A novel subset of T-helper cells: follicular T-helper cells and their markers

A viral vaccine design harnessing prior BCG immunization confers protection against Ebola virus

Previous studies have demonstrated the efficacy and feasibility of an anti-viral vaccine strategy that takes advantage of pre-existing CD4 + helper T (Th) cells induced by Mycobacterium bovis bacille Calmette-Guérin (BCG) vaccination. This strategy uses immunization with recombinant fusion proteins comprised of a cell surface expressed viral antigen, such as a viral envelope glycoprotein, engineered to contain well-defined BCG Th cell epitopes, thus rapidly recruiting Th cells induced by prior BCG vaccination to provide intrastructural help to virus-specific B cells. In the current study, we show that Th cells induced by BCG were localized predominantly outside of germinal centers and promoted antibody class switching to isotypes characterized by strong Fc receptor interactions and effector functions. Furthermore, BCG vaccination also upregulated FcγR expression to potentially maximize antibody-dependent effector activities. Using a mouse model of Ebola virus (EBOV) infection, this vaccine strategy provided sustained antibody levels with strong IgG2c bias and protection against lethal challenge. This general approach can be easily adapted to other viruses, and may be a rapid and effective method of immunization against emerging pandemics in populations that routinely receive BCG vaccination.

The complexities of T-cell dysfunction in chronic lymphocytic leukemia

Chronic lymphocytic leukemia (CLL) is a B-cell malignancy characterized by profound alterations and defects in the T-cell compartment. This observation has gained renewed interest as T-cell treatment strategies, which are successfully applied in more aggressive B-cell malignancies, have yielded disappointing results in CLL. Despite ongoing efforts to understand and address the observed T-cell defects, the exact mechanisms and nature underlying this dysfunction remain largely unknown. In this review, we examine the supporting signals from T cells to CLL cells in the lymph node niche, summarize key findings on T-cell functional defects, delve into potential underlying causes, and explore novel strategies for reversing these deficiencies. Our goal is to identify strategies aimed at resolving CLL-induced T-cell dysfunction which, in the future, will enhance the efficacy of autologous T-cell-based therapies for CLL patients.

Imbalance of Circulating Follicular Regulatory and Follicular Helper T Cell Subpopulations Is Associated with Disease Progression and Serum CYFRA 21-1 Levels in Patients with Non-small Cell Lung Cancer

OBJECTIVE

This study aimed to investigate the changes of follicular helper T (TFH) and follicular regulatory T (TFR) cell subpopulations in patients with non-small cell lung cancer (NSCLC) and their significance.

METHODS

Peripheral blood was collected from 58 NSCLC patients at different stages and 38 healthy controls. Flow cytometry was used to detect TFH cell subpopulation based on programmed death 1 (PD-1) and inducible co-stimulator (ICOS), and TFR cell subpopulation based on cluster determinant 45RA (CD45RA) and forkhead box protein P3 (FoxP3). The levels of interleukin-10 (IL-10), interleukin-17a (IL-17a), interleukin-21 (IL-21), and transforming growth factor-β (TGF-β) in the plasma were measured, and changes in circulating B cell subsets and plasma IgG levels were also analyzed. The correlation between serum cytokeratin fragment antigen 21-1 (CYFRA 21-1) levels and TFH, TFR, or B cell subpopulations was further explored.

RESULTS

The TFR/TFH ratio increased significantly in NSCLC patients. The CD45RA+FoxP3int TFR subsets were increased, with their proportions increasing in stages II to III and decreasing in stage IV. PD-1+ICOS+TFH cells showed a downward trend with increasing stages. Plasma IL-21 and TGF-β concentrations were increased in NSCLC patients compared with healthy controls. Plasmablasts, plasma IgG levels, and CD45RA+FoxP3int TFR cells showed similar trends. TFH numbers and plasmablasts were positively correlated with CYFRA 21-1 in stages I-III and negatively correlated with CYFRA 21-1 in stage IV.

CONCLUSION

Circulating TFH and TFR cell subpopulations and plasmablasts dynamically change in different stages of NSCLC, which is associated with serum CYFRA 21-1 levels and reflects disease progression.

Peripheral T-cell lymphoma with a T follicular-helper phenotype: A different entity? Results of the Spanish Real-T study

Nodal peripheral T-cell lymphoma (PTCL) with a T follicular helper phenotype (PTCL-TFH) is a new type of PTCL. We aimed to define its clinical characteristics and prognosis compared to PTCL not otherwise specified (PTCL-NOS) and angioimmunoblastic T-cell lymphoma (AITL). This retrospective observational study included 175 patients diagnosed with PTCL between 2008 and 2013 in 13 Spanish sites. Patient diagnosis was centrally reviewed, and patients were reclassified according to the World Health Organization (WHO) 2016 criteria: 21 patients as PTCL-NOS, 55 as AITL and 23 as PTCL-TFH. Median follow-up was 56.07 months (95% CI 38.7-73.4). Progression-free survival (PFS) and overall survival (OS) were significantly higher in patients with PTCL-TFH than in those with PTCL-NOS and AITL (PFS, 24.6 months vs. 4.6 and 7.8 months, respectively, p = 0.002; OS, 52.6 months vs. 10.0 and 19.3 months, respectively, p < 0.001). Histological diagnosis maintained an independent influence on both PFS (hazard ratio [HR] 4.1 vs. PTCL-NOS, p = 0.008; HR 2.6 vs. AITL, p = 0.047) and OS (HR 5.7 vs. PTCL-NOS, p = 0.004; HR 2.6 vs. AITL, p = 0.096), regardless of the International Prognostic Index. These results suggest that PTCL-TFH could have more favourable features and prognosis than the other PTCL subtypes, although larger series are needed to corroborate these findings.

Differences in the Tumor Microenvironment of EBV-Associated Gastric Cancers Revealed Using Single-Cell Transcriptome Analysis

Epstein-Barr virus (EBV) is a gamma-herpesvirus associated with nearly 10% of gastric cancers (GCs). These EBV-associated GCs (EBVaGCs) are molecularly, histopathologically, and clinically distinct from EBV-negative GCs (EBVnGCs). While viral genes in EBVaGCs contribute to the carcinogenesis process, viral proteins also represent foreign antigens that could trigger enhanced immune responses compared to EBVnGCs. Despite prior investigations of the EBVaGC tumor microenvironment (TME), the cellular composition has not been thoroughly explored. In this study, cellular subpopulations overrepresented in EBVaGCs were identified and molecularly characterized. Genes consistently expressed across both bulk tumor and single-cell RNA sequencing data were highlighted, with the expression across the identified cellular subpopulations analyzed. As expected, based on existing histopathological analysis, EBVaGC is characterized by abundant lymphocytic infiltration of the stroma. Our molecular analysis identified three unique immune cell subpopulations in EBVaGC: T and B cells expressing high levels of proliferation markers and B cells expressing T cell features. The proliferating T cell cluster also expressed markers of follicular T helper cells. Overall, EBVaGC also exhibited unique features indicative of a higher inflammatory response. These substantial differences within the TME suggest that further detailed exploration of the cellular composition of EBVaGCs is needed, which may identify cellular subpopulations and phenotypes associated with patient outcomes.

