Corrigendum: An in vitro study to elucidate the effects of Product Nkabinde on immune response in peripheral blood mononuclear cells of healthy donors.

[This corrects the article DOI: 10.3389/fphar.2024.1308913.].

An in vitro study to elucidate the effects of product Nkabinde on immune response in peripheral blood mononuclear cells of healthy donors.

Introduction: A significant number of the South African population still rely on traditional medicines (TM) as their primary healthcare due to their belief in their holistic healing and immune-boosting properties. However, little to no scientific data is available on the effects of most TM products on cytokine and cellular biomarkers of the immune response. Here, we evaluated the impact of traditional medicine [Product Nkabinde (PN)] in inducing cellular and cytokine biomarkers of inflammation in peripheral blood mononuclear cells (PBMCs) from eight healthy volunteers. Methods: PN was supplied by a local Traditional Health Practitioner (THP). The IC50 (half maximum concentration) of the standardized extract on isolated PBMCs was established using the cell viability assay over 24 h of incubation. Luminex and flow cytometry assays were used to measure cytokine and cellular levels in PBMCs stimulated with PN and/or PHA over 24, 48, and 72 h, respectively. Results: The IC50 concentration of PN in treated PBMCs was established at 325.3 µg/mL. In the cellular activation assay, the percentages of CD38-HLA-DR + on total CD4+ T cells were significantly increased in PBMCs stimulated with PN compared to unstimulated controls after 24 h (p = 0.008). PN significantly induced the production of anti-inflammatory IL-10 (p = 0.041); proinflammatory cytokines IL-1α (p = 0.003), TNF-α (p < 0.0001); and chemokine MIP-1ß (p = 0.046) compared to the unstimulated control after 24 h. At 48 h incubation, the production of proinflammatory cytokines IL-1α (p = 0.034) and TNF-α (p = 0.011) were significantly induced following treatment with PN. Conclusion: We conclude that the PN possesses in vitro immunomodulatory properties that may influence immune and inflammatory responses. More studies using PN are needed to further understand key parameters mediating induction, expression, and regulation of the immune response in the context of pathogen-associated infections.

Immunomodulatory Function of Pien Tze Huang in T Cell-Mediated Anti-tumor Activity against B16-F10, MC38 and Hep1-6 Tumor Models.

OBJECTIVE: To investigate the anti-tumor effects of Pien Tze Huang (PZH) in mouse models of B16-F10 melanoma, MC38 colorectal cancer, Hep1-6 hepatocellular carcinoma and chemically induced hepatocellular carcinoma model. METHODS: Various tumor models, including B16-F10, MC38 and Hep1-6 tumor hypodermic inoculation models, B16-F10 and Hep1-6 pulmonary metastasis models, Hep1-6 orthotopic implantation model, and chemically induced hepatocellular carcinoma model, were utilized to evaluate the anti-tumor function of PZH. Tumor growth was assessed by measuring tumor size and weight of solid tumors isolated from C57BL/6 mice. For cell proliferation and death of tumor cells in vitro, as well as T cell activation markers, cytokine production and immune checkpoints analysis, single-cell suspensions were prepared from mouse spleen, lymph nodes, and tumors after PZH treatment. RESULTS: PZH demonstrated significant therapeutic efficacy in inhibiting tumor growth (P<0.01). Treatment with PZH resulted in a reduction in tumor size in subcutaneous MC38 colon adenocarcinoma and B16-F10 melanoma models, and decreased pulmonary metastasis of B16-F10 melanoma and Hep1-6 hepatoma (P<0.01). However, in vitro experiments showed that PZH only had slight impact on the cell proliferation and survival of tumor cells (P>0.05). Nevertheless, PZH exhibited a remarkable ability to enhance T cell activation and the production of interferon gamma, tumor necrosis factor alpha, and interleukin 2 in CD4+ T cells in vitro (P<0.01 or P<0.05). Importantly, PZH substantially inhibited T cell exhaustion and boosted cytokine production by tumor-infiltrating CD8+ T cells (P<0.01 or P<0.05). CONCLUSION: This study has confirmed a novel immunomodulatory function of PZH in T cell-mediated anti-tumor immunity, indicating that PZH holds promise as a potential therapeutic agent for cancer treatment.

