Multiple Sclerosis (MS) is a debilitating disease that occurs when the body?s immune system incorrectly recognizes myelin, the matrix that insulates neurons in the central nervous system (CNS) as foreign. Current treatments for MS aim to reduce the severity of disease, but do not treat the cause, and require continual, frequent treatments over the lifetime of the patient to maintain disease remission, though the disease ultimately will progress. Unfortunately, these existing therapy options are also non-specific ? they cannot differentiate between myelin-specific inflammatory immune cells and other lymphocytes, leaving patients susceptible to opportunistic infections. Myelin-specific inflammatory cells are activated in lymph nodes (LNs), sites which coordinate immune cell interactions that control immune cell phenotypes. In the LNs, antigen presenting cells, including dendritic cells (DCs), present antigens ? such as myelin in MS ? to T and B cells. Depending on the signals present during this interaction, T cells can become inflammatory effector cells or regulatory cells (TREGS) that control the activity of inflammatory cells. During MS, these myelin-specific effector cells contribute to inflammation and neurodegeneration in the CNS. To overcome the limitations of current treatments, this proposal focuses on developing therapies that promote selective immune tolerance to myelin by inducing antigen-specific TREGS that can selectively control disease. To meet this goal, a direct LN injection technique will be used to deposit polymer particles co-loaded with myelin self-antigens and rapamycin, an immunomodulator, in LNs of mice induced with a relapsing-remitting model of MS. Studies have shown that the presence of Rapamycin, during the priming of a T cell can promote TREGS. Our lab has shown that a single injection of particles into LNs allows local programming of the LN microenvironment to promote TREGS, which permanently stopped and reversed disease-induced paralysis in a model of progressive MS. However, 85% of patients initially present with the relapsing-remitting form of MS, in which the immune system becomes reactive to different sections of myelin over time. This epitope spreading complicates treatment regimens, and therapies do not consistently work at all stages of disease. Thus, a relapsing-remitting model will allow for the study of epitope spreading, and how disease progresses when protection is conferred to an epitope at an earlier disease stage. Preliminary data shows that treating during the first wave of disease with a single iLN injection of particles co-loaded with rapamycin and the myelin epitope attacked during that wave can reverse disease and prevent relapse. This proposal will investigate how treatments at different stages of disease with different myelin epitopes alters disease progression and prevents relapse.

Public Health Relevance

Current treatments for Multiple Sclerosis (MS) do not differentiate between self-reactive inflammatory immune cells and healthy lymphocytes, which can leave patients immunocompromised. To overcome this limitation, next generation therapies seek to promote selective tolerance against the self-molecules attacked during MS by generating immune cells with regulatory functions. This proposal will investigate how degradable polymer depots loaded with regulatory signals and MS- relevant self-molecules can be used to locally control immune signaling in key tissues of immune cell development to reduce inflammation and stop disease in a pre-clinical model of relapsing-remitting MS, the type of MS that initially impacts most patients.

Agency
National Institute of Health (NIH)
Institute
National Institute of Allergy and Infectious Diseases (NIAID)
Type
Predoctoral Individual National Research Service Award (F31)
Project #
5F31AI143204-02
Application #
9867516
Study Section
Special Emphasis Panel (ZRG1)
Program Officer
Gondre-Lewis, Timothy A
Project Start
2019-01-30
Project End
2021-01-29
Budget Start
2020-01-30
Budget End
2021-01-29
Support Year
2
Fiscal Year
2020
Total Cost
Indirect Cost
Name
University of Maryland College Park
Department
Biomedical Engineering
Type
Biomed Engr/Col Engr/Engr Sta
DUNS #
790934285
City
College Park
State
MD
Country
United States
Zip Code
20742