IDH2 and TET2 mutations synergize to modulate T Follicular Helper cell functional interaction with the AITL microenvironment

Angioimmunoblastic T cell lymphoma (AITL) is a peripheral T cell lymphoma that originates from T follicular helper (Tfh) cells and exhibits a prominent tumor microenvironment (TME). IDH2 and TET2 mutations co-occur frequently in AITL, but their contribution to tumorigenesis is poorly understood. We developed an AITL mouse model that is driven by Idh2 and Tet2 mutations. Malignant Tfh cells display aberrant transcriptomic and epigenetic programs that impair TCR signaling. Neoplastic Tfh cells bearing combined Idh2 and Tet2 mutations show altered cross-talk with germinal center B cells that promotes B cell clonal expansion while decreasing Fas-FasL interaction and reducing B cell apoptosis. The plasma cell count and angiogenesis are also increased in the Idh2-mutated tumors, implying a major relationship between Idh2 mutation and the characteristic AITL TME. Our mouse model recapitulates several features of human IDH2-mutated AITL and provides a rationale for exploring therapeutic targeting of Tfh-TME cross-talk for AITL patients.

Mesenchymal stem cells-based therapy in liver diseases

Multiple immune cells and their products in the liver together form a complex and unique immune microenvironment, and preclinical models have demonstrated the importance of imbalances in the hepatic immune microenvironment in liver inflammatory diseases and immunocompromised liver diseases. Various immunotherapies have been attempted to modulate the hepatic immune microenvironment for the purpose of treating liver diseases. Mesenchymal stem cells (MSCs) have a comprehensive and plastic immunomodulatory capacity. On the one hand, they have been tried for the treatment of inflammatory liver diseases because of their excellent immunosuppressive capacity; On the other hand, MSCs have immune-enhancing properties in immunocompromised settings and can be modified into cellular carriers for targeted transport of immune enhancers by genetic modification, physical and chemical loading, and thus they are also used in the treatment of immunocompromised liver diseases such as chronic viral infections and hepatocellular carcinoma. In this review, we discuss the immunological basis and recent strategies of MSCs for the treatment of the aforementioned liver diseases. Specifically, we update the immune microenvironment of the liver and summarize the distinct mechanisms of immune microenvironment imbalance in inflammatory diseases and immunocompromised liver diseases, and how MSCs can fully exploit their immunotherapeutic role in liver diseases with both immune imbalance patterns.

Expression of Programmed Cell Death-1 and Programmed Cell Death Ligands in Nodal Peripheral T-Cell Lymphoma: Expression Pattern and Potential Prognostic Relevance

Programmed cell death (PD)/PD-ligands (PD-Ls) pathway plays an important role in the regulation of physiologic immune response. Several cancers, including lymphoma exhibit abnormal PD-1/PD-Ls expression, which may contribute to treatment failure, progression, and inferior outcomes. PD-1/PD-Ls expression has predominantly been described in B-cell lymphoma; such data in peripheral T-cell lymphoma (PTCL) is limited. We described PD-1/PD-Ls expression patterns and associations with clinical characteristics and outcomes, in patients with systemic PTCLs. Correlation between PD-1/PD-Ls expression and outcomes was analyzed in patients who received lymphoma-specific therapy. PD-1/PD-Ls expression was observed across all common PTCL histologies at different proportions (PD-1 0%–76.9%, PD-L1 38.5%–62.5%, and PD-L2 62.5%–100%) with PD-1 being highly expressed in angioimmunoblastic T-cell lymphoma. Baseline characteristics were comparable between PD-1/PD-Ls expression status. Of 47 patients who received lymphoma-specific therapy, outcomes were similar across all PD-L1/PD-L2 subgroups. In the Cox proportional hazard analysis, treatment response was the only factor associated with survival outcomes. However, PD-1/PD-Ls expression, either in lymphoma or stroma, was not a predictor for survival outcomes. In conclusion, differential PD-1/PD-Ls expressions were observed among various histological PTCL subtypes. In this study, we were unable to demonstrate an association between PD-1/PD-Ls expression, clinical characteristics, treatment response, and outcomes of PTCL patients.

Landscape of 4D Cell Interaction in Hodgkin and Non-Hodgkin Lymphomas

Simple Summary

Little is known about the motility and interaction of primary human lymphoma cells in lymph nodes. The aim of this study therefore was to analyze for the first time if there are differences in motility and interaction with bystander cells between different lymphoma types and normal lymph nodes. We observed systematic differences between B cells and PD1-positive T cells. Furthermore, most cases of Hodgkin lymphomas had fast moving PD1-positive T cells, whereas there was little movement in other lymphoma types. Some lymphomas, particularly Hodgkin lymphomas, presented enhanced cell contacts between neoplastic and reactive cells, suggesting a dependency of lymphoma growth on cellular interaction.

Abstract

Profound knowledge exists about the clinical, morphologic, genomic, and transcriptomic characteristics of most lymphoma entities. However, information is currently lacking on the dynamic behavior of malignant lymphomas. This pilot study aimed to gain insight into the motility of malignant lymphomas and bystander cells in 20 human lymph nodes. Generally, B cells were faster under reactive conditions compared with B cells in malignant lymphomas. In contrast, PD1-positive T cells did not show systematic differences in velocity between reactive and neoplastic conditions in general. However, lymphomas could be divided into two groups: one with fast PD1-positive T cells (e.g., Hodgkin lymphoma and mantle cell lymphoma; means 8.4 and 7.8 µm/min) and another with slower PD1-positive T cells (e.g., mediastinal grey zone lymphoma; mean 3.5 µm/min). Although the number of contacts between lymphoma cells and PD1-positive T cells was similar in different lymphoma types, important differences were observed in the duration of these contacts. Among the lymphomas with fast PD1-positive T cells, contacts were particularly short in mantle cell lymphoma (mean 54 s), whereas nodular lymphocyte-predominant Hodgkin lymphoma presented prolonged contact times (mean 6.1 min). Short contact times in mantle cell lymphoma were associated with the largest spatial displacement of PD1-positive cells (mean 12.3 µm). Although PD1-positive T cells in nodular lymphocyte-predominant Hodgkin lymphoma were fast, they remained in close contact with the lymphoma cells, in line with a dynamic immunological synapse. This pilot study shows for the first time systematic differences in the dynamic behavior of lymphoma and bystander cells between different lymphoma types.

Peripheral T-Cell Lymphoma, Not Otherwise Specified: Clinical Manifestations, Diagnosis, and Future Treatment

Peripheral T-cell lymphoma, not otherwise specified (PTCL_NOS) corresponds to about one fourth of mature T-cell tumors, which overall represent 10-12% of all lymphoid malignancies. This category comprises all T-cell neoplasms, which do not correspond to any of the distinct entities listed in the WHO (World Health Organization) Classification of Tumours of Haematopoietic and Lymphoid Tissues. In spite of the extreme variability of morphologic features and phenotypic profiles, gene expression profiling (GEP) studies have shown a signature that is distinct from that of all remaining PTCLs. GEP has also allowed the identification of subtypes provided with prognostic relevance. Conversely to GEP, next-generation sequencing (NGS) has so far been applied to a limited number of cases, providing some hints to better understand the pathobiology of PTCL_NOS. Although several pieces of information have emerged from pathological studies, PTCL_NOS still remains a tumor with a dismal prognosis. The usage of CHOEP (cyclophosphamide, doxorubicin, vincristine, prednisone, etoposide) followed by autologous stem cell transplantation may represent the best option, by curing about 50% of the patients whom such an approach can be applied to. Many new drugs have been proposed without achieving the expected results. Thus, the optimal treatment of PTCL_NOS remains unidentified.

