Two-signal blockade with anti-CD45RB and anti-CD154 monoclonal antibodies inhibits graft rejection via CD4-dependent mechanisms in allogeneic skin transplantation

Blockade of signal 1 or 2 for T-cell activation by the use of anti-CD45RB and anti-CD154 monoclonal antibodies (mAb) (two-signal blockade) has been proven effective in preventing or delaying graft rejection. However, the mechanisms of its immunomodulatory effects are clearly unknown and the present studies were performed to determine how the two-signal blockade modulate allogeneic immune responses, especially T-cell mediated cellular immunity, in a murine skin allograft model. We now report on the profound inhibition of alloreactive T cells by two-signal blockade via CD4-dependent mechanisms. C57BL/6 mice of BALB/c skin allograft were treated with anti-CD45RB, anti-CD154, CTLA4-Ig, or their combinations. For depletion of CD4 or CD8 T cells, the recipients received CD4-depleting or CD8-depleting mAb. We confirmed that survival of skin allograft was markedly prolongated in the two-signal blockade-treated group. In depletion study, anti-CD45RB, anti-CD154 and CD4-depleting mAb-treated group showed acute rejection of skin allograft in contrast to CD8-depleting group treated with the two-signal blockade. In the group treated with the two-signal blockade, the proportions of CD4+CD45RB(low) and CD8+CTLA-4 regulatory T cells were increased while effector CD8+ T cells, including IFN-gamma-secreting and CD8+CD62L(low) T cells, were decreased when compared with non-treated group. In contrast, the CD4-depleted group treated with the two-signal blockade resulted in recovery from immunoregulatory effects of two-signal blockade. In addition, results of IL-4 and IL-10 production were also showed CD4-dependence. Therefore, the two- signal blockade is accompanied by CD4-dependent mechanisms in allogeneic skin transplantation.     

Differential roles of T-cell subsets in regulation of ultraviolet radiation induced cutaneous photocarcinogenesis

Ultraviolet (UV) radiation, in particular the midwavelength range (UVB; 290-320 nm), is one of the most significant risk factors for the development of nonmelanoma skin cancer. UVB radiation-induced immunosuppression, which occurs in both humans and laboratory animals, contributes to their pathogenesis. However, there are conflicting reports on the relative role of CD4(+) and CD8(+) T cells in UVB induced skin cancer. The purpose of this study was to delineate the contribution of these two cell subpopulations to UVB induced immunosuppression and tumor development using C3H/HeN (WT), CD4 knockout (CD4(-/-) ) and CD8 knockout (CD8(-/-) ) mice. We observed that UVB induced skin carcinogenesis was retarded in terms of number of tumors per group, tumor volume and percentage of mice with tumors, in mice deficient in CD4(+) T cells compared with wild-type mice, whereas significantly greater (P < 0.05) numbers of tumors occurred in CD8(-/-) mice. These results indicate that, CD4(+) T cells promote tumor development while CD8(+) T cells have the opposite effect. Further, we found that CD4(+) T cells from tumor-bearing mice produced interleukin (IL)-4, IL-10, and IL-17 whereas CD8(+) T cells produced interferon-γ. Manipulation of T-cell subpopulations that are induced by UVB radiation could be a means of preventing skin cancers caused by this agent.     

Solar-simulated Ultraviolet Irradiation Induces Selective Influx of CD4+ T Lymphocytes in Normal Human Skin

