B-cell Markers Research Articles

Being associated with multiple diseases, CD79a, as a B-cell marker plays an important role in disease treatment and prognosis

CD79a, a membrane glycoprotein critical for B-cell receptor (BCR) signaling, plays a vital role in B-cell development and immune responses. It serves as a marker for normal and tumor B-cells and is implicated in the progression of various diseases, including B-cell lymphomas, leukemia, autoimmune disorders, and other systemic diseases such as neurological, hematological, and respiratory disorders. This review provides a comprehensive analysis of the discovery, molecular structure, and function of CD79a, along with its regulatory mechanisms at the transcriptional and post-translational levels. CD79a’s involvement in signaling pathways and its potential as a therapeutic target for novel treatments, such as chimeric antigen receptor-T (CAR-T) cell therapy and bispecific antibodies, are also explored. The review highlights emerging therapeutic strategies targeting CD79a, emphasizing its significance in the prognosis of CD79a-related diseases and the ongoing need for further research to optimize clinical interventions.

Genomic analysis defines distinct pancreatic and neuronal subtypes of lung carcinoid.

Lung carcinoids (L-CDs) are rare, poorly characterised neuroendocrine tumours (NETs). L-CDs are more common in women and are not the consequence of cigarette smoking. They are classified histologically as typical carcinoids (TCs) or atypical carcinoids (ACs). ACs confer a worse survival. Histological classification is imperfect, and there is increasing interest in molecular markers. We therefore investigated global transcriptomic and epigenomic profiles of 15 L-CDs resected with curative intent at Royal Brompton Hospital. We identified underlying mutations and structural abnormalities through whole-exome sequencing (WES) and single nucleotide polymorphism (SNP) genotyping. Transcriptomic clustering algorithms identified two distinct L-CD subtypes. These showed similarities either to pancreatic or neuroendocrine tumours at other sites and so were named respectively L-CD-PanC and L-CD-NeU. L-CD-PanC tumours featured upregulation of pancreatic and metabolic pathway genes matched by promoter hypomethylation of genes for beta cells and insulin secretion (p < 1 × 10-6). These tumours were centrally located and showed mutational signatures of activation-induced deaminase/apolipoprotein B editing complex activity, together with genome-wide DNA methylation loss enriched in repetitive elements (p = 2.2 × 10-16). By contrast, the L-CD-NeU group exhibited upregulation of neuronal markers (adjusted p < 0.01) and was characterised by focal spindle cell morphology (p = 0.04), peripheral location (p = 0.01), high mutational load (p = 2.17 × 10-4), recurrent copy number alterations, and enrichment for ACs. Mutations affected chromatin remodelling and SWI/SNF complex pathways. L-CD-NeU tumours carried a mutational signature attributable to aflatoxin and aristolochic acid (p = 0.05), suggesting a possible environmental exposure in their pathogenesis. Immunologically, myeloid and T-cell markers were enriched in L-CD-PanC and B-cell markers in L-CD-NeU tumours. The substantial epigenetic and non-coding differences between L-CD-PanC and L-CD-NeU open new possibilities for biomarker selection and targeted treatment of L-CD. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Point of care CD19 chimeric antigen receptor (CAR) T-cells for relapsed/refractory acute myeloid leukemia (AML) with aberrant CD19 antigen expression

Relapsed/refractory (r/r) acute myeloid leukemia (AML) is associated with poor prognosis. CD19 is a B-cell marker, is aberrantly expressed in AML, mostly with t(8; 21)(q22; q22.1). Here we report the results of a phase 2 study giving point of care produced CD19 CAR T- cells for r/r AML with aberrant expression of CD19 (NCT04257175). Lymphodepletion included fludarabine and cyclophosphamide The response was evaluated by bone marrow (BM) aspiration on day 28. Six patients (5 adults and 1 child) were included. Median number of previous chemotherapy lines was 4 (range, 3–8) and four patients received CAR T-cells 8–18 months post allogeneic hematopoietic stem cell transplantation (allo-HSCT). Cytokine release syndrome (CRS) of any grade occurred in all patients, and 1 patient had grade 3 CRS. Immune effector cell-associated neurotoxicity syndrome (ICANS) occurred in 2 patients at low grades. Tocilizumab was administered to 2 patients and corticosteroids to 3 patients. Four patients achieved a complete remission (CR), while 2/6 progressed (PD). Three patients (2 with CR and 1 with PD) underwent allo-HSCT (it was the second transplant in 2) 2–5 months post CAR T-cells infusion. The median duration of response in patients achieving CR was 8.5 (range; 3–14) months. However, all patients eventually died within 5 (1–18) months.In conclusion, CD19 CAR T- cell treatment for AML is feasible and safe. However, the response is short and should be followed by allo-HSCT. Hopefully, future long term results will be improved by combining the CAR T- cell therapy with the emerging novel effective anti-leukemic compounds.