Jing-Fang powder ethyl acetate extracts attenuate atopic dermatitis by modulating T-cell activity.

Jing-Fang powder ethyl acetate extract (JFEE) and its isolated C (JFEE-C) possess favorable anti-inflammatory and anti-allergic properties; however, their inhibitory effects on T cell activity remain unknown. In vitro, Jurkat T cells and primary mouse CD4+ T cells were used to explore the regulatory effects of JFEE and JFEE-C as well as their potential mechanisms on activated T cells. Furthermore, T cell-mediated atopic dermatitis (AD) mouse model was established to confirm these inhibitory effects in vivo. The results showed that JFEE and JFEE-C inhibited T cell activation by suppressing the production of interleukin-2 (IL-2) and interferon-gamma (IFN-γ) without showing cytotoxicity. Flow cytometry showed the inhibitory effects of JFEE and JFEE-C on the activation-induced proliferation and apoptosis of T cells. Pretreatment with JFEE and JFEE-C also decreased the expression levels of several surface molecules, including CD69, CD25, and CD40L. Moreover, it was confirmed that JFEE and JFEE-C inhibited T cell activation by downregulating the TGF-ß-activated kinase 1 (TAK1)/nuclear kappa-light-chain-enhancer of activated B cells (NF-κB)/mitogen-activated protein kinase (MAPK) signaling pathways. The combination of these extracts with C25-140 intensified the inhibitory effects on IL-2 production and p65 phosphorylation. The oral administration of JFEE and JFEE-C notably weakened AD manifestations, including the infiltration of mast cells and CD4+ cells, epidermis and dermis thicknesses, serum levels of immunoglobulin E (IgE) and thymic stromal lymphopoietin (TSLP), and gene expression levels of T helper (Th) cells-related cytokines in vivo. The underlying mechanisms of the inhibitory effects of JFEE and JFEE-C on AD were related to attenuating T cell activity through NF-κB/MAPK pathways. In conclusion, this study suggested that JFEE and JFEE-C exhibited anti-atopic efficacy by attenuating T cell activity and might possess a curative potential for T cell-mediated diseases.

Photonic Hyperthermia Synergizes with Immune-Activators to Augment Tumor-Localized Immunotherapy.

Photothermal immunotherapy, the combination of photothermal hyperthermia and immunotherapy, is a noninvasive and desirable therapeutic strategy to address the deficiency of traditional photothermal ablation for tumor treatment. However, insufficient T-cell activation following photothermal treatment is a bottleneck to achieve satisfactory therapeutic effectiveness. In this work, a multifunctional nanoplatform is rationally designed and engineered on the basis of polypyrrole-based magnetic nanomedicine modified by T-cell activators of anti-CD3 and anti-CD28 monoclonal antibodies, which have achieved robust near infrared laser-triggered photothermal ablation and long-lasting T-cell activation, realizing diagnostic imaging-guided immunosuppressive tumor microenvironment regulation following photothermal hyperthermia by reinvigorating tumor-infiltrating lymphocytes. By virtue of high-efficient immunogenic cell death and dendritic cell maturation combined with T-cell activation, this nanosystem markedly restrains primary and abscopal tumors as well as metastatic tumors with negligible side effects in vivo, exerting the specific function for suppressing tumor recurrence and metastasis by establishing a long-term memory immune response.

Oral administration of Helianthus annuus leaf extract ameliorates atopic dermatitis by modulation of T cell activity in vivo.