Abstract— The proportion and composition of the human cutaneous CD3+ T lymphocyte population was determined in situ following a single exposure to physiological, erythema-inducing doses of simulated solar radiation, mainly consisting of UV radiation. Biopsies were taken 1, 2 and 7 days after local irradiation of normal volunteers with 1,2 and 4 MED by a xenonarc lamp and immunohistochemistry was performed on cryostat sections. Ultraviolet radiation caused an initial decrease of intraepidermal CD3+ T-cell numbers or even could lead to T-cell depletion 24 and 48 h postirradiation, and this was followed by an infiltration of T cells in the epidermis as determined 1 week after UV exposure. The number of dermal CD3+ T ceDs was increased 24 h after irradiation, reached a maximum at 48 h and subsequently declined at day 7, though remained significantly higher than the unirradiated control Double staining demonstrated that the CD3+ T cells, which immigrated into the (epi)dermis upon UV exposure, coexpressed CD4 but not CD8. Therefore the CD4/CD8 ratio in skin was markedly increased during the first week upon UV exposure. Our time course study shows that UV radiation affects die T-cell population within human skin by depleting the majority of epidermal T cells and initiating a selective influx of CD4+ T cells.     

Maintenance of CD8+ T-cell anergy by CD4+CD25+ regulatory T cells in chronic graft-versus-host disease

In a murine model of systemic lupus erythematosus (SLE)-like chronic graft-versus-host disease (cGVHD), donor CD8+ T cells rapidly fall into anergy to host cells, while donor CD4+ T cells hyperactivate B cells and break B-cell tolerance to self-Ags in the recipient mouse. The functional recovery of donor CD8+ T cells can result in the conversion of cGVHD to acute GVHD (aGVHD), indicating that donor CD8+ T-cell anergy is a restriction factor in the development of cGVHD. In this report, we present evidence that donor CD4+CD25+ regulatory T cells (Treg cells) are critical in maintaining the donor CD8+ T-cell anergy and thus suppressing the development of aGVHD in mice that are naturally prone to cGVHD. Our results provide a novel insight into the role of Treg cells in determining cGVHD versus aGVHD.     

Small Molecule Degraders of Protein Tyrosine Phosphatase 1B and T-Cell Protein Tyrosine Phosphatase for Cancer Immunotherapy

Protein tyrosine phosphatase 1B (PTP1B) and T-cell protein tyrosine phosphatase (TC-PTP) play non-redundant negative regulatory roles in T-cell activation, tumor antigen presentation, insulin and leptin signaling, and are potential targets for several therapeutic applications. Here, we report the development of a highly potent and selective small molecule degrader DU-14 for both PTP1B and TC-PTP. DU-14 mediated PTP1B and TC-PTP degradation requires both target protein(s) and VHL E3 ligase engagement and is also ubiquitination- and proteasome-dependent. DU-14 enhances IFN-γ induced JAK1/2-STAT1 pathway activation and promotes MHC-I expression in tumor cells. DU-14 also activates CD8⁺ T-cells and augments STAT1 and STAT5 phosphorylation. Importantly, DU-14 induces PTP1B and TC-PTP degradation in vivo and suppresses MC38 syngeneic tumor growth. The results indicate that DU-14, as the first PTP1B and TC-PTP dual degrader, merits further development for treating cancer and other indications.     

Quantitative microarray analysis of intact glycolipid-CD1d interaction and correlation with cell-based cytokine production

The protein CD1d binds self and foreign glycolipids for presentation to CD1-restricted T cells by means of TCR recognition and activates T(H)1 and T(H)2 chemokine release. In this study, a variety of glycolipid ligands were attached to a microarray surface and their binding with dimeric CD1d was investigated. An alpha-galactosyl ceramide (alpha-GalCer) bearing a carbamate group at the 6'-OH position was tethered to the surface, and the dissociation constant on surface with CD1d was determined to reflect the multivalent interaction. Competition assays were then used to determine the dissociation constants (Ki) of new and intact glycolipids in solution. The 4-fluorophenyloctanoyl-modified alpha-GalCer (18) was found to bind most strongly with CD1d (Ki 0.21 microM), 2 orders of magnitude stronger than alpha-GalCer and more than three times more selective than alpha-GalCer for IFN-gamma release from NKT cells. Various alpha-GalCer analogues were analyzed, and the results showed that the binding affinity of glycolipids to CD1d correlates well with IFN-gamma production but poorly with IL-4 secretion by NKT cells, suggesting that tighter binding ligands could bias cytokine release through the T(H)1 pathway.     

