Th1-type CD4 Research Articles

Preclinical immunogenicity and safety of hemagglutinin-encoding modRNA influenza vaccines

Seasonal epidemics of influenza viruses are responsible for a significant global public health burden. Vaccination remains the most effective way to prevent infection; however, due to the persistence of antigenic drift, vaccines must be updated annually. The selection of vaccine strains occurs months in advance of the influenza season to allow adequate time for production in eggs. RNA vaccines offer the potential to accelerate production and improve efficacy of influenza vaccines. We leveraged the nucleoside-modified RNA (modRNA) platform technology and lipid nanoparticle formulation process of the COVID-19 mRNA vaccine (BNT162b2; Comirnaty®) to create modRNA vaccines encoding hemagglutinin (HA) (modRNA-HA) for seasonal human influenza strains and evaluated their preclinical immunogenicity and toxicity. In mice, a monovalent modRNA vaccine encoding an H1 HA demonstrated robust antibody responses, HA-specific Th1-type CD4+ T cell responses, and HA-specific CD8+ T cell responses. In rhesus and cynomolgus macaques, the vaccine exhibited durable functional antibody responses and HA-specific IFN-γ+ CD4+ T cell responses. Immunization of mice with monovalent, trivalent, and quadrivalent modRNA-HA vaccines generated functional antibody responses targeting the seasonal influenza virus(es) encoded in the vaccines that were greater than, or similar to, those of a licensed quadrivalent influenza vaccine. Monovalent and quadrivalent modRNA-HA vaccines were well-tolerated by Wistar Han rats, with no evidence of systemic toxicity. These nonclinical immunogenicity and safety data support further evaluation of the modRNA-HA vaccines in clinical studies.

The importance of the role of T-cell immunity in the development of modern tick-borne encephalitis vaccines

The tick-borne encephalitis (TBE) virus is highly pathogenic and can affect the central nervous system, leading to severe chronic effects or death. The only effective measure to combat TBE is vaccine prophylaxis. Vaccines that are currently used for mass immunization are based on inactivated TBE virus, they provide a protective immune response, but such vaccines require multiple administrations. A possible reason for short-term immunity is an incomplete functional T-cell response to these types of vaccines. The aim of this review is to analyze the literature on the role of the T-cell immune response in protecting the body from tick-borne encephalitis, its importance for vaccine development, and to consider approaches to the development of new TBE vaccines based on different platforms. When preparing the review, we analyzed the literature presented in scientific databases — PubMed, Scopus, Elsevier, Google Scholar as of April 2024. The following keywords were used for the search: vaccine, tick-borne encephalitis virus, T-cell immune response, flaviviruses. A several publications have demonstrated that T-cell responses following natural infection with TBE virus and after vaccination with inactivated virus are different. During viral infection, both Th1- and Th2-type CD4+ T cells and CD8+ T cells are activated and play an important role in the elimination of viral infection. After vaccination, the only Th2-type CD4+ T-cell response predominates, which may be the reason for the short-lived immune response. To date, a number of different types of experimental TBE vaccines are being studied, such as live-attenuated vaccines, viral vector vaccines, subunit vaccines, virus-like particles, DNA and mRNA vaccines, and polyepitope immunogens. In our opinion, the most promising in terms of T-cell response activation are vaccines based on T-cell polyepitope immunogens delivered in the form of DNA or mRNA.

Regulation of memory CD4+ T cell generation by intrinsic and extrinsic IL-27 signaling during malaria infection.

The generation and maintenance of memory T cells are regulated by various factors, including cytokines. Previous studies have shown that IL-27 is produced during the early acute phase of Plasmodium chabaudi chabaudi AS (Pcc) infection and inhibits the development of Th1-type memory CD4+ T cells. However, whether IL-27 acts directly on its receptor on Plasmodium-specific CD4+ T cells or indirectly via its receptor on other immune cells remains unclear. We aimed to determine the role of IL-27 receptor signaling in different immune cell types in regulating the generation and phenotype of memory CD4+ T cells during Plasmodium infection. We utilized Plasmodium-specific TCR transgenic mice, PbT-II, and Il27rα-/- mice to assess the direct and indirect effects of IL-27 signaling on memory CD4+ T-cell generation. Mice were transferred with PbT-II or Il27rα-/- PbT-II cells and infected with Pcc. Conditional knockout mice lacking the IL-27 receptor in T cells or dendritic cells were employed to discern the specific immune cell types involved in IL-27 receptor signaling. High levels of memory in PbT-II cells with Th1-shift occurred only when both PbT-II and host cells lacked the IL-27 receptor, suggesting the predominant inhibitory role of IL-27 signaling in both cell types. Furthermore, IL-27 receptor signaling in T cells limited the number of memory CD4+ T cells, while signaling in both T and dendritic cells contributed to the Th1 dominance of memory CD4+ T cells. These findings underscore the complex cytokine signaling network regulating memory CD4+ T cells during Plasmodium infection.

