Complete Freund's Adjuvant Immunization Research Articles

Th1 Biased Progressive Autoimmunity in Aged Aire-Deficient Mice Accelerated Thymic Epithelial Cell Senescence.

Although autoimmune diseases, such as rheumatoid arthritis and systemic lupus erythematosus, are frequently associated with premature aging of the thymus, a direct link is missing between autoimmunity and thymic atrophy. Here we monitored the progression of thymic involution in Aire-deficient mice, in which defective negative selection causes spontaneous and progressive development of autoimmunity. In young and middle-aged mice, Aire deficiency appeared to be protective as supported by the reduced β-gal+ epithelial cells and the enhanced thymic output. However, once the autoimmune phenotype was fully developed in aged Aire-deficient mice, their thymuses underwent accelerated involution. In comparison to the age-matched wildtype littermates, old Aire-deficient mice showed lower numbers of total thymocytes and recent thymic emigrants but more β-gal+ thymic epithelial cells. This phenomenon may partly be attributable to the increased number of activated Th1 cells homing to the thymus. This speculation was further supported by the enhanced thymic aging following repeated challenges with complete Freund’s adjuvant immunization. Taken together, the present study highlights a unique mechanism by which autoimmunity facilitates the senescence of thymic epithelial cells through returning Th1 cells.

Complete Freund's adjuvant induces experimental autoimmune myocarditis by enhancing IL-6 production during initiation of the immune response.

IntroductionComplete Freund's Adjuvant (CFA) emulsified with an antigen is a widely used method to induce autoimmune disease in animal models, yet the contribution of CFA to the immune response is not well understood. We compared the effectiveness of CFA with Incomplete Freund's Adjuvant (IFA) or TiterMax Gold Adjuvant (TMax) in experimental autoimmune myocarditis (EAM) in male mice.MethodsEAM was induced in A/J, BALB/c, and IL6KO BALB/c male mice by injection of the myocarditogenic peptide in CFA, IFA, or TMax on days 0 and 7. EAM severity was analyzed by histology on day 21. In addition, specific flow cytometry outcomes were evaluated on day 21.ResultsOnly mice immunized with CFA and myocarditogenic peptide on both days 0 and 7 developed substantial myocarditis as measured by histology. We observed a significantly increased level of IL6 in the spleen 3 days after CFA immunization. In the spleen and heart on day 21, there was an expansion of myeloid cells in CFA‐immunized mice, as compared to IFA or TMax‐immunized animals. Recombinant IL‐6 at the time of IFA immunization partially restored susceptibility of the mice to EAM. We also treated EAM‐resistant IL‐6 knockout mice with recombinant IL‐6 around the time of the first immunization, on days −1 to 2, completely restoring disease susceptibility, showing that the requirement for IL‐6 coincides with primary immunization. Examining APC populations in the lymph node draining the immunization site evidenced the contribution of IL‐6 to the CFA‐dependence of EAM was through controlling local dendritic cell (DC) trafficking.ConclusionsCFA used with myocarditogenic peptide twice is required to induce EAM in both A/J and Balb/c mice. Although IFA and TiterMax induce antibody responses, only CFA preferentially induced autoantigen‐specific responses. CFA expands monocytes in the heart and in the spleen. IL‐6 signaling is required during short window around primary immunization to induce EAM. In addition, IL‐6 deficient mice resistance to EAM could be reversed by injecting IL‐6 around first immunization. IL‐6 expands dendritic cell and monocytic populations and ultimately leads to a robust T‐cell driven immune response in CFA immunized mice.

LPS-matured CD11c+ bone marrow-derived dendritic cells can initiate autoimmune pathology with minimal injection site inflammation.

The pathogenesis of human autoimmune disorders is incompletely understood. This has led to the development of numerous murine models in which the pathogenesis of autoimmunity can be probed and the efficacy of novel therapies can be tested. One of the most widely-used murine models of autoimmunity is experimental autoimmune encephalomyelitis (EAE). To induce autoimmune pathology, mice are often immunized with an autoantigen alongside an adjuvant, typically complete Freund's adjuvant (CFA). Unfortunately, CFA causes significant inflammation at the site of administration. Despite the well-recognized complication of injection site inflammation, CFA with autoantigen immunization is widely used to induce central nervous system autoimmunity. We performed a literature review which allowed us to estimate that over 10,000 mice were immunized with CFA in published EAE studies in 2013. In this study, we demonstrated that subcutaneously administered myelin basic protein (MBP)-pulsed CD11c+ bone marrow-derived dendritic cells (BMDC) were as effective at inducing EAE as subcutaneously administered MBP plus CFA. Importantly, we also discovered that the CD11c+ BMDC caused significantly less injection site inflammation than MBP plus CFA immunization. This study demonstrated that the use of CD11c+ BMDC can enable the development of autopathogenic T-cells to be studied in vivo without the unwanted side-effects of long-lasting injection site inflammation. This model represents a significant refinement to existing EAE models and may lead to the improvement of the welfare of experimental mice used to study the development of autoimmunity in vivo.

In vivo antiarthritic activity of Rosa centifolia L. flower extract.