Efficient amplification of melanoma-specific CD8+ T cells using artificial antigen presenting complex

In vitro large amplification of tumor-specific cytotoxic T lymphocytes (CTLs) and adoptive transfer of these cells is one of the most promising approaches to treat malignant diseases in which an effective immune response is not achieved by active immunization. However, generating sufficient numbers of tumor-specific CTLs stimulated with autologous antigen presenting cells (APCs) in vitro is one of the most problematic steps in the adoptive cell transfer (ACT) therapy. To circumvent this problem, we have developed an artificial antigen presenting complex (aAPCs) using MHC class I molecules loaded with a melanoma-specific TRP-2 peptide epitope. Our results show that TRP-2-specific CD8+ T cells elicited by immunization with recombinant adenovirus expressing the mini-gene epitope are efficiently stimulated and amplified in vitro to a greater extent by aAPCs than by natural splenic APCs. These aAPC-induced CTLs recognized endogenously processed antigens present on B16F10 melanoma cells. Efficient stimulation and proliferation of antigen- specific T cells was also confirmed using ovalbumin peptide-loaded aAPCs and OT-I TCR transgenic cells. These results demonstrate that prior in vivo immunization, which increases the precursor frequency, simplifies posterior expansion of tumor- specific CD8+ T cells, and aAPCs is superior to autologous APC for in vitro amplification. This "prime and expand" regimen can be an alternative method for large amplification of rare tumor-specific CTLs and aAPCs should be a useful tool for ACT immunotherapy.     

Further Characterization of UVB Radiation Effects on Langerhans Cells: Altered Expression of the Costimulatory Molecules B7-1 and B7-2

We have reported previously that low-dose UVB radiation (UVBR, 50-200 J/m²) perturbs the antigen-presenting cell (APC) function of murine Langerhans cells (LC) by interfering with yet undefined costimulatory signals. In this study, we investigated (1) the effects of UVBR on the expression of the costimulatory molecules B7-1 and B7-2 on murine LC, (2) the functional consequences of defective B7-1 and B7-2 signalling on primary and secondary T-cell responses induced by LC and (3) the mechanism by which UVBR interferes with B7-1 and B7-2 expression. Ultraviolet-B radiation dose-dependently inhibited the culture-induced upregulation of B7-1 and B7-2 on LC from both UVB-susceptible (UVB_s, C57BL/6) and UVB-resistant (UVB_R, Balb/c) mice and abrogated their capacity to stimulate proliferation of naive alloreactive T cells and of the KLH (keyhole limpet hemocyanin)-specific T helper (Th)1 clone HDK-1. The UVBR-induced suppression of B7-1 and B7-2 on LC and their perturbed APC function were related, because exogenous triggering of the B7/CD28 pathway with a stimulatory monoclonal antibody (mAb) for CD28 to UVB-irradiated LC partially restored T-cell proliferation. Such reconstitution was not observed when the mAb was added to killed LC, indicating that the UVBR-induced suppression of APC function was not due to lethal effects on LC. Conditioned supernatants from UVB-irradiated epidermal cells did not inhibit the functional upregulation of B7-1 and B7-2, suggesting that UVBR inhibits B7-1 and B7-2 upregulation by acting directly on LC and not by altering LC costimulatory function via release of soluble immunosuppressive factors. In conclusion, UVBR distorts the functional expression of B7-1 and B7-2 on LC from both UVBs and UVBR mice, thereby contributing to the failure of UVB-irradiated LC to stimulate resting alloreactive T cells or KLH-specific Thl cells.     