Current Knowledge about CD3+CD20+ T Cells in Patients with Multiple Sclerosis.

Multiple sclerosis (MS) is a disease of the central nervous system (CNS) characterized by inflammation and autoimmune responses. This review explores the participation of T cells, particularly certain CD3+CD20+ T cells, in the clinical manifestations of MS and highlights their presence in diagnosed patients. These T cells show aberrant expression of CD20, normally considered a B-cell marker. In this review, relevant journal articles available in PubMed and CINAHL were identified by employing diverse search terms, such as MS, CD3+CD20+ T cells, the incidence and significance of CD3+CD20+ T cells in MS patients, and the impact of rituximab treatment. The search was limited to articles published in the ten-year period from 2014 to 2024. The results of this review suggest that most scholars agree on the presence of CD3+CD20+ T cells in cerebrospinal fluid. Emerging concepts relate to the fundamental role of CD20-expressing T cells in determining the target and efficacy of MS therapeutics and the presence of T cells in the cerebrospinal fluid of MS patients. The results clearly show that CD20+ T cells indicate disease chronicity and high disease activity.

Enhanced Efficacy of Gastric Cancer Treatment through Targeted Exosome Delivery of 17-DMAG Anticancer Agent.

In this study, we explored the potential of genetically engineered exosomes as vehicles for precise drug delivery in gastric cancer therapy. A novel antitumor strategy using biocompatible exosomes (Ex) was devised by genetically engineering adipose-derived stem cells to express an MKN45-binding peptide (DE532) on their surfaces. 17-(Dimethylaminoethylamino)-17-demethoxygeldanamycin (17-DMAG) was encapsulated in engineered exosomes, resulting in 17-DMAG-loaded DE532 exosomes. In both in vitro and in vivo experiments using mouse gastric cancer xenograft models, we demonstrated that 17-DMAG-loaded DE532 Ex exhibited superior targetability over DE532 Ex, 17-DMAG-loaded Ex, and Ex. Administration of the 17-DMAG-loaded DE532 Ex yielded remarkable antitumor effects, as evidenced by the smallest tumor size, lowest tumor growth rate, and lowest excised tumor weight. Further mechanistic examinations revealed that the 17-DMAG-loaded DE532 Ex induced the highest upregulation of the pro-apoptotic marker B-cell lymphoma-2-like protein 11 and the lowest downregulation of the anti-apoptotic marker B-cell lymphoma-extra large. Concurrently, the 17-DMAG-loaded DE532 Ex demonstrated the lowest suppression of antioxidant enzymes, such as superoxide dismutase 2 and catalase, within tumor tissues. These findings underscore the potential of 17-DMAG-loaded DE532 exosomes as a potent therapeutic strategy for gastric cancer, characterized by precise targetability and the potential to minimize adverse effects.

Eosinophils in hidradenitis suppurativa patients exhibit pro-inflammatory traits, implicating a potential pathogenic role in the disease.

Hidradenitis suppurativa (HS) is an inflammatory skin disease characterized by painful nodules, abscesses and purulent secretions in intertriginous regions. Intense pruritus frequently accompanies HS lesions, adding further discomfort for patients. While Th17 pathway activation is implicated in HS pathogenesis, disease mechanisms are still not fully understood, and therapeutics are lacking. Previous reports raise a potential role for eosinophils in HS, showing a strong association of eosinophil levels with disease severity. To investigate eosinophils in HS, we recruited patients and matched healthy controls and then performed flow-cytometry studies, eosinophil stimulation assays, and lesional skin staining for eosinophils. We found that HS patients reported similar levels of pain and itch. Compared to matched controls, HS blood exhibited decreased mature eosinophils and increased numbers of immature eosinophils, coupled with a significant increase in dermal eosinophilic infiltrates. Additionally, IL-17RA+ eosinophils were highly and significantly correlated with multiple HS-related clinical scores. In both stimulated and unstimulated conditions, HS eosinophils showed an inflammatory phenotype versus controls, including an increase in costimulatory T- and B-cell markers (e.g. CD5 and CD40) following all stimulations (TNFα/IL-17A/IL-17F). These findings highlight the significance of pruritus in HS and suggest a higher turnover of eosinophils in HS blood, potentially due to the consumption of eosinophils in skin lesions. Our data delineate the features and functions of eosinophils in HS and suggest that eosinophils participate in disease pathogenesis, advancing Th17-related inflammation. Further studies are needed to investigate eosinophils' response to current HS treatments and their potential as a therapeutic target in the disease.