BACKGROUND: Atopic dermatitis (AD) is multifactorial disease that is highly involved in the activity of T cells from the skin lesion. Seeds of Helianthus annuus extract have been traditionally used as anti-inflammatory reagent but few studies have been reported on leaf of H. annuus that are discarded uselessly as an immunomodulator. PURPOSE: Therefore, here, the regulatory effect of Helianthus annuus extract (HAE) on AD via suppression of T cell activity was investigated. METHODS: The efficacy of HAE was evaluated in T cells stimulated with CD3/CD28 antibody and PMA/A23187. And demonstration of the alleviating effect of HAE on AD in the ears of Balb/c female mice stimulated with mite extract and DNCB. RESULTS: Pre-treatment with HAE abrogates IL-2 production from activated T cells. It was also found that HAE suppresses the expression of surface molecules in activated T cells. Cell viability results demonstrated that HAE is not associated with cytotoxicity in resting and activated T cells. Besides, we exhibited that regulated phosphorylation of MAPK through TAK1-IKKα-NFκB by pre-treatment with HAE leads to the suppressive effect of HAE on T cell activation. Oral administration of HAE attenuates manifestations of AD including reduced thickness of dermis and epidermis, decreased IgE level in serum, and declined mRNA levels of atopic cytokines on ear tissues. The ameliorative effect of HAE on AD was found to be associated with suppressed activity of T cells from draining lymph nodes. CONCLUSION: Therefore, our results provide that HAE alleviates AD symptoms via modulation of T cell activity. In addition, these results suggest the immunomodulatory effect of HAE on T-cell mediated diseases.

Arginine-based cationic liposomes accelerate T cell activation and differentiation in vitro.

Cationic liposomes are versatile lipid nanocarriers to improve the pharmacological properties of drug payloads. Recent advantages include the application of their intrinsic immunostimulatory effects to enhance immune activation. Herein, we report for the first time the structural effect of cationic lipids in promoting T cell activation and differentiation in vitro. Two types of cationic liposomes R3C14 and R5C14 were prepared from single type of lipids Arg-C3-Clu2C14 or Arg-C5-Clu2C14, which bear arginine head group and ditetradecyl tails but vary in the carbon number of the spacer in between. Murine CD8 or CD4 T cells were pretreated with 50 µM of each type of liposomes for 2 h, followed by stimulation with anti-CD3/CD28 antibodies for 24 h. In comparison to liposome-untreated T cells, R5C14-pretreatment induced a robust T cell activation (IL-2, CD25+) and differentiation into effector cells (CD44high, CD62Llow), whereas R3C14 did not show comparable effect. Furthermore, a weak activation of nuclear factor of activated T cells (NFAT) was detected in Jurkat-Lucia NFAT cells (InvivoGen), suggesting a potential signaling pathway for the liposomal effect. Although R5C14 liposomes did not activate T cells without subsequent CD3/CD28 stimulation, this study implied a recessive effect of some cationic adjuvant in priming T cells to enhance their responsiveness to antigens.

Docosahexaenoic acid supplementation represses the early immune response against murine cytomegalovirus but enhances NK cell effector function.

BACKGROUND: Docosahexaenoic acid (DHA) supplementation is beneficial for several chronic diseases; however, its effect on immune regulation is still debated. Given the prevalence of cytomegalovirus (CMV) infection and because natural killer (NK) cells are a component of innate immunity critical for controlling CMV infection, the current study explored the effect of a DHA-enriched diet on susceptibility to murine (M) CMV infection and the NK cell effector response to MCMV infection. RESULTS: Male C57BL/6 mice fed a control or DHA-enriched diet for 3 weeks were infected with MCMV and sacrificed at the indicated time points postinfection. Compared with control mice, DHA-fed mice had higher liver and spleen viral loads at day 7 postinfection, but final MCMV clearance was not affected. The total numbers of NK cells and their terminal mature cell subset (KLRG1+ and Ly49H+ NK cells) were reduced compared with those in control mice at day 7 postinfection but not day 21. DHA feeding resulted in higher IFN-γ and granzyme B expression in splenic NK cells at day 7 postinfection. A mechanistic analysis showed that the splenic NK cells of DHA-fed mice had enhanced glucose uptake, increased CD71 and CD98 expression, and higher mitochondrial mass than control mice. In addition, DHA-fed mice showed reductions in the total numbers and activation levels of CD4+ and CD8+ T cells. CONCLUSIONS: These results suggest that DHA supplementation represses the early response to CMV infection but preserves NK cell effector functions by improving mitochondrial activity, which may play critical roles in subsequent MCMV clearance.