Abstract 3962: A CCR6+Th1-like CD4+T-cell cluster involved in HEV formation predicted lung cancer patients requiring anti-CTLA-4 therapy

Abstract Background: CD4+ T cells are known to help in cytotoxic T-cell priming, clonal proliferation, migratory and infiltrative capacity, and target cell killing function by licensing dendritic cells. Although CXCR3+ CCR6- classical Th1 CD4+ T cells are thought to be essential for acute cellular immunity, such as antiviral responses, the details of Th1-type CD4+ T cells required for anti-tumor immunity as a long-term chronic T cell immune responses over years remain unclear. We reported the Th7R, a CCR6 expressing Th1-like CD4+ T cell cluster predicted anti-PD-1 antibody therapy efficacy and postoperative recurrence-free survival. Objective: In this study, we focus on two Th1-like CD4+ T cell clusters, Th1 and Th7R, to determine their functions and roles in long-lasting anti-tumor immune phenomena. Methods: We studied patients with advanced stage lung cancer treated with immune checkpoint inhibitors (Pembrolizumab monotherapy n=63, Ipilimumab + Nivolumab n=148) and stage I-II lung cancer patients undergoing surgery (n=54). Mass cytometry, single cell RNA sequencing, and immunohistochemical staining were performed using peripheral blood, tumor-infiltrating lymphocytes and lymph node T cells. These studies were approved by the IRB of Saitama Medical University International Medical Center, and all patients gave written consent. Results: Unlike classical Th1, which highly expresses PRF1, GZMB, GNLY, and NKG7, Th7R expressed LTβ, CXCR6, CTLA-4, CD28, and CXCL13. Analysis of HEV index (MECA79+/CD31+ vessels) by MECA79 and CD31 staining of tumor tissues showed that Th7R in peripheral blood correlated with tumor tissue HEV index, suggesting that LTβ and CXCL13 expressed by Th7R are involved in HEV formation.Th1 mainly expressed PD-1 and did not express CTLA-4, whereas Th7R expressed both PD-1 and CTLA-4. When pre-treatment peripheral Th7R quartile was used to analyze OS after Ipilimumab + Nivolumab treatment, both the top 25% and intermediate 50% patients showed favorable prognosis, but the lower 25% had significantly poor OS. In contrast, only the top 25% Th7R patients but not the intermediate 50% and lower 25% patients who were treated with Pembrolizumab had favorable OS. Thus, it is likely that the Th7R intermediate 50% patients required anti-CTLA-4 therapy to achieve antitumor immune responses. These results may be useful for stratification of patients requiring anti-CTLA-4 antibody therapy as well as for predicting the therapeutic response of Ipilimumab + Nivolumab. Conclusion: Th7R exhibits LTβ and CXCL13 expression, which is absent in classical Th1, and may help maintain sustained T-cell immunity through HEV/TLS formation. Th7R may be a biomarker to select the patients who benefit from anti-CTLA-4 treatment. Citation Format: Hiroshi Kagamu, Satoshi Yamasaki, Atsuhito Mouri, Ou Yamaguchi, Ayako Shiono, Fuyumi Nishihara, Yu Miura, Kosuke Hashimoto, Hisao Imai, Kyoichi Kaira, Kunihiko Koabayashi, Katsuhisa Horimoto. A CCR6+Th1-like CD4+T-cell cluster involved in HEV formation predicted lung cancer patients requiring anti-CTLA-4 therapy [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3962.

Correlation of peripheral blood and endometrial immunophenotyping in ART: is peripheral blood sampling useful?