Transformation of t(14;18)-negative follicular lymphoma to plasmablastic lymphoma: a case report with analysis of genetic evolution

BackgroundFollicular lymphoma (FL) is characterized by t(14;18)(q32;q21) involving the IGH and BCL2 genes. However, 10–15% of FLs lack the BCL2 rearrangement. These BCL2-rearrangement−negative FLs are clinically, pathologically, and genetically heterogeneous. The biological behavior and histological transformation of such FLs are not adequately characterized. Here, we report the first case of t(14;18)-negative FL that rapidly progressed to plasmablastic lymphoma (PBL).Case presentationA previously healthy 51-year-old man presented with leg swelling. Computed tomography (CT) showed enlarged lymph nodes (LNs) throughout the body, including both inguinal areas. Needle biopsy of an inguinal LN suggested low-grade B-cell non-Hodgkin lymphoma. Excisional biopsy of a neck LN showed proliferation of centrocytic and centroblastic cells with follicular and diffuse growth patterns. Immunohistochemical analysis showed that the cells were positive for CD20, BCL6, CD10, and CD23. BCL2 staining was negative in the follicles and weak to moderately positive in the interfollicular areas. BCL2 fluorescence in situ hybridization result was negative. Targeted next-generation sequencing (NGS) revealed mutations in the TNFRSF14, CREBBP, STAT6, BCL6, CD79B, CD79A, and KLHL6 genes, without evidence of BCL2 or BCL6 rearrangement. The pathologic and genetic features were consistent with t(14;18)-negative FL. Two months after one cycle of bendamustine and rituximab chemotherapy, the patient developed left flank pain. Positron emission tomography/CT showed new development of a large hypermetabolic mass in the retroperitoneum. Needle biopsy of the retroperitoneal mass demonstrated diffuse proliferation of large plasmablastic cells, which were negative for the B-cell markers, BCL2, BCL6, and CD10; they were positive for MUM-1, CD138, CD38, and C-MYC. The pathologic findings were consistent with PBL. The clonal relationship between the initial FL and subsequent PBL was analyzed via targeted NGS. The tumors shared the same CREBBP, STAT6, BCL6, and CD79B mutations, strongly suggesting that the PBL had transformed from a FL clone. The PBL also harbored BRAF V600E mutation and IGH::MYC fusion in addition to IGH::IRF4 fusion.ConclusionsWe propose that transformation or divergent clonal evolution of FL into PBL can occur when relevant genetic mutations are present. This study broadens the spectrum of histological transformation of t(14;18)-negative FL and emphasizes its biological and clinical heterogeneity.

Diagnostic potential of vitreoretinal lymphoma by detection of gene mutations with NGS in 25 Chinese patients

BackgroundVitreoretinal lymphoma (VRL) is a rare malignant lymphoproliferative tumor. Our study aimed to investigate the mutational profile of VRL distinguishing from uveitis using next-generation sequencing (NGS) analysis on small amounts of vitreous fluid. MethodsVitreous samples from twenty-six eyes of twenty VRL patients and six eyes of five uveitis patients were enrolled. All vitreous samples underwent cytology, immunocytochemistry for B-cell markers, cytokines analysis of IL-10 and IL-6, and flow cytometry. NGS was performed in vitreous specimens from the 25 patients using 82 DLBCL-targeted mutation panels. Vitreous fluids from 8 cases were performed paired NGS-based mutation analysis on both cell-free DNA (cfDNA) and genomic DNA. ResultsThe sensitivity and accuracy rates for vitreous cytology were 70 % and 76 %, and for cytokine analysis (IL-10/IL-6 > 1) were 65 % and 72 %, respectively. Overall, the common mutations in VRL were PIM1 (88.5 %), IGLL5 (88.5 %), KMT2C (73 %), MYD88 (77 %), CD79B (50 %) and TBL1XR1 (46.2 %). In addition, the genetic mutation in cfDNA was consistent with that in genomic DNA in eight VRL cases. ConclusionsThe mutation analysis of 82 DLBCL-targeted spectrum mutation panels by NGS on the vitreous samples is a sensitive and specific tool for distinguishing VRL from uveitis. Utilizing cfDNA for NGS analysis may serve as a liquid biopsy to aid in the diagnosis of VRL, particularly when using small-volume aspirate.

The Genetic Landscape of Primary Breast Marginal Zone Lymphoma Identifies a Mutational-driven Disease With Similarities to Ocular Adnexal Lymphoma.

