Non-lymphoid Cells Research Articles

Impact on N-Glycosylation profile of monoclonal anti-D antibodies as a way to control their immunoregulatory and cytotoxic properties

Prophylaxis of hemolytic disease of newborns is based on the ability of polyclonal anti-D antibodies for suppressing maternal immune response against D-positive fetal red blood cells. The immunosuppressive effect of anti-D antibody is mediated by interaction between its Fc-fragment and low-affinity IgG Fc-receptor (FcγR) on the immune cell. No clinically effective monoclonal anti-D antibody (mAb) that can replace polyclonal anti-D immunoglobulin has been developed yet. The goals of this study were comparison of structural and functional properties of human anti-D polyclonal and monoclonal Abs and assessment of the possibility to manipulate the effector properties of the mAb. N-Glycosylation and particularly the content of nonfucosylated glycans are crucial for affinity of mAb to FcγRIIIA, which plays the key role in the clearance of sensitized cells. We studied and compared glycoprofiles and FcγRIIIA-mediated hemolytic ability of human polyclonal antibodies and anti-D mAbs produced by human B-cell lines, human-rodent heterohybridomas, and a human non-lymphoid cell line PER.C6. Replacement of producing cell line and use of glycosylation modulators can convert an inert mAb into an active one. Nevertheless, rodent cell lines, as well as human non-lymphoid cells, distort natural glycosylation of human IgG and could lead to the loss of immunosuppressive properties. All of the anti-D mAbs secreted by human B-cell lines have a glycoprofile close to human serum IgG. Hence, the constant ratio of IgG glycoforms in human serum is predetermined by glycosylation at the level of the individual antibody-producing cell. The anti-D fraction of polyclonal anti-D immunoglobulin compared to the total human IgG contains more nonfucosylated glycans. Thus, only human transformed B-cells are an appropriate source for efficient anti-D mAbs that can imitate the action of polyclonal anti-D IgG.

Human Tissues Contain CD141hi Cross-Presenting Dendritic Cells with Functional Homology to Mouse CD103+ Nonlymphoid Dendritic Cells

SummaryDendritic cell (DC)-mediated cross-presentation of exogenous antigens acquired in the periphery is critical for the initiation of CD8+ T cell responses. Several DC subsets are described in human tissues but migratory cross-presenting DCs have not been isolated, despite their potential importance in immunity to pathogens, vaccines, and tumors and tolerance to self. Here, we identified a CD141hi DC present in human interstitial dermis, liver, and lung that was distinct from the majority of CD1c+ and CD14+ tissue DCs and superior at cross-presenting soluble antigens. Cutaneous CD141hi DCs were closely related to blood CD141+ DCs, and migratory counterparts were found among skin-draining lymph node DCs. Comparative transcriptomic analysis with mouse showed tissue DC subsets to be conserved between species and permitted close alignment of human and mouse DC subsets. These studies inform the rational design of targeted immunotherapies and facilitate translation of mouse functional DC biology to the human setting.

Terminal deoxynucleotidyl transferase requires KU80 and XRCC4 to promote N-addition at non-V(D)J chromosomal breaks in non-lymphoid cells

Terminal deoxynucleotidyl transferase (TdT) is a DNA polymerase that increases the repertoire of antigen receptors by adding non-templated nucleotides (N-addition) to V(D)J recombination junctions. Despite extensive in vitro studies on TdT catalytic activity, the partners of TdT that enable N-addition remain to be defined. Using an intrachromosomal substrate, we show here that, in Chinese hamter ovary (CHO) cells, ectopic expression of TdT efficiently promotes N-additions at the junction of chromosomal double-strand breaks (DSBs) generated by the meganuclease I-SceI and that the size of the N-additions is comparable with that at V(D)J junctions. Importantly, no N-addition was observed in KU80- or XRCC4-deficient cells. These data show that, in a chromosomal context of non-lymphoid cells, TdT is actually able to promote N-addition at non-V(D)J DSBs, through a process that strictly requires the components of the canonical non-homologous end-joining pathway, KU80 and XRCC4.