Using a comprehensive flow cytometric panel, simultaneously obtained mid-luteal immunophenotypes from peripheral blood and endometrium were compared and values correlated. Is a peripheral blood evaluation of reproductive immunophenotype status meritorious relative to local endometrial evaluation to directly assess the peri-implantation environment? Fifty-five patients had a mid-luteal biopsy to assess the local endometrial immunophenotype, while simultaneously providing a peripheral blood sample for analysis. Both samples were immediately assessed using a comprehensive multi-parameter panel, and lymphocyte subpopulations were described and compared. Distinct lymphocyte proportions and percentage differences were noted across the two compartments, confirming the hypothesis that they are distinct environments. The ratio of CD4 + to CD8 + T cells were reversed between the two compartments, as were Th1 and Th2-type CD4 + T cell ratios. Despite these differences, some direct relationships were noted. Positive Pearson correlations were found between the levels of CD57 + expressing natural killer cells, CD3 + NK-T cells and CD4 + Th1 cells in both compartments. Flow cytometric evaluation provides a rapid and objective analysis of lymphocyte subpopulations. Endometrial biopsies have become the gold standard technique to assess the uterine immunophenotype in adverse reproductive outcome, but there may still a place for peripheral blood evaluation in this context. The findings demonstrate significant variations in cellular proportions across the two regions, but some positive correlations are present. Immunological assessment of these specific peripheral blood lymphocyte subtypes may provide insight into patients with potential alterations of the uterine immune environment, without the risks and inconveniences associated with an invasive procedure.

Understanding pathogen-host interplay by expression profiles of lncRNA and mRNA in the liver of Echinococcus multilocularis-infected mice.

Almost all Echinococcus multilocularis (Em) infections occur in the liver of the intermediate host, causing a lethal zoonotic helminthic disease, alveolar echinococcosis (AE). However, the long non-coding RNAs (lncRNAs) expression profiles of the host and the potential regulatory function of lncRNA during Em infection are poorly understood. In this study, the profiles of lncRNAs and mRNAs in the liver of mice at different time points after Em infection were explored by microarray. Thirty-one differentially expressed mRNAs (DEMs) and 68 differentially expressed lncRNAs (DELs) were found continuously dysregulated. These DEMs were notably enriched in “antigen processing and presentation”, “Th1 and Th2 cell differentiation” and “Th17 cell differentiation” pathways. The potential predicted function of DELs revealed that most DELs might influence Th17 cell differentiation and TGF-β/Smad pathway of host by trans-regulating SMAD3, STAT1, and early growth response (EGR) genes. At 30 days post-infection (dpi), up-regulated DEMs were enriched in Toll-like and RIG-I-like receptor signaling pathways, which were validated by qRT-PCR, Western blotting and downstream cytokines detection. Furthermore, flow cytometric analysis and serum levels of the corresponding cytokines confirmed the changes in cell-mediated immunity in host during Em infection that showed Th1 and Th17-type CD4+ T-cells were predominant at the early infection stage whereas Th2-type CD4+ T-cells were significantly higher at the middle/late stage. Collectively, our study revealed the potential regulatory functions of lncRNAs in modulating host Th cell subsets and provide novel clues in understanding the influence of Em infection on host innate and adaptive immune response.

Type 2 Innate Lymphoid Cells (ILC2s) Create Tissue Environment that Facilitates Accumulation of Antigen-specific Th2 Cells in the Lung

ILC2s produce cytokines that mediate type 2 inflammation and tissue homeostasis and promote development of antigen-specific Th2-type CD4+ cells. However, little is known whether and how ILC2s contribute to adaptive immune responses in the lung tissues.

Reciprocal SH2-SH3 Domain Contacts between ITK Molecules Limit T Cell Receptor Signaling in Th2-type CD4+ T Cells

ABSTRACT The nonreceptor tyrosine kinase ITK is a key component of the T cell receptor (TCR) signaling pathway and is required for cytokine production by CD4+ T cells that have differentiated into Th2 cells. Structural and biochemical studies suggest that contacts between the SH2 and SH3 domains of ITK mediate intermolecular self-association, forming a structure that restrains ITK activity by interfering with interactions between ITK and other components of the TCR signaling pathway. Wild-type (WT) ITK and a panel of ITK mutants containing amino acid substitutions in the SH2 and SH3 domains were tested for self-association and for binding to the adaptor protein SLP76, a key ligand for the ITK SH2 domain. WT and ITK mutants were also expressed in Itk-deficient CD4+ T cells via retroviral-mediated gene delivery to analyze their ability to support TCR signaling and cytokine production by Th2 cells. Specific amino acid substitutions in the ITK SH2 or SH3 domains impaired self-association, with the greatest effects being seen when both intermolecular SH2-SH3 domain contacts were disrupted. Two of the SH2 domain substitutions tested reduced ITK self-association but had no effect on binding to SLP-76. When their function was analyzed in Th2 cells, ITK proteins with diminished self-association activity supported greater IL-4 production and calcium flux in response to TCR stimulation compared to WT ITK. Our findings indicate that intermolecular contacts between ITK molecules can restrain the amplitude of TCR signaling, suggesting ITK is a limiting factor for responses by CD4+ T cells.

