Search Results (7,513)

(1) Background: Despite the success of combination antiretroviral therapy (cART), immune recovery in treated HIV infection remains heterogeneous, and discordant immune–virologic responses persist in a substantial proportion of people living with HIV (PLWH). These patterns may reflect ongoing immune dysregulation despite effective viral suppression. This study aimed to characterize discordant treatment classifications, evaluate immune imbalance using the CD4/CD8 ratio, identify associated clinical predictors, and assess opportunistic infection burden in a Romanian cohort of people living with HIV receiving long-term cART. (2) Methods: A retrospective cross-sectional study was conducted in 462 adults with HIV-1 infection receiving cART at the “Prof. Dr. Matei Balș” National Institute of Infectious Diseases, Bucharest (2018–2021). PLWH were classified as concordant responders (CR), immunological discordant responders (ID), or virological discordant responders (VD) based on plasma HIV-1 RNA and CD4+ T-cell count thresholds. Immune dysregulation was assessed using the CD4/CD8 ratio. Multinomial logistic, logistic, and negative binomial regression models were used to identify predictors of discordant responses, severe CD4/CD8 ratio inversion, and opportunistic infection burden. (3) Results: Discordant responses were observed in 30.7% of PLWH (14.5% ID, 16.2% VD). CD4/CD8 ratio inversion occurred in 71.2% and severe inversion in 40.0%. Significant differences across clinical classification groups were found for CD4+T-cell counts (H = 153.62, p < 0.001, ε² = 0.33) and CD4/CD8 ratio (H = 115.10, p < 0.001, ε² = 0.25), while CD8+ counts were similar (p = 0.571). Male sex was associated with both ID and VD, and severe CD4/CD8 inversion was strongly associated with ID. Opportunistic infection burden was associated with duration of HIV infection and CDC stage. (4) Conclusions: Discordant immune–virologic responses remain frequent during long-term cART and are characterized by persistent immune imbalance reflected by CD4/CD8 ratio inversion. The CD4/CD8 ratio may provide clinically relevant information on immune recovery beyond CD4+ T-cell counts. Full article

Background/Objectives: The emergence of SARS-CoV-2 variants and breakthrough infections underscores the need for next-generation vaccines capable of protecting from natural infection and/or preventing virus transmission. Intranasal vaccination offers a promising approach by eliciting local immune responses in the nasal mucosa, the primary site of infection and reservoir for transmissible virus. We evaluated two live-attenuated, respiratory syncytial virus-vectored vaccines in which the RSV F and G surface glycoproteins were replaced with a chimeric SARS-CoV-2 Spike protein from the ancestral USA/WA-1/2020 strain (MV-014-212) or the Delta variant (MV-014-212-delta). Methods: K18-hACE2 mice and LVG Syrian hamsters were vaccinated with a single intranasal dose of MV-014-212 or MV-014-212-delta. Systemic and mucosal immunity were assessed following vaccination, and protection was evaluated following Delta SARS-CoV-2 challenge. In vaccinated hamsters, morbidity, viral shedding, and lung inflammation and injury were also assessed following natural exposure to infected cagemates. Results: A single intranasal dose of either vaccine elicited systemic and mucosal immunity in K18-hACE2 mice, including serum neutralizing antibodies, Spike-specific memory B cells and plasmablasts, and Spike-specific CD8⁺ lung-resident memory T cells. Although MV-014-212-delta vaccination provided the best protection against the Delta variant virus challenge, both vaccines decreased viral loads in nasal discharge, lung, and brain, and reduced weight loss and mortality. In naturally acquired infection studies, vaccinated hamsters exposed to infected cagemates exhibited minimal weight loss, limited viral replication within the nasal mucosa, and attenuated lung pathology. Conclusions: Intranasal RSV-vectored vaccines can elicit broad protective respiratory immunity, suggesting that this platform could be leveraged for other respiratory pathogens. Full article

