■ AbstractType 1 diabetes development in NOD mice appears to require both CD4 + and CD8 + T cells. However, there are some situations where it has been suggested that either CD4 + or CD8 + T cells are able to mediate diabetes in the absence of the other population. In the case of transgenic mice, this may reflect the numbers of antigen-specific T cells able to access the pancreas and recruit other cell types such as macrophages leading to a release of high concentrations of damaging cytokines. Previous studies examining the requirement for CD8 + T cells have used antibodies specific for CD8α. It is known that CD8α is expressed not only on αβ T cells, but also on other cell types, including a DC population that may be critical for presenting islet antigen in the pancreatic draining lymph nodes. Therefore, we have reexamined the need for both CD4 + and CD8 + T cell populations in diabetes development in NOD mice using an antibody to CD8β. Our studies indicate that by using highly purified populations of T cells and antibodies specific for CD8 + T cells, there is indeed a need for both cell types. In accordance with some other reports, we found that CD4 + T cells appeared to be able to access the pancreas more readily than CD8 + T cells. Despite the ability of CD4 + T cells to recruit CD11b class II positive cells, diabetes did not develop in the absence of CD8 + T cells. These studies support the observation that CD8 + T cells may be final effector cells. As both T cell populations are clearly implicated in diabetes development, we have used a combination of non-depleting antibodies to target both CD4-positive and CD8-positive cells and found that this antibody combination was able to reverse diabetes onset in NOD mice as effectively as anti-CD3 antibodies.Keywords: type 1 diabetes · T cell · CD4+ · CD8+ · NOD · NOD.scid · pancreas infiltration · CD8 alpha chain · dendritic cell · IgG2 antibody · aCD3 antibody

SummaryAlthough thyroglobulin (Tg), the thyroid prohormone, is well known as a T cell dependent autoantigen in human and experimental autoimmune thyroid disease, very little is known about the molecular basis of Tg recognition by T cells. In this paper, we have characterized the epitopes recognized by .two clonotypically distinct, murine Tg autoreactive T cell hybridomas, CH9 and ADA2 . In vitro iodination of a Tg preparation which was deficient in in vivo organified iodine was first used to confirm our previous observation that these T cells recognize iodination-related epitopes in the Tg molecule . Affinity chromatography of tryptic peptides derived from normally iodinated human Tg revealed that these epitopes were exclusively located in thyroxine (T4) containing peptides. Through the use of synthetic T4-containing peptides, representing the four major hormonogenic sites in Tg, we demonstrated that both CH9 and ADA2 recognize an epitope containing the T4 at position 2553 in human Tg. Sets of overlapping 5mer to 12mer peptides around this T4 showed that the most potent peptide was a 9mer beginning at Asp 2551. The T4 was shown to be a critical residue, since its replacement with any of the 20 naturally occurring amino acids produced only nonstimulatory peptides. Since the T cell hybridomas could also be stimulated by major histocompatibility complex class II positive (interferon-, y-treated) thyroid epithelial cells in vitro, and their parent T cell lines can induce thyroiditis on adoptive transfer, the T4-containing Tg sequence described here is implicated as a pathogenic epitope in murine thyroid autoimmunity. T he production of the thyroid hormones thyroxine (T4),t tri-iodothyronine (T3) and reverse T3 (rT3) is dependent on the organification of iodine into thyroglobulin (Tg), the major protein product of the thyroid (1, 2) . This involves thyroid peroxidase catalyzed iodination of tyrosine residues in Tg to form mono-and di-iodotyrosines and their subsequent crosslinking to form the iodothyronines T3 and T4. These mature Tg molecules are stored in a colloidal form in the lumen of thyroid follicles. Secretion of T4 and T3 involves the endocytosis and subsequent proteolysis of colloidal Tg, which releases the hormone residues for diffusion into the circulation . The recent cloning of the genes coding for Tg from several species has allowed the precise localization 1 Abbreviations used in this paper.

In response to the 2014-2015 Ebola virus disease outbreak in West Africa, Johns Hopkins Medicine created a biocontainment unit to care for patients infected with Ebola virus and other high-consequence pathogens. The unit team examined published literature and guidelines, visited two existing U.S. biocontainment units, and contacted national and international experts to inform the design of the physical structure and patient care activities of the unit. The resulting four-bed unit allows for unidirectional flow of providers and materials and has ample space for donning and doffing personal protective equipment. The air-handling system allows treatment of diseases spread by contact, droplet, or airborne routes of transmission. An onsite laboratory and an autoclave waste management system minimize the transport of infectious materials out of the unit. The unit is staffed by self-selected nurses, providers, and support staff with pediatric and adult capabilities. A telecommunications system allows other providers and family members to interact with patients and staff remotely. A full-time nurse educator is responsible for staff training, including quarterly exercises and competency assessment in the donning and doffing of personal protective equipment. The creation of the Johns Hopkins Biocontainment Unit required the highest level of multidisciplinary collaboration. When not used for clinical care and training, the unit will be a site for research and innovation in highly infectious diseases. The lessons learned from the design process can inform a new research agenda focused on the care of patients in a biocontainment environment.

The use of immunosuppressive drugs in the management of autoimmunity penalizes a large part of the immune system for the misdemeanors of a small minority of T cells. An ideal form of therapy would be one in which it were possible to render the immune system tolerant of the inciting antigens with minimal effects on other responses. We here show that it is possible to re-establish self tolerance in an animal model of insulin-dependent diabetes mellitus without prior deletion of CD4+ T cells using a short course of therapy with a non-lytic monoclonal antibody to the CD4 adhesion receptor on T cells. This tolerance can be achieved even when diabetogenic cells are already in the pancreas. Primary responses to antigens given after therapy has ceased are normal and secondary responses to antigens seen prior to, but not during, the period of antibody therapy can remain unaffected. This suggests that intervention with selected CD4 antibodies may have significant advantages over and above that provided not only by conventional immunosuppression but also over that provided by a depleting antibody.