Catecholaminergic signalling through thymic nerve fibres, thymocytes and stromal cells is dependent on both circulating and locally synthesized glucocorticoids

Glucocorticoids have been shown to modulate the expression of noradrenaline metabolizing enzymes and β(2)- and α(1B)-adrenoceptors in a tissue- and cell- specific manner. In the thymus, apart from extensive sympathetic innervation, a regulatory network has been identified that encompasses catecholamine-containing non-lymphoid and lymphoid cells. We examined a putative role of adrenal- and thymus-derived glucocorticoids in modulation of rat thymic noradrenaline levels and adrenoceptor expression. Seven days postadrenalectomy, the thymic levels of mRNAs encoding tyrosine hydroxylase, dopamine β-hydroxylase, monoamine oxidase-A and, consequently, noradrenaline were decreased. Catecholamine content was diminished in autofluorescent nerve fibres (judging by the intensity of fluorescence) and thymocytes (considering HPLC measurements of noradrenaline and the frequency of tyrosine hydroxylase-positive cells), while it remained unaltered in non-lymphoid autofluorescent cells. In addition, adrenalectomy diminished the thymocyte expression of β(2)- and α(1B)-adrenoceptors at both mRNA and protein levels. Administration of ketoconazole (an inhibitor of glucocorticoid synthesis/action; 25 mg kg(-1) day(-1), s.c.) to glucocorticoid-deprived rats increased the thymic levels of tyrosine hydroxylase, dopamine β-hydroxylase and, consequently, noradrenaline. The increased intensity of the autofluorescent cell fluorescence in ketoconazole-treated rats indicated an increase in their catecholamine content, and suggested differential glucocorticoid-mediated regulation of catecholamines in thymic lymphoid and non-lymphoid cells. In addition, ketoconazole increased the thymocyte expression of α(1B)-adrenoceptors. Thus, this study indicates that in the thymus, as in some other tissues, glucocorticoids not only act in concert with cateholamines, but they may modulate catecholamine action by tuning thymic catecholamine metabolism and adrenoceptor expression in a cell-specific manner. Additionally, the study indicates a role of thymus-derived glucocorticoids in this modulation.

CD45-deficient severe combined immunodeficiency caused by uniparental disomy

Analysis of the molecular etiologies of SCID has led to important insights into the control of immune cell development. Most cases of SCID result from either X-linked or autosomal recessive inheritance of mutations in a known causative gene. However, in some cases, the molecular etiology remains unclear. To identify the cause of SCID in a patient known to lack the protein-tyrosine phosphatase CD45, we used SNP arrays and whole-exome sequencing. The patient's mother was heterozygous for an inactivating mutation in CD45 but the paternal alleles exhibited no detectable mutations. The patient exhibited a single CD45 mutation identical to the maternal allele. Patient SNP array analysis revealed no change in copy number but loss of heterozygosity for the entire length of chromosome 1 (Chr1), indicating that disease was caused by uniparental disomy (UPD) with isodisomy of the entire maternal Chr1 bearing the mutant CD45 allele. Nonlymphoid blood cells and other mesoderm- and ectoderm-derived tissues retained UPD of the entire maternal Chr1 in this patient, who had undergone successful bone marrow transplantation. Exome sequencing revealed mutations in seven additional genes bearing nonsynonymous SNPs predicted to have deleterious effects. These findings are unique in representing a reported case of SCID caused by UPD and suggest UPD should be considered in SCID and other recessive disorders, especially when the patient appears homozygous for an abnormal gene found in only one parent. Evaluation for alterations in other genes affected by UPD should also be considered in such cases.