Characterization of CD4-Positive Lymphocytes in the Antiviral Response of Olive Flounder (Paralichthys oliveceus) to Nervous Necrosis Virus

The presence of CD4 T lymphocytes has been described for several teleost species, while many of the main T cell subsets have not been characterized at a cellular level, because of a lack of suitable tools for their identification, e.g., monoclonal antibodies (mAbs) against cell markers. We previously described the tissue distribution and immune response related to CD3ε and CD4-1 T cells in olive flounder (Paralichthys oliveceus) in response to a viral infection. In the present study, we successfully produce an mAb against CD4-2 T lymphocytes from olive flounder and confirmed its specificity using immuno-blotting, immunofluorescence staining, flow cytometry analysis and reverse transcription polymerase chain reaction (RT-PCR). Using these mAbs, we were able to demonstrate that the CD3ε T cell populations contain both types of CD4⁺ cells, with the majority of the CD4 T cell subpopulations being CD4-1⁺/CD4-2⁺ cells, determined using two-color flow cytometry analysis. We also examined the functional activity of the CD4-1 and CD4-2 cells in vivo in response to a viral infection, with the numbers of both types of CD4 T cells increasing significantly during the virus infection. Collectively, these findings suggest that the CD4 T lymphocytes in olive flounder are equivalent to the helper T cells in mammals in terms of their properties and function, and it is the CD4-2 T lymphocytes rather than the CD4-1 T cells that play an important role in the Th1 immune response against viral infections in olive flounder.

Application of a 5 Marker Panel to the Routine Diagnosis of Peripheral T-Cell Lymphoma With T-Follicular Helper Phenotype

The 2017 World Health Organization update introduced a new category of nodal peripheral T-cell lymphoma with T-follicular helper phenotype (PTCL-TFH) defined by expression of at least 2 or 3 TFH markers. Our study assesses the utility of an immunohistochemical panel of 5 TFH markers (CD10, BCL6, PD-1, CXCL13, and ICOS) for identification of TFH phenotype in angioimmunoblastic T-cell lymphoma (AITL) and PTCL not otherwise specified (NOS). Immunohistochemical for the 5 markers was performed on 22 cases of AITL and 29 cases of PTCL-NOS. Cases were reviewed for morphologic features characteristic of AITL. All AITL cases showed expression of ≥2 TFH markers. This panel resulted in reclassification of 41% PTCL-NOS cases to PTCL-TFH. Positive percent agreement for the TFH phenotype is 97% for PD1, 94% for ICOS, 44% for CD10 and CXCL13, and 29% for BCL6. Negative percent agreement for TFH phenotype is 100% for CD10, BCL6, and CXCL13, 82% for ICOS and 71% for PD1. AITL cases were more likely than PTCL-TFH cases to contain expanded CD21-positive follicular dendritic cell meshworks, clear cell cytology and polymorphous inflammatory background; however, there was a significant (P<0.005) Kruskal-Wallis trend in all morphologic variables between the 3 groups suggesting a continuum from PTCL-NOS to PTCL-TFH to AITL. The median number of morphologic features of AITL also correlated significantly with number of TFH markers positive (Spearman coefficient ρ=0.759). In summary, the stain panel chosen will have an impact on cases classified as PTCL-TFH. This entity may exist along a spectrum between PTCL-NOS and AITL.

Increased frequency of PD-1hiCXCR5- T cells and B cells in patients with newly diagnosed IgA nephropathy

Recent research has identified a population of PD-1^hiCXCR5⁻ ‘peripheral helper’ T (Tph) cells that simulate plasma cell differentiation by interactions between IL-21 and SLAMF5. However, the alteration of circulating Tph and CD138⁺ B in IgA nephropathy (IgAN) remains poorly understood. Flow cytometry analysis was used to measure the frequency of circulating PD-1^hiCXCR5⁻ T cells and CD138⁺ B cells in 37 patients with IgAN and 23 healthy controls (HCs). Estimated glomerular filtration rate (eGFR), 24 h urinary protein and serum cytokine concentrations were measured. The percentage of different subsets of circulating PD-1^hiCXCR5⁻ T cells and CD138⁺ B cells were significantly higher in patients with IgAN compared to HCs. Pretreatment, the percentage of different subsets of circulating PD-1^hiCXCR5⁻ T cells and CD138⁺ B cells were negatively correlated with eGFR, the percentage of circulating CD138⁺ B cells was positively correlated with 24-h urinary protein concentration, and the percentage of circulating PD-1^hiCXCR5⁻, CD28⁺ and ICOS⁺ T cells. Posttreatment, the percentage of different subsets of circulating PD-1^hiCXCR5⁻ T cells and CD138⁺ B cells and serum IL-21 concentration were significantly reduced. Different subsets of circulating PD-1^hiCXCR5⁻ T cells contribute to the progression and pathogenesis of IgAN by regulating the differentiation of CD138⁺ B cells through a combination of surface molecules.

[Revised WHO classification of tumors of hematopoietic and lymphoid tissues, 2017 (4th edition):lymphoid tumors]

The paper is devoted to changes in the 4^th edition of the WHO classification of lymphoid tumors in the 2017 revision, to the principles of the structure and features of the classification. It discusses changes in the identification of new clinical and morphological categories and in the abolition of some previously existing ones. New information about lymphoid tumors, their immunophenotypic and molecular characteristics of classification importance are briefly outlined. The absolute need for molecular genetic studies for the diagnosis of certain lymphoproliferative diseases is underlined. The characteristics of lymphoid pretumor states are given.

Transcriptome Network Analysis Identifies CXCL13-CXCR5 Signaling Modules in the Prostate Tumor Immune Microenvironment

The tumor immune microenvironment (TIME) consists of multiple cell types that contribute to the heterogeneity and complexity of prostate cancer (PCa). In this study, we sought to understand the gene-expression signature of patients with primary prostate tumors by investigating the co-expression profiles of patient samples and their corresponding clinical outcomes, in particular “disease-free months” and “disease reoccurrence”. We tested the hypothesis that the CXCL13-CXCR5 axis is co-expressed with factors supporting TIME and PCa progression. Gene expression counts, with clinical attributes from PCa patients, were acquired from TCGA. Profiles of PCa patients were used to identify key drivers that influence or regulate CXCL13-CXCR5 signaling. Weighted gene co-expression network analysis (WGCNA) was applied to identify co-expression patterns among CXCL13-CXCR5, associated genes, and key genetic drivers within the CXCL13-CXCR5 signaling pathway. The processing of downloaded data files began with quality checks using NOISeq, followed by WGCNA. Our results confirmed the quality of the TCGA transcriptome data, identified 12 co-expression networks, and demonstrated that CXCL13, CXCR5 and associated genes are members of signaling networks (modules) associated with G protein coupled receptor (GPCR) responsiveness, invasion/migration, immune checkpoint, and innate immunity. We also identified top canonical pathways and upstream regulators associated with CXCL13-CXCR5 expression and function.