The immunological composition of the microenvironment has shown relevance for diagnosis, prognosis, and therapy in solid tumors but remains underexplored in acute leukemias. We investigated the significance of the acute myeloid leukemia (AML) bone marrow microenvironment in predicting chemosensitivity and long-term remission in pediatric patients. We analyzed 32 non-promyelocytic pediatric AML patients at diagnosis using a NanoString PanCancer IO 360 assay, RNA sequencing, and deep-phenotype flow cytometry analyses. The findings were validated using the pediatric TARGET AML dataset. A short signature of three interferon (IFN)-related genes (GBP1, PARP12, and TRAT1) distinguished patients with chemosensitive disease and reduced minimal residual disease after induction chemotherapy. The signature stratified patients overall, and within the clinically defined “standard-risk” group, patients with high gene expression at diagnosis had significantly longer overall survival. The leukemia microenvironment associated with this signature showed enrichment of non-exhausted CD4⁺ and CD8⁺ T cytotoxic lymphocytes and expansion of CD8⁺ T effector memory cells re-expressing CD45RA (TEMRA) in patients with a favorable prognosis. Our results show the importance of the bone marrow microenvironment in pediatric AML and provide tools for a refined stratification of “standard-risk” patients, lacking adequate risk-oriented therapies. They also offer a promising guide for tackling immune pathways and exploiting immune-targeted therapies. Full article

Background: Responses to atezolizumab plus bevacizumab (Atezo+Bev) in hepatocellular carcinoma (HCC) are heterogeneous, and response determinants remain unclear. We investigated whether spatial proximity between PD-L1(+) tumor-associated macrophages (TAMs) and CD8(+) T cells represents an immune niche associated with Atezo+Bev responsiveness. Methods: Multiplex immunohistochemistry was performed on biopsies from patients treated with Atezo+Bev (n = 23) or lenvatinib (n = 20). An interaction variable was defined via nearest-neighbor analysis as CD8(+) T cells within 25 µm of PD-L1(+) TAMs, normalized to cell counts. Associations with tumor shrinkage and progression-free survival (PFS) were examined. CD8(+) T cell phenotypes were evaluated via GZMB and TIM3. Transcriptomic profiling of resected HCCs (n = 8) was conducted using next-generation sequencing and gene set enrichment analysis (GSEA). Results: In a patient with responsive and non-responsive lesions, the responsive lesion showed closer PD-L1(+) TAM-CD8(+) T cell proximity. In cohort analyses, the interaction variable was associated with tumor shrinkage and prolonged PFS in the Atezo+Bev group, whereas PD-L1(+) TAM or CD8(+) T cell density alone was not predictive. This association was absent in the lenvatinib cohort. High-interaction tumors showed increased GZMB(+) and TIM3(+) CD8(+) T cells. Transcriptomic analysis revealed the upregulation of inflammatory, cytotoxic, chemotactic, and immunoregulatory genes, with enrichment of the chemokine, IFN-gamma, and IL-10 signaling pathways. Conclusions: Spatial proximity between PD-L1(+) TAMs and CD8(+) T cells defines an immune niche characterized by coexisting immune activation and regulatory programs and is strongly associated with Atezo+Bev responsiveness in HCC. Quantification of this spatial interaction may serve as a biopsy-based biomarker for immunotherapy stratification. Full article

Granuloma annulare is a non-infectious granulomatous dermatosis with a probable pathogenic mechanism of delayed-type hypersensitivity, in which the dermal histiocytic granulomatous infiltrate is usually accompanied by a lesser component of lymphocytes. Although there are more common clinical and histopathological patterns of presentation, there are less well-known variants that may pose significant diagnostic challenges by mimicking other inflammatory cutaneous processes or even neoplastic conditions. One of the rarest forms of granuloma annulare is the pseudolymphomatous variant, in which the lymphocytic component is not only highly prominent but may, in some cases, partially or completely obscure the histiocytic component itself. This feature, together with the fact that the clinical presentation of this variant is often atypical—frequently lacking the characteristic annular morphology of conventional granuloma annulare—renders the diagnosis particularly challenging. From an immunohistochemical standpoint, the infiltrates described are predominantly composed of T cells, with only a sparse and scattered B-cell component. In this article, we present a case of granuloma annulare with a pseudolymphomatous B-cell component (PAX5⁺, CD79⁺) and minimal T-cell involvement, observed in a 4 mm skin nodule located on the shoulder of a 48-year-old male. This case therefore broadens the concept of pseudolymphomatous granuloma annulare to include infiltrates predominantly composed of B lymphocytes. Full article