E2A and CBP/p300 Act in Synergy To Promote Chromatin Accessibility of the Immunoglobulin κ Locus

V(D)J recombination of Ig and TCR genes is strictly regulated in a lineage- and stage-specific manner by the accessibility of target gene chromatin to the recombinases RAG1 and RAG2. It has been shown that enforced expression of the basic helix-loop-helix protein, E2A, together with RAG1/2 in a nonlymphoid cell line BOSC23 can induce V(D)J recombination in endogenous Igκ and TCR loci by increasing chromatin accessibility of target gene segments. In this study, we demonstrate that ectopically expressed E2A proteins in BOSC23 cells have the ability to bind directly to the promoter and recombination signal sequence of Vκ genes and to recruit histone acetyltransferase CBP/p300. Overexpression of CBP/p300 in conjunction with E2A results in enhancement of E2A-induced histone acetylation, germline transcription, and Igκ rearrangement. Conversely, knockdown of endogenous CBP/p300 expression by small interfering RNA leads to a decrease in histone acetylation, germline transcription and Igκ rearrangement. Furthermore, analyses using a mouse pre-B cell line revealed that endogenous E2A proteins also bind to a distinct set of Vκ genes and regulatory regions in the mouse Igκ locus and act to increase histone acetylation by recruiting p300, confirming the similar findings observed with BOSC23 cells. These observations indicate that E2A plays critical roles in inducing Igκ rearrangement by directly binding to and increasing chromatin accessibility at target gene segments.

The induction of FoxP3 in naive T cells is dependent upon the transcription factors TFE3 and TFEB. (163.4)

Abstract TFE3 and TFEB are members of the basic helix-loop-helix leucine zipper MiTF/TFE (Microphthalmia-associated transcription factor) family of transcription factors. They are ubiquitously expressed in human and murine tissue and form homo- and/or heterodimers to bind the E-box core sequence CAYGTG. Using a transgenic mouse line expressing a trans dominant negative (TDN) inhibitor of TFE3 and TFEB in T cells, we previously showed that CD40L is a key target of both TFE3 and TFEB and that inactivating these molecules causes hyper IgM syndrome. Unexpectedly, we now show that naïve T cells from these mice have a significant defect in the in vitro differentiation into the inducible T regulatory (iTreg) phenotype, demonstrated by reduced induction of the hallmark Treg transcription factor, FoxP3. Although Smad7, a negative regulator of TGFβ signaling, is a target gene of TFE3 in non-lymphoid cells, preliminary results indicate its expression is unaffected in these cells, as is the phosphorylation of Smad3, indicating TGFβ signaling pathway is intact. This suggests TFE3/B are important in Treg differentiation, possibly as direct regulators of the FoxP3 gene. This combined evidence demonstrates a multiplicity of roles for TFE3 and TFEB in T cell function.

Selective Accumulation of Th2-skewing Immature Erythroid Cells in Developing Neonatal Mouse Spleen

Environmental factors likely regulate neonatal immunity and self-tolerance. However, evidence that the neonatal immune system is suppressed or deviated is varied depending on the antigen and the timing of antigen exposure relative to birth. These disparate findings may be related to the availability of the appropriate antigen presenting cells but also point to the possibility of homeostatic changes in non-lymphoid cells in the relevant lymphoid tissues. Here we show that, while leukocytes are the most abundant cell population present in spleen during the first 4-5 days after birth, a massive accumulation of nucleated immature erythroid population in the spleen takes places on day 6 after birth. Although the relative frequency of these immature erythorid cells slowly decreases during the development of neonates, they remain one of the most predominant populations up to three weeks of age. Importantly, we show that the immature erythroid cells from neonate spleen have the capacity to modulate the differentiation of CD4 T cells into effector cells and provide a bias towards a Th2 type instead of Th1 type. These nucleated erythroid cells can produce cytokines that participate in the Th2/Th1 balance, an important one being IL-6. Thus, the selective accumulation of immature erythroid cells in the spleen during a specific period of neonatal development may explain the apparent differences observed in the type(s) of immune responses generated in infants and neonates. These findings are potentially relevant to the better management of immune deficiency in and to the design of vaccination strategies for the young.