Extranodal marginal zone lymphomas (eMZL) can occur in any organ and site of the body. Recent research has shown that they differ from organ to organ in terms of their mutational profile. In this study, we investigated a cohort of primary breast marginal zone lymphomas (PBMZL) to get a better insight into their morphologic and molecular profile. A cohort of 15 cases (14 female and 1 male) was characterized by immunohistochemistry (IHC) for 19 markers, fluorescence in situ hybridization (FISH), and high throughput sequencing (HTS) using a lymphoma panel comprising 172 genes. In addition, PCR for the specific detection of Borrelia spp. and metagenomics whole genome sequencing were performed for infectious agent profiling. Follicular colonization was observed in most cases, while lymphoepithelial lesions, though seen in many cases, were not striking. All 15 cases were negative for CD5, CD11c, and CD21 and positive for BCL2 and pan B-cell markers. There were no cases with BCL2 , BCL10 , IRF4 , MALT1 , or MYC translocation; only 1 had a BCL6 rearrangement. HTS highlighted TNFAIP3 (n=4), KMT2D (n=2), and SPEN (n=2) as the most frequently mutated genes. There were no Borrelia spp. , and no other pathogens detected in our cohort. One patient had a clinical history of erythema chronicum migrans affecting the same breast. PBMZL is a mutation-driven disease rather than fusion-driven. It exhibits mutations in genes encoding components affecting the NF-κB pathway, chromatin modifier-encoding genes, and NOTCH pathway-related genes. Its mutational profile shares similarities with ocular adnexal and nodal MZL.

Abstract PO4-28-09: Upregulation of the immune checkpoint protein B7-H3 is associated with an immune suppressive microenvironment in progression from in situ to invasive lobular breast cancer

Abstract Invasive lobular breast cancer (ILC) is an understudied subtype of breast cancer characterized by late recurrence, metastasis to serosal surfaces including the peritoneum, and poor long-term outcomes. Lobular carcinoma in situ (LCIS) is a non-obligate precursor to ILC but is associated with a 30% increased risk of developing ILC. Therefore, understanding the underlying changes that occur in the invasive lobular cells as well as their tumor microenvironment (TME) during the transition from LCIS to ILC is critical for the development of novel therapeutic targets that could be used in early disease. To address this, we used combined spatial whole genome transcriptomics and a 97-protein proteomics assay to examine the spatial molecular profiles of coexistent LCIS and ILC. PanCK-positive tumor cells and panCK-negative stromal cells were segmented and analyzed separately for both RNA and protein. Despite the close spatial proximity of LCIS and ILC, there were notable differences in gene and protein expression in the tumor cells as well as the tumor microenvironment (TME). RNA profiling revealed significant upregulation of genes encoding essential components of the extracellular matrix, including type I, 3 and 5 collagens, small leucine-rich proteoglycans byglycan (BGN) and lumican (LUM), periostin (POSTN) and secreted protein acidic and cysteine rich (SPARC). Metalloprotease genes MMP2 and MMP11 were also upregulated. Genes highly expressed in the LCIS tumor compartment were KRT5, KRT14 KRT17 and MYLK which are highly expressed in myoepithelial cells at the periphery of the LCIS. One of the most upregulated proteins in ILC cells was B7 homology 3 protein (B7-H3) or Cluster of Differentiation 276 (CD276). B7-H3 is a transmembrane immunoregulatory protein belonging to the B7 family (that also includes PD-L1 and PD-L2). This immune checkpoint protein is overexpressed in many tumors but is barely expressed in normal cells. B7-H3 has been associated with several aspects of cancer progression, such as evasion of tumor immune surveillance and metastasis, and is strongly linked to poor prognosis in cancer. Compared to the LCIS TME, B7-H3 was also the most upregulated protein in the ILC TME along with the tumor-promoting M1 macrophage marker CD68 and the regulatory T-cell marker FOXP3. The lymphocyte marker CD45 was downregulated as well as T-cell proteins CD3, CD40 and granzyme B. Moreover, CD27, a memory B-cell marker was most highly expressed in the TME surrounding LCIS compared to ILC. Overall, these molecular profiles support a transition to a toward a much more immunosuppressive environment for invasive tumor cells compared to LCIS. Based on these data, our working hypothesis is that upregulation of B7-H3 on lobular tumor cells promotes invasion allowing interaction with laminins, integrins and other ECM proteins in the basement membrane and the interstitial membrane as LCIS acquire invasive properties of ILC. Furthermore, upregulation of B7-H3 on CD3+ HLA-DR+ expressing antigen presenting cells also promotes a suppressive immune microenvironment by inhibiting T-cell proliferation and downregulating cytokine production. In sum, these strongly concurrent spatial transcriptome and protein data suggest that B7-H3 and the immune suppressive network of ILC may be a promising target for early stage lobular breast cancer. B7-H3 Inhibitors could be explored in the neoadjuvant setting to evaluate the efficacy of immunotherapy in primary ILC. Citation Format: Lynda Bennett, Sunati Sahoo, Cheryl Lewis, Indu Raman, Candace Frerich, Guanchun Chen, Min Xu, Suzanne Conzen. Upregulation of the immune checkpoint protein B7-H3 is associated with an immune suppressive microenvironment in progression from in situ to invasive lobular breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO4-28-09.