Background: Despite hybrid and vaccine-induced immunity, SARS-CoV-2 continues to cause disease. The characterization of humoral and cellular immune responses is essential for guiding prevention strategies and booster dose policies; Methods: A prospective cohort study was conducted with 131 hospitalized patients with confirmed COVID-19 in the Aburrá Metropolitan Valley, Colombia. Clinical and immunological data were evaluated on days 1–3, days 5–7, days 8–12, and 4–5 months after diagnosis. Humoral immunity was assessed by enzyme-linked immunosorbent assay (ELISA), chemiluminescent microparticle immunoassay (CMIA), and neutralization testing, and cellular immunity by CD4⁺/CD8 T-cell responses. Results: vaccinated patients had higher baseline levels of IgG and neutralizing antibody positivity than unvaccinated patients (ELISA 89.1% vs. 60.0%; CMIA 86.4% vs. 50.0%; neutralizing antibodies 88.2% vs. 65.0%), but cases of severe disease occurred in both groups. Adults aged ≥65 years had higher antibody positivity, but severe disease persisted. Mortality at 28 days was 7.6%, mainly among critically ill patients with comorbidities. Antibodies persisted at 4–5 months but were lower in those with severe acute disease. Those who received the booster dose showed stronger CD4⁺/CD8⁺ activation (notably against the Omicron variant) than unvaccinated/partially vaccinated patients. Conclusions: Vaccination improved humoral and cellular responses, but severe breakthrough infections still occurred, particularly in high-risk patients. Full article

Background/Objectives: Spontaneous remission (SR) of acute myeloid leukemia (AML) offers unique clinical insights into host anti-tumor immunity. However, the comprehensive clinical landscape and molecular dynamics of blast clearance and subsequent relapse remain unclear. This study aimed to elucidate these dynamics. Methods: We conducted a two-phase observational study: a systematic pooled analysis of 66 adult AML SR cases (1990–2024) to define clinical triggers and outcomes and longitudinal molecular tracking of two institutional cases to map clonal shifts (with immune profiling for Patient 1 and genomic tracking for both). Results: In the pooled analysis, infection was the predominant trigger, accounting for 78.6% (95% CI: 65.6–88.4%) of SR events. The dataset showed male predominance and monocytic leukemia enrichment (57.6% [95% CI: 44.1–70.4%]), suggesting lineage-specific susceptibility. SR duration and relapse risk were independent of the infection trigger, AML subtype, or age. When integrated with these clinical patterns, institutional tracking was consistent with a biphasic evolutionary model: an acute IL-8 surge alongside NKT and CD4+ T cell activation coincided with blast clearance, as observed primarily in Patient 1. Subsequently, the emergence of TP53 or NRAS mutations within persistent DNMT3A-mutated clones during relapse raised the hypothesis that unresolved chronic inflammation could potentially exert selective pressure favoring resistant subclones. Such interpretations remain correlational and require prospective validation. Conclusions: Our findings outline a clinical–evolutionary framework for AML SR. Remission durability likely relies on balancing acute immune activation with underlying clonal stability. These observational insights highlight complex immune-genomic crosstalk, generating hypotheses for future prospective investigations. Full article