Rapid Screen for Antiviral T-Cell Immunity with Nanowire Electrochemical Biosensors.

The ability to rapidly assess and monitor patient immune responses is critical for clinical diagnostics, vaccine design, and fundamental investigations into the presence or generation of protective immunity against infectious diseases. Recently, findings on the limits of antibody-based protection provided by B-cells have highlighted the importance of engaging pathogen-specific T-cells for long-lasting and broad protection against viruses and their emergent variants such as in SARS-CoV-2. However, low-cost and point-of-care tools for detecting engagement of T-cell immunity in patients are conspicuously lacking in ongoing efforts to assess and control population-wide disease risk. Currently available tools for human T-cell analysis are time and resource-intensive. Using multichannel silicon-nanowire field-effect transistors compatible with complementary metal-oxide-semiconductor, a device designed for rapid and label-free detection of human T-cell immune responses is developed. The generalizability of this approach is demonstrated by measuring T-cell responses against melanoma antigen MART1, common and seasonal viruses CMV, EBV, flu, as well as emergent pandemic coronavirus, SARS-CoV-2. Further, this device provides a modular and translational platform for optimizing vaccine formulations and combinations, offering quick and quantitative readouts for acquisition and persistence of T-cell immunity against variant-driven pathogens such as flu and pandemic SARS-CoV-2.

Gekko gecko extract attenuates airway inflammation and mucus hypersecretion in a murine model of ovalbumin-induced asthma.

ETHNOPHARMACOLOGICAL RELEVANCE: Gekko gecko is used as a traditional medicine for various diseases including respiratory disorders in northeast Asian countries, mainly Korea, Japan, and China. AIM OF THE STUDY: Allergic asthma is a chronic respiratory disease caused by an inappropriate immune response. Due to the recent spread of coronavirus disease 2019, interest in the treatment of pulmonary disorders has rapidly increased. In this study, we investigated the anti-asthmatic effects of G. gecko extract (GGE) using an established mouse model of ovalbumin-induced asthma. MATERIALS AND METHODS: To evaluate the anti-asthmatic effects of GGE, we evaluated histological changes and the responses of inflammatory mediators related to allergic airway inflammation. Furthermore, we investigated the regulatory effects of GGE on type 2 helper T (Th2) cell activation. RESULTS: Administration of GGE attenuated asthmatic phenotypes, including inflammatory cell infiltration, mucus production, and expression of Th2 cytokines. Furthermore, GGE treatment reduced Th2 cell activation and differentiation. CONCLUSIONS: These results indicate that GGE alleviates allergic airway inflammation by regulating Th2 cell activation and differentiation.

Assay format diversity in pre-clinical immunogenicity risk assessment: Toward a possible harmonization of antigenicity assays.

A major impediment to successful use of therapeutic protein drugs is their ability to induce anti-drug antibodies (ADA) that can alter treatment efficacy and safety in a significant number of patients. To this aim, in silico, in vitro, and in vivo tools have been developed to assess sequence and other liabilities contributing to ADA development at different stages of the immune response. However, variability exists between similar assays developed by different investigators due to the complexity of assays, a degree of uncertainty about the underlying science, and their intended use. The impact of protocol variations on the outcome of the assays, i.e., on the immunogenicity risk assigned to a given drug candidate, cannot always be precisely assessed. Here, the Non-Clinical Immunogenicity Risk Assessment working group of the European Immunogenicity Platform (EIP) reviews currently used assays and protocols and discusses feasibility and next steps toward harmonization and standardization.

