Search Results (279)

Systemic lupus erythematosus (SLE) is a severe autoimmune disease characterized by autoantibody production and multi-organ involvement. Anifrolumab, a monoclonal antibody targeting the type I interferon (IFN) receptor, has been approved for the treatment of SLE. Our aim was to investigate the long-term effects of inhibited type I IFN signaling on circulating follicular helper T subsets (T_FH), follicular regulatory T cells (T_FR), and B lymphocyte subpopulations, reflecting the ongoing germinal center reactions in SLE patients. Peripheral blood samples were obtained from ten SLE patients before the initiation of anifrolumab treatment, and at months 6 and 12 of the intervention period. Flow cytometry analysis was performed to assess the frequencies of circulating T_FH cell subsets, T_FR cells, and certain B cell subpopulations. Serological parameters, including autoantibody levels and complement components, were determined as part of the routine diagnostic evaluation. We observed a significant and sustained reduction in the percentage of activated circulating T_FH cells. Notably, the frequency of CXCR3⁻CCR6⁺ T_FH17 cells decreased, whereas the proportion of CXCR3⁺CCR6⁻ T_FH1 cells increased significantly. Furthermore, the proportion of the IgD⁻CD27⁻ double-negative B lymphocytes was also significantly reduced. These findings suggest that anifrolumab therapy attenuates T_FH cell activation, which may contribute to its clinical efficacy by modulating germinal center responses in SLE. Full article

Background: Toxoplasma gondii (T. gondii) causes severe disease in immunocompromised individuals and pregnant women, underscoring the urgent need for effective vaccines against toxoplasmosis. The dense granule protein 5 (GRA5) of T. gondii plays a key role in parasitic cyst formation. Methods: This study evaluated the protective immune responses induced by a virus-like particle (VLP) vaccine expressing the T. gondii-derived antigen GRA5 in a mouse model challenged with the ME49 strain of T. gondii. GRA5 VLPs were generated using a baculovirus expression system, and VLP formation was confirmed by Western blotting and visualized using transmission electron microscopy. Mice were intranasally immunized with GRA5 VLPs three times at 4-week intervals to induce immune responses, followed by infection with T. gondii ME49. Results: Intranasal immunization with GRA5 VLPs induced parasite-specific IgG antibody responses in the serum and both IgG and IgA antibody responses in the brain. Compared to the non-immunized group, immunized mice exhibited significantly higher levels of germinal center B cells and antibody-secreting cell responses. Moreover, the VLP vaccine suppressed the production of IFN-γ and IL-6 cytokines, leading to a significant reduction in brain inflammation and decreased cyst counts following lethal challenge with T. gondii ME49 infection. Conclusion: These findings suggest that the GRA5 VLP vaccine derived from T. gondii elicits a protective immune response, highlighting its potential as an effective vaccine candidate against toxoplasmosis. Full article

Antibody-mediated rejection (ABMR) caused by donor-specific Abs (DSAs) is still the leading cause of late graft loss following clinical organ transplantation, and effective strategies to combat ABMR are still elusive. We previously showed that rIL-2 complexed with anti-IL-2 mAb clone JES6-1A12 (IL-2 cplx) leads to the selective expansion of regulatory T cells (Tregs) and the prolonged survival of MHC-mismatched skin allografts. Although the grafts were eventually rejected, mice failed to develop DSAs. Here, we investigated the impact of IL-2 cplx on the humoral response and germinal center (GC) reaction during allograft rejection. IL-2 cplx treatment prevents Bcl-6 upregulation, leading to suppressed development of GC T and B cells. The IL-2 cplx-induced impairment of GC development limits IgG allo-Ab production but allows for IgM synthesis. By employing a hapten–carrier system to investigate affinity maturation, we found that IL-2 cplx induces a distinct shift in specific Ab production favoring low-affinity IgM while simultaneously decreasing IgG responses. These findings illuminate the potential of IL-2 cplx therapy for inducing humoral tolerance, potentially paving the way for refining strategies aimed at preventing and treating ABMR. Full article