Effects of Follicular Helper T Cells and Inflammatory Cytokines on Myasthenia Gravis

BACKGROUND

Myasthenia gravis (MG) is an autoimmune disorder mediated by antibodies against the acetylcholine receptors (AChR) of the skeletal muscles. An imbalance in various T helper (Th) cells, including Th1, Th2, Th17, Th22 and follicular helper T (TFH) cells, has been found associated with immunological disturbances.

OBJECTIVE

In this study, we aim to investigate the role of the Th cells in peripheral blood of MG patients.

MATERIALS AND METHODS

A total of 33 MG patients and 34 age matched controls were enrolled in this study. Peripheral blood mononuclear cells (PBMCs) were isolated using Ficoll-Paque density gradient centrifugation assay. The proportion of TFH cells in PBMC were analyzed using flow-cytometry assay by determining the levels of cellular markers CD4, CXCR5, CD45RO, CD45RA and ICOS and PD-1. The levels of IFN-γ, IL-4, IL-17 and IL-21 in serum were analyzed by Cytometric Bead Array. The serum IL-22 level was analyzed by ELISA.

RESULTS

The frequency of TFH cells in PBMCs was higher than those in healthy subjects and correlated to the severity of MG patients. The levels of pro-inflammatory cytokines IFN-γ, IL-17 and IL-21 were elevated in the serum of MG patients, while there were no significant differences regarding the levels of IL-4 and IL-22 between MG patients and control subjects.

CONCLUSION

Our findings suggest that Th cells and their cytokines balance of MG patients are involved in the clinical condition or severity of MG disease.

Maternal Immunity Influences Vertical Transmission of Hepatitis B to Newborns

Vertical transmission of hepatitis B virus (HBV) from the mother to the newborn often results in viral persistence. To understand mechanisms of maternofetal HBV transmission, we studied maternal immunity and peripheral blood mononuclear cell (PBMC) transcriptome in mothers and newborns. We included 50 mothers and babies who were hepatitis B surface antigen (HBsAg) positive: 22 HBV transmitting mothers (group [Gr.] I) and 28 HBV nontransmitting mothers (Gr. II) to newborns and 10 healthy mother-baby pairs (Gr. III). PBMCs were analyzed for HBV-specific dendritic cells (DCs), T cells, T follicular helper (TFh) cells, B cells, functional immune responses, and cytokine levels as well as transcriptome signatures to identify immune gene expression correlates for protective immunity. Group II mothers had lower HBsAg levels (3.82 × 10³ versus 1.493 × 10⁴; P < 0.0001) with greater HBV-specific responses of DCs, T cells, TFh cells, and B cells than Gr. I mothers. Frequencies of TFh cells were lower in Gr. I mothers, with reduced interleukin-21 (IL-21) levels, and these inversely correlated with HBV DNA levels. Cut-off levels of 9.5% and 8.93% from the receiver operating curve predicted the involvement of TFh cells and B cells in HBV transmission. Transcriptome signatures revealed that maternal gene imprints were reflected in the newborns. Genes related to DCs, TFh cells, and B cells were increased in Gr. II, and Gr. II newborns showed a boost in cellular and humoral responses after vaccination. Conclusion: In mothers infected with HBV, low serum IL-21 levels and decreased TFh-cell and plasma B-cell frequencies are associated with vertical transmission of HBV to newborns. These features are indicative of low protective maternal immunity.

Primary Cutaneous Follicular Helper T-Cell Lymphoma: A Case Series and Review of the Literature

Primary cutaneous follicular helper T-cell (Tfh) lymphoma is a recently described variant of peripheral T-cell lymphoma-not otherwise specified. This particular variant, usually presenting as a sudden onset of multiple plaques and nodules, is characterized by tumoral atypical T cells that express an array of Tfh markers, such as inducible T-cell costimulator, Bcl-6, CXCL13, PD-1, and CD10. The authors now present 3 patients whose known clinical skin findings are consistent with PTCL of Tfh origin (PTCL-Tfh). The typically protracted pattern of skin disease manifesting as scaly patches and plaques encountered in mycosis fungoides was not seen in our 3 cases, and there were distinguishing light microscopic and phenotypic features. These cases are similar to the few previous reported cases of PTCL-Tfh, although systemic involvement was not seen. The categorization of additional patients into this PTCL subtype in the medical literature would be needed to further characterize this new entity and may lead to better targeted treatments based on specific T-cell subtypes.

Using Murine Models to Investigate Tumor-Lymphoid Interactions: Spotlight on Chronic Lymphocytic Leukemia and Angioimmunoblastic T-Cell Lymphoma

The role of the tumor microenvironment in leukemias and lymphomas is well established, yet the intricacies of how the malignant cells regulate and influence their non-malignant counterparts remain elusive. For example, chronic lymphocytic leukemia (CLL) is an expansion of malignant CD5⁺CD19⁺ B cells, yet the non-malignant T cells play just as large of a role in disease presentation and etiology. Herein, we review the dynamic tumor cell to lymphoid repertoire interactions found in two non-Hodgkin's lymphoma subtypes: CLL and angioimmunoblastic T-cell lymphoma. We aim to highlight the pivot work done in the murine models which recapitulate these diseases and explore the insights that can be gained from studying the immuno-oncological regulation of non-malignant lymphoid counterparts.

Primary Cutaneous Follicular Helper T-cell Lymphoma in a Patient With Neurofibromatosis Type 1: Case Report and Review of the Literature

Patients with neurofibromatosis type 1 (NF-1) have a well-known predisposition for certain types of malignancies, including lymphoproliferative disorders. Cutaneous T-cell lymphoma (CTCL) has been reported in patients with NF-1, although it is considered a rare entity in this subset of patients. Cutaneous follicular helper T-cell lymphoma (CTFHCL) is a recently emerged rare subtype of CTCL with peculiar clinical and histopathological features and represents a diagnostic and therapeutic challenge. Only a few cases of CTFHCL have been reported in the literature. We report a case of CTFHCL in a patient with NF-1 and compare our findings with previously reported cases. We aim to raise awareness among pathologists regarding this rare subtype of CTCL and emphasize characteristic histological features of CTFHCL, which can be confused with B-cell lymphomas and lead to mismanagement.

T-cell Lymphomas: Updates in Biology and Diagnosis

Nodal-based peripheral T-cell lymphomas are heterogeneous malignancies with overlapping morphology and clinical features. However, the current World Health Organization classification scheme separates these tumors into prognostically relevant categories. Since its publication, efforts to uncover the gene expression profiles and molecular alterations have subdivided these categories further, and distinct subgroups are emerging with specific profiles that reflect the cell of origin for these tumors and their microenvironment. Identification of the perturbed biologic pathways may prove useful in selecting patients for specific therapies and associating biomarkers with survival and relapse.

