[Show abstract][Hide abstract] ABSTRACT: Protein vaccines combined with adjuvants have been widely used to induce immune responses, especially the humoral immune response, against molecular targets including parasites. Follicular T helper (Tfh) cells are the specialized providers of B-cell help, however, the induction of Tfh cells in protein vaccination has been rarely studied. Here, we report that the Schistosoma japonicum recombinant protein (SjGST-32) combined with tacrolimus (FK506) augmented the induction of Tfh cells, which expressed the canonical markers CXCR5, BCL6, and IL-21, and enhanced the humoral immune responses in BALB/c mice. Furthermore, the expression of IL-21R on germinal center (GC) B cells and memory B cells increased in immunized mice, which indicated that IL-21 from the induced Tfh cells interacted with IL-21R for activation of B cells and maintenance of long-lived humoral immunity. Our results suggest that helminth protein vaccine combined with FK506 induces Tfh cell for stimulating humoral immune responses and inducing long-lived humoral immunity.
[Show abstract][Hide abstract] ABSTRACT: Vaccination could induce immune tolerance and protected NOD mice from the development of type I diabetes (T1D). We previously demonstrated that insulin peptide (B9-23) combined with dexamethasone (DEX) stimulated the expansion of antigen specific regulatory T (Treg) cells which in turn effectively prevented T1D in NOD mice. Here, we aimed to investigate the therapeutic effect of tolerogenic vaccination for T1D treatment.
The diabetic NOD mice (Blood glucose level ≧250 mg/dl) were treated with B9-23 and DEX twice. The tolerance was restored by blocking maturation of dendritic cells (DCs) and inducing Treg cells in treated NOD mice. Remarkably, the reduction of autoreactive effector memory CD4 T (Tm) cells and the induction of functional effector memory Treg (mTreg) cells contributed to the improvement of T1D in treated NOD mice.
Tolerogenic vaccination restored tolerance and ameliorated T1D by suppressing effector CD4 Tm cells and inducing effector mTreg cells. Our findings implicate the potential of tolerogenic vaccination for T1D treatment.
[Show abstract][Hide abstract] ABSTRACT: DNA vaccination is a promising strategy for activating immune responses against hepatitis B virus (HBV) infection. However, the accumulated data have shown that DNA vaccination alone generates weak immune responses. To enhance the immunogenicity of HBV DNA vaccine, lectin purified from pleurotus ostreatus (POL) was used as adjuvant of HBV DNA vaccine for C57BL/6 and HBV surface antigen transgenic (HBVsAg-Tg) mice. Our data demonstrate that low dose of POL (1µg/mouse) in conjunction with HBV DNA vaccine stimulated stronger HBV-specific delayed-type hypersensitivity (DTH) responses and higher HBV-specific IgG level than that in high dose of POL groups (5µg/mouse and 10µg/mouse). POL activated strong Th2 and Tc1 cell responses in immunized C57BL/6 and HBVsAg-Tg mice. POL as adjuvant of HBV DNA vaccine effectively enhanced HBV surface protein antibody (HBVsAb) and decreased HBVsAg level for HBV Tg mice treatment. Furthermore, POL infiltrated more lymphocytes excluding Th1, Th2 and Tc1 cell subtypes to liver of HBVsAg-Tg mice. Together, these results suggest that POL as adjuvant enhanced immunogenicity of HBV DNA vaccination and effectively stimulated immune reaponse for HBsAg-Tg mice treatment. Our findings implicate the potential of mushroom lectin as adjuvant of HBV DNA vaccine.
[Show abstract][Hide abstract] ABSTRACT: Regulatory T (Treg) cells can be induced with DNA vaccinations and protect mice from the development of experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis (MS). Tacrolimus (FK506) has been shown to have functions on inducing immunosuppression and augmenting apoptosis of pathologic T cells in autoimmune disease. Here we examined the therapeutic effect of DNA vaccine in conjunction with FK506 on EAE.
After EAE induction, C57BL/6 mice were treated with DNA vaccine in conjunction with FK506. Functional Treg cells were induced in treated EAE mice and suppressed Th1 and Th17 cell responses. Infiltrated CD4 T cells were reduced while Treg cells were induced in spinal cords of treated EAE mice. Remarkably, the activated CD4 T cells augmented apoptosis, but the induced Treg cells resisted apoptosis in treated EAE mice, resulting in alleviation of clinical EAE severity.
DNA vaccine in conjunction with FK506 treatment ameliorates EAE by enhancing apoptosis of CD4 T cells and resisting apoptosis of induced Treg cells. Our findings implicate the potential of tolerogenic DNA vaccines for treating MS.
[Show abstract][Hide abstract] ABSTRACT: DNA vaccines have been widely used to induce immune responses against molecular targets. In this study, we explored the possibility of using DNA vaccine combined with the immunosuppressant FK506 (tacrolimus) to antigen-specifically suppress unwanted immune responses and prevent autoimmune ovarian disease. To that end, we immunized C57BL/6 mice with a DNA vaccine encoding mouse zona pellucida 3 (ZP3) together with FK506. The immunization induced ZP3-specific CD4(+)CD25(+)Foxp3(+) regulatory T cells (Treg), which suppressed the induction of ZP3-specific delayed-type hypersensitivity in the animals. Significantly, the immunization also protected the animals from experimentally induced autoimmune ovarian disease. These results suggest that DNA vaccination in the presence of FK506 may be used to induce Treg cells and prevent AOD.
No preview · Article · Apr 2012 · Immunological Investigations