Glycosylation is an essential biological process that adds structural and functional diversity to cells and molecules, participating in physiological processes such as immunity. The immune response is driven and modulated by protein‐attached glycans that mediate cell‐cell interactions, pathogen recognition and cell activation. Therefore, abnormal glycosylation can be associated with deranged immune responses. Within human diseases presenting immunological defects are congenital disorders of glycosylation (CDG), a family of around 130 rare and complex genetic diseases. In this review, we have identified 23 CDG with immunological involvement, characterized by an increased propensity to—often life‐threatening—infection. Inflammatory and autoimmune complications were found in 7 CDG types. CDG natural history(ies) and the mechanisms behind the immunological anomalies are still poorly understood. However, in some cases, alterations in pathogen recognition and intracellular signaling (eg, TGF‐β1, NFAT, and NF‐κB) have been suggested. Targeted therapies to restore immune defects are only available for PGM3‐CDG and SLC35C1‐CDG. Fostering research on glycoimmunology may elucidate the involved pathophysiological mechanisms and open new therapeutic avenues, thus improving CDG patients' quality of life.

Congenital disorders of glycosylation (CDG) are a rapidly growing family of genetic diseases comprising more than 85 known distinct disorders. They show a great phenotypic variability ranging from multi-organ/system to mono-organ/system involvement with very mild to extremely severe expression. Immunological dysfunction has a significant impact on the phenotype in a minority of CDG. CDG with major immunological involvement are ALG12-CDG, MAGT1-CDG, MOGS-CDG, SLC35C1-CDG and PGM3-CDG. This review discusses the variety of immunological abnormalities reported in human CDG. Understanding the immunological aspects of CDG may contribute to a better management/treatment of these pathologies and possibly of more common diseases, such as inflammatory diseases.

Dendritic cells (DCs) hold promise for anti-cancer immunotherapy. However, clinically, their efficiency is limited and novel strategies to improve DC-mediated anti-tumor responses are needed. Human DCs display high content of sialic acids, which inhibits their maturation and co-stimulation capacity. Here, we aimed to understand whether exogenous desialylation of DCs improves their anti-tumor immunity. Compared to fully sialylated DCs, desialylated human DCs loaded with tumor-antigens showed enhanced ability to induce autologous T cells to proliferate, to secrete Th1 cytokines, and to specifically induce tumor cell apoptosis. Desialylated DCs showed an increased expression of MHC-I and -II, co-stimulatory molecules and an augmented secretion of IL-12. Desialylated HLA-A*02:01 DCs pulsed with gp100 peptides displayed enhanced peptide presentation through MHC-I, resulting in higher activation ofgp100280–288 specific CD8+ cytotoxic T cells. Desialylated murine DCs also exhibited increased MHC and co-stimulatory molecules and higher antigen cross-presentation via MHC-I. These DCs showed higher ability to activate antigen-specific CD4+ and CD8+ T cells, and to specifically induce tumor cell apoptosis. Collectively, our data demonstrates that desialylation improves DCs' ability to elicit T cell-mediated anti-tumor activity, due to increased MHC-I expression and higher antigen presentation via MHC-I. Sialidase treatment of DCs may represent a technology to improve the efficacy of antigen loaded-DC-based vaccines for anti-cancer immunotherapy.

Mesenchymal stromal cells (MSC) isolated from synovial tissues constitute a novel source of stem-like cells with promising applications in cartilage regeneration and potentially in other regenerative medicine and tissue-engineering settings. Detailed characterization of these cells is lacking, thus compromising their full potential. Here we present the detailed characterization of the ex vivo expansion of synovium-derived stromal cells collected by three different biopsy methods: synovium-direct biopsy, arthroscopic trocar shaver blade filtrate, and cells isolated from synovial fluid (SF) samples. Isolation success rates were >75% for all sources. MSC obtained from the different samples displayed the characteristic immunophenotype of adult MSC, expressing CD73, CD90, and CD105. Arthroscopic shaver blade-derived cells showed the higher proliferation capacity measured by the fold increase (FI) in total cell number over several passages and considering their cumulative population doublings (CPD; 15 ± 0.85 vs. 13 ± 0.73 for synovium vs. 11 ± 0.97 for SF). Also, these cells were able to sustain an increased proliferation under hypoxic (2% O ) conditions (FI 55 ± 4 vs. 37 ± 7) after 17 days in culture. Expanded cells were able to differentiate successfully along the osteogenic, adipogenic, and chondrogenic lineages in vitro. Overall, these results demonstrate that synovial tissues represent a promising source for the isolation of human MSC, while depicting the variability associated to the biopsy method used, which impact cell behavior in vitro.

Maturation of human Dendritic Cells (DCs) is characterized by increased expression of antigen presentation molecules, and overall decreased levels of sialic acid at cell surface. Here, we aimed to identify sialylated proteins at DC surface and comprehend their role and modulation. Mass spectrometry analysis of DC’s proteins, pulled down by a sialic acid binding lectin, identified molecules of the major human histocompatibility complex class I (MHC-I), known as human leucocyte antigen (HLA). After desialylation, DCs showed significantly higher reactivity with antibodies specific for properly folded MHC-I-β2-microglobulin complex and for β2-microglobulin but showed significant lower reactivity with an antibody specific for free MHC-I heavy chain. Similar results for antibody reactivities were observed for TAP2-deficient lymphoblastoid T2 cells, which express HLA-A*02:01. Using fluorescent peptide specifically fitting the groove of HLA-A*02:01, instead of antibody staining, also showed higher peptide binding on desialylated cells, confirming higher surface expression of MHC-I complex. A decay assay showed that desialylation doubled the half-life of MHC-I molecules at cell surface in both DCs and T2 cells. The biological impact of DC´s desialylation was evaluated in co-cultures with autologous T cells, showing higher number and earlier immunological synapses, and consequent significantly increased production of IFN-γ by T cells. In summary, sialic acid content modulates the expression and stability of complex MHC-I, which may account for the improved DC-T synapses.

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Com foco na produção do crítico literário Astrojildo Pereira, este ensaio procura sugerir pontos de contato entre o tempo contraditório da inserção do país na história do capital e a formação de um partido comunista no Brasil.

Não é comum, em lugar algum, que dois críticos literários surjam entre os melhores explicadores de uma nação por quase um século. Partindo da analise schwarziana do método crítico de Antonio Candido, o ensaio explora as relações de afinidade e de diferenciação dos dois críticos literários confrontados em dois momentos decisivos: o modernismo e o legado de 1930 e o desenvolvimentismo (e seu fracasso) desde o Golpe de 1964.