Effective induction of melanoma-antigen-specific CD8+ T cells via Vγ9γδT cell expansion by CD56(high+) Interferon-α-induced dendritic cells

Aberrant myelomonocytic CD56 expression predicts response to cyclosporine therapy in pediatric patients with moderate aplastic anemia

Objects

This study aimed to investigate the expression patterns and clinical significance of neural cell adhesion molecule-positive (CD56+) myelomonocytes in pediatric patients with moderate aplastic anemia (mAA).

Methods

Fifty-six pediatric patients with mAA were enrolled in this study. The patients' clinical characteristics, laboratory data, and response to cyclosporine therapy were obtained. CD56 expression on bone marrow myelomonocytic cells was investigated using flow cytometry. The association between aberrant CD56 expression and cyclosporine response was evaluated by a multivariate analysis.

Results

CD56+ myelomonocytes were detected in 43% of the mAA cases. Aberrant CD56 expression was frequent on immature CD45dimCD16dim granulocytes and mature CD45brightCD14bright monocytes. Compared with patients with CD56- myelomonocytes (CD56- patients), patients with CD56+ myelomonocytes (CD56+ patients) were in moderate hematological condition and had a distinct bone marrow cellular composition profile, which included an increased proportion of myeloid cells and CD56bright natural killer cells and a reduced proportion of CD4+ T cells, CD8+ T cells, and B cells. The multivariate analysis determined that CD56+ myelomonocytes were a favorable factor for achieving response at 6 months after cyclosporine therapy. There was a trend towards a lower 3-year rate of evolution to severe aplastic anemia or relapse among the CD56+ patients (8%) than the CD56- patients (22%).

Conclusion

CD56+ patients had an increased myeloid compartment and better prognosis compared with CD56- patients. The findings demonstrated the favorable role of CD56+ myelomonocytes in aplastic anemia progression.

Vγ9γδ T Cell Induction by Human Umbilical Cord Blood Monocytes-Derived, Interferon-α-Stimulated Dendritic Cells

Dendritic cells (DC) are professional antigen-presenting cells that activate T cells to kill cancer cells. The extracellular products of DCs have also been reported to perform the same function. In this study, we examined the in vitro differentiation of umbilical cord blood monocytes into DCs in the presence of GM-CSF, and interferon (IFN)-α. The resulting DC population (called IFN-DCs) were then matured in the presence of TNF-α, and pulsed with total protein extracted from A549 cancer cell line. The pulsed DCs and their conditioned medium were then used to stimulate allogeneic lymphocytes (alloLym). The proliferation and cytotoxicity of alloLym were then determined. The results showed that after 5 days of differentiation, the stimulated monocytes had the typical morphology and characteristic surface markers of DCs. Both unpulsed and pulsed IFN-DCs can induce the proliferation of alloLym, especially Vγ9γδ T cells. The conditioned medium from pulsed and unpulsed IFN-DCs culture also prompted the growth of Vγ9γδ T cells. Moreover, alloLym stimulated with pulsed DCs and their conditioned medium had a greater cytotoxic effect on A549 cells than the ones that were not stimulated. Our results indicated that IFN-DCs and their conditioned medium could induce the anti-tumor immunity in vitro, providing evidence for application of cord blood monocytes-derived, interferon-α- stimulated dendritic cells and their extracellular products in anti-cancer therapy.

Melatonin administration provokes the activity of dendritic reticular cells in the seminal vesicle of Soay ram during the non-breeding season

Dendritic cells (DCs) are innate immune cells which engulf, process and present antigens to the naïve T-lymphocyte cells. However, little is known about the effect of melatonin on the DCs. The present study aimed to investigate the morphology and distribution of the DCs by transmission electron microscopy and Immunohistochemistry after melatonin administration. A total of 8 out of 15 adult ram was randomly selected to receive the melatonin implant and the remaining 7 animals received melatonin free implants. DCs showed positive immunoreactivity for CD117, S-100 protein and CD34. There is an obvious increase in the number of the positive immunoreactive cells to CD3, estrogen receptor alpha and progesterone in the treated groups. The expression of CD56 and MHCII in the DCs was abundant in the treated groups. The ultrastructure study revealed that melatonin exerts a stimulatory effect on the DCs which was associated with increment in the secretory activity of DCs. The secretory activity demarcated by an obvious increase in the number of mitochondria, cisternae of rER and a well-developed Golgi apparatus. The endosomal- lysosomal system was more developed in the treated groups. A rod-shaped Birbeck granule was demonstrated in the cytoplasm of the melatonin treated group. DCs were observed in a close contact to telocytes, T-Lymphocytes, nerve fibers and blood vessels. Taken together, melatonin administration elicits a stimulatory action on the DCs and macrophages through increasing the size, the number and the endosomal compartments which may correlate to increased immunity.

