Juan Carlos Jaume Lab

Juan Carlos Jaume, MD — Major Research Interests

Type 1 Diabetes

Islet expressing GAD65 (green) with DAPI (Blue)
3D (i3DISCO) image of transgenic T1D mouse islet (GAD65-green, DAPI Blue)

Our group has been studying autoimmune diabetes for many years. Recently, we have developed a humanized mouse model of Type 1 Diabetes (T1D). We believe this model will help understand the pathophysiology of T1D. More importantly, the model will be a great resource for T1D therapeutic strategies. Our mouse model of T1D resembles most features of the human condition. 

Immune Pathology of T1D Project:

Our mice carry human diabetes susceptibility as they are transgenic for the human MHCII gene known to occur in most T1D patients and develop diabetes upon either  and environmentally triggered event or an intrinsic phenomena early in life. Our mice immune system attacks pancreatic β-cells in a chronically progressive manner. Animals initially develop anti-GAD65 antibodies while lymphocytic infiltration builds up in the peri- and intra-islet location. Glucose intolerance and diabetes later develops. Animals also manifest the classic diabetes complications observed in humans (i.e., retinopathy, nephropathy, and neuropathy). This project involves studying the natural history of the disease progression in our model. 

Islet expressing Insulin (red) in 3D confocal imaging
Transgenic mouse islet expressing Insulin (red) by 3D confocal imaging

T1D Immune Cell Resetting Project:

The pancreatic islet microenvironment of T1D patients exhibits a pro-inflammatory T cell bias. Refitting of these T cells towards anti-inflammatory cells may mitigate the progression of the disease. One possible way of accomplishing that is by using immune modulators that reset pro-inflammatory T cell bias or enrich regulatory Treg cell presence.  We have observed that inhibition of a eukaryotic translation initiation factor, elF5A, by N1-Guanyl-1, 7-Diaminoheptane (GC7) lowers the Th1/Th17 ratio and increases the Treg cell populations. Most importantly, the eIF5A inhibition increased the IFNγ+IL17+ CD4 T cell population, which illustrates that the pancreatic islet immune microenvironment is plastic in nature.  Moreover, the reduction of the pro-inflammatory bias in pancreatic islet microenvironment allowed for improvement of β-cell functionality in terms of Glucose Tolerance Test (GTT) response and total pancreatic insulin content. 

Islet expressing Insulin (red) with DAPI (Blue) in 3D confocal imaging
Transgenic mouse islet expressing Insulin (red) with DAPI (Blue)
also by 3D confocal imaging 

Gut Microbiome and Type 1 Diabetes Project:

During the first three years of life, the gut microbiota undergoes a dynamic change in taxonomic diversity and this is a time during which juvenile T1D initiates. We are investigating the dynamic changes of the intestinal microbiome and the host immune-pathological signatures in a longitudinal study to develop predictive models associated with the onset and progression of T1D in our model. Due to the lack of longitudinal studies, it is still unclear whether intestinal dysbiosis drives the pathogenesis of T1D or if T1D drives intestinal dysbiosis. 

Antigen-Specific Tregs and TID Project:

Regulatory T (Treg) cells play a critical role in the maintenance of tolerance and are an ideal target for the development of therapies designed to suppress inflammation and autoimmunity. Emerging data indicate that, compared with polyclonal Tregs, adoptive transfer of antigen-specific Tregs are advantageous in terms of reduced risk of nonspecific immune suppression and need for fewer cells.

Islet overexpressing Green Fluorescent Protein (GFP)
Islets overexpressing PDL1-Green Fluorescent Protein (GFP) 

Islet expressing PDL-1 (green) with DAPI (Blue)
IClose-up of islet overexpressing PDL1 (green) with DAPI (Blue) 

The successful use of chimeric antigen receptors (CAR) technology for the generation of antigen-specific effector T cells against cancers suggests that a similar approach could be used to generate antigen-specific Tregs. The goal of this project is to develop pancreatic beta cell-specific CAR Tregs utilizing lentiviral gene transfer and CRISPR/Cas9 based technologies. The antigen-specific CAR Tregs are being studied for their therapeutic potential in our humanized mouse model of TID. 

Programmed Death 1 Ligand 1 (PD-L1) in T1D Project:

A newly FDA approved set of immunotherapeutic drugs is giving hope for cancer treatment.  One group of those drugs, the check-point inhibitors, works by blocking PD1-PDL1 pathway which is used by cancer to evade tumor immunity. Unfortunately, this treatment approach induces a serious side effect, autoimmune diabetes, which is being increasingly reported. No other FDA approved drugs have ever been reported to induce T1D which highlights the importance of the PD1-PDL1 pathway in maintaining pancreatic islet immune tolerance. The goal of this project is to elucidate critical genetic mechanisms affecting the PDL1 expression in pancreatic islets of TID patients, and to exploit these mechanisms for developing “check-point targeted" therapeutics against T1D. 

Thyroid Autoimmunity and Thyroid Cancer: 

Our group is also involved in studying autoimmune thyroid diseases like Hashimoto thyroiditis and Graves Disease. We have profiled intra-thyroidal immune cells in these autoimmune diseases and in the surrounding of thyroid cancer.  We have found that thyroid cancer seems to immune-edit tumor immunity by biasing T cells to a Double Negative (DN) T cell phenotype.