Cutaneous T-cell lymphoma (CTCL), primarily mycosis fungoides (MF) and Sézary syndrome (SS), has long been characterized as a neoplasm of mature memory T cells, based on monoclonal T-cell receptor (TCR) rearrangements and tissue-resident memory (TRM)/central memory (TCM) T-cell phenotypes. This review synthesizes converging population-genetic, multi-omic, and single-cell evidence to argue that this characterization is incomplete and that a progenitor-based model better accounts for the full spectrum of disease biology. We present evidence that initiating mutations arise in hematopoietic stem or early lymphoid progenitor survive thymic selection, and diversify after TCR assembly, resulting in branched evolution across both blood and skin. In SS, paired analyses reveal > 200 shared variants between CD34⁺ progenitors and Sézary cells, as well as signal-joint T-cell receptor excision circle (sjTREC) positivity, providing direct progenitor-level evidence. In MF, convergent signals, multiple malignant clonotypes per lesion, greater blood–skin than skin–skin clonotype overlap, and compartment-specific CNV subclones, implicate hematogenous seeding and reseeding. Population-scale lymphoid clonal hematopoiesis and lymphoid-pattern mosaic chromosomal alterations define a compatible antecedent state. Spatial single-cell atlases and trajectory analyses map site-conditioned programs in skin, including Th2-skewed cytokines, microbial responses, and UV signatures, that select and expand subclones and explain inter- and intra-patient heterogeneity. This framework reconciles mature immunophenotypes with upstream initiation and clarifies why compartment-focused therapies often reshape rather than eradicate disease. It yields testable predictions and actionable implications: trials should pair multicompartment cytoreduction with strategies that attenuate progenitor-derived reservoirs, restore immune balance, and repair skin barrier dysfunction. A progenitor-initiated, niche-adapted model provides a coherent scaffold for more durable control in CTCL. Full article

Background: Sézary syndrome (SS) is an aggressive leukemic variant of cutaneous T-cell lymphoma (CTCL) with distinct clinical and biological features compared to rarer entities such as primary cutaneous CD8⁺ aggressive epidermotropic cytotoxic T-cell lymphoma (PCAECTCL). Although recurrent genomic alterations in CTCL have been described, comparative analyses at the pathway level across biologically divergent subtypes remain limited. Here, we leveraged a conversational artificial intelligence (AI) platform for precision oncology to enable rapid, integrative, and hypothesis-driven interrogation of publicly available genomic datasets. Methods: We conducted a secondary analysis of somatic mutation and clinical data from the Columbia University CTCL cohort accessed via cBioPortal. Cases were stratified into SS (n = 26) and PCAECTCL (n = 13). High-confidence coding variants were curated and mapped to biologically relevant signaling pathways and functional gene categories implicated in CTCL pathogenesis. Pathway-level mutation frequencies were compared using Fisher’s exact tests, with effect sizes quantified as odds ratios. Tumor mutational burden (TMB) was compared using the Wilcoxon rank-sum test. Subtype-specific co-mutation patterns were evaluated using pairwise association analyses and visualized through oncoplots and network heatmaps. A conversational AI agent, AI-HOPE, was used to iteratively refine cohort definitions, prioritize pathway-level signals, and contextualize findings. Results: TMB was comparable between SS and PCAECTCL (p = 0.96), indicating no significant difference in global mutational load. In contrast, pathway-centric analyses revealed marked qualitative differences. SS demonstrated enrichment of alterations in epigenetic regulators, tumor suppressor and cell-cycle control pathways, NFAT signaling, and DNA damage response mechanisms, consistent with transcriptional dysregulation and immune modulation. PCAECTCL exhibited relatively higher frequencies of alterations involving epigenetic regulators and MAPK pathway signaling, suggesting distinct oncogenic dependencies. Co-mutation analysis revealed a more constrained and focused interaction landscape in SS, whereas PCAECTCL displayed broader and more heterogeneous co-mutation networks, indicative of divergent evolutionary trajectories. Notably, ERBB2 mutations were significantly enriched between subtypes (p = 0.031), highlighting a potential subtype-specific therapeutic vulnerability. Conclusions: This study demonstrates that SS is distinguished from PCAECTCL not by increased mutational burden but by distinct pathway-level architectures, particularly involving epigenetic regulation, immune signaling, and transcriptional control. These findings generate biologically grounded, testable hypotheses for subtype-specific therapeutic targeting and underscore the value of conversational AI as a scalable framework for accelerating discovery in translational cancer genomics. Full article