This research centers on the sand-fixing plant known as Stipagrostis pennata, from which the β-glucosidase gene SpBGLU25 was successfully cloned using the molecular cloning method. SpBGLU25 encodes a hydrophilic and stable protein made up of 193 amino acids, located in the cell membrane. qRT-PCR analysis indicated that the expression of the SpBGLU25 is closely linked to the drought stress tolerance of S. pennata. Following this, functional validation was performed using an Arabidopsis overexpression system. The overexpression of transgenic Arabidopsis lines showed significantly improved drought tolerance under PEG and mannitol treatments. Assessments of germination, root length, and physiological indicators such as proline, malondialdehyde content, soluble sugars, and relative leaf water content (RLWC) further confirmed the enhanced performance of the overexpressing plants. Additionally, the comparative transcriptomic analysis of SpBGLU25-OE Arabidopsis compared to the wild-type (WT) showed that differentially upregulated genes were primarily enriched in categories of “cellular process,” “cell,” and “catalytic activity.” KEGG pathway enrichment analysis indicated that the genes were mainly concentrated in the pathways of phenylpropanoid biosynthesis and plant hormone signal transduction. These findings provide a crucial foundation for further investigation into the function of the SpBGLU25 and its role in regulating plant tissue development and adaptation to stress. This research is anticipated to offer new theoretical insights and genetic resources for enhancing plant stress tolerance through genetic engineering. Full article

Background: Self-administered orally dissolving films (ODFs) encapsulating inactivated influenza vaccines represent an effective strategy for stimulating mucosal immunity. While this vaccination method offers several advantages over conventional influenza vaccines, a comparative efficacy study remains lacking. Methods: Female BALB/c mice were immunized with inactivated A/PR/8/34 (H1N1) either via orogastric inoculation or through the oral mucosal delivery using pullulan and trehalose-based ODF vaccines. Each group received equivalent antigen doses across three immunizations. Humoral responses and antibody functionality were assessed using sera collected post-immunization. After lethal viral challenge, other immunological and virological parameters were determined in corresponding tissues. Body weight and survival were monitored over a 14-day period after challenge. Results: ODF vaccination elicited significantly higher virus-specific IgA levels, HAI titers, and neutralizing antibody activity than oral gavage. After the viral challenge, ODF-immunized mice exhibited stronger IgG and IgA responses in respiratory tissues, increased antibody-secreting cells in lungs and spleen, and elevated germinal center B cells and CD8⁺ T cell responses. Both vaccination methods reduced lung pro-inflammatory cytokines and provided full protection against lethal challenge; however, the ODF group showed lower cytokine levels, better weight maintenance, and reduced viral loads. Conclusions: ODF vaccination elicits more robust systemic and mucosal immune responses than oral vaccination and may serve as a promising alternative method of influenza vaccine delivery. Full article

Isolated intrahepatic lymphoid follicles (ILFs), also referred to as reactive lymphoid hyperplasia, are rare benign lymphoid proliferations that can closely mimic hepatocellular carcinoma (HCC) on imaging. This case highlights the diagnostic complexity of hepatic mass lesions in chronic hepatitis B patients, particularly when radiologic and serologic features raise concern for malignancy. A 60-year-old man with chronic hepatitis B presented with a liver mass, elevated alpha-fetoprotein levels, and imaging findings of heterogeneous arterial enhancement, all suggestive of HCC. Despite initial treatment with atezolizumab plus bevacizumab, the lesion progressed, leading to an extended left hepatectomy. Histopathological examination revealed well-formed lymphoid follicles with reactive germinal centers, without evidence of malignancy or granulomatous inflammation. Serum IgG was elevated, and ANA was positive, supporting the possibility of an underlying immune-mediated process. The patient showed clinical and serologic improvement following corticosteroid therapy, with no evidence of recurrence at 10-month follow-up. This case underscores the importance of histopathological confirmation in hepatic masses with atypical features and highlights the need to consider benign immune-related mimickers in the differential diagnosis, particularly in the era of immunotherapy. Full article

Follicles (Fs)/Germinal Centers (GCs) in tonsils and lymph nodes are dynamic microenvironments where diverse immune cell populations interact for the development of antibody responses against pathogens. The accurate in situ phenotypic analysis of these immune cells is a prerequisite for the comphehensive understanding of GC development. In this study, we explore unsupervised clustering approaches for distinguishing cell populations within F/GCs using marker expression data. We evaluate multiple clustering algorithms and find that k-means clustering provides the most effective separation of distinct cell subsets. Additionally, we investigate the predictive potential of common GC markers (CD3, CD4, CD20 and BCL6) for PD-1 expression, an important immune checkpoint regulator. Our analysis demonstrates that PD-1 expression can be reliably inferred using these markers, suggesting potential applications for automated cell classification in immunological studies. This approach enhances our ability to analyze immune cell heterogeneity and may contribute to improved understanding of GC dynamics in health and disease. Our findings support the use of computational clustering for high-dimensional immune profiling. Full article