Mitochondrial-Linked De Novo Pyrimidine Biosynthesis Dictates Human T-Cell Proliferation but Not Expression of Effector Molecules.

T-cell activation upon antigen stimulation is essential for the continuation of the adaptive immune response. Impairment of mitochondrial oxidative phosphorylation is a well-known disruptor of T-cell activation. Dihydroorotate dehydrogenase (DHODH) is a component of the de novo synthesis of pyrimidines, the activity of which depends on functional oxidative phosphorylation. Under circumstances of an inhibited oxidative phosphorylation, DHODH becomes rate-limiting. Inhibition of DHODH is known to block clonal expansion and expression of effector molecules of activated T cells. However, this effect has been suggested to be caused by downstream impairment of oxidative phosphorylation rather than a lower rate of pyrimidine synthesis. In this study, we successfully inhibit the DHODH of T cells with no residual effect on oxidative phosphorylation and demonstrate a dose-dependent inhibition of proliferation of activated CD3+ T cells. This block is fully rescued when uridine is supplemented. Inhibition of DHODH does not alter expression of effector molecules but results in decreased intracellular levels of deoxypyrimidines without decreasing cell viability. Our results clearly demonstrate the DHODH and mitochondrial linked pyrimidine synthesis as an independent and important cytostatic regulator of activated T cells.

In-vitro Immunomodulatory activity of Azadirachta indica A.Juss. Ethanol: water mixture against HIV associated chronic CD4+ T-cell activation/ exhaustion.

BACKGROUND: In Sub-Saharan Africa, herbal therapy continues to be utilized for HIV-1 disease management. However, the therapeutic benefits of these substances remain ambiguous. To date, little is known about the effects of these plant extracts on chronic CD4 + T-cell activation and exhaustion which is partly driven by HIV-1 associated microbial translocation. METHODS: Effects of Azadirachta indica, Momordica foetida and Moringa oleifera ethanol: water mixtures on cell viability were evaluated using the Guava PCA system. Then, an in-vitro cell culture model was developed to mimic CD4+ T cell exposures to antigens following HIV-1 microbial translocation. In this, peripheral blood mononuclear cells (PBMCs) isolated from HIV negative (n = 13), viral load < 1000 copies per mL (n = 10) and viral load > 1000 copies per mL (n = 6) study participants from rural Uganda were treated with Staphylococcus enterotoxin B (SEB). Then, the candidate plant extract (A. indica) was added to test the potential to inhibit corresponding CD4+ T cell activation. Following BD Facs Canto II event acquisition, variations in %CD38, %CD69, Human Leukocyte Antigen -DR (HLA-DR), Programmed cell death protein 1 (PD-1), T-cell immunoglobulin and mucin domain-containing protein 3 (Tim-3), interferon gamma (IFN γ) and interleukin 2 (IL-2) CD4 + T cell expression were evaluated. RESULTS: Following exposure to SEB, only A. indica demonstrated a concentration-dependent ability to downregulate the levels of CD4 + T cell activation. At the final concentration of 0.500 µg/mL of A. indica, a significant downregulation of CD4 + CD38 + HLA-DR+ expression was observed in HIV negative (p < 0.0001) and both HIV infected groups (P = 0.0313). This plant extract also significantly lowered SEB induced % CD4+ T cell HLADR, PD-1 and Tim-3 levels. PD-1 and CD69 markers were only significantly downmodulated in only the HIV negative ((p = 0.0001 and p = 0.0078 respectively) and viral load< 1000 copies per ml (p = 0.0078) groups. CONCLUSION: A. indica exhibited the in-vitro immunomodulatory potential to inhibit the continuum of SEB induced CD4+ T-cell activation/ exhaustion without impacting general T-cell specific functions such as cytokine secretion. Additional studies are needed to confirm A. indica as a source of natural products for targeting persistent immune activation and inflammation during ART.