The Evolving Landscape of Flowcytometric Minimal Residual Disease Monitoring in B-Cell Precursor Acute Lymphoblastic Leukemia.

Detection of minimal residual disease (MRD) is a major independent prognostic marker in the clinical management of pediatric and adult B-cell precursor Acute Lymphoblastic Leukemia (BCP-ALL), and risk stratification nowadays heavily relies on MRD diagnostics. MRD can be detected using flow cytometry based on aberrant expression of markers (antigens) during malignant B-cell maturation. Recent advances highlight the significance of novel markers (e.g., CD58, CD81, CD304, CD73, CD66c, and CD123), improving MRD identification. Second and next-generation flow cytometry, such as the EuroFlow consortium's eight-color protocol, can achieve sensitivities down to 10-5 (comparable with the PCR-based method) if sufficient cells are acquired. The introduction of targeted therapies (especially those targeting CD19, such as blinatumomab or CAR-T19) introduces several challenges for flow cytometric MRD analysis, such as the occurrence of CD19-negative relapses. Therefore, innovative flow cytometry panels, including alternative B-cell markers (e.g., CD22 and CD24), have been designed. (Semi-)automated MRD assessment, employing machine learning algorithms and clustering tools, shows promise but does not yet allow robust and sensitive automated analysis of MRD. Future directions involve integrating artificial intelligence, further automation, and exploring multicolor spectral flow cytometry to standardize MRD assessment and enhance diagnostic and prognostic robustness of MRD diagnostics in BCP-ALL.

The Oncolytic Effect of Aerva lanata on Osteosarcoma Cell Lines via the Apoptotic Signaling Pathway.

Introduction Osteosarcoma, a malignant bone tumor, poses significant treatment challenges, necessitating the development of alternative therapeutic strategies. Aerva lanata (A. lanata), a medicinal plant with traditional use in various healthcare systems, has anti-cancer properties. This study looks at the oncolytic effect of A. lanata extract on osteosarcoma cell lines (sarcoma osteogenic-Saos2). Aim The aim of this study was to investigate the oncolytic effect of Aerva lanata on Saos2 cell lines through the apoptotic signaling pathway. Materials and methods A. lanata extract was prepared using Soxhlet extraction, and its cytotoxic effects on Saos2 cells were assessed using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Real-time polymerase chain reaction (RT-PCR) analysis of gene activity was used to assess the extract's effect on apoptotic signaling pathways. Results The MTT assay demonstrated a dose-dependent decrease in Saos2 proliferation following treatment with A. lanata extract at concentrations ranging from 50 μg to 200 μg. The standard deviations observed ranged from 1.414 to 7.071. Gene expression analysis revealed that the extract led to a reduction in the messenger ribonucleic acid (mRNA) levels of the anti-apoptotic marker B-cell lymphoma 2 (Bcl2), with standard deviations ranging from 1 to 0.535. Conversely, it induced an increase in the mRNA levels of the tumor suppressor protein p53, with standard deviations ranging from 1 to 1.835. These findings suggest that the extract modulates the apoptotic pathways of the Bcl2 and p53 genes. Conclusion A. lanata extract exhibits promising anti-cancer activity against Saos2 osteosarcoma cell lines, inducing apoptosis by downregulating Bcl2 and increasing p53. The study's findings suggest that A. lanata may be useful as a natural treatment for osteosarcoma.

Esophageal carcinoma with SMARCA4 mutation: a narrative review for this rare entity.