Immunoglobulin G expression and its colocalization with complement proteins in papillary thyroid cancer

Except for the well-known immunoglobulin G (IgG) producing cell types, ie, mature B lymphocytes and plasma cells, various non-lymphoid cell types, including human cancer cells, neurons, and some specified epithelial cells, have been found to express IgG. In this study, we detected the expression of the heavy chain of IgG (IgGγ) and kappa light chain (Igκ) in papillary thyroid cancer cells. Using in situ hybridization, we detected the constant region of human IgG1 (IGHG1) in papillary thyroid cancer cells. With laser capture microdissection followed by RT-PCR, mRNA transcripts of IGHG1, Igκ, recombination activating gene 1 (RAG1), RAG2, and activation-induced cytidine deaminase genes were successfully amplified from isolated papillary thyroid cancer cells. We further confirmed IgG protein expression with immunohistochemistry and found that none of the IgG receptors was expressed in papillary thyroid cancer. Differences in the level of IgGγ expression between tumor size, between papillary thyroid cancer and normal thyroid tissue, as well as between papillary thyroid cancer with and without lymph node metastasis were significant. Taken together, these results indicate that IgG is produced by papillary thyroid cancer cells and that it might be positively related to the growth and metastasis of papillary thyroid cancer cells. Furthermore, it was demonstrated that IgGγ colocalized with complement proteins in the same cancer cells, which could indicate that immune complexes were formed. Such immune complexes might consist of IgG synthesized by the host against tumor surface antigens and locally produced anti-idiotypic IgG with specificity for the variable region of these ‘primary' antibodies. The cancer cells might thus escape the host tumor-antigen-specific immune responses, hence promoting tumor progression.

Comment on "Pseudopautrier's Abscess"

Comment on Pseudopautrier's Abscess Dear Editor: We read with great interest article by Lee et al.1 entitled three dimensional conformal radiotherapy for hyperkeratotic plantar mycosis fungoides1. We agree with effectiveness of three-dimensional conformal radiotherapy for hyperkeratotic plantar mycosis fungoides (MF) and appreciate educational figures. However, in this case report, authors have described the presence of intraepidermal collections of mononuclear cells showing hyperchromatic atypical cells that were compatible with Pautrier's microabscesses (PA). We would like to suggest intraepidermal mononuclear collections described by authors are not consistent with PA, but with pseudopautrier abscesses (PPA), regarded as a marker of spongiotic processs. PA are one of pathologic hallmarks of MF. They represent punch-out spaces in epidermis filled with malignant T-lymphocytes (sometimes cerebriform). The aggregates of clonal T cells around Langerhans' cells explain dependence of T cells on interactions with these dendritic cells, particularly in early stages of disease2. PPA were first described as spongiotic stimulants of PA by Ackerman et al.3 in 1974. They consist of Langerhans cells, histiocytes, stellate keratinocytes and rare lymphocytes. In one study by Candiago et al.4, they were found in a variety of inflammatory disorders showing epidermal spongiosis, and were particularly frequent in spongiotic (43.4%), in lichenoid dermatitis (10%), and notably in MF (13.3%). Moreover, according to Kang et al.5, PPA were expressed in up to 25.5% of MF (24/94). They emphasize that differential diagnostic hallmarks between PPA and PA are morphology, cell types, and particularly additional immunohistochemical findings, as shown in Fig. 1, ​,22. Fig. 1 (A) Histopathologic findings show pseudopautrier abscess (PPA, arrow) with focal spongiosis and spongiotic vesicles (H&E, ×100). (B~D) CD1a (B) as well as CD68 (D) is expressed on most cells within PPA (arrow), but negative for CD3 (C). ... Fig. 2 (A) Histopathologic findings display Pautrier's microabscess (PA, arrow) (H&E, ×100). (B~E) Most cells within PA (arrow) are positive for CD3, but negative for CD1a, CD68, and high molecular weight cytokeratin. Histologic findings considered as PA by Lee et al.1 favor more PPA, judging from adjacent prominent spongiosis, and predominance of nonlymphoid cells, showing presence of histiocyte, Langerhans cell, and stellate keratinocyte without atypical features. Additional immunohistochemical study will be also useful in differential diagnosis, using CD1a, CD3, CD4, CD68, and high molecular cytokeratin5. PPA are not an infrequent histologic finding in MF, particularly more common with MF palmaris et plantaris referring to hyperkeratotic MF5. Thus, it is not suitable to exclude diagnosis of MF unquestionably, when PPA are seen in biopsy specimen. In addition, when collections of intraepidermal mononuclear cells are observed in typical MF, clinician should be cautious before concluding they are PA, and a careful histological and immunohistochemical evaluation must be performed carefully to distinguish PPA from PA.