Specific antibody response of patients with common variable immunodeficiency to BNT162b2 coronavirus disease 2019 vaccination

Specific antibody response of patients with common variable immunodeficiency to BNT162b2 coronavirus disease 2019 vaccination

CD49d marks Th1 and Tfh-like antigen-specific CD4+ T cells during Plasmodium chabaudi infection.

Upon activation, specific CD4+ T cells up-regulate the expression of CD11a and CD49d, surrogate markers of pathogen-specific CD4+ T cells. However, using T-cell receptor transgenic mice specific for a Plasmodium antigen, termed PbT-II, we found that activated CD4+ T cells develop not only to CD11ahiCD49dhi cells, but also to CD11ahiCD49dlo cells during acute Plasmodium infection. CD49dhi PbT-II cells, localized in the red pulp of spleens, expressed transcription factor T-bet and produced IFN-γ, indicating that they were type 1 helper T (Th1)-type cells. In contrast, CD49dlo PbT-II cells resided in the white pulp/marginal zones and were a heterogeneous population, with approximately half of them expressing CXCR5 and a third expressing Bcl-6, a master regulator of follicular helper T (Tfh) cells. In adoptive transfer experiments, both CD49dhi and CD49dlo PbT-II cells differentiated into CD49dhi Th1-type cells after stimulation with antigen-pulsed dendritic cells, while CD49dhi and CD49dlo phenotypes were generally maintained in mice infected with Plasmodium chabaudi. These results suggest that CD49d is expressed on Th1-type Plasmodium-specific CD4+ T cells, which are localized in the red pulp of the spleen, and can be used as a marker of antigen-specific Th1 CD4+ T cells, rather than that of all pathogen-specific CD4+ T cells.

CD69+ Th2-type CD4+ T Cells are Responsible for Long-term Memory Responses to Allergens in the Lungs

Persistent and recurrent inflammation in airway mucosa plays a central role in allergic airway diseases. However, our knowledge is limited regarding the mechanisms that explain development and maintenance of immunologic memory in the lungs. The goal of this project was to fill this gap by using mouse models.

Myeloid and lymphoid cell immune exhaustion profiles during murine visceral leishmaniasis

Abstract Leishmaniasis is a chronic disease of reticuloendothelial organs that is usually controlled by TH1-type CD4 T cells. Anti-microbicidal responses are ineffective during disease progression, and it is reported that T cells in humans and dogs with visceral leishmaniasis (VL) express markers of cell exhaustion. We hypothesized that myeloid cells provide counter-receptors for inhibitory receptors on T cells at the local sites of Leishmania infantum infection, inhibiting T cell effector functions. We examined inhibitory receptors PD1, LAG3, CTLA4 and TIM3 on lymphoid cells, and ligands PDL1, MHCII, CD80 and Galectin 9 on myeloid cells using flow cytometry, throughout 10 weeks of infection. In livers of infected mice, an increased population of neutrophils with DC features (CD11c+MHCII+) expressing PD-L1 and IL-10 was also observed. In all infected samples an increased DC subset with reduced expression of MHCII, CD80 and CCR7 and higher expression of Galectin 9, PD-L1 and IL-10, was also detected suggesting a pro-exhaustion profile of those cells in infected mice. Furthermore, CD4 and CD8 T cells in infected mice expressed higher levels of the exhaustion markers LAG3, CTLA4 and PD-1 than uninfected mice, with greater proportions of exhausted CD8 than CD4 T cells in livers and spleens. Majority of Ag-experienced CD8 T PD-1+ cells in liver and spleens produced IL-10, whereas most Ag-experienced CD4 T PD-1+ cells produced IFN-γ at the time points studied, suggesting that CD8 T cells assume an exhausted phenotype earlier than CD4 T cells. Data also suggest that both DC and neutrophil subsets could represent a pro-exhaustion myeloid population that may influence the unresponsiveness of lymphocytes in infected tissues during visceral leishmaniasis.

