Molecular motion of the main chain for a series of poly(alkyl L-glutamate)s as studied by H-2 NMR

H-2 NMR measurements were carried out for a series of poly(alkyl L-glutamate)s (PALG) in which the H-1 of the amide group in the main chain is replaced by H-2 in order to investigate the mobility and motional mode of the main chain. At low temperature, the H-2 spectra were typical powder patterns, which have three principal values. The temperature dependencies for the H-2 NMR spectra varied with the side chain length. For PALG with a short side chain length, Deltanu(1), Deltanu(2), and Deltanu(3) are almost constant in all temperature ranges. As the side chain length increases, the difference between the peaks and shoulders decreased with temperature. For PG-12-N-D, the peaks and shoulders are fused at high temperature in a liquid crystalline state. The mobility and molecular motion of the main chain is discussed based on the obtained H-2 NMR spectra

IL-17A and Streptococcus pneumoniae respiratory infection: Prospects for the development of new immunotherapies

Nasopharyngeal colonization by Streptococcus pneumoniae constitutes a pre-requisite for development of pneumonia and invasive pneumococcal diseases. Colonization is typically asymptomatic and is resolved due to a dynamic and complex interplay between microbiota, host immune system and environmental factors. Working with a murine model of pneumococcal nasopharyngeal colonization, we have shown that IL-17A is a key cytokine in this process, since Il17a-/- mice were persistently colonized for up to 6 months whereas wild type mice cleared colonization in 10 days. We are currently trying to elucidate the downstream mechanisms that may account for the phenotype showed in Il17a-/- mice, including the production of specific antibodies, as well as the recruitment of innate cells and the expression of immune mediators in WT and Il17a-/- mice. On the other hand, we have studied the role of IL-17A in the development of protective immunity against acute pneumococcal pneumonia. Previously, we showed that prior sublethal infection resulted in solid protection against invasive pneumonia which is associated with over expression of IL-17A together with the presence of Th17 cells in the lungs. However, Il17a-/- mice showed same level of protection than WT, demonstrating that IL-17A by itself is not essential for protective immunity. Interestingly Il17a-/- mice showed overexpression of other IL-17 related genes suggesting a complex network where compensatory effects may be occurring. Finally, we have developed and tested alternative immunotherapies against pneumococcal pneumonia, and have evaluated the role of IL17A in the protection afforded. Overall, we believe that deciphering the molecular basis of protective immunity will result in the development of new cost-effective immunotherapies against pneumococcal pneumonia

Hyaluronic acid of low molecular weight triggers the invasive “hummingbird” phenotype on gastric cancer cells

The overproduction and deposition of hyaluronic acid (HA) of different sizes in the tumor microenvironment is associated with cancer metastasis. Here, the development of layerâ byâ layer (LbL) constructs containing HA of different molecular weights (i.e., 5.6, 618, and 1450 kDa) that mimic the HAâ rich cancer extracellular matrix is described to study the effect of the HA's size on the behavior of gastric cancer cells (AGS). The results demonstrate that LbL constructs with short HA, i.e., 5.6 kDa, activate the cytoskeleton rearrangement leading to the â hummingbirdâ morphology, promote high cellular motility, and activate signaling pathways with increased expression of pâ ERK1/2 and pâ AKT. In addition, it is demonstrated that this malignant transformation involves an active participation of the HA coreceptor RHAMM in AGS cells.The authors acknowledge the financial support from the European Commission’s H2020 Programme, under grant agreements H2020-WIDESPREAD-2014-668983-FORECAST and H2020-MSCA-RISE-2019-872648-MEPHOS. S.A. acknowledge the Portuguese Foundation for Science and Technology (FCT) for the PhD grant (SFRH/BD/112075/2015). The authors also thank Ramon Novoa-Caballal for performing the GPC experiments and data analysis

A critical role for regulatory T cells in driving cytokine profiles of Th17 cells and their modulation of glioma microenvironment.

IL-17A, produced by Th17 cells, may play a dual role in antitumor immunity. Using the GL261-glioma model, we investigated the effects of Th17 cells on tumor growth and microenvironment. Th17 cells infiltrate mouse gliomas, increase significantly in a time-dependent manner similarly to Treg and do not express Foxp3. To characterize the direct effects of Th17 cells on GL261 murine gliomas and on tumor microenvironment, we isolated IL-17-producing cells enriched from splenocytes derived from naïve (nTh17) or glioma-bearing mice (gTh17) and pre-stimulated in vitro with or without TGF-β. Spleen-derived Th17 cells co-expressing IL-17, IFN-γ and IL-10, but not Treg marker Foxp3, were co-injected intracranially with GL261 in immune-competent mice. Mice co-injected with GL261 and nTh17 survived significantly longer than gTh17 (P < 0.006) and gliomas expressed high level of IFN-γ and TNF-α, low levels of IL-10 and TGF-β. In vitro IL-17 per se did not exert effects on GL261 proliferation; in vivo gliomas grew equally well intracranially in IL-17 deficient and wild-type mice. We further analyzed relationship between Th17 cells and Treg. Treg were significantly higher in splenocytes from glioma-bearing than naïve mice (P = 0.01) and gTh17 produced more IL-10 than IFN-γ (P = 0.002). In vitro depletion of Treg using PC61 in splenocytes from glioma-bearing mice causes increased IL-17/IFN-γ cells (P = 0.007) and decreased IL-17/IL-10 cells (P = 0.03). These results suggest that Th17 polarization may be induced by Treg and that Th17 cells in gliomas modulate tumor growth depending on locally produced cytokines

Rheumatoid synovial fluid interleukin-17-producing CD4 T cells have abundant tumor necrosis factor-alpha co-expression, but little interleukin-22 and interleukin-23R expression

Introduction\ud Th17 cells have been implicated in the pathogenesis of rheumatoid arthritis (RA). The aim of this study was to systematically analyse the phenotype, cytokine profile and frequency of interleukin-17 (IL-17) producing CD4-positive T cells in mononuclear cells isolated from peripheral blood, synovial fluid and synovial tissue of RA patients with established disease, and to correlate cell frequencies with disease activity. \ud \ud Methods\ud Flow cytometry was used to analyse the phenotype and cytokine production of mononuclear cells isolated from peripheral blood (PBMC) (n = 44), synovial fluid (SFMC) (n = 14) and synovium (SVMC) (n = 10) of RA patients and PBMC of healthy controls (n = 13). \ud \ud Results\ud The frequency of IL-17-producing CD4 T cells was elevated in RA SFMC compared with RA PBMC (P = 0.04). However, the frequency of this population in RA SVMC was comparable to that in paired RA PBMC. The percentage of IL-17-producing CD4 T cells coexpressing tumor necrosis factor alpha (TNFα) was significantly increased in SFMC (P = 0.0068). The frequency of IFNγ-producing CD4 T cells was also significantly higher in SFMC than paired PBMC (P = 0.042). The majority of IL-17-producing CD4 T cells coexpressed IFNγ. IL-17-producing CD4 T cells in RA PBMC and SFMC exhibited very little IL-22 or IL-23R coexpression. \ud \ud Conclusions\ud These findings demonstrate a modest enrichment of IL-17-producing CD4 T cells in RA SFMC compared to PBMC. Th17 cells in SFMC produce more TNFα than their PBMC counterparts, but are not a significant source of IL-22 and do not express IL-23R. However, the percentage of CD4 T cells which produce IL-17 in the rheumatoid joint is low, suggesting that other cells may be alternative sources of IL-17 within the joints of RA patients. \ud \u