Increased ratio of ICOS(+) /PD-1(+) follicular helper T cells positively correlates with the development of human idiopathic membranous nephropathy

To identify the frequencies of different subsets of peripheral blood follicular helper T (Tfh) cells in human idiopathic membranous nephropathy (IMN), 39 patients with new onset IMN and 18 age- and gender-matched healthy controls (HC) were enrolled for this study. The frequency of Tfh cells in venous blood were measured by flow cytometry, while concentration of serum IL-21 was detected by enzyme-linked immunosorbent assay. Correlation between the clinical features of IMN and Tfh cells was assessed by Spearman's rank correlation test. Overall, the frequencies of total, ICOS(+) , and PD-1(+) Tfh cells were increased in IMN patients, while the ratio of ICOS(+) /PD-1(+) Tfh cells positively correlated with IMN progression. However, the elevated serum IL-21 level in three subgroups of IMN patients, stratified based on 24-h urine protein levels, was not statistically significant compared to HC. Nonetheless, intracellular IL-21 in Tfh cells was generally increased in all IMN patients, and closely correlated with IMN development. Finally, the frequency of IL-21(+) Tfh cells and the ratio of ICOS(+) /PD-1(+) Tfh cells were positively correlated with the estimated 24-h urine protein of IMN patients. The data indicated that Tfh cells contribute to the pathogenicity of IMN. The ratio of ICOS(+) /PD-1(+) Tfh cells and the frequency of IL-21(+) Tfh cells may be indicators for evaluating the IMN development.

Increased CD4+CXCR5+T follicular helper cells in diabetic nephropathy

BACKGROUND

T follicular helper (Tfh) cells are known to regulate humoral immune response. In this study we examined the correlation of different subsets of peripheral blood Tfh cells in patients with diabetic nephropathy (DN).

METHODS

A total of 23 DN patients and 15 healthy controls (HC) were investigated for various subsets of Tfh cells by flow cytometry. The molecules ICOS⁺, PD-1⁺, CD28⁺, CD154⁺, IL-21⁺, IFN-γ⁺, IL-4⁺, IL-17⁺ Tfh cells were examined. The subsets of B cells were investigated by flow cytometry. The levels of 24 h urinary protein and estimated glomerular filtration rate (eGFR) were calculated. A potential correlation between the number of different subsets of Tfh cells, B cells and DN, was assessed.

RESULTS

The circulating CD4⁺CXCR5⁺PD-1⁺, PD-1⁺CD154⁺, PD-1⁺CD28⁺, PD-1⁺IL-21⁺, PD-1⁺IL-4⁺, PD-1⁺-IL-17⁺-Tfh cell counts, CD38⁺CD19⁺, CD38⁺CD19⁺CD40⁺ B cells and plasma levels of IL-21 were significantly increased in DN patients (p < 0.05), as compared to that in the HC group. Furthermore, the circulating CD4⁺CXCR5⁺PD-1⁺ Tfh cell counts negatively correlated with eGFR; Tfh cell counts positively correlated with 24 h urinary protein concentration in DN patients. Post-treatment, there was a significant reduction in the CD4⁺CXCR5⁺PD-1⁺ Tfh cell counts and its subsets, with a corresponding decrease in plasma levels of IL-6 and IL-17A (p < 0.05) in DN patients, as compared to the HCs.

CONCLUSION

An increased number of CD4⁺CXCR5⁺PD-1⁺ Tfh cells were observed in DN patients, which may be new targets for intervention in DN.

A critical role of T follicular helper cells in human mucosal anti-influenza response that can be enhanced by immunological adjuvant CpG-DNA

T Follicular helper cells (TFH) are considered critical for B cell antibody response, and recent efforts have focused on promoting TFH in order to enhance vaccine efficacy. We studied the frequency and function of TFH in nasopharynx-associated lymphoid tissues (NALT) from children and adults, and its role in anti-influenza antibody response following stimulation by a live-attenuated influenza vaccine (LAIV) or an inactivated seasonal virus antigen (sH1N1). We further studied whether CpG-DNA promotes TFH and by which enhances anti-influenza response. We showed NALT from children aged 1.5-10 years contained abundant TFH, suggesting efficient priming of TFH during early childhood. Stimulation by LAIV induced a marked increase in TFH that correlated with a strong production of anti-hemagglutinin (HA) IgA/IgG/IgM antibodies in tonsillar cells. Stimulation by the inactivated sH1N1 antigen induced a small increase in TFH which was markedly enhanced by CpG-DNA, accompanied by enhanced anti-HA antibody responses. In B cell co-culture experiment, anti-HA responses were only seen in the presence of TFH, and addition of plasmacytoid dendritic cell to TFH-B cell co-culture enhanced the TFH-mediated antibody production following CpG-DNA and sH1N1 antigen stimulation. Induction of TFH differentiation from naïve T cells was also shown following the stimulation. Our results support a critical role of TFH in human mucosal anti-influenza antibody response. Use of an adjuvant such as CpG-DNA that has the capacity to promote TFH by which to enhance antigen-induced antibody responses in NALT tissue may have important implications for future vaccination strategies against respiratory pathogens.

Elevated follicular helper T cells and expression of IL-21 in thyroid tissues are involved in the pathogenesis of Graves' disease

The follicular helper T cell (Tfh) and IL-21 have been shown to play an important role in many autoimmune diseases. However, less is known about their role in Graves' disease (GD). This study aimed to investigate the expression of Tfhs and related factors (IL-21, IL-21R, CXCR5, and CXCL13) in GD thyroid tissues and to explore the effect of IL-21 on thyroid follicular cells (TFCs). The expression of Tfh-related factors in GD and normal thyroid tissues was validated using immunohistochemistry, real-time polymerase chain reaction and Western blotting. Confocal microscopy confirmed the presence of Tfh and IL-21R on CD4(+)T-/CD19(+)B cell in GD thyroid tissues. Furthermore, the effect of IL-21 on cAMP production in TFCs upon thyroid-stimulating antibody (TSAb) stimulation was also examined by an in vitro bioassay. The increased expression of Tfh-related factors was observed in GD thyroid tissues compared to control subjects. Confocal microscopy further confirmed the presence of Tfhs and the expression of IL-21R on CD4(+)T cells and CD19(+)B cells in GD thyroid tissues. Moreover, the expression of IL-21mRNA in GD thyroid tissues was correlated with the levels of thyroid autoantibodies. Additionally, IL-21 could indirectly promote cAMP production upon TSAb stimulation in TFCs when cooperating with lymphocytes, and GD TFCs were more sensitive to IL-21 stimulation than normal TFCs. There is increased expression of Tfhs and related factors (IL-21, IL-21R, CXCR5, and CXCL13) in GD thyroid tissues, and the expression of IL-21mRNA in GD thyroid tissues was found to correlate with the serum levels of thyroid autoantibodies and thyroid hormones. Moreover, IL-21 could indirectly enhance the biological activity of TFCs upon TSAb stimulation when cooperating with lymphocytes in vitro, particularly in GD TFCs, suggesting that Tfh and IL-21 might be involved in the pathogenesis of GD.

Follicular helper T-cell-related lymphomas

In this issue of Blood, Wang et al describe the occurrence and pathogenetic relevance of IDH2R172 mutations in angioimmunoblastic T-cell lymphoma (AITL).