Immunogenicity and Vaccine Potential of InsB, an ESAT-6-Like Antigen Identified in the Highly Virulent Mycobacterium tuberculosis Beijing K Strain.

Our group recently identified InsB, an ESAT-6-like antigen belonging to the Mtb9.9 subfamily within the Esx family, in the Mycobacterium tuberculosis Korean Beijing strain (Mtb K) via a comparative genomic analysis with that of the reference Mtb H37Rv and characterized its immunogenicity and its induced immune response in patients with tuberculosis (TB). However, the vaccine potential of InsB has not been fully elucidated. In the present study, InsB was evaluated as a subunit vaccine in comparison with the most well-known ESAT-6 against the hypervirulent Mtb K. Mice immunized with InsB/MPL-DDA exhibited an antigen-specific IFN-γ response along with antigen-specific effector/memory T cell expansion in the lungs and spleen upon antigen restimulation. In addition, InsB immunization markedly induced multifunctional Th1-type CD4+ T cells coexpressing TNF-α, IL-2, and IFN-γ in the lungs following Mtb K challenge. Finally, we found that InsB immunization conferred long-term protection against Mtb K comparable to that conferred by ESAT-6 immunization, as evidenced by a similar level of CFU reduction in the lung and spleen and reduced lung inflammation. These results suggest that InsB may be an excellent vaccine antigen component for developing a multiantigenic Mtb subunit vaccine by generating Th1-biased memory T cells with a multifunctional capacity and may confer durable protection against the highly virulent Mtb K.

Ascaris lumbricoides coinfection reduces tissue damage by decreasing IL-6 levels without altering clinical evolution of pulmonary tuberculosis or Th1/Th2/Th17 cytokine profile.

Immunological control of Mycobacterium tuberculosis infection is dependent on the cellular immune response, mediated predominantly by Th1 type CD4+ T cells. Polarization of the immune response to Th2 can inhibit the host immune protection against pathogens. Patients with tuberculosis coinfected with helminths demonstrate more severe pulmonary symptoms, a deficiency in the immune response against tuberculosis, and an impaired response to anti-tuberculosis therapy. We evaluated the cellular immune response and the impact of the presence of Ascaris lumbricoides on the immune and clinical response in pulmonary tuberculosis patients. Ninety-one individuals were included in the study: 38 tuberculosis patients, 11 tuberculosis patients coinfected with Ascaris lumbricoides and other helminths, 10 Ascaris lumbricoides patients, and 34 non-infected control individuals. Clinical evolution of pulmonary tuberculosis was studied on 0, 30, 60, and 90 days post-diagnosis of Mycobacterium tuberculosis and Ascaris lumbricoides. Furthermore, immune cells and plasma cytokine profiles were examined in mono/coinfection by Mycobacterium tuberculosis and Ascaris lumbricoides using flow cytometry. There were no statistical differences in any of the evaluated parameters and the results indicated that Ascaris lumbricoides infection does not lead to significant clinical repercussions in the presentation and evolution of pulmonary tuberculosis. The association with Ascaris lumbricoides did not influence the Th1, Th2, and Th17 type responses, or the proportions of T lymphocyte subpopulations. However, higher serum levels of IL-6 in tuberculosis patients may explain the pulmonary parenchymal damage.

High Serum sCD40 and a Distinct Colonic T Cell Profile in Ulcerative Colitis Associated With Primary Sclerosing Cholangitis.

There is a strong association between primary sclerosing cholangitis [PSC] and ulcerative colitis [UC], but the immunological link between the two diseases is obscure. We compared serum cytokine profiles of patients with PSC-UC and UC, and investigated a number of selected cytokines in colonic biopsy samples. We also assessed the presence and activation of T cells in peripheral blood and colonic mucosa. Serum samples from 22 patients with PSC-UC, 28 patients with UC, and 19 controls were analysed by a proximity extension assay including 92 inflammatory cytokines. Biopsies from caecum, sigmoid colon, and rectum were collected from the same patients. Quantitative analysis for IFN-γ, IL-2, IL-4, IL-5, IL-13, IL-17A/ E/F, IL-21, IL-22, IL-23, and IL-27 was carried out on tissue homogenates. T cell phenotype was evaluated by flow cytometry. By multivariate analysis we identified a cluster of serum cytokines with higher levels in PSC-UC, and sCD40 in particular was strongly associated with this patient group. In contrast, colonic cytokines were only modestly increased in PSC-UC, whereas several Th1-, Th2-, and Th17-associated cytokines were increased in UC. Patients with PSC-UC had increased colonic levels of CXCR3-positive CD8+ T cells but fewer CD25-positive CD4+ T cells. An increased CRTH2/CXCR3-quote indicated a predominance of Th-2 type CD4+ T cells in UC patients. Our study reveals different cytokine profiles and T cell profiles in PSC-UC and UC, with higher systemic levels of cytokines in PSC-UC, and a more pronounced colonic inflammation in UC. Serum sCD40 could potentially be investigated as a marker for PSC in UC.