Immunotoxic effects of cis-urocanic acid exposure in C57BL/6N and C3H/HeN mice

Exposure to ultraviolet radiation results in increased levels of intradermal cis-urocanic acid (cUCA) and alters cutaneous immunity by interfering with processing and presentation of antigen by Langerhans cells. Reports on effects of systemic immunotoxicity with 30 day cUCA exposure in laboratory rodents include thymic atrophy, thymic hypocellularity and decreased T-cell-mediated immunity; however, immune effects of single exposure or 5 day cUCA administration, which may better mimic human exposures, are poorly defined. The present study initially evaluated immune effects of single, 5 day, and 4 week cUCA exposure in C57BL/6N mice. Single administration of intradermal cUCA resulted in decreased splenocyte phagocytosis that persisted for 30 days after cUCA exposure. Five day consecutive cUCA exposure decreased numbers of phenotypically mature CD4(+)CD8(-) and CD4(-)CD8(+) (single positive) thymocytes, increased CD4(+)CD8(+) (double positive) immature thymocytes and increased splenocyte proliferation. Prolonged cUCA exposure (4 weeks) caused profound thymic hypocellularity and splenic hypercellularity and increased splenic macrophage chemiluminescence. Because of this apparent sensitivity of C57BL/6N mice to cUCA, thymic hypocellularity was compared between C57BL/6N and C3H/HeN mice dosed with cUCA, and was found to be more pronounced in the C57BL/6N strain. These results are an extension of previous conclusions on immune modulation caused by cUCA in the spleen and thymus. Further, the observed variation in sensitivity between the mouse strains is consistent with known genetic susceptibility of these strains to the immunomodulatory effects of exposure to sunlight.     

Introduction of the CIITA gene into tumor cells produces exosomes with enhanced anti-tumor effects

Exosomes are small membrane vesicles secreted from various types of cells. Tumor-derived exosomes contain MHC class I molecules and tumor-specific antigens, receiving attention as a potential cancer vaccine. For induction of efficient anti-tumor immunity, CD4+ helper T cells are required, which recognize appropriate MHC class II-peptide complexes. In this study, we have established an MHC class II molecule-expressing B16F1 murine melanoma cell line (B16F1- CIITA) by transduction of the CIITA (Class II transactivator) gene. Exosomes from B16-CII cells (CIITA- Exo) contained a high amount of MHC class II as well as a tumor antigen TRP2. When loaded on dendritic cells (DCs), CIITA-Exo induced the increased expression of MHC class II molecules and CD86 than the exosomes from the parental cells (Exo). In vitro assays using co-culture of immunized splenocytes and exosome-loaded DCs demonstrated that CIITA-Exo enhanced the splenocyte proliferation and IL-2 secretion. Consistently, compared to B16-Exo, CIITA-Exo induced the increased mRNA levels of inflammatory cytokines such as TNF-α, chemokine receptor CCR7 and the production of Th1-polarizing cytokine IL-12. A tumor preventive model showed that CIITA-Exo significantly inhibited tumor growth in a dose-dependent manner. Ex vivo assays using immunized mice demonstrated that CIITA-Exo induced a higher amount of Th1-polarized immune responses such as Th1-type IgG2a antibodies and IFN-γ cytokine as well as TRP2-specific CD8+ T cells. A tumor therapeutic model delayed effects of tumor growth by CIITA-Exo. These findings indicate that CIITA-Exo are more efficient as compared to parental Exo to induce anti-tumor immune responses, suggesting a potential role of MHC class II-containing tumor exosomes as an efficient cancer vaccine.     

In vivo ligation of glucocorticoid-induced TNF receptor enhances the T-cell immunity to herpes simplex virus type 1

GITR (glucocorticoid-induced TNF receptor) is a recently identified member of the TNF receptor superfamily. The receptor is preferentially expressed on CD4(+)CD25(+) regulatory T cells and GITR signals break the suppressive activity of the subset. In this study, we wanted to reveal the in vivo function of GITR in herpes simplex virus type 1 (HSV-1) infection. A single injection of anti-GITR mAb (DTA-1) immediately after viral infection significantly increased the number of CD4(+) and CD8(+) T cells expressing CD25, an activation surface marker, and secreting IFN-gamma. We confirmed these in vivo observations by showing ex vivo that re-stimulation of CD4(+) or CD8(+) T cells with a CD4(+) or CD8(+) T-cell-specific HSV-1 peptide, respectively, induced a significant elevation in cell proliferation and in IFN-gamma secretion. Our results indicate that GITR signals play a critical role in the T-cell immunity to HSV-1.     