A higher frequency of CD4(+)CXCR5(+) T follicular helper cells in patients with newly diagnosed Henoch-Schönlein purpura nephritis

T follicular helper (TFH) cells play an important role in the humoral immune responses. The aim of this study was to examine the frequency of different subsets of CD4(+)CXCR5(+) TFH cells and B cells in patients with new-onset Henoch-Schönlein purpura nephritis (HSPN). The numbers of different subsets of CD4(+)CXCR5(+) TFH cells, B cells and the constituents of serum cytokines were detected in a total of 25 patients with newly diagnosed HSPN before and after treatment, and in 14 healthy controls (HC). The potential connection of these cells with the clinical characteristics in HSPN patients was analyzed. The numbers of circulating CD4(+)CXCR5(+), CD4(+)CXCR5(+)ICOS(+) and CD4(+)CXCR5(+)PD-1(+) TFH cells, CD86(+)CD19(+), CD38(+)CD19(+) B cells and serum IL-2, IL-4, IL-17A, IL-21 and IFN-γ were significantly higher in HSPN patients (p<0.05) than in HC. Before and after treatment the numbers of CD4(+)CXCR5(+) TFH cells were negatively correlated with the values of eGFR (r=-0.7162, p<0.05; r=-0.732, p<0.05, respectively). Similarly the numbers of CD4(+)CXCR5(+)PD-1(+) TFH cells were negatively correlated with 24-h urinary proteins (r=-0.4013, p<0.05; r=-0.7857, p<0.05, respectively), and the numbers of CD4(+)CXCR5(+)ICOS(+) TFH cells were positively correlated with the levels of serum IL-21 (r=0.5186, p<0.05; r=0.8503, p<0.05, respectively) and 24-h urinary protein (r=0.6045, p<0.05; r=0.833, p<0.05, respectively) in these patients, regardless of treatment. Following treatment the numbers of CD4(+)CXCR5(+), CD4(+)CXCR5(+)PD-1(+), and CD4(+)CXCR5(+)ICOS(+) TFH cells, as well as serum levels of IL-21 were significantly reduced, however IL-4 levels were noticeably increased (p<0.05). A higher frequency of circulating CD4(+)CXCR5(+) TFH cells existed in patients with HSPN and may be a viable therapeutic target.

Peripheral T-cell and NK cell lymphoproliferative disorders: cell of origin, clinical and pathological implications

T-cell lymphoproliferative disorders are a heterogeneous group of neoplasms with distinct clinical-biological properties. The normal cellular counterpart of these processes has been postulated based on functional and immunophenotypic analyses. However, T lymphocytes have been proven to be remarkably capable of modulating their properties, adapting their function in relationship with multiple stimuli and to the microenvironment. This impressive plasticity is determined by the equilibrium among a pool of transcription factors and by DNA chromatin regulators. It is now proven that the acquisition of specific genomic defects leads to the enforcement/activation of distinct pathways, which ultimately alter the preferential activation of defined regulators, forcing the neoplastic cells to acquire features and phenotypes distant from their original fate. Thus, dissecting the landscape of the genetic defects and their functional consequences in T-cell neoplasms is critical not only to pinpoint the origin of these tumors but also to define innovative mechanisms to re-adjust an unbalanced state to which the tumor cells have become addicted and make them vulnerable to therapies and targetable by the immune system. In our review, we briefly describe the pathological and clinical aspects of the T-cell lymphoma subtypes as well as NK-cell lymphomas and then focus on the current understanding of their pathogenesis and the implications on diagnosis and treatment.

IL-33 Enhances Humoral Immunity Against Chronic HBV Infection Through Activating CD4(+)CXCR5(+) TFH Cells

This study aimed to investigate the potential effect of interleukin 33 (IL-33) on humoral responses to hepatitis B virus (HBV) and the possible mechanisms underlying the action of IL-33 in regulating follicular helper T (TFH) cells. The impact of IL-33 treatment on the levels of serum HBV DNA, HBsAg, HBeAg, HBsAb, and HBeAb, as well as the frequencies of CD4(+)CXCR5(+) TFH cells in wild-type HBV transgenic (HBV-Tg) mice and in a transwell coculture of HepG2.2.15 with IL-33-treated peripheral blood mononuclear cells (PBMCs) were determined. Furthermore, the gene transcription profiles in IL-33-treated TFH cells were determined by microarrays. IL-33 treatment significantly reduced the levels of serum HBV DNA, HBsAg, and HBeAg, but increased the levels of HBsAb and HBeAb in HBV-Tg mice, accompanied by increased frequency of splenic infiltrating CD4(+)CXCR5(+) TFH cells in HBV-Tg. Similarly, coculture of HepG2.2.15 cells with IL-33-treated PBMCs reduced the levels of HBV DNA, HBsAg, and HBeAg, but increased the levels of HBsAb and HBeAb. Microarray analyses indicated that IL-33 significantly modulated the transcription of many genes involved in regulating TFH activation and differentiation. Our findings suggest that IL-33 may activate TFH cells, promoting humoral responses to HBV during the pathogenic process.

Increased circulating follicular helper T cells and activated B cells correlate with disease severity in patients with psoriasis

BACKGROUND

Follicular Helper T (TFH) Cells are a population of recently discovered CD4(+) T cells involved in autoimmune diseases. However, the contribution of TFH cells in patients with psoriasis remains unknown.

OBJECTIVE

We aimed to investigate the levels of TFH cells, B cells and their clinical relevance in patients with psoriasis.

METHODS

Using multi-colour flow cytometry, we detected different subsets of TFH cells and B cells in the peripheral blood of 27 patients with psoriasis and 13 healthy donors. Serum IL-21 levels were measured by ELISA. The relationship between the levels of TFH cells, IL-21, B cells and disease severity were analysed.

RESULTS

Compared with healthy donors, higher levels of circulating CD3(+) CD4(+) CXCR5(+) cells, CD3(+) CD4(+) CXCR5(+) ICOS(+), CD3(+) CD4(+) CXCR5(+) PD-1(+), CD3(+) CD4(+) CXCR5(+) ICOS(+) PD-1(+) TFH cells and CD19(+) IgD(+) CD27(-) naive B, CD19(+) CD86(+) activated B, but lower levels of CD19(+) IgD(+) CD27(+) preswitch and CD19(+) IgD(-) CD27(+) postswitch memory B cells, were observed in patients with psoriasis. In addition, serum IL-21 levels in patients with psoriasis were significantly higher than those in healthy donors, and showed to be positively correlated with the levels of different subsets of TFH cells, and the level of CD19(+) CD86(+) B cells was also correlated with TFH cells and IL-21 levels. Furthermore, a significant correlation was found between the levels of CD3(+) CD4(+) CXCR5(+) ICOS(+) TFH cells, CD3(+) CD4(+) CXCR5(+) ICOS(+) PD-1(+) TFH cells, CD19(+) CD86(+) B cells and IL-21 with Psoriasis Area and Severity Index scores.

CONCLUSION

The levels of TFH cells and activated B cells were increased in the peripheral blood of patients with psoriasis, and positively correlated with disease severity. These results suggest that TFH cells and activated B cells may play a role in the pathogenesis of psoriasis.

