. A hypothesis to overcome first limitation is the development of an intranasal vaccine, self-administered, able to achieve not only systemic immunity, but also sIgA on the vaginal mucosa which would be a great advantage to prevent the sexually transmitted disease cases. Injectable hepatitis B vaccines that are already available in the market led to achieving protection mainly through a strong antibody-mediated response. For chronic hepatitis, a strong cellular immune response would also be required. The aim of this review is to give an overview of the work done in recent years, with the objective of developing a vaccine that can be administered by intranasal route. A discussion of the leading studies is presented, focusing not only on potential antigens, but also on promising adjuvants for the hepatitis B antigen. The results of the immune response generated with different formulations are summarized in tables. It is important to note that almost all studies claimed the induction of specific mucosal immune response (sIgA) and a balanced cellular and humoral Th1/Th2 or a Th1-type immune response. The further evaluation of these formulations, using a laboratory animal model of viral hepatitis B, would allow scientific community to conclude about the utility of these new adjuvants, particularly on a combined immunotherapy strategy for chronic hepatitis B.

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