Function of γδ T cells in tumor immunology and their application to cancer therapy

T cells of the γδ lineage are unconventional T cells with functions not restricted to MHC-mediated antigen presentation. Because of their broad antigen specificity and NK-like cytotoxicity, γδ T-cell importance in tumor immunology has been emphasized. However, some γδ T-cell subsets, especially those expressing IL-17, are immunosuppressive or tumor-promoting cells. Their cytokine profile and cytotoxicity are seemingly determined by cross-talk with microenvironment components, not by the γδTCR chain. Furthermore, much about the TCR antigen of γδ T cells remains unknown compared with the extreme diversity of their TCR chain pairs. Thus, the investigation and application of γδ T cells have been relatively difficult. Nevertheless, γδ T cells remain attractive targets for antitumor therapy because of their independence from MHC molecules. Because tumor cells have the ability to evade the immune system through MHC shedding, heterogeneous antigens, and low antigen spreading, MHC-independent γδ T cells represent good alternative targets for immunotherapy. Therefore, many approaches to using γδ T cells for antitumor therapy have been attempted, including induction of endogenous γδ T cell activation, adoptive transfer of expanded cells ex vivo, and utilization of chimeric antigen receptor (CAR)-T cells. Here, we discuss the function of γδ T cells in tumor immunology and their application to cancer therapy.Subject terms: Innate immune cells, Tumour immunology     

Consecutive low doses of cyclosporine A induce pro-inflammatory cytokines and accelerate allograft skin rejection

Cyclosporine A (CsA) is a fungus-derived molecule with potent immunosuppressive activity that has been largely used to downregulate cell-mediated immune responses during transplantation. However, previous data have indicated that CsA shows immunomodulatory activity that relays on the antigen concentration and the dose of CsA used. To test the hypothesis that minimal doses of CsA may show different outcomes on grafts, we used an experimental model for skin transplants in mice. ICR outbred mice received skin allografts and were either treated daily with different doses of CsA or left untreated. Untreated mice showed allograft rejection within 14 days, with graft necrosis, infiltration of neutrophils and macrophages and displayed high percentages of CD8+ T cells in the spleens, which were associated with high serum levels of IL-12, IFN-g and TNF-α. As expected, mice treated with therapeutic doses of CsA (15 mg/kg) did not show allograft rejection within the follow-up period of 30 days and displayed the lowest levels of IL-12, IFN-g and TNF-α as well as a reduction in CD8+ lymphocytes. In contrast, mice treated with consecutive minimal doses of CsA (5×10(-55) mg/kg) displayed an acute graft rejection as early as one to five days after skin allograft; they also displayed necrosis and strong inflammatory infiltration that was associated with high levels of IL-12, IFN-g and TNF-α. Moreover, the CD4+ CD25hiFoxP3+ subpopulation of cells in the spleens of these mice was significantly inhibited compared with animals that received the therapeutic treatment of CsA and those treated with placebo. Our data suggest that consecutive, minimal doses of CsA may affect Treg cells and may stimulate innate immunity.     

Oclacitinib,a Janus Kinase Inhibitor,Reduces the Frequency of IL-4- and IL-10-, but Not IFN-γ-, Producing Murine CD4+ and CD8+ T Cells and Counteracts the Induction of Type 1 Regulatory T Cells