Esophageal carcinoma with switch/sucrose nonfermenting (SWI/SNF)-related, matrix-associated, actin-dependent regulator of chromatin, subfamily A, member 4 (SMARCA4) mutation is a rare variant of malignant esophageal epithelial neoplasm, which is characterized by the loss of SMARCA4/BRG1 protein on immunohistochemistry or alterations in the SMARCA4 gene on sequencing. Only a few case series and case reports of esophageal carcinoma with SMARCA4 mutations have been published in the English literature; the rarity of the disease poses significant diagnostic challenges for surgical pathologists and could potentially lead to delayed or suboptimal patient care. Herein, we reviewed the available literature on esophageal carcinoma with SMARCA4 mutations to discuss its epidemiology, clinical presentation, pathological and molecular features, diagnostic challenges, treatment, and prognosis. The PubMed, Scopus, Ovid, and Google Scholar databases were extensively reviewed. The references included in the articles were cross-examined to identify any missing articles. We searched for all published literature on esophageal carcinoma with SMARCA4 mutations from inception of the databases to date. Esophageal carcinoma with SMARCA4 mutations is most common in middle-aged and older men. Barrett esophagus and gastroesophageal reflux disease (GERD) are the most associated risk factors. Dysphagia was the most common initial clinical presentation. Esophagogastroduodenoscopy (EGD) is the preferred diagnostic modality. Microscopically, the tumor cells exhibited epithelioid features mixed with variable components of rhabdoid and glandular differentiation. The tumor cells showed variable immunoreactivity for cytokeratin and sometimes weakly expressed neuroendocrine or B-lymphocyte markers (Pax5), which are potential diagnostic pitfalls. Melanoma marker tests showed negative results. The SMARCB1/INI1 protein remains intact, and a definitive diagnosis necessitates the presence of either SMARCA4/BRG1 protein loss or SMARCA4 gene mutations. Esophageal carcinoma with SMARCA4 mutations shows overly aggressive behavior and presents with advanced stages of disease; most patients succumb to the disease within 1 year of initial diagnosis. Esophageal carcinoma with SMARCA4 mutation is an overly aggressive disease, and further research on the affected molecular pathway may help improve its prognosis.

Water-in-oil adjuvant challenges in fish vaccination: An experimental inactivated adjuvanted vaccine against betanodavirus infection in Senegalese sole.

The extensive growth of intensive fish farming has led to a massive spread of infectious diseases. Nervous necrosis virus (NNV) is the causative agent of the viral encephalo- and retinopathy disease which has become a major threat for fish farming all over the globe. The devastating mortality rates recorded in disease outbreaks, especially when infected specimens are at early stages of development, have a high economic impact on the sector. Currently, vaccines are the most cost-effective preventing tool in the fight against viruses. Inactivated vaccines have the advantage of simplicity in their development at the same time as present the antigen in a similar manner than the natural infection in the host. Nevertheless, they usually trigger weaker immune responses needing adjuvants to boost their effectiveness. In this work, we have intraperitoneally vaccinated Senegalese sole juveniles (Solea senegalensis) with a previously designed inactivated vaccine against NNV based on binary ethylenimine (BEI), mixed or not with an oil-adjuvant. Our results demonstrated the potential activation of different immune pathways when the vaccine was administered alone compared to the oil-adjuvanted vaccine, both resulting in an equivalent partial improvement in survival following a NNV challenge. However, whilst the vaccine alone led to a significant increase in specific antibodies, in the adjuvanted version those antibodies were kept basal although with a slight improvement in their neutralization capacity. At transcriptional level, neither vaccine (adjuvanted or not) triggered the immune system activation during the vaccination period. However, after NNV infection, the BEI-inactivated vaccines alone and oil-adjuvanted both elicited the stimulation of antiviral responsive genes (rtp3, herc4), antigen presentation molecules (mhcii) and T-cell markers (cd8a) in the head-kidney. Additionally, the oil-adjuvanted vaccine appears to stimulate mediator cytokines (il6) and B-cell markers (ight and ighm). Surprisingly, when the adjuvant was administered alone, fish showed the highest survival rates concomitantly with a lack of NNV-IgM production, pointing to the possible induction of different immune pathways than the B-cell responses via antibodies by the adjuvant. Since this combined vaccine did not succeed in the full extension of protection against the pathogen, further studies should be performed focusing on unravelling the molecular mechanisms through which adjuvants trigger the immune response, both independently and when added to a vaccine antigen.

Abstract 3732: Peripheral pharmacodynamic activity of epcoritamab as monotherapy and in combination with rituximab + lenalidomide in patients with follicular lymphoma