P2X7 is an adenosine 5′-triphosphate (ATP)-gated ion channel. CD39 (ectonucleotidase triphosphate diphosphohydrolase-1) hydrolyses ATP to reduce its extracellular concentration to limit P2X7 activation. Both P2X7 and CD39 are present on leukocytes. Ficoll-Paque density gradient centrifugation is widely used to isolate human peripheral blood mononuclear cells (PBMCs), yet the extent to which other density gradient centrifugation methods influence the expression of cell surface molecules remains unclear. Using mass cytometry, this study compared the proportions of mononuclear leukocyte subsets and the relative amount of cell surface P2X7 and CD39 detected on these cells in paired, bar-coded cryopreserved human PBMC samples isolated by Ficoll-Paque or SepMate Tube density gradient centrifugation. Both techniques yielded similar proportions of mononuclear leukocyte subsets. P2X7 and CD39 were detected across all cell subsets, with the relative amount of P2X7 or CD39 comparable between separation methods. Relatively minor but statistically significant differences were observed for some populations. P2X7 expression was higher on CD3⁺, CD4⁺, and conventional CD4⁺ T cells, and naïve B cells, and lower on myeloid dendritic cells, while CD39 expression was lower on regulatory T cells in SepMate Tube samples compared to Ficoll-Paque samples. Overall, Ficoll-Paque and SepMate Tube density gradient centrifugation yield comparable results within PBMC samples, supporting the use of either method in studies examining immune phenotypes including the purinergic molecules P2X7 and CD39. Full article

CD20 × CD3 bispecific antibodies (BsAbs) have emerged as a meaningful therapeutic option for relapsed or refractory diffuse large B-cell lymphoma (DLBCL), redirecting endogenous T cells against malignant B cells independently of major histocompatibility complex-mediated antigen presentation, and have received regulatory approval after at least two prior lines of therapy. However, a substantial proportion of patients experience primary resistance or early relapse, underscoring the need to characterize the underlying biological mechanisms, which are the focus of this review. Several tumor-intrinsic determinants of resistance have been identified, including CD20 loss driven by MS4A1 mutations, alternative splicing, and gene deletion, as well as genomic reprogramming involving TP53, MYC, and NOTCH1 alterations. T-cell dysfunction represents another critical resistance domain, encompassing inadequate intratumoral cytotoxic CD8+ T-cell infiltration, expansion of immunosuppressive regulatory and follicular helper T cells, progressive exhaustion with upregulation of PD-1, LAG-3, TIM-3, and TIGIT, and impaired T-cell fitness from prior treatment exposure. Microenvironmental barriers, including checkpoint ligand upregulation, PD-L1-enriched extracellular vesicles, spatial exclusion of effector cells from immune-cold germinal center-like niches, hypoxia, and metabolic competition, further reinforce immune escape. Emerging strategies to overcome resistance include epigenetic priming, checkpoint inhibitor combinations, 4-1BB costimulatory approaches, and next-generation multispecific antibody designs. Full article