Comparison of immunogenicity and vaccine efficacy between heat-shock proteins, HSP70 and GrpE, in the DnaK operon of Mycobacterium tuberculosis

Antigens (Ags) in Mycobacterium tuberculosis (Mtb) that are constitutively expressed, overexpressed during growth, essential for survival, and highly conserved may be good vaccine targets if they induce the appropriate anti-Mtb Th1 immune response. In this context, stress response-related antigens of Mtb might serve as attractive targets for vaccine development as they are rapidly expressed and are up-regulated during Mtb infection in vivo. Our group recently demonstrated that GrpE, encoded by rv0351 as a cofactor of heat-shock protein 70 (HSP70) in the DnaK operon, is a novel immune activator that interacts with DCs to generate Th1-biased memory T cells in an antigen-specific manner. In this study, GrpE was evaluated as a subunit vaccine in comparison with the well-known HSP70 against the hyper-virulent Mtb Beijing K-strain. Both HSP70- and GrpE-specific effector/memory T cells expanded to a similar extent as those stimulated with ESAT-6 in the lung and spleen of Mtb-infected mice, but GrpE only produced a similar level of IFN-γ to that produced by ESAT-6 stimulation during the late phase and the early phase of Mtb K infection, indicating that GrpE is highly-well recognised by the host immune system as a T cell antigen. Mice immunised with the GrpE subunit vaccine displayed enhanced antigen-specific IFN-γ and serum IgG2c responses along with antigen-specific effector/memory T cell expansion in the lungs. In addition, GrpE-immunisation markedly induced multifunctional Th1-type CD4+ T cells co-expressing IFN-γ, TNF-α, and IL-2 in the lungs of Mtb K-infected mice, whereas HSP70-immunisation induced mixed Th1/Th2 immune responses. GrpE-immunisation conferred a more significant protective effect than that of HSP70-immunisation in terms of bacterial reduction and improved inflammation, accompanied by the remarkable persistence of GrpE-specific multifunctional CD4+ T cells. These results suggest that GrpE is an excellent vaccine antigen component for the development of a multi-antigenic Mtb subunit vaccine by generating Th1-biased memory T cells with multifunctional capacity, and confers durable protection against the highly virulent Mtb K.

Co-delivery of Doxorubicin and Interferon-γ by Thermosensitive Nanoparticles for Cancer Immunochemotherapy.

A dual-sensitive nanoparticle delivery system was constructed by incorporating an acid sensitive hydrazone linker into thermosensitive nanoparticles (TSNs) for co-encapsulating doxorubicin (DOX) and interferon γ (IFNγ) and to realize the co-delivery of chemotherapy and immunotherapy agents against melanoma. DOX, a chemotherapeutic drug, was conjugated to TSNs by a pH-sensitive chemical bond, and IFNγ, a potent immune-modulator, was absorbed into TSNs through the thermosensitivity and electrostatics of nanoparticles. Consequently, the dual sensitive drug-loaded TSN delivery systems were successfully built and showed an obvious core-shell structure, good encapsulation efficiency of drugs, sustained and sensitive drug release, prolonged circulation time, as well as excellent synergistic antitumor efficiency against B16F10 tumor bearing mice. Moreover, the combinational antitumor immune responses of hydrazone bearing DOX/IFNγ-TSN (hyd) were strengthened by activating Th1-type CD4+ T cells, cytotoxic T lymphocytes, and natural killer cells, downregulating the expression levels of immunosuppressive cytokines, such as IL10 and TGFβ, and upregulating the secretion of IL2 and TNFα. Taken together, the multifunctional TSNs system provides a promising strategy for multiple drugs co-delivery with distinct properties.

Centrin-Deleted Leishmania donovani Parasites Help CD4+ T Cells to Acquire Th1 Phenotype and Multi-Functionality Through Downregulation of CD200-CD200R Immune Inhibitory Axis.