Abstract Introduction: Epcoritamab (DuoBody®-CD3xCD20) is a subcutaneous IgG1 bispecific antibody that simultaneously binds to CD3 on T cells and CD20 on malignant B cells, inducing activation and cytotoxic activity of T cells to mediate killing of target lymphoma cells. Epcoritamab is approved in the US for the treatment of adults with relapsed/refractory (R/R) diffuse and high-grade large B-cell lymphoma after ≥2 lines of systemic therapy (also approved in Europe, the UK, Japan, and Canada). Here we present the pharmacodynamic effects of epcoritamab as monotherapy (EPCORE NHL-1: NCT03625037) or in combination with rituximab + lenalidomide (R2) (EPCORE NHL-2: NCT04663347) in peripheral blood of patients with follicular lymphoma (FL), a heterogeneous disease for which many patients have an unmet medical need for efficacious, well-tolerated, off-the-shelf therapies. Methods: In EPCORE NHL-1 expansion phase, adults with R/R FL received epcoritamab monotherapy; in EPCORE NHL-2, adults with R/R (arm 2) or newly diagnosed (ND) (arm 6) FL received epcoritamab combined with R2. B-cell markers and T-cell proliferation and activation markers in whole blood were assessed using validated flow cytometry assays. Cytokines in plasma were measured using a validated multiplex immunoassay. Results: Epcoritamab as monotherapy and in combination with R2 induced rapid depletion of circulating peripheral B cells (CD19+) in patients with detectable peripheral B cells at baseline. Additionally, within the first 2 cycles, epcoritamab monotherapy induced a transient elevation of peripheral CD8+ and CD4+ T cells expressing proliferation (Ki67+%) and activation (HLA-DR+% and PD-1+%) markers. R/R and ND patient groups treated with epcoritamab + R2 showed a trend for greater induction of proliferating and activated peripheral T cells. Likewise, elevation in T-cell absolute counts was observed from cycle 2 onward, with a trend of higher levels with epcoritamab + R2 vs epcoritamab monotherapy. In addition, a moderate but transient elevation of circulating cytokines including IFNγ, IL-6, and IL-10 during cycle 1 was observed with epcoritamab monotherapy and epcoritamab + R2. Importantly, IL-6 and IL-10 returned to approximate baseline levels prior to the subsequent dose. Compared with epcoritamab monotherapy, patients treated with epcoritamab + R2 showed a trend for lower median levels of IL-6 peaks 24 hours after the first full dose. Conclusion: The pharmacodynamic activity of epcoritamab combined with R2 in R/R and ND FL was consistent with epcoritamab’s mechanism of action as monotherapy. Epcoritamab + R2 showed a favorable pharmacodynamic profile with a trend toward increased T-cell activation and T-cell elevation, and lower IL-6 levels. These data support the ongoing phase 3 trial of epcoritamab + R2 compared with R2 alone in patients with R/R FL (EPCORE FL-1: NCT05409066). Citation Format: Han Si, Jimin Zhang, Monica Wielgos-Bonvallet, Lorenzo Falchi, Kim Linton, Wojciech Jurczak, David Belada, Işıl Altıntaş, Mariana Sacchi, Elena Favaro, Ali Rana, Daniela Hoehn, David Soong, Christopher W. Chiu, Maria Jure-Kunkel. Peripheral pharmacodynamic activity of epcoritamab as monotherapy and in combination with rituximab + lenalidomide in patients with follicular lymphoma [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3732.

Effect of Plasmapheresis on the Efficacy of Rituximab in Antibody-Mediated Rejection Patients

BACKGROUND: Rituximab and plasmapheresis (PP) are used to suppress and eliminate antibody production in patients suffering from antibody-mediated rejection (AMR). Herein, we discuss a case where rituximab was less effective after PP for treating AMR.CASE: A 55-year-old male patient underwent kidney transplantation, and her renal function remained normal for 1 year. Subsequently, renal function declined, and DSA(donor-specific antibodies) showed positive results. A biopsy of the transplanted kidney revealed antibody-mediated rejection. On the day of the biopsy, the medical staff administered rituximab 200 mg, followed by IVIG(IV immunoglobulin) and PP the next day. The time interval between PP + IVIG treatment and rituximab was 12 h. As a result, the B-cell markers CD 19 and CD 20 did not decrease sufficiently, and the patient's creatinine and GFR(glomerular filtration rate) muscles did not recover adequately.CONCLUSION: We report a case in which plasmapheresis was administered shortly after rituximab injection, resulting in insufficient B-cell inhibition due to the removal of rituximab.

Marginal Zone B Cells Are Necessary for the Formation of Anti-donor IgG After Allogeneic Sensitization.

The formation of anti-major histocompatibility complex (MHC) antibodies is a significant barrier for many patients awaiting organ transplantation. Patients with preformed anti-MHC antibodies have limited options for suitable donors, and the formation of donor-specific anti-MHC antibodies after transplantation is a harbinger of graft rejection. Despite the recognized importance of anti-MHC antibodies, the mechanisms responsible for the differentiation of B cells after exposure to allogeneic antigens are poorly understood. To evaluate the differentiation of B cells in response to allogeneic antigen, we used a model of H-2 b C57Bl/6 sensitization with H-2 d antigen. We used a class I MHC tetramer-based approach to identify allogeneic B cells and flow cytometric crossmatch to identify allogeneic IgM and IgG. We found that although the formation of anti-H-2 d IgG was robust, few class-switched B cells and germinal center B cells were formed. Antigen-specific B cells did not express classical memory B-cell markers after sensitization but had an IgM + CD21 + marginal zone B-cell phenotype. The frequency of marginal zone B cells increased after sensitization. Depletion of marginal zone B cells before sensitization or skin grafting resulted in a significant diminution of anti-H-2 d IgG and fewer germinal center B cells. Adoptive transfer experiments revealed that marginal zone B cells more efficiently differentiated into germinal center B cells and anti-donor IgG-producing cells than follicular B cells. These results demonstrate an important role for marginal zone B cells as a reservoir of alloreactive B cells that are activated by allogeneic antigens.

