The Effect of Immunosuppressive Adjuvant Kynurenine on Type 1 Diabetes Vaccine

Inducing antigen-specific tolerance is a promising treatment for preventing or reversing Type 1 diabetes (T1D). In contrast to a vaccine that induces immune responses against pathogens, a tolerogenic vaccine can suppress immunity against antigens causing diseases by administrating a mixture of self-antigens with an adjuvant that decreases the strength of antigen-specific response. Kynurenine (Kyn) is an endogenous substance that can inhibit the natural killer cell and T cell proliferation and promote the differentiation of naïve T cells into regulatory T cells (Tregs). In this study, we evaluated the efficacy of Kyn as a novel suppressive adjuvant. Kyn was co-immunized with GAD65 phage vaccine to induce Treg cells and tolerogenic responses for the prevention of T1D in NOD mouse model. Mice were subcutaneously immunized two times with 1011 Pfu (100μL,1012 Pfu/ml) GAD65 phage vaccine doses mixed with 200 μg of Kyn. Serum antibodies and cytokines were detected by ELISA and electrochemiluminescence, respectively. Flow cytometry assay was used to analyze DC and Treg. MTS was used for the analysis of spleen lymphocyte proliferation. RNA sequencing was used to investigate mRNA and miRNA expression profiles in spleen lymphocytes. Compared to GAD65 phage vaccine alone, co-immunization of Kyn and GAD65 phage vaccine resulted in the prevention of hyperglycemia in 60% of mice for at least one month. Further, Kyn enhances GAD65-specific Th2-mediated immune responses; regulates the Th1/Th2 imbalance and increases the secretion of Th2 cytokines and the number of CD4+CD25+Foxp3+T cells; suppresses DC maturation and GAD65-specific T lymphocyte proliferation. Moreover, we integrated Kyn related miRNA and mRNA expression profiles obtained from the spleen lymphocyte RNA-sequencing which was stimulated by Kyn in vitro. These data provide an important basis for understanding the mechanisms underlying Kyn as an immunosuppressive adjuvant which regulated the immune response. These findings suggest that Kyn can serve as an effective suppressive adjuvant candidate for Type 1 diabetes vaccines.

Analysis of Immune Responses in Mice Orally Immunized with Recombinant pMG36e-SP-TSOL18/Lactococcus lactisand pMG36e-TSOL18/Lactococcus lactisVaccines ofTaenia solium

Cysticercosis is a cosmopolitan zoonotic parasitic disease infected by larval ofTaenia solium(T. solium). Several drugs for the treatment of cysticercosis, such as praziquantel, albendazole, and mebendazole, have certain toxicity and side effects. Considering that there is no vaccine available, we studied a new vaccine for cysticercosis in this study. The completeTSOL18gene and the optimizedSP-TSOL18gene fragments were obtained using PCR-based accurate synthesis method. The secretory and intracellular recombinant pMG36e-SP-TSOL18/Lactococcus lactis(L. lactis) and pMG36e-TSOL18/L. lactisvaccines ofT. soliumwere prepared. Immune responses in mice orally immunized with these two recombinantL. lactisvaccines were analyzed by the determination of specific antibodies (IgG, IgG1, IgG2a, and sIgA) in serum, spleen lymphocyte proliferation, and cytokines (IL-2, IFN-γ, IL-4, and IL-10) in spleen lymphocyte culture supernatant. Our results showed that, after the first immunization, in these two recombinantL. lactisvaccine groups, the levels of serum specific IgG, IgG2a, and IgG1 increased on 14–56 d and reached the highest level on days 42, 42, and 28, respectively. The level of specific sIgA of intestinal mucosa also increased on 14–56 d and reached the highest level on day 42. The level of spleen lymphocyte proliferation increased on 14–56 d and reached the highest level on day 42. The levels of IL-2, IFN-γ, IL-4, and IL-10 in spleen lymphocyte culture supernatant increased on 14–56 d and reached the highest level on days 42, 42, 28, and 28, respectively. These results indicated that the recombinant pMG36e-SP-TSOL18/L. lactisand pMG36e-TSOL18/L. lactisvaccines can induce specific cellular, humoral, and mucosal immune responses in mice with oral vaccination. More importantly, the recombinant pMG36e-SP-TSOL18/L. lactisvaccine has a better immune effect. In summary, these results demonstrated the possibility of usingL. lactisstrain as a vector to deliver protective antigens ofT. solium.

RECOMBINANT ANTIGENS OF PSEUDOMONAS AERUGINOSA: EFFECT ON IMMUNE RESPONSE IN MICE

Aim. Study the effect of recombinant antigens of P. aeruginosa on key effectors of the immune system. Materials and methods. Mice were immunized intraperiotoneally with 25 jig of OprF and 50 jig of anatoxin sorbed on aluminium hydroxide gel with a 2 week interval. 7 days after the last immunization spleen lymphocyte subpopulation structure was evaluated by flow cytometry. Cytokine levels in mice sera were studied after a single immunization with recombinant OprF and anatoxin at 4, 8, 24 hours and 14 days by flow cytometry using FlowCytomix Mouse Thl/Th2 10 plex. Results. OprF recombinant antigens and anatoxin affect molecular-cell mechanisms of immune response resulting in alteration of expression of differentiating and activating molecules as well as synthesis of Thl/Th2/Thl7/Th21/Th22 cytokines in mice that are necessary for effective presentation of the antigen. Conclusion. Complex of recombinant OprF and anatoxin facilitated formation of complete immune response against pseudomonas.

Resveratrol promotes recovery of immune function of immunosuppressive mice by activating JNK/NF-κB pathway in splenic lymphocytes

Resveratrol, a natural compound found in over 70 plants, is known to possess immunoregulatory effects and anti-inflammatory activity. It has been shown that resveratrol has regulatory effects on different signaling pathways in different diseases. However, few reports have evaluated the effects of resveratrol on reinforcing immunity recovery via activating nuclear factor-κB (NF-κB) pathway and Jun N-terminal kinases (JNK) pathway. The present study aimed to assess immune-enhancing activity and underlying mechanism of resveratrol in immunosuppressive mice. Previously, we reported that resveratrol could promote mouse spleen lymphocyte functions to recover the immune system effectively. In the present study, we show that resveratrol could upregulate the expressions of NF-κB, IκB kinase, JNK, and c-jun in splenic lymphocytes of immunosuppressive mice. Taken together, our results indicate that resveratrol could promote recovery of immunologic function in immunosuppressive mice by activating JNK/NF-κB pathway.