Diffuse large B-cell lymphoma (DLBCL), recognized as the most prevalent variant of adult non-Hodgkin lymphoma, presents considerable challenges in diagnosis owing to its diverse morphological features and frequent extranodal involvement, which may frequently mimic nonhematopoietic neoplasms. The 2022 WHO Classification of Lymphoid and Hematopoietic Tissues provides essential updates, highlighting the necessity of combining morphology, immunohistochemistry, cytogenetics, and molecular testing for precise subclassification. This review presents a practical method for differentiating DLBCL from other aggressive B-cell neoplasms, such as Burkitt lymphoma, B-lymphoblastic lymphoma, and mantle cell lymphoma. It highlights vital diagnostic tools, including CD45, B/T-cell markers, germinal center markers, and the Hans algorithm, as well as the role of FISH in identifying rearrangements of key genes MYC, BCL2, and BCL6, which are significant for recognizing double-hit and triple-hit lymphomas. Special focus is given to EBV-associated DLBCL and uncommon subtypes featuring plasmablastic or ALK-positive traits. This review aims to enhance diagnostic accuracy and ensure appropriate treatment strategies for patients with large B-cell lymphomas by emphasizing thorough morphological evaluation, specific adjunct testing, and adherence to the most recent classification standards. Full article

Background: 2-Phenoxyethanol (2-PE) has been safely included as a preservative and/or stabilizer in more than thirty vaccine formulations at amounts ranging from 0.5 to 5 mg per dose; however, the nonclinical safety data publicly available for intramuscular (IM) or subcutaneous (SC) administration are relatively limited. Here, in addition to the available clinical and nonclinical data for 2-PE, we summarize the nonclinical safety data of experimental 13vPnC (Prev(e)nar 13) formulations with or without 2-PE. Methods: Two repeat-dose toxicity studies in rabbits, one for a 2-PE-free formulation of 13vPnC and the other for an MDV formulation of 13vPnC with 5 mg/dose 2-PE, were conducted as part of an overall nonclinical safety package for vaccine development. The studies were designed and conducted in compliance with the relevant guidelines and regulations. Results: In repeat-dose toxicity studies in rabbits, five IM administrations of a preservative-free 13vPnC single-dose syringe formulation or a 13vPnC multi-dose vial (MDV) formulation containing 5 mg 2-PE/0.5 mL dose were well tolerated with no systemic toxicity. Robust serotype-specific IgG antibody responses to each of the 13 pneumococcal serotypes were also confirmed for both formulations. The observations for the 13vPnC MDV including local inflammatory reaction, increases in fibrinogen, and increased splenic germinal centers were nonadverse, reversible, and consistent with findings previously observed for the IM administration of vaccines, including the 2-PE-free 13vPnC single-dose syringe formulation. Conclusions: Together with the other available nonclinical and clinical data of 2-PE and vaccine formulations containing 2-PE and following the 3Rs principle, our risk-assessment-based recommendation is that no additional nonclinical safety studies are needed when evaluating a 2-PE-containing presentation of a previously well-characterized vaccine product if the amount of 2-PE is ≤10 mg/dose. Full article