Expression of follicular helper T-cell markers in primary cutaneous T-cell lymphoma

The follicular helper T cells (TFH) seemed to be expressed in several subsets of T-cell lymphomas. However, their expression in cutaneous T-cell lymphomas (CTCLs) has been rarely described. We investigated the clinical features, histopathological morphology, and expression of TFH markers in CTCLs. Forty-nine patients (24 men and 25 women) diagnosed with CTCL were examined, 25 patients with mycosis fungoides (MF) and 24 with other CTCLs. Immunohistochemical staining for CD10, Bcl-6, inducible costimulator, CXCL13, and PD-1 were performed. Relation between PD-1 and clinical course in MF was evaluated. PD-1 was detected in 21 of 25 (84.0%) MF cases and in 11 of 24 (45.8%) other CTCL cases. Bcl-6, CXCL13, inducible costimulator, and CD10 were occasionally expressed in most T-cell lymphomas, including MF. The staining for PD-1 was negative in all the MF cases with large-cell transformation. No correlation was observed between disease course and PD-1 expression rate in the MF cases. In conclusion, among the TFH markers, PD-1 was most frequently expressed in CTCL. PD-1 was expressed in most MF. PD-1 expression rates were significantly higher in MF than in other CTCLs.

Global transcriptome analysis and enhancer landscape of human primary T follicular helper and T effector lymphocytes

T follicular helper (Tfh) cells are a subset of CD4(+) T helper cells that migrate into germinal centers and promote B-cell maturation into memory B and plasma cells. Tfh cells are necessary for promotion of protective humoral immunity following pathogen challenge, but when aberrantly regulated, drive pathogenic antibody formation in autoimmunity and undergo neoplastic transformation in angioimmunoblastic T-cell lymphoma and other primary cutaneous T-cell lymphomas. Limited information is available on the expression and regulation of genes in human Tfh cells. Using a fluorescence-activated cell sorting-based strategy, we obtained primary Tfh and non-Tfh T effector cells from tonsils and prepared genome-wide maps of active, intermediate, and poised enhancers determined by chromatin immunoprecipitation-sequencing, with parallel transcriptome analyses determined by RNA sequencing. Tfh cell enhancers were enriched near genes highly expressed in lymphoid cells or involved in lymphoid cell function, with many mapping to sites previously associated with autoimmune disease in genome-wide association studies. A group of active enhancers unique to Tfh cells associated with differentially expressed genes was identified. Fragments from these regions directed expression in reporter gene assays. These data provide a significant resource for studies of T lymphocyte development and differentiation and normal and perturbed Tfh cell function.

A higher frequency of CD4⁺CXCR5⁺ T follicular helper cells in adult patients with minimal change disease

Background. T follicular helper (TFH) cells are involved in the humoral immune responses. This study is aimed at examining the frequencies of different subsets of CD4⁺CXCR5⁺ TFH cells in adult patients with minimal change disease (MCD). Methods. A total of 27 patients and 14 healthy controls (HC) were characterized for the levels of sera cytokines, inducible T-cell costimulator (ICOS), and programmed death 1 (PD-1) of positive TFH cells by flow cytometry. The level of sera IL-21 was examined; 24 h urinary protein and eGFR were calculated. The potential correlation between the frequency of different subsets of TFH cells and the values of clinical measures in MCD patients were analyzed. Results. The frequency of circulating CD4⁺CXCR5⁺, CD4⁺CXCR5⁺ICOS⁺, and CD4⁺CXCR5⁺PD-1⁺ TFH cells and the levels of sera IL-17A, IFN-γ, IL-2, IL-10, IL-4, and IL-21 were significantly higher in MCD patients (P < 0.05) than that in the HC group. Furthermore, the percentages of circulating CD4⁺CXCR5⁺ TFH cells were negatively correlated with the values of eGFR (r = −0.4849, P < 0.05) and the percentages of CD4⁺CXCR5⁺PD-1⁺ TFH cells were correlated positively with the levels of serum IL-21 (r = 0.6137, P < 0.05) and 24 h urinary protein (r = 0.1410, P < 0.05) in those patients. Also, the percentages of CD4⁺CXCR5⁺ICOS⁺ TFH cells were correlated positively with the levels of serum IL-21 (r = 0.6201, P < 0.05) and 24 h urinary protein (r = 0.7519, P < 0.05). Following standard therapies, the percentages of circulating CD4⁺CXCR5⁺, CD4⁺CXCR5⁺PD-1⁺, and CD4⁺CXCR5⁺ICOS⁺ TFH cells and the levels of serum IL-21 were significantly reduced, but the levels of serum IL-4 and IL-10 were increased (P < 0.05). Conclusions. A higher frequency of CD4⁺CXCR5⁺ TFH cells that existed in adult patients with MCD could be new target for intervention of MCD.

Frequency of CD4+CXCR5+ TFH cells in patients with hepatitis b virus-associated membranous nephropathy

The frequency of different subsets of CD4(+)CXCR5(+) TFH cells and serum cytokine levels were analyzed in a total of 14 patients with newly diagnosed hepatitis B virus-associated membranous nephropathy (HBV-MN), 12 individuals with immune-tolerant HBV infection (HBV-IT) and 12 healthy controls (HC). Serum cytokine levels were measured before and 10-12 weeks after treatment. Significantly higher frequency of CD4(+)CXCR5(+), CD4(+)CXCR5(+)ICOS(+) and CD4(+)CXCR5(+)PD-1(+) TFH cells, and higher serum levels of IL-17A, IFN-γ, IL-2, IL-10, IL-4 and IL-21 were detected in HBV-MN patients compared to the HC. The percentage of CD4(+)CXCR5(+) TFH cells and serum IL-21 level in HBV-MN patients were also higher than the HBV-IT. The percentage of CD4(+)CXCR5(+) TFH cell was negatively correlated with the value of eGFR, and the percentage of CD4(+)CXCR5(+)ICOS(+) TFH cells was positively correlated with the 24-h urinary protein concentration. Notably, the percentage of CD4(+)CXCR5(+)PD-1(+) TFH cells was positively correlated with serum IL-21 level and 24-h urinary protein concentration. Treatment with prednisone or/and immunosuppressive drugs significantly reduced the frequency of CD4(+)CXCR5(+), CD4(+)CXCR5(+)PD-1(+) TFH cells and serum IL-21 level, but increased IL-4 and IL-10 levels in the patients. CD4(+)CXCR5(+) TFH cells, especially CD4(+)CXCR5(+)PD-1(+) TFH cells may participate in the pathogenesis of HBV-MN.

CD4+CXCR5+ follicular helper T cells in salivary gland promote B cells maturation in patients with primary Sjogren's syndrome

OBJECTIVE

To examine amount of CD4+CXCR5+Tfh cells and B cells subsets in salivary gland and peripheral blood from patients with primary Sjogren's syndrome (pSS) and to analyze whether the frequency of CD4+CXCR5+Tfh cells is associated with pSS pathologic process.

METHODS

The percentages of CD4+CXCR5+Tfh cells and B cell subsets were examined by flow cytometry. B-lymphocyte chemoattraetant (BLC; also called CXCL13), IL-21, IL-6 from the serum of pSS patients was assessed by polymerase chain reaction-enzyme-linked immunosorbent assay (ELISA).

