The anti-inflammatory effect of the SOCC blocker SK&F 96365 on mouse lymphocytes after stimulation by Con A or PMA/ionomycin

Antitumor Immunotherapy of Sialic Acid and/or GM1 Modified Coenzyme Q10 Submicron Emulsion

Immunotherapy is a novel therapeutic approach for controlling and killing tumor cells by stimulating or reconstituting the immune system, among which T cells serve as immune targets. Herein, we used coenzyme Q10 (CoQ10), which has both immune activation and avoids adverse reactions, as a model drug and developed four CoQ10 submicron emulsions modified with sialic acid (SA) and/or monosialotetrahexosyl ganglioside (GM1). On the one hand, SA interacts with L-selectins on the surface of T cells after entering the circulatory system, leading to activation of T cells and enhancement of antitumor immune responses. On the other hand, owing to its immune camouflage, GM1 can prolong the circulation time of the preparation in the body, thereby increasing the accumulation of the drug at the tumor site. In vitro and in vivo experiments showed that SA-modified preparations exhibited stronger immune activation and inhibition of tumor proliferation. Pharmacokinetic experiments showed that GM1-modified preparations have longer circulation times in vivo. However, SA and GM1 co-modification did not produce a synergistic effect on the preparation. In conclusion, the SA-modified CoQ10 submicron emulsion (Q10-SE) showed optimal antitumor efficacy when administered at a medium dose (6 mg CoQ10 kg^-1). In this study, the submicron emulsion model was used as a carrier, and the tumor-bearing mice were used as animal models. In addition, CoQ10 submicron emulsion was modified with SA-CH with active targeting function and/or GM1 with long-circulation function to explore the antitumor effects of different doses of CoQ10 submicron emulsion, and to screen the best tumor immunotherapy formulations of CoQ10.

Immunomodulatory Effects of the Meretrix Meretrix Oligopeptide (QLNWD) on Immune-Deficient Mice

The aim of this study was to explore the immunomodulatory effects of the Meretrix meretrix oligopeptide (MMO, QLNWD) in cyclophosphamide (CTX)-induced immune-deficient mice. Compared to untreated, CTX-induced immune-deficient mice, the spleen and thymus indexes of mice given moderate (100 mg/kg) and high (200 mg/kg) doses of MMO were significantly higher (p < 0.05), and body weight loss was alleviated. Hematoxylin-eosin (H&E) staining revealed that MMO reduced spleen injury, thymus injury, and liver injury induced by CTX in mice. Furthermore, MMO boosted the production of immunoglobulin G (IgG) and hemolysin in the serum and promoted the proliferation and differentiation of spleen T-lymphocytes. Taken together, our findings suggest that MMO plays a vital role in protection against immunosuppression in CTX-induced immune-deficient mice and could be a potential immunomodulatory candidate for use in functional foods or immunologic adjuvants.

Involvement of H-Ras in the adaptive immunity of Nile tilapia by regulating lymphocyte activation

H-Ras is a guanosine triphosphatase (GTPase), which acts as a molecular switch and controls multiple important cellular processes including lymphocyte activation and function. However, regulatory mechanism of adaptive immune response by H-Ras remains unclear in non-mammalian animals. In the present study, we investigated the involvement of H-Ras in lymphocyte activation with a teleost model Oreochromis niloticus. H-Ras from O. niloticus (On-H-Ras) is highly conserved with those from other vertebrates. The mRNA of On-H-Ras showed a wide expression pattern in the lymphoid-tissues and with the highest level in liver. After Aeromonas hydrophila infection, transcription of On-H-Ras was significantly induced on day 8 but came back to basal level on day 16, suggesting that On-H-Ras potentially participated in primary response during the adaptive immunity. Furthermore, On-H-Ras mRNA was obviously up-regulated when leukocytes were activated by T lymphocyte mitogen PHA in vitro. Meanwhile, protein level of H-Ras was also augmented once leukocytes were stimulated with lymphocyte receptor signaling agonist PMA and ionomycin. More importantly, once Ras activity was inhibited by specific inhibitor, the up-regulation of lymphocyte activation marker CD122 was obviously impaired during lymphocyte activation process. Therefore, On-H-Ras regulated lymphocyte activation through both mRNA and protein level. Altogether, our results illustrated the involvement of H-Ras in teleost adaptive immunity via controlling lymphocyte activation, and thus provided a novel perspective to understand evolution of the lymphocyte-mediated adaptive immunity.