We are also studying the role of innate immune-cell surveillance players like NK cells and macrophages, which are complimentary to each other in their actions against in thyroid cancer. Our laboratory is studding the molecular basis of macrophage-NK cell interface in thyroid cancer, Euthyroid Hashimoto (ETH) and Graves (GD). 

Research chart

Modulation of Macrophage-NK cell interaction by Flagellin Project: 

NK cells affect the phenotypic and functional behavior of macrophage subsets, and in turn the macrophages impact the cytotoxic capacity and cytokine secretory potential of NK cells. This cellular cross-talk has implication in the outcome of not just thyroid diseases but other various autoimmune diseases and cancers. Flagellin is emerging as a potent immune modulator, shaping both the innate and adaptive arms of immunity. Here, we wanedt to explore how flagellin modulates the Macrophage-NK cell cross-talk. Our ultimate goal is to explore the use of flagellin as potent anti-tumor agent in thyroid cancers. 

Macrophages were differentiated from human PBMCs into M1 and M2 macrophages

Macrophages were differentiated from human PBMCs into M1 and M2 phenotypes

Clinical Research Projects: 

Latent Autoimmune Diabetes of Adult Database Study 

Most patients with adult onset diabetes are diagnosed as type 2. Adult patients with type 1 diabetes are rare. However, within the type 2 diabetes population there is an increasingly recognize group with type 1 characteristics. This group of late-onset type 1 diabetes patients is currently addressed as Latent Autoimmune Diabetes of Adults (LADA). The University of Toledo and ProMedica Health System serve a large diabetes population. Over the last year and a half, we have identified many cases of LADA in previously diagnosed type 2 patients. Furthermore, the number of cases seems to be increasing every month. These patients were diagnosed as LADA on a case-by-case basis. If all patients with type 2 diabetes were to be screened for LADA, it is speculated that the numbers may substantially increase. 

Anti-Program Cell Death-1 Pathway Blockade and Type 1 Diabetes Development (NEW MEDTRONIC GRANT AWARD)

Nivolumab (anti-PD-1) is a newly FDA approved monoclonal antibody which blocks the programmed death receptor for the treatment of metastatic melanoma.  This drug works by allowing for T-cell activation to continue beyond regulatory control thus  further attacking the tumor. Type 1 Diabetes was not described as an adverse event during Novilumab's FDA approval. Recently, our lab was one of the first to published a temporal association of Anti-PD-1 and Anti-PD-1L treatment with Type 1 Diabetes (Jennifer B. Hao et al., 2017; http://journals.aace.com/doi/pdf/10.4158/EP161410.CR).  Continuous Glucose Monitoring Systems are being proposed as tools for detection of early onset diabetes post-Nivolumab (and other check-point inhibitors) treatment. 

Thyroid Nodule Database Study:

Thyroid nodules are common with a prevalence of 50% to 67% of the general population. With the increasing use of radiographic imaging, non-palpable thyroid nodules are commonly detected during imaging studies unrelated to the thyroid (i.e. carotid Doppler). The current guidelines recommend ultrasound (US) guided fine needle aspiration (FNA) biopsy of nodules > 10 mm or < 10mm nodules with suspicious US findings or high risk patients. Of the patients undergoing FNA for thyroid nodules, 5-15% are found to have malignancy. It is still unclear if the prevalence of thyroid cancer of non-palpable thyroid nodules is similar to that reported for palpable lesions. Nodules found to be benign by FNA biopsy are monitored with US evaluation every 12 months. FNA biopsy is repeated if there is growth of the nodule or new suspicious sonographic signs such as microcalcifications are found. A recent study that looked at 1985 patients who underwent an US guided FNA biopsy of thyroid nodules found that the prevalence of thyroid cancer was similar between patients with a solitary nodule (14.8%) and patients with multiple nodules (14.9%). Another study that looked at the predictive value of sonographic features in 865 nodules found that there was no significant relationship. 

Recently, our studies provided an interesting new view on the role of tumor-associated Double Negative (DN) T cells with potentially immunomodulatory activity in thyroid cancer. The identification of DN T cells is a novel observation, it would not only add to the growing understanding on the role of tumor infiltrating lymphocytes in thyroid cancer but might open a new approach for diagnosis/prognosis of thyroid cancer. (Imam et al., 2014; http://erc.endocrinology-journals.org/content/21/3/505.long, Frank Weber, 2014; http://erc.endocrinology-journals.org/content/21/3/C1.long).  We have an IRB approved protocol for the collection of thyroid samples to investigate the tumor immune microenvironment further.

Insulin Antibodies and Insulin Resistance:

Anti-insulin antibodies were first described in the 1970s, before the introduction of human insulin and insulin analogs, in patients receiving beef and pork insulin. Since recombinant human insulin became available, the presence of these antibodies is thought to be rare. Poorly controlled type 2 diabetes patients require higher doses of insulin for better glycemic control, and more and more patients seem to need concentrated insulins such as U-500 Regular insulin to overcome insulin resistance and achieve the very  glycemic control. If concentrated insulins were to induce the generation of antibodies against insulin, in turn these antibodies could be a contributing factor for insulin resistance (Hao JB., et al., 2017; http://care.diabetesjournals.org/content/diacare/40/2/e19.full.pdf).  We have developed a database to address this issue.

Last Updated: 2/12/20