Interleukin -7 (IL-7) Increases Metabolic Thymic and CNS Activity

Interleukin-7 (IL-7) is currently used in a number of clinical trials in humans, including treatment trials for patients with HIV or HCV infection. We would like to draw the attention concerning the impact of IL-7 on the central nervous system (CNS), since most clinical evaluations may not include detailed CNS examination, e.g. Positron Emission Tomography - Computed Tomography (PET-CT) or the evaluation of changes in complex behavior patterns. Increased IL-7-mediated thymic activity demonstrates that viable thymic tissue can be activated in younger individuals; we observed also increased metabolic activity in bone marrow. This has also been observed in clinical studies with individuals who received 30 and 60 μg IL-7 /kg bodyweight leading to increased B-cell progenitors, yet without increased numbers of peripheral B-cells. In summary, our results suggest that IL-7 is able to activate thymic tissue, if functionally receptive. Increased CNS metabolic activity after IL-7 application suggests to monitor the effects of IL-7 for more complex neurological functions and the CNS-metabolic axis in more controlled, comprehensive study settings. It also prepares to consider effects of cytokines on networks of non-lymphoid cells and tissues in patients enrolled in IL-7 trials.

Follicular dendritic cell sarcoma of the tonsil

Follicular dendritic cells (FDCs) are non-phagocytic, non-lymphoid cells of immune system, which are necessary for antigen presentation and regulation of the reactions in the germinal centers of lymph node. Follicular dendritic cell sarcoma (FDCS) is unusual and those with an extranodal origin in the head and neck region are extremely rare. Here, we report a case of FDCS of the left tonsil in a 27-year-old male patient. The patient presented with swelling of the left tonsil and resultant difficulty in swallowing for last three months. The tumor was excised and was sent for histopathologic examination. Microscopic examination and immunohistochemical analysis proved the case to be FDCS. After the diagnosis, the patient received post-operative radiotherapy. The patient is on six months follow-up which is uneventful.