The purpose of the present study was to broaden the knowledge and understanding of the effects of oclacitinib (OCL), a Janus kinase inhibitor, on T cells in the context of both the immune mechanisms underlying anti-inflammatory and anti-allergic properties of the drug and its safety. The results indicate that beneficial effects of OCL in the treatment of skin allergic diseases may be partially mediated by the inhibition of IL-4 production in CD4⁺ and CD8⁺ T cells. To a certain extent, the antiproliferative effect of OCL on CD8⁺ T cells may also contribute to its therapeutic effect. The study found that OCL does not affect the proliferation of CD4⁺ T cells or the number of IFN-γ- and IL-17-producing CD4⁺ and CD8⁺ T cells. Moreover, OCL was found to counteract the induction of type 1 regulatory T (Tr1) cells and to act as a strong inhibitor of IL-10 production in both CD4⁺ and CD8⁺ T cells. Thus, these results indicate that beneficial effects of OCL in the treatment of skin allergic diseases are not mediated through: (a) the abolishment of IFN-γ and IL-17-production in CD4⁺ and CD8⁺ T cells; (b) generation of Tr1 cells; (c) inhibition of CD4⁺ T cell proliferation; (d) induction of IL-10 production in CD4⁺ T cells. The results of this study strongly suggest that, with respect to the evaluated parameters, OCL exerts a suppressive effect on Th2- but not Th1-mediated immunity.     

Cell electrophoretic characterization of abnormally expanded lymphocytes in autoimmune lprcg, lpr, gld and Yaa mice, and of thymocyte subsets.

Autoimmune mice carrying the lprcg/lprcg(lprcg),lpr/lpr(lpr),gld/gld(gld) and Yaa genes exhibit massive lymphoproliferation and a systemic lupus erythematosus-like syndrome. The surface markers of abnormally expanded lymphocytes used were Thy-1+, CD4-CD8- (double negative, DN) and CD45+ for lprcg, lpr, gld and (lprcg X gld) hybrid (F1-lprcg-gld) mice, and Ig+ for Yaa mice. To characterize the cell surface properties and differentiation pathway of lymphocytes in autoimmune mice, the cell electrophoretic mobility (EPM) was determined for the lymph node (LN), spleen and thymus cells. The EPM of lymphocytes derived from swollen LN was of the T cell type in lprcg, lpr, gld and F1-lprcg-gld mice, but of the B cell type in Yaa mice, indicating that the EPM of abnormally proliferated lymphocytes in autoimmune mice reflects their origin, and that the surface properties detected as a net negative charge were the same in abnormal and normal lymphocytes. The electrophoretic behavior of whole thymocytes was also the same in autoimmune and normal mice. The DN, and CD4+CD8- and CD4-CD8+ (single positive, SP) thymocytes from normal mice exhibited high EPM, while CD4+CD8+ (double positive, DP) thymocytes exhibited low EPM. According to the recent concept of intrathymic T cell differentiation (Schwartz, R. H., Cell. 1989, 57, 1073-1081), it is suggested that EPM of thymocytes may change with maturation in the following manner: DN thymocytes with high EPM----DP thymocytes with low EPM----SP thymocytes and autoimmune DN T cells with high EPM.     

Bystander CD4+ T cells: crossroads between innate and adaptive immunity

T cells are the central mediators of both humoral and cellular adaptive immune responses. Highly specific receptor-mediated clonal selection and expansion of T cells assure antigen-specific immunity. In addition, encounters with cognate antigens generate immunological memory, the capacity for long-term, antigen-specific immunity against previously encountered pathogens. However, T-cell receptor (TCR)-independent activation, termed “bystander activation”, has also been found. Bystander-activated T cells can respond rapidly and secrete effector cytokines even in the absence of antigen stimulation. Recent studies have rehighlighted the importance of antigen-independent bystander activation of CD4⁺ T cells in infection clearance and autoimmune pathogenesis, suggesting the existence of a distinct innate-like immunological function performed by conventional T cells. In this review, we discuss the inflammatory mediators that activate bystander CD4⁺ T cells and the potential physiological roles of these cells during infection, autoimmunity, and cancer.Subject terms: T cells, CD4-positive T cells     

Does Exposure to UV Radiation Induce a Shift to a Th-2-like Immune Reaction?