Persimmon leaf extract protects mice from atopic dermatitis by inhibiting T cell activation via regulation of the JNK pathway.

Persimmon leaf extracts (PLE) have been widely used as a traditional medicine in East Asian countries. The effects of persimmon leaves, including antioxidant, antiinflammatory, hypotensive, and anti-allergy effects, have been investigated; however, there is little evidence on the inhibition of T cell activation in vitro and effects on T cell-related diseases, such as atopic dermatitis (AD), in vivo by persimmon leaves. PLE (50 µg/mL) effectively attenuated the mRNA levels of IL-2 in Jurkat T cells stimulated with PMA/A23187 and Staphylococcus enterotoxin E-loaded Raji B cells without causing cytotoxicity. In Jurkat T cells stimulated with PMA/A23187, treatment with 50 µg/mL PLE blocked the translocation of p65 and IκBα degradation. Moreover, the JNK signaling pathway in Jurkat T cells stimulated with PMA/A23187 was affected by treatment with PLE. The oral administration of PLE markedly attenuated AD manifestations in mice, including ear thickness, IgE levels, and lymph node sizes. These results indicate PLE significantly blocked T cell activation via NF-κB signaling and the JNK pathway. This suggests underlying mechanisms of PLE involving the control of effector cytokines produced by activated T cells in ear tissue and lymph nodes, as well as the infiltration of mast cells and the therapeutic potential of AD.

Chinese herbal medicine SS-1 inhibits T cell activation and abrogates TH responses in Sjögren's syndrome.

BACKGROUND/PURPOSE: Sjögren's syndrome (SS) is an autoimmune disease and its conventional treatment has exhibited limited therapeutic efficacy. Traditional Chinese medicine has been demonstrated to ameliorate the sicca symptoms of SS by decreasing the level of TH1 and TH2 cytokines and increasing salivary flow rate. A newly designed traditional Chinese medicine, SS-1, showed improved efficacy in alleviating the dryness symptoms of SS patients in the National Taiwan SS cohort investigation. Here, we investigated the effect of SS-1 on T cell responses. METHODS: SS-1 was authenticated and its major compounds were verified by high-performance liquid chromatography. We examined the effects of SS-1 on the activation and TH1, TH2, and TH17 polarization of murine T cells. We also determined the level of TH1, TH2, and TH17 cytokine RNA in peripheral blood mononuclear cells of SS patients before and after SS-1 treatment. RESULTS: SS-1 treatment inhibits the activation and TH1, TH2, and IL-17A+IFNγ+ TH polarization of murine T cells. SS-1 treatment also significantly reduces IFN-γ, IL-4, and IL-13 expression, and moderately reduces IL-17A expression in peripheral blood mononuclear cells of SS patients. CONCLUSION: Our results suggest that SS-1 inhibits T cell activation and diminishes TH1, TH2, and IL-17+IFN-γ+ TH responses in SS patients.

Clinical trait-connected network analysis reveals transcriptional markers of active psoriasis treatment with Liangxue-Jiedu decoction.