Ankylosing spondylitis (AS) is a chronic immune-mediated inflammatory disease affecting the axial skeleton, characterized by progressive structural damage and functional impairment. Although biologic therapies targeting tumor necrosis factor and interleukin-17 have improved clinical outcomes, a substantial proportion of patients fail to achieve sustained disease control. Emerging evidence suggests that metabolic alterations may contribute to AS pathogenesis; however, systematic characterization of metabolism-related biomarkers and their regulatory networks remains limited, and the interplay between metabolic dysfunction and immune dysregulation in AS is poorly understood. Two whole-blood GEO datasets (GSE25101, GSE73754; n = 104) were integrated as the primary analytical cohort. A third dataset (GSE11886, n = 18; monocyte-derived macrophages) was included for exploratory cross-tissue analysis. Differential expression analysis identified 847 DEGs, which were refined to 16 metabolism-related genes through weighted gene co-expression network analysis (WGCNA) and GeneCards database filtering. Eleven machine learning algorithms with 5-fold cross-validation were applied to construct diagnostic models and identify hub genes. Validation analyses included immune cell infiltration estimation using CIBERSORT, metabolic pathway activity assessment via ssGSEA, single-cell transcriptomics from GSE268839, functional enrichment through GSEA/GSVA, and chromosomal localization analysis. A competing endogenous RNA (ceRNA) regulatory network was constructed to map post-transcriptional regulation. Natural compounds from 66 AS-treating traditional Chinese medicines were screened against hub genes using deep learning-based binding prediction. Multiple machine learning algorithms achieved comparable cross-validated performance (CV AUC range 0.741–0.836; top five models: 0.805–0.836) using the six hub genes (MFN2, SLC27A3, RHOB, SMG7, AKR1B1, LCOR) identified through SHAP-based feature importance analysis of the PLS model. Leave-one-dataset-out validation between the two whole-blood cohorts showed that all algorithms exceeded an AUC of 0.77 in Round 1 (validate: GSE73754, n = 72; best AUC 0.861), while Round 2 (validate: GSE25101, n = 32) yielded more modest performance (best AUC, 0.715) reflecting the smaller validation sample. Exploratory application to GSE11886 (macrophage-derived samples) showed near-chance performance, consistent with the tissue-source discrepancy. AS patients exhibited significant downregulation of oxidative phosphorylation, TCA cycle, and glycolysis pathways (p < 0.01), accompanied by elevated glutathione metabolism (p < 0.001). Immune cell deconvolution revealed reduced CD8+ T cell proportions correlating with MFN2 downregulation, and increased neutrophil frequencies correlating with SLC27A3 upregulation. Exploratory single-cell analysis indicated that RHOB expression was relatively enriched in border-associated macrophages and fibroblasts, while AKR1B1 was more prominently expressed in vascular endothelial cells and plasmacytoid dendritic cells. The ceRNA network identified 21 miRNAs and 65 lncRNAs forming 86 regulatory interactions, with four key regulatory axes (SATB1-AS1/miR-539-5p/LCOR, FAM95B1/miR-223-3p/RHOB, LINC01106/miR-106a-5p/MFN2, AATBC/miR-185-5p/SMG7) predicted to regulate hub gene expression. Compound screening identified betaine, pyruvic acid, citric acid, etc., as top-ranking candidates, with MFN2 showing the highest binding capacity among hub genes. This study provides an integrative framework linking metabolic reprogramming with immune dysfunction in AS. The six-gene diagnostic signature showed preliminary discriminatory ability in the available datasets, while the ceRNA regulatory network and natural compound screening results prioritize candidate regulatory pathways and compounds for future validation. These findings advance our understanding of AS pathogenesis and may guide future biomarker development and targeted intervention strategies. Full article

Background: High-risk cytogenetic multiple myeloma (HRMM) confers inferior outcomes despite significant therapeutic advances. Real-world data characterizing contemporary treatment patterns across lines of therapy in this population are limited. Methods: We conducted a multicenter retrospective study of 205 patients with HRMM diagnosed between January 2009 and January 2024. High-risk cytogenetics were defined according to the International Myeloma Working Group (IMWG) and Revised International Staging System (R-ISS) criteria as the presence of del(17p), t(4;14), t(14;16), t(14;20), and/or gain/amplification of 1q21. Treatment regimens were categorized by the number of agents (doublet, triplet, quadruplet), mechanism of action (proteasome inhibitor [PI]-based, immunomodulatory drug [IMiD]-based, and anti-CD38 monoclonal antibody-based), and specific regimen composition. Treatment patterns were analyzed across three treatment eras and stratified by age (<70 vs. ≥70 years). Results: The cohort included 205 patients (median age, 62 years [interquartile range [IQR], 54–68 years]; 78.5% aged <70 years). Double-hit and triple-hit cytogenetics were present in 60.0% and 7.3% of patients, respectively. For first-line induction, triplet therapy predominated (81.0%, n = 166), followed by quadruplet (8.8%, n = 18), doublet (5.9%, n = 12), and multi-agent chemotherapy (2.9%, n = 6). By mechanism of action, PI + IMiD combinations were the most common (63.4%, n = 130), followed by PI-based (19.0%, n = 39), anti-CD38-based (10.2%, n = 21), and IMiD-based (2.9%, n = 6) regimens. Era-stratified analysis revealed a significant increase in quadruplet utilization from 3.2% in Era 1 (2009–2015) to 20.3% in Era 3 (2020–2024), with anti-CD38-containing frontline regimens administered to 26.6% of patients in the contemporary era (p < 0.001). Second-line induction was required in 50 patients (24.4%), with anti-CD38-based triplets comprising the most common approach (30.0%). Autologous stem cell transplantation (ASCT) was performed in 75.1% of patients overall, with significantly higher utilization in those aged <70 years (83.9% vs. 43.2%). Maintenance therapy was administered to 71.7% of patients (n = 147), with IMiD-based regimens predominating (53.1%), followed by PI + IMiD combinations (27.9%) and anti-CD38-containing regimens (10.2%). Despite intensive therapy, 69.4% of patients on maintenance experienced disease relapse, with higher rates observed in younger patients (74.8% vs. 41.7%). Conclusions: In this real-world HRMM cohort, the PI + IMiD triplet regimen remained the predominant induction approach, with a significant shift toward quadruplet and anti-CD38-containing regimens in the contemporary era. However, substantial relapse rates during maintenance underscore the continued unmet need in HRMM and support the early integration of novel therapeutic strategies, including quadruplet induction and BCMA-directed agents, in this population. Full article