Γδ T Cell-Based Immunotherapy in Melanoma: State of the Art

Metastatic melanoma is still associated with a poor prognosis, and there is increasing interest in immunotherapy alone or in combination with other adjuvant therapies. Γδ T lymphocytes play a pivot role in the immune response against cancer, but while γδ-based immunotherapy is already a clinical reality for several solid tumors, data on melanoma are still limited and fragmented. This systematic review presents preclinical and clinical evidence for a role of γδ T lymphocytes in immunotherapeutic strategies for advanced melanoma and discusses research state of the art and future perspectives. Current strategies focus on in vivo stimulation, and ex vivo adoptive therapy and vaccination; results are promising, but further studies are needed to better investigate the interactions in tumoral microenvironment and to improve clinical efficacy of immunotherapeutic protocols.

Morphological characteristic and functional dependencies of dendritic cell in developing rabbit lung during fetal and neonatal life

Recently, pulmonary DC deserved the attention of researchers and clinicians as it was implicated in many diseases afflicting human lungs. However, there are no available data about the morphological or functional features of pulmonary dendritic cells in fetal or early neonatal life. The present study aimed to demonstrate the morphological development of DCs using light-, electron-microscopy, and immunohistochemistry. DCs showed strong immunoreactivity for both CD8 and CD56. Moreover, DCs strongly expressed CD34, VEGF, NSE, and connexin-43 within the developing pulmonary tissue. By SEM, DCs were polyhedral in shape with short cell processes in fetal life. By the advancement of the age, DCs became more numerous and exhibited rounded to oval cell bodies with many fine dendrites. TEM revealed that at early fetal life, DCs were characterized by their heterochromatic indented nuclei, few cell processes and few organelles. With the advancement of age, DCs showed dendrite-like processes and displayed signs of high endocytic activities with releasing of secretory materials. At late fetal life, DCs showed an obvious increase in the nuclear/cytoplasmic ratio and they exhibited a unique connection with type II pneumocytes and pulmonary endothelium by gap junction. In the early neonate, the DCs cells were seen in association with T-lymphocytes, neutrophils, telocytes (TCs), and air-blood barrier. They possessed many fine dendrites, the characteristic Birbeck granules and many vesicles. DCs may contribute to apoptosis, endocytosis, and angiogenesis. The difference in the maturation status may reflect different roles for DCs in the lung. The immature DCs may have an antigen-uptake role through endocytosis, while mature DCs may involve in antigen presentation to T-cells.

Dendritic cells cross-talk with tumour antigen-specific CD8+ T cells, Vγ9γδT cells and Vα24NKT cells in patients with glioblastoma multiforme and in healthy donors

The finding that dendritic cells (DCs) orchestrate innate and adaptive immune responses has stimulated research on harnessing DCs for developing more effective vaccines for DC therapy. The expression of cytomegalovirus (CMV) antigens in glioblastoma multiforme (GBM) presents a unique opportunity to target these viral proteins for tumour immunotherapy. Here, we demonstrate that Vγ9γδT cells, innate immune cells activated by zoledronate (Z) and Vα24 natural killer (Vα24NK) cells, innate/adaptive immune cells activated by α‐galactosylceramide (G) can link innate and adaptive immunities through cross‐talk with interferon (IFN) DCs from patients with glioblastoma multiforme (GBM) and healthy donors in a manner that can amplify the activation and proliferation of CMVpp65‐specific CD8⁺ T cells. The IFN DCs derived from patients with GBM used in this study express lower levels of programmed cell death ligand (PD)‐L1 and PD‐L2 and higher levels of C‐C receptor 7 (CCR7) than the most commonly used mature interleukin (IL)‐4 DCs. The expression level of programmed cell death 1 (PD‐1) on CD8⁺ T cells, including CMVpp65‐specific CD8⁺ T cells, expanded by IFN DCs pulsed with the CMVpp65‐peptide and Z plus G (IFN DCs/P+Z+G), was lower than that expanded by IFN DCs pulsed with the peptide alone (IFN DCs/P). Multi‐functional T cells, including human leucocyte antigen (HLA)‐A*0201‐restricted CMVpp65‐specific CD8⁺ T cells, Vγ9γδT cells and Vα24NKT cells, efficiently kill the HLA‐A*0201‐positive GBM cell line expressing CMVpp65 protein (T98G). These findings indicate that DC therapy using IFN DCs/P+Z+G and/or CTL therapy using CMVpp65‐specific CD8⁺ T cells expanded by IFN DCs/P+Z+G may lead to a good clinical outcome for patients with GBM.

CD56 in the Immune System: More Than a Marker for Cytotoxicity?