Phillygenin exhibits anti-inflammatory activity through modulating multiple cellular behaviors of mouse lymphocytes

Context: Phillygenin (PHI) is an intestinal metabolite of phillyrin from the genus Forsythia. Although the regulatory activity of Forsythia on immune system has been investigated, the effect of PHI on activated lymphocytes is poorly understood. Objective: This study was aimed to discuss the possible anti-inflammation potential of PHI on mitogen-activated stimulated lymphocytes in vitro. Methods: Mice spleen lymphocytes were incubated with PHI for 4 h, and then stimulated with concanavalin A (Con A) or phorbol 12-myristate 13-acetate/ionomycin (PMA + Ion). Cell viability was assayed by cell counting kit-8 (CCK-8). The expression of CD69 and CD25, proliferation, cell cycle, intracellular Ca²⁺ concentration, apoptosis, mitochondrial inner membrane potential (ΔΨm), mitochondrial permeability transition (MPT), interleukin-2 (IL-2), interferon-γ (IFN-γ), and tumor necrosis factor-α (TNF-α) were analyzed by flow cytometry. The expression of cyclin B1, cyclin D1, Cyclin E, and the phosphorylation of c-jun N-terminal kinase (JNK), extracellular signal-regulated kinase 1/2 (Erk1/2) and p38 were assayed by western blotting. Results: The results showed that PHI inhibited the proliferation of Con A-activated lymphocytes and induced a G₀/G₁ phase arrest by suppressing cyclin D1 and cyclin E. Meanwhile, PHI antagonized Con A-induced T cells activation through blocking intracellular Ca²⁺ overload and suppressing the phosphorylation of JNK and Erk1/2. Both Con A and PMA + Ion-induced secretion of IL-2, IFN-γ, and TNF-α were attenuated by PHI. PHI enhanced Con A-induced lymphocytes apoptosis through decreasing ΔΨm and increasing MPT. Conclusion: These results suggest that PHI exhibits its anti-inflammatory activity through modulating multiple cellular behaviors, leading to the suppression of the adaptive immune response.

The anti-proliferative effect of cation channel blockers in T lymphocytes depends on the strength of mitogenic stimulation

Ion channels are crucially important for the activation and proliferation of T lymphocytes, and thus, for the function of the immune system. Previous studies on the effects of channel blockers on T cell proliferation reported variable effectiveness due to differing experimental systems. Therefore our aim was to investigate how the strength of the mitogenic stimulation influences the efficiency of cation channel blockers in inhibiting activation, cytokine secretion and proliferation of T cells under standardized conditions. Human peripheral blood lymphocytes were activated via monoclonal antibodies targeting the TCR-CD3 complex and the co-stimulator CD28. We applied the blockers of Kv1.3 (Anuroctoxin), KCa3.1 (TRAM-34) and CRAC (2-Apb) channels of T cells either alone or in combination with rapamycin, the inhibitor of the mammalian target of rapamycin (mTOR). Five days after the stimulation ELISA and flow cytometric measurements were performed to determine IL-10 and IFN-γ secretion, cellular viability and proliferation. Our results showed that ion channel blockers and rapamycin inhibit IL-10 and IFN-γ secretion and cell division in a dose-dependent manner. Simultaneous application of the blockers for each channel along with rapamycin was the most effective, indicating synergy among the various activation pathways. Upon increasing the extent of mitogenic stimulation the anti-proliferative effect of the ion channel blockers diminished. This phenomenon may be important in understanding the fine-tuning of T cell activation.

Depletion of H2S during obesity enhances store-operated Ca2+ entry in adipose tissue macrophages to increase cytokine production

The increased production of proinflammatory cytokines by adipose tissue macrophages (ATMs) contributes to chronic, low-level inflammation during obesity. We found that obesity in mice reduced the bioavailability of the gaseous signaling molecule hydrogen sulfide (H2S). Steady-state, intracellular concentrations of H2S were lower in ATMs isolated from mice with diet-induced obesity than in ATMs from lean mice. In addition, the intracellular concentration of H2S in the macrophage cell line RAW264.7 was reduced during an acute inflammatory response evoked by the microbial product lipopolysaccharide (LPS). Reduced intracellular concentrations of H2S led to increased Ca(2+) influx through the store-operated Ca(2+) entry (SOCE) pathway, which was prevented by the exogenous H2S donor GYY4137. Furthermore, GYY4137 inhibited the Orai3 channel, a key component of the SOCE machinery. The enhanced production of proinflammatory cytokines by RAW264.7 cells and ATMs from obese mice was reduced by exogenous H2S or by inhibition of SOCE. Together, these data suggest that the depletion of macrophage H2S that occurs during acute (LPS-induced) or chronic (obesity) inflammation increases SOCE through disinhibition of Orai3 and promotes the production of proinflammatory cytokines.