MSCs From Patients with Myelofibrosis Display a Fibrotic Phenotype

Abstract 5160Myeloproliferative neoplasms (MPNs) are characterized by the excessive production of terminally differentiated nonlymphoid cells or platelets in the bone marrow. They represent a heterogenous group of clonal hematologic malignancies and are classified into chronic myeloid leukemia (CML), essential thrombocythemia (ET), polycythemia vera (PV) and primary myelofibrosis (PMF) and other rarer diseases.MPNs are often associated with extramedullary hematopoiesis and progressive hepatosplenomegaly due to displacement of hematopoietic progenitor cells from the BM to spleen and liver. Progenitor mobilization follows the enhanced deposition of extracellular matrix proteins, which can be found in the bone marrow of MPN patients.Nonhematopoietic bone marrow stromal cells (BMSCs) and their precursors (mesenchymal stem cells) are believed to be conditioned by abundantly released growth factors from the pathological hematopoietic clone in MPNs and in turn contribute to a modified niche environment which participates in the maintenance of the malignant clone and in disease progression.We therefore aimed at the comparative analysis of BMSCs from MPN patients (displaying myelofibrosis 0–1) and healthy donors as well as at their matrix remodelling capacity.BMSCs from PMF patients were obtained by trephine biopsies and isolated by plastic adherence in IMDM, 20% FCS and cortisone. BMSCs from PMF patients fulfilled MSC criteria according to common consensus (Dominici et al., 2007). To compare their potential to support hemato-lymphopoiesis, we analyzed their hemato-lymphotropic cytokine transcription by RT-PCR. MSCs from MPN patients and healthy donors expressed gene transcripts for M-CSF, SDF-1, LIF, FLT3L, Oct-4, SCF, IL-6 and IL-7, suggesting no significant difference in cytokine production. However, when activated through contact with collagen I/III and embedded in three-dimensional scaffolds, MSCs from MPN-patients extensively remodelled the collagenous matrix compared to healthy donors. Under osteogenic and undifferentiated culture conditions, the extracellular matrix (ECM) production by MPN-MSC was strongly enhanced compared to MSCs from healthy controls as shown by RT-PCR and immunohistochemistry for collagen I, IV, fibronectin, laminin and osteopontin. Furthermore, MSCs from MPN patients significantly contracted and densified the collagenous matrix and the ECM deposition by MSCs from MPN patients was highly comparable to the ECM changes observed in corresponding bone punches. We therefore hypothesize that MSCs from MPN patients are primed to produce enhanced ECM proteins, whereas their capacity to support hematopoiesis seems to be unchanged. Disclosures:No relevant conflicts of interest to declare.

Immunologic Studies in Humans.

Immunologic Studies in Humans.

Cellular and Nerve Fibre Catecholaminergic Thymic Network: Steroid Hormone Dependent Activity

The thymus plays a critical role in establishing and maintaining the peripheral T-cell pool. It does so by providing a microenvironment within which T-cell precursors differentiate and undergo selection processes to create a functional population of major histocompatibility complex-restricted, self-tolerant T cells. These cells are central to adaptive immunity. Thymic T-cell development is influenced by locally produced soluble factors and cell-to-cell interactions, as well as by sympathetic noradrenergic and endocrine system signalling. Thymic lymphoid and non-lymphoid cells have been shown not only to express beta- and alpha(1)- adrenoceptors (ARs), but also to synthesize catecholamines (CAs). Thus, it is suggested that CAs influence T-cell development via both neurocrine/endocrine and autocrine/paracrine action, and that they serve as immunotransmitters between thymocytes and nerves. CAs acting at multiple sites along the thymocyte developmental route affect T-cell generation not only numerically, but also qualitatively. Thymic CA level and synthesis, as well as AR expression exhibit sex steroid-mediated sexual dimorphism. Moreover, the influence of CAs on T-cell development exhibits glucocorticoid-dependent plasticity. This review summarizes recent findings in this field and our current understanding of complex and multifaceted neuroendocrine-immune communications at thymic level.

Caveolin-1 Orchestrates TCR Synaptic Polarity, Signal Specificity, and Function in CD8 T Cells

TCR engagement triggers the polarized recruitment of membrane, actin, and transducer assemblies within the T cell-APC contact that amplify and specify signaling cascades and T effector activity. We report that caveolin-1, a scaffold that regulates polarity and signaling in nonlymphoid cells, is required for optimal TCR-induced actin polymerization, synaptic membrane raft polarity, and function in CD8, but not CD4, T cells. In CD8(+) T cells, caveolin-1 ablation selectively impaired TCR-induced NFAT-dependent NFATc1 and cytokine gene expression, whereas caveolin-1 re-expression promoted NFATc1 gene expression. Alternatively, caveolin-1 ablation did not affect TCR-induced NF-κB-dependent Iκbα expression. Cav-1(-/-) mice did not efficiently promote CD8 immunity to lymphocytic choriomeningitis virus, nor did cav-1(-/-) OT-1(+) CD8(+) T cells efficiently respond to Listeria monocytogenes-OVA after transfer into wild-type hosts. Therefore, caveolin-1 is a T cell-intrinsic orchestrator of TCR-mediated membrane polarity and signal specificity selectively employed by CD8 T cells to customize TCR responsiveness.