Over the past years, the phenotypic and functional boundaries distinguishing the main cell subsets of the immune system have become increasingly blurred. In this respect, CD56 (also known as neural cell adhesion molecule) is a very good example. CD56 is the archetypal phenotypic marker of natural killer cells but can actually be expressed by many more immune cells, including alpha beta T cells, gamma delta T cells, dendritic cells, and monocytes. Common to all these CD56-expressing cell types are strong immunostimulatory effector functions, including T helper 1 cytokine production and an efficient cytotoxic capacity. Interestingly, both numerical and functional deficiencies and phenotypic alterations of the CD56⁺ immune cell fraction have been reported in patients with various infectious, autoimmune, or malignant diseases. In this review, we will discuss our current knowledge on the expression and function of CD56 in the hematopoietic system, both in health and disease.

Identification of Novel HLA-A*0201-Restricted CTL Epitopes in Chinese Vitiligo Patients

Generalized vitiligo is an autoimmune disease characterized by melanocyte loss, which results in patchy depigmentation of skin and hair. Recent studies suggested the key role of CD8⁺T lymphocytes for mediating immune response in vitiligo through melanocyte differentiation antigens, including tyrosinase, gp100 and MelanA/Mart-1. However, the specific epitopes of these auto-antigens are still unknown. In our study, we predicted the possible HLA-A*0201-restricted nonapeptides overlaying the full-length amino acid sequences of these three known antigens and investigated the lymphocytes reactivity to these nonapeptides by Elispot assay. In addition, we evaluated the abilities of these nonapeptides to activate CD8⁺T cells. We screened out 5 possible epitopes originated from tyrosinase and gp100, numbered P28, P41, P112, P118 and P119. Among these 5 epitopes, notably, P28 and P119 played the dominant role in activating CTLs, with a significant increase in proliferation rate and Interferon-γ (IFN-γ) production of CD8⁺T cells. Nevertheless, antigen-specific T cell reactivity was not detected in MelanA/Mart-1 peptides. Our studies identified two novel epitopes originated from proteins of gp100 and tyrosinase, which may have implications for the development of immunotherapies for vitiligo.

Generation of lentivirus-induced dendritic cells under GMP-compliant conditions for adaptive immune reconstitution against cytomegalovirus after stem cell transplantation

Background

Reactivation of latent viruses such as human cytomegalovirus (HCMV) after allogeneic hematopoietic stem cell transplantation (HSCT) results in high morbidity and mortality. Effective immunization against HCMV shortly after allo-HSCT is an unmet clinical need due to delayed adaptive T cell development. Donor-derived dendritic cells (DCs) have a critical participation in stimulation of naïve T cells and immune reconstitution, and therefore adoptive DC therapy could be used to protect patients after HSCT. However, previous methods for ex vivo generation of adoptive donor-derived DCs were complex and inconsistent, particularly regarding cell viability and potency after thawing. We have previously demonstrated in humanized mouse models of HSCT the proof-of-concept of a novel modality of lentivirus-induced DCs (“SmyleDCpp65”) that accelerated antigen-specific T cell development.

Methods

Here we demonstrate the feasibility of good manufacturing practices (GMP) for production of donor-derived DCs consisting of monocytes from peripheral blood transduced with an integrase-defective lentiviral vector (IDLV, co-expressing GM-CSF, IFN-α and the cytomegalovirus antigen pp65) that were cryopreserved and thawed.

Results

Upscaling and standardized production of one lot of IDLV and three lots of SmyleDCpp65 under GMP-compliant conditions were feasible. Analytical parameters for quality control of SmyleDCpp65 identity after thawing and potency after culture were defined. Cell recovery, uniformity, efficacy of gene transfer, purity and viability were high and consistent. SmyleDCpp65 showed only residual and polyclonal IDLV integration, unbiased to proto-oncogenic hot-spots. Stimulation of autologous T cells by GMP-grade SmyleDCpp65 was validated.

Conclusion

These results underscore further developments of this individualized donor-derived cell vaccine to accelerate immune reconstitution against HCMV after HSCT in clinical trials.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-015-0599-5) contains supplementary material, which is available to authorized users.

Empowering gamma delta T cells with antitumor immunity by dendritic cell-based immunotherapy

Gamma delta (γδ) T cells are the all-rounders of our immune-system with their major histocompatibility complex-unrestricted cytotoxicity, capacity to secrete immunosti-mulatory cytokines and ability to promote the generation of tumor antigen-specific CD8⁺ and CD4⁺ T cell responses. Dendritic cell (DC)-based vaccine therapy has the prospective to harness these unique features of the γδ T cells in the fight against cancer. In this review, we will discuss our current knowledge on DC-mediated γδ T cell activation and related opportunities for tumor immunologists.