The protozoan parasite Leishmania has evolved several strategies to undermine host defense mechanisms by inducing Th2-type adaptive immunity and suppressing effector functions of Th1 phenotype. In our earlier studies, using centrin gene-deleted Leishmania (LdCen−/−) parasites as an immunogen, we have shown induction of an effective Th1-type immunity and robust memory responses that mediate protection against virulent challenge. However, role of inhibitory signals in Leishmania vaccine induced immunity in general, and LdCen−/− in particular has not been studied. Herein, we report that immunization with LdCen−/− parasites produces more functional Th1-type CD4+ T cells via downregulation of CD200–CD200R immune inhibitory axis compared to wild-type infection. We found that expression of CD200 and CD200R was significantly reduced in LdCen−/− infection compared to wild-type infection. Diminished CD200–CD200R signaling in LdCen−/− infection enabled proliferation of CD4+ T cells and resulted in the induction of pro-inflammatory cytokines and suppression of anti-inflammatory response. The effects of diminished CD200–CD200R signaling by LdCen−/− were most evident in the suppression of IL-10-producing CD4+ T cells that helped enhance more Th1 cytokine producing and multi-functional T cells compared to wild-type infection. In vivo blocking of CD200 expression with anti-CD200 treatment in wild-type infected mice limited Th2 response as indicated by reduction of IL-10-producing Tr1 cells and reduced parasite burden. On the other hand, treatment with anti-CD200 improved the LdCen−/− vaccine-induced multifunctional response and reduction in splenic parasite load upon challenge. Taken together, these studies demonstrate the role of CD200–CD200R signals in the protection induced by LdCen−/− parasites.

Human CD4 T-Cells With a Naive Phenotype Produce Multiple Cytokines During Mycobacterium Tuberculosis Infection and Correlate With Active Disease.

T-cell-mediated immune responses play a fundamental role in controlling Mycobacterium tuberculosis (M. tuberculosis) infection, and traditionally, this response is thought to be mediated by Th1-type CD4+ T-cells secreting IFN-γ. While studying the function and specificity of M. tuberculosis-reactive CD4+ T-cells in more detail at the single cell level; however, we found a human CD4+ T-cell population with a naive phenotype that interestingly was capable of producing multiple cytokines (TCNP cells). CD4+ TCNP cells phenotyped as CD95lo CD28int CD49dhi CXCR3hi and showed a broad distribution of T cell receptor Vβ segments. They rapidly secreted multiple cytokines in response to different M. tuberculosis antigens, their frequency was increased during active disease, but was comparable to latent tuberculosis infection in treated TB patients. These results identify a novel human CD4+ T-cell subset involved in the human immune response to mycobacteria, which is present in active TB patients’ blood. These results significantly expand our understanding of the immune response in infectious diseases.

IL-27 controls allergic airway inflammation via Foxp3+ regulatory T cells

Abstract Asthma is a chronic inflammatory disease in the lung mediated by allergen reactive Th2 type CD4 T cells producing the Th2 type cytokines. We recently reported that IL-27 plays a key role in Treg functions to control Th17-mediated autoimmune inflammation. However, a role for IL-27 in modulating Treg function during Th2-mediated allergic airway inflammation remains unclear. Here, we report that during cockroach antigen (CA)-induced allergic airway inflammation, IL-27 attenuates inflammatory responses primarily via Foxp3+ Tregs. Sensitizing mice with CA in alum followed by intranasal challenge induces allergic airway inflammation characterized by infiltration of eosinophils and effector CD4 T cells expressing Th2 cytokines in the lung. Recombinant IL-27 administration prior to antigen challenge significantly reduces the inflammation. Accumulation of CD4 T cells expressing inflammatory cytokines is dramatically reduced in the inflamed sites following IL-27 administration. However, IL-27-mediated treatment effects are completely lost when Foxp3+ Tregs are deleted prior to CA challenge. Adoptive transfer of wild type Tregs restores IL-27-mediated inhibition of airway inflammation, suggesting that Tregs may be the direct responders of IL-27. IL-27 stimulation in Tregs increases expression of lymphocyte activation gene 3 (Lag3), a surface molecule implicated in Treg functions. Unlike WT type cells, adoptive transfer of Tregs deficient in Lag3 fails to attenuate airway inflammation even after IL-27 administration. Taken together, these results demonstrate a novel IL-27-dependent Treg function to control allergic airway inflammation