Mechanisms of T Cell Development and Transformation

T cells are the key mediators in cell-mediated immunity. Their development and maturation involve a complex variety of interactions with nonlymphoid cell products and receptors. Highly specialized to defend against bacterial and viral infections, T cells also mediate immune surveillance against tumor cells and react to foreign tissues. T cell progenitors originate in the bone marrow and, through a series of defined and coordinated developmental stages, enter the thymus, differentiate, undergo selection, and eventually mature into functional T cells. The steps in this process are regulated through a complex transcriptional network, specific receptor-ligand pair interactions, and sensitization to trophic factors, which mediate the homing, proliferation, survival, and differentiation of developing T cells. This review examines the processes and pathways involved in the highly orchestrated development of T cell fate specification under physiological as well as pathological conditions.

Second messenger role for Mg2+ revealed by human T-cell immunodeficiency

SummaryThe magnesium ion, Mg2+, is essential for all life as a cofactor for ATP, polyphosphates such as DNA and RNA, and metabolic enzymes, but whether it plays a role in intracellular signaling similar to Ca2+ is unknown. In this study, we identify mutations in the magnesium transporter gene, MAGT1, in a novel X-linked human immunodeficiency characterized by CD4 lymphopenia, severe chronic viral infections, and defective T lymphocyte activation. We demonstrate that a rapid transient Mg2+ influx is induced by antigen receptor stimulation in T cells or growth factor stimulation in non-lymphoid cells. MagT1 deficiency abrogates the Mg2+ influx leading to impaired responses to antigen receptor engagement including defective activation of phospholipase Cγ and a markedly impaired Ca2+ influx in T cells but not B cells. These observations reveal a role for Mg2+ as an intracellular second messenger and identify MagT1 as a possible target for novel therapeutics.

Ursolic Acid Suppresses Interleukin-17 (IL-17) Production by Selectively Antagonizing the Function of RORγt Protein

Th17 cells have recently emerged as a major player in inflammatory and autoimmune diseases via the production of pro-inflammatory cytokines IL-17, IL-17F, and IL-22. The differentiation of Th17 cells and the associated cytokine production is directly controlled by RORγt. Here we show that ursolic acid (UA), a small molecule present in herbal medicine, selectively and effectively inhibits the function of RORγt, resulting in greatly decreased IL-17 expression in both developing and differentiated Th17 cells. In addition, treatment with UA ameliorated experimental autoimmune encephalomyelitis. The results thus suggest UA as a valuable drug candidate or leading compound for developing treatments of Th17-mediated inflammatory diseases and cancer.

Integrase inhibitors effective against human T-cell leukemia virus type 1

Drugs targeting the viral enzyme integrase have been in use for several years as part of the treatment regimen for patients with Human Immunodeficiency Virus Type 1 (HIV-1) and similar classes of compounds have been shown to inhibit Human T-Cell Leukemia Virus Type 1 (HTLV-1) integration in vitro. The current study shows that the clinically approved HIV-1 integrase inhibitor, Raltegravir, as well as the more recent diketo acid derivative, MK-2048, are active inhibitors of HTLV-1 infection in vitro. These agents were effective in inhibiting cell-free and cell-to-cell transmission of HTLV-1 in lymphoid and non-lymphoid cells. The drugs also inhibited HTLV-1 immortalization of human peripheral blood mononuclear cells. A novel adaptation of the Alu assay for viral integration was used to show that the drugs inhibit viral integration without affecting reverse transcription. These data support the administration of Raltegravir and other integrase inhibitors as treatments for patients with HTLV-1 associated diseases.