Peripheral T-cell lymphomas (PTCLs) are malignancies of mature T cells with a poor prognosis. Most PTCL cases express follicular T-helper (T_FH) cell antigens and are classified as T_FH cell lymphoma (TFHL). Contact-dependent signaling between CD40 and its ligand, CD154, is essential for immune functions. CD154 is expressed by activated T cells, while CD40 is found on B cells, follicular and other dendritic cells, macrophages, and stromal cells. Although the CD40–CD154 crosstalk is a key costimulatory pathway in immune responses, data on its role in PTCLs are limited. To explore the role of the CD40–CD154 axis in TFHLs, we conducted an in-depth immunomorphological study of 111 PTCL cases, including 93 TFHL cases. We found that neoplastic T cells in TFHL are consistently CD154-positive. The CD154 expression increased in histologically advanced cases and correlated with the extent of CD40 positivity. We showed that CD154-positive neoplastic T cells recapitulate the intranodal migration of normal TFH cells, disrupting and remodeling each functional compartment, thereby explaining the disease-related immune dysfunction. Our findings indicate that pathological CD40–CD154 interaction is a potential driver mechanism in TFHL and offers a promising target for future therapies. Full article

Despite prolonged viral inhibition with combination antiretroviral therapy (ART), HIV-1 survives as genetically intact, replication-capable proviruses within durable CD4+ T-cell fractions, involving central memory, transitional memory, and stem cell-like memory populations, as well as within tissue-resident compartments including lymphoid follicles and gut-associated lymphoid tissue. Reservoir stability is preserved via clonal growth of infected cells and epigenetic processes that impose proviral transcriptional silencing. As a result, current therapeutic approaches seek to either directly alter proviral survival or to improve immune-driven elimination of infected cells. At the molecular level, investigational strategies such as CRISPR–Cas9 and CRISPR–Cas12 gene-editing systems are intended to remove or induce inactivating mutations inside embedded proviral DNA, as well as alter host entrance co-receptors such as CCR5 to provide cellular resistance to infection. In addition, pharmacologic latency regulation is being studied via histone deacetylase inhibitors, protein kinase C agonists, and bromodomain inhibitors to reverse latency, along with Tat inhibitors and other transcriptional repressors aimed to persistently silence proviral expression. Moreover, immunological techniques aim to counteract inefficient endogenous antiviral defenses. Broadly neutralizing antibodies with tailored Fc-driven effector functions are under examination for both neutralization and antibody-dependent cellular cytotoxicity. Therapeutic vaccine approaches seek to elevate polyfunctional HIV-specific CD8+ T-cell responses, while adoptive cellular approaches, involving CAR-T cells aiming HIV envelope epitopes, remain in early clinical research. Immune checkpoint blockade is also being investigated to reverse T-cell depletion inside reservoir-rich tissues. Nevertheless, the key obstacles continue to be the diverse reservoir composition, restricted tissue penetration, viral escape, and safety limitations. The molecular and translational obstacles that characterize attempts toward an HIV cure must be addressed through ongoing multidisciplinary research. Full article