Optical genomic mapping is a helpful tool for detecting CCND1 rearrangements in CD5-negative small B-cell lymphoma: Two cases of leukemic non-nodal mantle cell lymphoma

Optical genome mapping (OGM) is a new DNA-based technology which provides comprehensive examination of the entire genome. We report two patients who presented with splenomegaly and leukocytosis with lymphocytosis including villous lymphocytes. Neither patient had lymphadenopathy. Bone marrow evaluation showed involvement by small B-cell lymphoma in a sinusoidal and interstitial distribution, and immunophenotypic analysis showed that the neoplastic cells were positive for B-cell markers and cyclin D1 but were negative for SOX11 and CD5. Initially, the clinicopathologic features in both patients were thought to be suspicious for hairy cell leukemia variant or splenic marginal zone lymphoma. However, OGM detected CCND1 rearrangement: t(2;11)/IGK::CCND1 in one case and t(11;14)/IGH::CCND1 in the other case. These cases illustrate the valuable role OGM can play in establishing the diagnosis of MCL. Case 1 also contributes to the paucity of literature on the rare occurrence of IGK::CCND1 in MCL.

Co-expression of regulatory B-cell markers, transforming growth factor β and interleukin-10 as a prognostic factor in diffuse large B-cell lymphoma

Regulatory B cells (Bregs) suppress antitumor immunity by producing anti-inflammatory cytokines such as transforming growth factor β (TGF-β) and interleukin-10 (IL-10) and promoting tumor growth. It is unknown whether diffuse large B-cell lymphoma (DLBCL), a common subtype of B-cell malignancy, exhibits characteristics similar to those of Bregs. This study aimed to clarify the features of DLBCLs carrying Breg markers. In 123 DLBCL cases, we evaluated TGF-β and IL-10 expression in tumor biopsy samples using immunohistochemical staining and retrospectively analyzed their clinicopathological characteristics. Fifteen cases (12.2 %) classified as Breg-type DLBCL were positive for both TGF-β and IL-10. Breg-type DLBCL is mainly classified as having activated B cell-like cells of origin. Breg-type DLBCL cases showed significantly worse progression-free survival and overall survival (OS) than other DLBCL cases (P = 0.0016 and P = 0.042, respectively). In multivariate analysis, Breg-type DLBCL significantly affected OS (hazard ratio, 3.13; 95 % confidence interval 1.15–8.55; P = 0.025). Gene expression analysis showed that the expression of follicular dendritic cell-associated genes (FCER2, PIK3CD, FOXO1) was downregulated in Breg-type DLBCLs compared to other DLBCLs. These results suggest that the double expression of Breg markers, TGF-β and IL-10, in tumor cells indicates a poor prognosis in DLBCL patients. Further studies evaluating genomic abnormalities could confirm the characteristics of Breg-type DLBCL.

Clinicopathologic features of relapsed CD19(-) B-ALL in CD19-targeted immunotherapy: Biological insights into relapse and LILRB1 as a novel B-cell marker for CD19(-) B lymphoblasts.

The mechanism of relapsed CD19(-) B-ALL after anti-CD19 immunotherapy (Kymriah [CART-19] and blinatumomab) is under active investigation. Our study aims to assess LILRB1 as a novel B-cell marker for detecting CD19(-) B-lymphoblasts and to analyze the clinicopathologic/genetic features of such disease to provide biological insight into relapse. Six patients (3 males/3 females, median age of 14 years) with relapsed CD19(-) B-ALL were analyzed for cytogenetic/genetic profile and immunophenotype. CD19(-) B-ALL emerged after an interval of 5.8 months following anti-CD19 therapy. Five of six patients had B-cell aplasia, indicative of a persistent effect of CART or blinatumomab at relapse. Importantly, LILRB1 was variably expressed on CD19(-) and CD19(+) B lymphoblasts, strong on CD34(+) lymphoblasts and dim/partial on CD34(-) lymphoblasts. Three of six patients with paired B-ALL samples (pre- and post-anti-CD19 therapy) carried complex and different cytogenetic abnormalities, either as completely different or sharing a subset of cytogenetic abnormalities. LILRB1 can be used as a novel B-cell marker to identify CD19(-) B lymphoblasts. The emergence of CD19(-) B-ALL appears to be associated with complex cytogenetic evolutions. The mechanism of CD19(-) B-ALL relapse under anti-CD19 immune pressure remains to be explored by comprehensive molecular studies.