ETHNOPHARMACOLOGICAL RELEVANCE: Psoriasis is a complex recurrent inflammatory skin disease with different pathological changes in different stages. Psoriasis in its active stage, which is comparable to the blood-heat type in traditional Chinese medicine (TCM), has been treated by Liangxue Jiedu Decoction (LJD) in TCM for decades, with proven efficacy. According to TCM theories, LJD has the function of removing heat and pathogenic factors from the blood. AIM OF THE STUDY: We aimed to investigate the molecular features associated with the active stage psoriasis and identify genes responding to LJD treatment accompanied by lesion remission. MATERIALS AND METHODS: Healthy volunteers and psoriasis patients who met specific diagnostic criteria were recruited. Twenty-six transcriptomes were profiled from the peripheral blood mononuclear cells (PBMCs) of 10 psoriasis patients (pre- and post-treatment) and 6 healthy volunteers. RNA sequencing data were analyzed using an integrated approach combining differential gene expression analysis (DGEA) and weighted gene co-expression network analysis (WGCNA), by which gene expression was linked to multiple clinical traits, including psoriasis area and severity index (PASI), as well as the improvement rate of skin lesions (ΔPASI). The actions of LJD were then verified using an in vitro cell assay coupled to flow cytometric analysis and RT-PCR. RESULTS: We identified four network modules with statistical significance (P < 0.05), two of which connected to the PASI score, while the other two connected to 8-week treatment and ΔPASI, respectively. In psoriasis patients, activated inflammatory pathways and inhibited G-protein signaling genes (GTPase IMAP family member and G protein-coupled receptor) co-occurred, with high expression of CD83 and CD69, and low expression of CD160 and CD180, compared with the health. Accompanying LJD treatment and lesion remission, the expression of CD69 and cell cycle-related genes, including CCNA2, CCNB2, CDK1, and TOP2A, was down-regulated. The inhibitory role of LJD on CD69 expression was confirmed by the decline of activating naïve CD4+ T lymphocytes. CONCLUSION: Our study suggests that active psoriasis is characterized by unbalanced immune status with dendrite cell and lymphocyte-associated inflammatory activation as well as NK cell- and B cell-associated defense response aberrance. LJD played an inhibitory role in T cell activation, a process located downstream pathological cascade of psoriasis.

Bovine IgG Prevents Experimental Infection With RSV and Facilitates Human T Cell Responses to RSV.

Respiratory syncytial virus (RSV) infections represent a major burden of disease in infants and are the second most prevalent cause of death worldwide. Human milk immunoglobulins provide protection against RSV. However, many infants depend on processed bovine milk-based nutrition, which lacks intact immunoglobulins. We investigated the potential of bovine antibodies to neutralize human RSV and facilitate-cell immune activation. We show cow's milk IgG (bIgG) and Intravenous Immunoglobulin (IVIG) have a similar RSV neutralization capacity, even though bIgG has a lower pre-F to post-F binding ratio compared to human IVIG, with the majority of bIgG binding to pre-F. RSV is better neutralized with human IVIG. Consequently, we enriched RSV specific T cells by culturing human PBMC with a mixture of RSV peptides, and used these T cells to study the effect of bIgG and IVIG on the activation of pre-F-pecific T cells. bIgG facilitated in vitro T cell activation in a similar manner as IVIG. Moreover, bIgG was able to mediate T cell activation and internalization of pathogens, which are prerequisites for inducing an adaptive viral response. Using in vivo mouse experiments, we showed that bIgG is able to bind the murine activating IgG Fc Receptors (FcγR), but not the inhibiting FcγRII. Intranasal administration of the monoclonal antibody palivizumab, but also of bIgG and IVIG prevented RSV infection in mice. The concentration of bIgG needed to prevent infection was ~5-fold higher compared to IVIG. In conclusion, the data presented here indicate that functionally active bIgG facilitates adaptive antiviral T cell responses and prevents RSV infection in vitro and in vivo.

Development and characterization of a human Th17-driven ex vivo skin inflammation model.