T-follicular helper (Tfh) cells, a specialized subset of CD4⁺ cells, are the immune mediators connecting cellular and humoral immunity, as they lead B-cell proliferation within germinal centers, and orchestrate their response, including activation, class switching, and production of a diverse array of high-affinity antibodies. Their interactions with B cells is regulated by a wide complex of transcriptional and cytokine-driven pathways. A major contribution of Tfh cells to autoimmune diseases is through their production of cytokines, particularly IL-21, which supports the proliferation and differentiation of autoreactive B cells. Elevated levels of circulating Tfh-like cells and IL-21 have been observed in patients with systemic lupus erythematosus (SLE) and rheumatoid arthritis (RA) correlating strongly with disease severity and autoantibody levels. The feedback loop between Tfh cells and IL-21 or other signal pathways, such as Bcl-6, ICOS, and PD-1, not only sustains Tfh cell function but also drives the continuous expansion of autoreactive B cells, leading to chronic inflammation through the production of high-affinity pathogenic autoantibodies. By understanding these interactions, Tfh pathways may serve as potential therapeutic targets, with IL-21, ICOS, and PD1 blockades emerging as promising innovative therapeutic strategies to manage autoimmune diseases. Although a variety of studies have been conducted investigating the role of Tfh cells in SLE and RA, this review aims to reveal the gap in the literature regarding the role of such subpopulations in the pathogenesis of other autoimmune diseases, such as Anca-associated vasculitis (AAV), and express the need to conduct similar studies. Tfh cell-related biomarkers can be used to assess disease activity and transform autoimmune disease treatment, leading to more personalized and effective care for patients with chronic autoimmune conditions. Full article

Follicular lymphoma (FL) is a heterogeneous and incurable disease. One of the hallmark features of FL cells is the introduction of N-glycosylation (N-gly) amino acid sequence motifs into the immunoglobulin variable (IgV) region through ongoing somatic hypermutation (SHM) in the early stages of lymphoma development. These N-gly motifs, containing oligomannoses, are rarely found in healthy B cells but evidently play a crucial role in the clonal evolution and survival of FL cells in the hostile environment of germinal centers. The random nature of the ongoing SHM in FL occasionally results in the loss of productive immunoglobulin (Ig) genes or the elimination of N-gly motifs in productive genes. Such events typically lead to clonal deletion, as demonstrated by the longitudinal analysis of FL samples. However, rare N-gly-negative subclones demonstrate prolonged survival with evidence of ongoing SHM, giving rise to new N-gly-negative subclones before eventual deletion. This observation suggests the presence of specific mechanisms supporting their survival and proliferation. This perspective examines the current literature and explores whether a detailed transcriptomic and functional comparison of FL subclones characterized by different N-gly statuses, with a particular focus on N-gly-negative subclones, will lead to a comprehensive understanding of both N-gly-dependent and independent pro-survival and proliferative transcriptional signatures. Specifically, it aims to deepen our understanding of FL pathobiology and identify novel therapeutic targets for better disease management. Full article

Background/Objectives: Primary cutaneous B-cell lymphomas (PCBCL) are a rare and heterogeneous group of non-Hodgkin lymphomas that are confined to the skin at diagnosis and exhibit a tendency for cutaneous recurrence. The 5th edition of the World Health Organization and the 2022 International Consensus Classification recognize three main subtypes: primary cutaneous follicle center lymphoma (PCFCL), primary cutaneous marginal zone lymphoma/lymphoproliferative disorder (PCMZL/LPD), and primary cutaneous diffuse large B-cell lymphoma, leg type (PCDLBCL,LT). These subtypes differ in clinical behavior, histopathologic features, immunophenotype, and molecular alterations. Diagnosis and management remain challenging for clinicians. This review aims to provide a comprehensive overview of the defining features and current treatment strategies for PCBCL. Methods: This narrative review synthesizes current literature on the clinical, morphologic, immunohistochemical, and molecular characteristics of PCBCL. It also evaluates the diagnostic utility of immunohistochemistry, gene expression profiling, and molecular assays, particularly in distinguishing primary cutaneous disease from secondary cutaneous involvement by systemic lymphomas. Results: PCFCL arises from germinal center B-cells and must be differentiated from nodal follicular lymphoma. PCMZL/LPD is derived from post-germinal center B-cells and is often linked to chronic antigenic stimulation. Both PCFCL and PCMZL/LPD are indolent and associated with favorable outcomes. By contrast, PCDLBCL,LT is an aggressive lymphoma characterized by genetic alterations activating the NF-κB pathway, commonly including mutations to MYD88 and CD79B. Treatment strategies vary by subtype, ranging from localized therapies for indolent lymphomas to systemic chemoimmunotherapy for aggressive PCBCL. Emerging therapies, such as Bruton tyrosine kinase inhibitors and immunoregulatory agents, are being investigated for relapsed/refractory disease. Conclusions: PCBCL encompass distinct clinicopathologic entities with subtype-specific diagnostic and therapeutic considerations. While current management is guided by clinical behavior, significant knowledge gaps remain regarding the molecular mechanisms underlying skin tropism, immune evasion, and disease progression. Future research could focus on improving molecular characterization and developing personalized and immune-based therapies to enhance outcomes. This review consolidates current knowledge and highlights innovations aimed at advancing the diagnosis and treatment of PCBCL in clinical practice. Full article