RESULTS

The percentages of CD4+CXCR5+Tfh cells in peripheral blood were increased in pSS patients, but decreased after treatment with glucocorticoid and/or immunosuppressive drugs. Abnormal B cell subsets appeared in salivary and peripheral blood of pSS patients. The frequency of salivary CD4+CXCR5+Tfh cells was positively correlated with CD19+CD27+ memory B cells and CD19+CD27high plasma cells. Also increase of salivary CD19+CD27high plasma cells was positively associated with serum ANA titer of pSS patients.

CONCLUSIONS

CD4+CXCR5+Tfh cells are significantly increased in salivary and peripheral blood in pSS patients with aberrant CD19+CD27+ memory B cells and CD19+CD27high plasma cells, suggesting that CD4+CXCR5+Tfh cells may contribute to the pathogenesis of pSS by promoting the maturation of B cells.

Cytokine Gene Expression in CD4 Positive Cells of the Japanese Pufferfish, Takifugu rubripes

CD4⁺ T (Th) cells are a central component of the adaptive immune response and are divided into distinct sets based on their specific cytokine production pattern. Several reports have suggested that fish possess Th subset activity similar to that of mammals. The aim of the present study was to isolate CD4⁺ T cells from the blood of Japanese pufferfish, Fugu rubripes, and to characterize their cytokine expression profile. We produced a specific antibody against Fugu CD4 and performed cell sorting with the magnetic activated cell sorting system. Sorted Fugu CD4⁺ cells were characterized by morphology and expression analysis of cell marker genes. Fugu CD4⁺ cells expressed T-cell marker genes but not macrophage or B-cell marker genes. In addition, peripheral blood lymphocytes were stimulated with lipopolysaccharide (LPS), polycytidylic acid (polyI:C), concanavalin A (ConA) prior to sorting, and then Multiplex RT-PCR was used to examine the expression of Th cytokines by the stimulated Fugu CD4⁺ cells. LPS and polyI:C stimulation upregulated the expression of Th1, Th17 and Treg cytokines and downregulated the expression of Th2 cytokines. ConA stimulation upregulated the expression of all Th cytokines. These results suggest that fish exhibit the same upregulation of Th-specific cytokine expression as in mammals.

Intranodular clusters of activated cells with T follicular helper phenotype in nodular lymphocyte predominant Hodgkin lymphoma: a pilot study of 32 cases from Finland

In nodular lymphocyte predominant Hodgkin lymphoma (NLPHL), little is known about the presence of intranodular clusters of cytologically activated lymphoid cells producing a moth-eaten pattern histologically. This pilot study of 32 NLPHL cases from Finland ascertained (1) the frequency of the intranodular clusters of activated lymphoid cells, (2) the immunophenotype of the activated cells, (3) the size and immunophenotype of the rosetting cells, and (4) the clinical significance of the activated cells. Histologically, intranodular clusters of activated cells produced a moth-eaten pattern in 100% (32 cases; subtle in 62.5%, overt in 37.5%). In immunostains, activated cells in subtle clusters (20 cases) were very difficult to identify. Twelve cases had overt clusters of activated cells, which were positive with CD3, CD4, PD1, CXCL13 (T follicular helper [T(FH)] phenotype), but rarely with Ki-67 and BCL2. Most activated rosetting cells had the same immunophenotype as the nonrosetting cells, except for CXCL13. Clinical presentation for all 32 Finnish patients was distinctive: 97% men, 97% with peripheral lymphadenopathy and 35.5% with stage III/IV disease. Only 22% relapsed; 97% were in remission. There was no significant clinical difference between cases with overt and subtle clusters. Intranodular activated TFH cells in NLPHL appeared to be nonproliferating and not long-living, and they were not associated with any adverse clinical outcome. Although most activated cells were TFH cells, it seemed that they were unable to increase the number of malignant cells. The pathogenetic role of the intranodular activated TFH and the small T cells in NLPHL needs further investigation.

ESMO Consensus conferences: guidelines on malignant lymphoma. part 2: marginal zone lymphoma, mantle cell lymphoma, peripheral T-cell lymphoma

To complement the existing treatment guidelines for all tumour types, ESMO organizes consensus conferences to focus on specific issues in each type of tumour. In this setting, a consensus conference on the management of lymphoma was held on 18 June 2011 in Lugano, next to the 11th International Conference on Malignant Lymphoma. The conference convened ∼30 experts from all around Europe, and selected six lymphoma entities to be addressed; for each of them, three to five open questions were to be addressed by the experts. For each question, a recommendation should be given by the panel, referring to the strength of the recommendation based on the level of evidence. This consensus report focuses on the three less common lymphoproliferative malignancies: marginal zone lymphoma, mantle cell lymphoma, and peripheral T-cell lymphomas. A first report had focused on diffuse large B-cell lymphoma, follicular lymphoma, and chronic lymphocytic leukaemia.

Expansion of circulating counterparts of follicular helper T cells in patients with myasthenia gravis

Growing evidence has demonstrated that dysfunction of follicular helper T (TFH) cells results in an abnormal positive selection of autoreactive B cells, which contributes to the development of autoimmune diseases. This study reveals that the frequency of circulating counterparts of TFH cells in myasthenia gravis (MG) patients is significantly higher compared to healthy controls. Interestingly, the frequencies of circulating TFH cells were positively correlated with the levels of serum anti-AChR Ab in MG patients. Our data suggest the presence of overactivation and expansion of circulating counterparts of TFH cells in MG patients, which may contribute to the immunopathogenesis of MG.

Follicular T-cell lymphoma: a member of an emerging family of follicular helper T-cell derived T-cell lymphomas

Unlike B-cell lymphomas, where knowledge of normal B-cell origin and differentiation has greatly contributed to their classification, the current classification of peripheral T-cell lymphomas is limited by a lack of understanding of their cellular origin. In the current World Health Organization classification of lymphomas, follicular T-cell lymphoma was formally recognized as a morphologic variant of peripheral T-cell lymphoma, not otherwise specified. There is growing evidence, however, that follicular T-cell lymphoma may be a unique clinicopathologic entity based on its morphologic features and derivation from follicular helper T-cells. In addition, there are abundant recent data supporting the concept that follicular helper T-cells can give rise to other types of T-cell lymphoma, including angioimmunoblastic T-cell lymphoma, primary cutaneous CD4+ small/medium T-cell lymphoma, and a subset of neoplasms, in addition to follicular T-cell lymphoma, currently classified as peripheral T-cell lymphoma, not otherwise specified. In this review, we focus primarily on the clinicopathologic, immunophenotypic, and molecular features of follicular T-cell lymphoma and discuss its potential relationship with other types of T-cell lymphoma thought to be derived from follicular helper T-cells.

New molecular insights into peripheral T cell lymphomas

Peripheral T cell lymphomas (PTCLs) are heterogeneous neoplasms and represent about 12% of all lymphoid malignancies. They are often regarded as "orphan diseases," a designation that does not reflect their real incidence but rather signifies the difficulties encountered in their classification, diagnosis, and treatment. Here we revise the current understanding of the pathobiological characteristics of the most common nodal PTCLs by focusing on the contribution given by high-throughput technologies and the identification of potential therapeutic targets proposed by translational studies.