In addition to being the primary cause of skin cancer, UV radiation is immune suppressive and there appears to be a link between the ability of UV to suppress the immune response and induce skin cancer. Cytokines made by UV-irradlated keratinocytes play an essential role in activating immune suppression. In particular, we have found that keratinocyte-derlved interleukin (IL)-10 is responsible for the systemic impairment of antigenpresenting cell function and the UV-induced suppression of delayed-type hypersensitivity (DTH). Antigen presentation by splenic adherent cells isolated from UV-irradiated mice to T helper-1 type T (Th1) cells is suppressed, whereas antigen presentation to T helper-2 type T (Th2) cells is enhanced. The enhanced antigen presentation to Th2 cells and the impaired presentation to Th1 cells can be reversed in vivo by injecting the UV-irradiated mice with monoclonal anti-IL-10 antibody. Furthermore, immune suppression can be transferred from UV-irradiated mice to normal recipients by adoptive transfer of T cells. Injecting the recipient mice with anti-IL-4 or anti-IL-10 prevents the transfer of immune suppression, suggesting the suppressor cells are Th2 cells. In addition, injecting UV-irradiated mice with IL-12, a cytokine that has been shown to be the primary inducer of Th1 cells, and one that prevents the differentiation of Th2 cells in vivo, reverses UV-induced immune suppression. These findings support the hypothesis that UV exposure activates IL-10 secretion, which depresses the function of Th1 cells, while enhancing the activity of Th2 cells.     

The Immunological Effect of 8-Methoxypsoralen and UVA Treatment on Murine T-Cell Leukemia

Abstract— 8-Methoxypsoralen (8-MOP) plus long-wavelength UV radiation (UVA, 320–400 nm) have been used to treat various diseases such as cutaneous T-cell lymphoma, systemic scleroderma, rheumatoid arthritis and rejection of heart transplants. However, the immunological mechanism of this treatment remains unknown. In this report, we investigated the effect of 8-MOP/UVA on the modulation of the immunogenicity of a T-cell leukemia cell line (RL ♂l cells). The results demonstrated that the stimulator function of the in vitro 8-MOP/UVA-treated RL♂ cells was enhanced in both RL ♂1-specific allogeneic and syngeneic immune responses. Furthermore, the enhancement of the immunogenicity of the 8-MOP/UVA-treated RL♂ cells was found to be strongly associated with the increase of intercellular adhesion molecule-1 expression on these 8-MOP/UVA-treated tumor cells. Therefore, our findings suggested that the alteration of the expression of the immune-related cell surface molecules might be an important effect of 8-MOP/UVA treatment on the elevation of the immunogenicity of the 8-MOP/UVA-treated tumor cells.     

Bombyx batryticatus Protein-Rich Extract Induces Maturation of Dendritic Cells and Th1 Polarization: A Potential Immunological Adjuvant for Cancer Vaccine

Bombyx batryticatus, a protein-rich edible insect, is widely used as a traditional medicine in China. Several pharmacological studies have reported the anticancer activity of B. batryticatus extracts; however, the capacity of B. batryticatus extracts as immune potentiators for increasing the efficacy of cancer immunotherapy is still unverified. In the present study, we investigated the immunomodulatory role of B. batryticatus protein-rich extract (BBPE) in bone marrow-derived dendritic cells (BMDCs) and DC vaccine-immunized mice. BBPE-treated BMDCs displayed characteristics of mature immune status, including high expression of surface molecules (CD80, CD86, major histocompatibility complex (MHC)-I, and MHC-II), increased production of proinflammatory cytokines (tumor necrosis factor-α and interleukin-12p70), enhanced antigen-presenting ability, and reduced endocytosis. BBPE-treated BMDCs promoted naive CD4⁺ and CD8⁺ T-cell proliferation and activation. Furthermore, BBPE/ovalbumin (OVA)-pulsed DC-immunized mice showed a stronger OVA-specific multifunctional T-cell response in CD4⁺ and CD8⁺ T cells and a stronger Th1 antibody response than mice receiving differently treated DCs, which showed the enhanced protective effect against tumor growth in E.G7 tumor-bearing mice. Our data demonstrate that BBPE can be a novel immune potentiator for a DC-based vaccine in anticancer therapy.