T follicular helper (Tfh) cells are a specialized subset of CD4+ T lymphocytes that are essential for the development of long-lasting humoral immunity. Tfh cells facilitate B lymphocyte maturation, promote germinal center formation, and drive high-affinity antibody production. Our current knowledge of Tfh interactions with the humoral immune system effectors suggests that they have a critical role in supporting the immune response against viral infections. This review discusses the mechanisms through which Tfh cells influence anti-viral immunity, highlighting their interactions with B cells and their impact on antibody quality and quantity. We explore the role of Tfh cells in viral infections and examine how vaccine design can be improved to enhance Tfh cell responses. Innovative vaccine platforms, such as mRNA vaccines and self-assembling protein nanoplatforms (SAPNs), are promising strategies to enhance Tfh cell activation. Their integration and synergistic combination could further enhance immunity and Tfh responses (SAPN-RNA vaccines). In summary, we provide a comprehensive overview of the current insights into Tfh cells’ role during viral infections, emphasizing their potential as strategic targets for innovative vaccine development. Full article

In the north and center of Chile, there has been a significant environmental contamination by copper due to natural factors, mining activities and use of agricultural fertilizers and pesticides. Copper (Cu) soil contamination is of important concern in agriculture, food safety, and human health. Soil copper concentrations higher than 100–150 mg/kg can be toxic for plants and other organisms. Therefore, identification of copper-tolerant crops is of great interest for sustainable cultivation purposes. Quinoa is a promising candidate as a copper-tolerant crop, owing to its wide genetic diversity, high adaptability to different environmental conditions, and tolerance to abiotic stresses. In this work, we evaluated the effect of copper on 21 accessions of quinoa (including 19 accessions from different geographical locations of Chile) in order to identify tolerant and sensitive accessions. Our results show that (1) Germination parameters of quinoa are negatively affected in the presence of increasing Cu concentrations, with differential inhibition values among accessions. (2) Early seedling growth of accessions was differentially affected in the presence of Cu. (3) Plant biomass production (relative fresh and dry weights) was also affected by Cu, with significant differences between accessions. A Principal Component Analysis (PCA) of these data identified accessions based on Cu tolerance. (4) A clear regional pattern was observed when comparing accessions from northern, central, and southern Chile, suggesting local adaptation to Cu-rich soils. Thus, significant differences in copper tolerance between accessions were observed, revealing genetic diversity in copper tolerance among quinoa accessions. Tolerant accessions of quinoa can have important applications in sustainable agriculture. Full article

High-grade B-cell lymphoma (HGBL), not otherwise specified (NOS), is a rare entity within the spectrum of B-cell lymphomas. HGBL, NOS remains a diagnosis of exclusion with limited data available on the optimal clinical approach. We report a case of a 67-year-old man with HGBL, NOS with a germinal center B-cell (GCB) immunophenotype. The disease was characterized by an aggressive clinical course, refractory to multiple lines of cytotoxic chemotherapy, immunotargeted treatment, therapy with a PD-1 inhibitor, and haploidentical hematopoietic stem cell transplantation (haplo-HSCT). Ultimately, the disease progression led to the patient’s death nine months post-diagnosis. A FISH assay identified a sole genetic rearrangement: BCL2/IGH. Whole-exome sequencing revealed a number of significant somatic mutations, such as TP53 p.C238G, B2M p.L12R, STAT6 p.D419G, STAT3 p.S614R, TREX1 p.T49fs, and CREBBP p.C367Ter, as well as a high focal amplification of the MUC3A gene and the deletion of the short arm of chromosome 17 (del(17p)). An inactivating somatic mutation in the TREX1 gene (p.T49fs) has not been previously described in patients with non-Hodgkin lymphomas. Additionally, our analysis uncovered a key cancer hallmark: tumor genomic instability, manifested as a high tumor mutational burden, which likely contributed to the aggressive disease course. Full article