Immunogenicity and escape mechanisms of allogeneic tendon-derived stem cells

The immunogenicity of tendon-derived stem cells (TDSCs) has implications for their clinical use for the promotion of tendon repair. The immunogenicity and escape mechanisms of rat patellar TDSCs were examined after allogeneic transplantation. Our results showed that TDSCs exhibited low immunogenicity as evidenced by the following: (i) the incubation of target TDSCs with immunized serum did not show antibody recognition and did not induce the complement-dependent cytotoxicity; (ii) target TDSCs elicited a very low level of lymphocyte proliferation and did not exhibit host lymphocyte-mediated cytotoxicity; and (iii) target TDSCs dose dependently suppressed the phorbol 12-myristate 13-acetate (PMA)- and ionomycin-induced host lymphocyte proliferation. For the mechanistic studies, TDSCs expressed major histocompatibility complex (MHC)-I but a very low level of MHC-II, CD86 and CD80 for the induction of T-cell response. Also, TDSCs were found to express intracellular Fas and FasL. γ-IFN pretreatment did not increase the level of MHC-II and CD86 for the upregulation of immune response. Moreover, the immunosuppressive mediators indoleamine 2,3-dioxygenase (IDO) and transforming growth factor-beta 1 (TGF-β1) were found not to be involved in the escape mechanism of target TDSCs from host lymphocyte attack. In conclusion, allogeneic TDSCs exhibited low immunogenicity. Allogeneic TDSCs might be used for transplantation.

Antiallergic asthma properties of brazilin through inhibition of TH2 responses in T cells and in a murine model of asthma

This study aimed to determine whether brazilin exhibits anti-inflammatory effects that inhibit T helper cell type II (T(H)2) responses and whether it suppresses allergic inflammation reactions in a murine model of asthma. We found that brazilin inhibited the mRNA and protein expression of interleukin (IL)-4 and IL-5 induced by phorbol myristate acetate (PMA) and cAMP in EL-4 T cells in a dose-dependent manner. Following the intratracheal instillation of brazilin in ovalbumin (OVA)-immunized mice, we found that brazilin-treated mice exhibited decreases in the release of IL-4, IL-5, IL-13, eotaxin-1, and tumor necrosis factor-α in bronchoalveolar lavage fluid (BALF); inhibited T(H)2 functioning via a decrease in IL-4 production; and exhibited attenuation of OVA-induced lung eosinophilia, airway hyperresponsiveness, and airway remodeling. These results suggest that brazilin exhibits anti-T(H)2 effects both in vitro and in vivo and may possess therapeutic potential for allergic diseases.

Topographical and biological evidence revealed FTY720-mediated anergy-polarization of mouse bone marrow-derived dendritic cells in vitro

Abnormal inflammations are central therapeutic targets in numerous infectious and autoimmune diseases. Dendritic cells (DCs) are involved in these inflammations, serving as both antigen presenters and proinflammatory cytokine providers. As an immuno-suppressor applied to the therapies of multiple sclerosis and allograft transplantation, fingolimod (FTY720) was shown to affect DC migration and its crosstalk with T cells. We posit FTY720 can induce an anergy-polarized phenotype switch on DCs in vitro, especially upon endotoxic activation. A lipopolysaccharide (LPS)-induced mouse bone marrow-derived dendritic cell (BMDC) activation model was employed to test FTY720-induced phenotypic changes on immature and mature DCs. Specifically, methods for morphology, nanostructure, cytokine production, phagocytosis, endocytosis and specific antigen presentation studies were used. FTY720 induced significant alterations of surface markers, as well as decline of shape indices, cell volume, surface roughness in LPS-activated mature BMDCs. These phenotypic, morphological and topographical changes were accompanied by FTY720-mediated down-regulation of proinflammatory cytokines, including IL-6, TNF-α, IL-12 and MCP-1. Together with suppressed nitric oxide (NO) production and CCR7 transcription in FTY720-treated BMDCs with or without LPS activation, an inhibitory mechanism of NO and cytokine reciprocal activation was suggested. This implication was supported by the impaired phagocytotic, endocytotic and specific antigen presentation abilities observed in the FTY720-treated BMDCs. In conclusion, we demonstrated FTY720 can induce anergy-polarization in both immature and LPS-activated mature BMDCs. A possible mechanism is FTY720-mediated reciprocal suppression on the intrinsic activation pathway and cytokine production with endpoint exhibitions on phagocytosis, endocytosis, antigen presentation as well as cellular morphology and topography.