Introduction:Rosa centifolia L. (Rosaceae) have been used for the treatment of joint pain and rheumatoid arthritis (RA) in the traditional system of medicine.Aim:In this study, the antiarthritic activity of the alcoholic extract from the floral parts of R. centifolia was investigated.Materials and Methods:The anti-inflammatory and antiarthritic activity of R. centifolia alcoholic extract (RCAE: 32, 64, and 128 mg/kg) was evaluated using the carrageenan-induced paw edema and complete Freund's adjuvant (CFA) induced arthritis model. Serum from arthritic rats was collected for the estimation of pro-inflammatory cytokine levels. Further, the safety of RCAE was evaluated in an acute and sub-acute (28-day) oral toxicity study.Results:RCAE (64 and 128 mg/kg) significantly (P < 0.01) inhibited carrageenan-induced paw edema at 1, 3, and 6 h post carrageenan challenge and demonstrated significant (P < 0.01) antiarthritic activity on days 3, 7, 14, and 21 day following CFA immunization. Further, RCAE (128 mg/kg) treatment also produced a significant (P < 0.01) decrease in circulating pro-inflammatory cytokine levels as compared with control. Further, no toxicologically significant treatment-related effects were observed in the oral sub-acute toxicity study conducted with the extract.Conclusion:The result of study demonstrates the antiarthritic activity of R. centifolia and validates its traditional use for the treatment of RA.

Adjuvant treatment suppresses IL-17 production by T cell-independent myeloid sources in nonobese diabetic mice

Recent studies have shown that Th17 cells, as a distinct lineage from Th1 and Th2 subsets, play an obligatory role in the pathogenesis of autoimmune diseases. It is well known that immunotherapy with Complete Freund's adjuvant (CFA) is effective in preventing from the onset of autoimmune diabetes in nonobese diabetic (NOD) mice. In the present study, we investigated whether CFA treatment restrained Th17 development and down-regulated Th17-related cytokine production in NOD mice. Th17-related cytokines (i.e. IL-17A, IL-17F, IL-21, IL-22, IL-23, IL-6, TGF-β) production in splenocytes was decreased dramatically on day 18 following CFA immunization. This effect was also observed at 10 and 20 week after adjuvant treatment. Injection of IL-17 into CFA-treated diabetes-free mice led to occurrence of overt diabetes, indicating that therapeutic effects of adjuvant treatment may be partially due to suppressing Th17 commitment. Interestingly, the main producer of IL-17 resided in a population of myeloid cells, which negatively expressed makers of neutrophil or macrophages. IL-23 stimulation did not alter the distribution of IL-17 in myeloid cells. Furthermore, this pattern of IL-17 expression was also present in Balb/c and C57BL/6 strains. These findings may have important implications for understanding of mechanisms underlying adjuvant treatment on autoimmune diseases.

CD4 +CD25 + naturally occurring regulatory T cells and not lymphopenia play a role in the pathogenesis of iodide-induced autoimmune thyroiditis in NOD-H2 h4 mice

NOD-H2 h4 mice, which express I-A k on the NOD background, spontaneously develop autoimmune thyroiditis, a model of Hashimoto thyroiditis in humans, by adding iodide in the drinking water. Parental NOD mice have previously been shown to have intrinsic numerical abnormalities in peripheral lymphocytes and lymphocyte subpopulations such as CD4 +CD25 + naturally occurring regulatory T cells (Treg). Therefore we first investigated whether the similar abnormalities exist in NOD-H2 h4 mice. We observed that, compared with other non-autoimmune disease prone BALB/c and C57BL/6 mice, NOD-H2 h4 mice have lower numbers of splenocytes, CD3 +T, CD4 +T and CD8 +T cells but the ratios of Treg to CD4 +T cells were comparable. Increasing the numbers of peripheral lymphocytes by Complete Freund's Adjuvant immunization or splenocyte transfer did not affect development of thyroiditis, indicating that lymphopenia does not play a critical role in the pathogenesis of thyroiditis. We next examined the significance of Treg by depleting this lymphocyte subset with anti-CD25 antibody. Treg depletion, performed 4 days before the administration of NaI water for 8 weeks, significantly exacerbated thyroiditis ( p < 0.01). Anti-thyroglobulin antibody titers also increased by Treg depletion ( p < 0.01) without changing the IgG2b to IgG1 ratios. In addition, expression levels of mRNA for IFN-γ and IL-4 were enhanced in parallel. However, T 4 levels were similar between antibody-treated and untreated groups. Additional anti-CD25 administration at 3 weekly intervals did not influence these results. These data, together with previous studies on other mouse models of inducible thyroiditis and Graves’ disease, indicate the role played by Treg in keeping anti-thyroid autoimmune reaction in check in experimental autoimmune thyroid diseases.

Adjuvant immunotherapy is dependent on inducible nitric oxide synthase.

Rodents immunized with complete Freund's adjuvant (CFA) are resistant to subsequent attempts to induce autoimmune disease, while animals immunized with incomplete Freund's adjuvant (IFA) remain susceptible. Mycobacterial extracts can stimulate inducible nitric oxide synthase (NOS2) gene transcription. Robust expression of NOS2 has been linked to suppression of T cell proliferation and alterations in immune responses. Our studies investigated the hypothesis that the immunoprotective effect of CFA before immunization requires functional NOS2. NOS2 gene expression is chronically elevated in lymph nodes and spleens of CFA-immunized mice. Maximal expression of NOS2 after CFA immunization requires the presence of functional type I tumor necrosis factor alpha receptor (TNFR1) and interferon gamma. Groups of nontreated and CFA-preimmunized male C57BL/6J or C57BL/6NOS2(-/)- mice were immunized with myelin oligodendrocyte glycoprotein (MOG) peptide 35-55 in CFA to induce experimental allergic encephalomyelitis (EAE). Wild-type C57BL/6J mice were protected from the development of symptoms of EAE, while the NOS2(-/)- mice failed to be protected. NOS2-dependent effects of CFA included an augmentation of the MOG-specific IgG1 response, a decrease in interleukin 6 production by MOG-reactive lymphocytes, and a marked decrease in mononuclear cell infiltrates in the central nervous system. These studies support the hypothesis that CFA immunization modulates immune responses through a nitric oxide-dependent mechanism.