Skin models mimicking features of psoriasis-related inflammation are needed to support the development of new drugs in dermatology. Reconstructed skin models lack tissue complexity, including a fully competent skin barrier, and presence and/or diversity of immune cells. Here, we describe InflammaSkin®, a novel human Th17-driven ex vivo skin inflammation model. In this model, skin-resident T cells are in situ activated by intradermal injection of anti-CD3 and anti-CD28 antibodies and Th17 cell polarization is sustained by culture in a chemically defined medium supplemented with IL-1ß, IL-23 and TGF-ß for seven days. The acquired Th17 signature is demonstrated by the sustained secretion of IL-17A, IL-17AF, IL-17F, IL-22, IFN-γ, and to some degree IL-15 and TNF-α observed in the activated ex vivo skin inflammation model compared with the non-activated skin model control. Furthermore, expression of S100A7 and Keratin-16 by keratinocytes and loss of epidermal structure integrity occur subsequently to in situ Th17cell activation, demonstrating cellular crosstalk between Th17 cells and keratinocytes. Finally, we demonstrate the use of this model to investigate the modulation of the IL-23/IL-17 immune axis by topically applied anti-inflammatory compounds. Taken together, we show that by in situ activation of skin-resident Th17 cells, the InflammaSkin® model reproduces aspects of inflammatory responses observed in psoriatic lesions and could be used as a translational tool to assess efficacy of test compounds.

Screening of FDA-Approved Drug Library Identifies Adefovir Dipivoxil as Highly Potent Inhibitor of T Cell Proliferation.

Repositioning of approved drugs for identifying new therapeutic purposes is an alternative, time and cost saving strategy to classical drug development. Here, we screened a library of 786 FDA-approved drugs to find compounds, which can potentially be repurposed for treatment of T cell-mediated autoimmune diseases. Investigating the effect of these diverse substances on mitogen-stimulated proliferation of both, freshly stimulated and pre-activated (48 h) peripheral blood mononuclear cells (PBMCs), we discovered Adefovir Dipivoxil (ADV) as very potent compound, which inhibits T cell proliferation in a nanomolar range. We further analyzed the influence of ADV on proliferation, activation, cytokine production, viability and apoptosis of freshly stimulated as well as pre-activated human T cells stimulated with anti-CD3/CD28 antibodies. We observed that ADV was capable of suppressing the proliferation in both T cell stimulation systems in a dose-dependent manner (50% inhibition [IC50]: 63.12 and 364.8 nM for freshly stimulated T cells and pre-activated T cells, respectively). Moreover, the drug impaired T cell activation and inhibited Th1 (IFN-γ), Th2 (IL-5), and Th17 (IL-17) cytokine production dose-dependently. Furthermore, ADV treatment induced DNA double-strand breaks (γH2AX foci expression), which led to an increase of p53-phospho-Ser15 expression. In response to DNA damage p21 and PUMA are transactivated by p53. Subsequently, this caused cell cycle arrest at G0/G1 phase and activation of the intrinsic apoptosis pathway. Our results indicate that ADV could be a new potential candidate for treatment of T cell-mediated autoimmune diseases. Prospective studies should be performed to verify this possible therapeutic application of ADV for such disorders.

Selective effects of ginseng pectins on galectin-3-mediated T cell activation and apoptosis.

Galectin-3 (Gal-3) can induce T-cell activation and apoptosis and plays a role in tumor immune tolerance. Here, we demonstrate that ginseng pectins selectively inhibit Gal-3-induced T-cell apoptosis, while not affecting T-cell activation. This finding stands in contrast to that from the use of modified citrus pectin (MCP) and potato galactan (P-galactan) that inhibit both. Whereas PKC/ERK and ROS/ERK pathways are involved in both T-cell activation and apoptosis, the Ras/PI3K/Akt pathway is unique to T-cell activation. Ginseng pectins selectively inhibit the ROS/ERK pathway. Using the Sarcomar-180 mouse model in which Gal-3 expression is increased, we found that ginseng pectins (but not MCP or P-galactan) significantly promote T-cell proliferation and IL-2 expression, and inhibit tumor growth by 45%. These in vivo data correlate well with selective effects of pectins on Gal-3-mediated T-cell apoptosis and activation. Our study suggests a novel approach for the development of polysaccharide-based agents that target Gal-3 function.