Name: Video: Mycobacterial Antigen Preparation
Uploaded: 2023-05-12T14:55:00
Description: 269 Views. Mycobacterial Antigen Preparation

mycobacterial antigen preparation

Immunogenicity Enhancement by Mycobacterium paratuberculosis in Autoimmune Encephalomyelitis

Experimental autoimmune encephalomyelitis (EAE) is a common model for the study of human demyelinating disorders1. There are several models of EAE: active immunization using different myelin peptides in combination with potent adjuvants, passive immunization by in vitro transfer of myelin-specific CD4+ lymphocytes, and transgenic models of spontaneous EAE2. Each of these models has specific features that allow different aspects of EAE to be studied, such as the onset, effector phase, or chronic phase. The myelin oligodendrocyte glycoprotein (MOG) model of EAE is a good model to study the immune-mediated mechanisms of chronic neuroinflammation and demyelination, as it is characterized by mononuclear inflammatory infiltration, demyelination in peripheral white matter, and reduced recovery after the disease peak1.
MOG-EAE is induced by immunization of susceptible mice with the peptide MOG35-55 in complete Freund&#39;s adjuvant (CFA), followed by an intraperitoneal injection of pertussis toxin. This increases the permeability of the blood-brain barrier and allows myelin-specific T-cells activated in the periphery to reach the central nervous system (CNS), where they will be reactivated3. CFA plays a key role in the induction of EAE by enhancing the antigen uptake by antigen-presenting cells and the expression of cytokines related to humoral- and cell-mediated responses4. This mechanism is mainly due to the presence of killed Mycobacterium tuberculosis emulsified in oil, the components of which provide a strong stimulus for the immune system5. In fact, the induction of EAE is directly related to the amount of mycobacterium present during the antigenic challenge6.
The addition of other killed mycobacteria, such as Mycobacterium butyricum, to incomplete Freund&#39;s adjuvant7, as well as the effect of adjuvant combinations8, can modulate the clinical course of EAE and consequently influence the reproducibility of the results. Mycobacterium avium subspecies paratuberculosis (MAP), the etiologic agent of Johne&#39;s disease in ruminants, has been associated with inflammatory disorders of the human CNS9, as its antigenic components are capable of eliciting a strong humoral- and cell-mediated response in patients with multiple sclerosis and neuromyelitis optica spectrum disorder9. Therefore, in this protocol, we show an alternative and reproducible method to induce MOG-EAE by replacing M. tuberculosis in CFA with M. paratuberculosis.

Author Spotlight: Adjuvant Activity of Mycobacterium paratuberculosis in Enhancing the Immunogenicity of Autoantigens During Experimental Autoimmune Encephalomyelitis  

Adjuvant Activity of Mycobacterium paratuberculosis in Enhancing the Immunogenicity of Autoantigens During Experimental Autoimmune Encephalomyelitis

Watch this Scientific Journal Video about Mycobacterial Antigen Preparation at JoVE.com

Mycobacterial Antigen Preparation  

Research

JoVE Journal

Immunology and Infection

269 Views. Mycobacterial Antigen Preparation

Video: Mycobacterial Antigen Preparation  

Experimental autoimmune encephalomyelitis (EAE) induced by myelin oligodendrocyte glycoprotein (MOG) requires immunization by a MOG peptide emulsified in complete Freund&#39;s adjuvant (CFA) containing inactivated Mycobacterium tuberculosis. The antigenic components of the mycobacterium activate dendritic cells to stimulate T-cells to produce cytokines that promote the Th1 response via toll-like receptors. Therefore, the amount and species of mycobacteria present during the antigenic challenge are directly related to the development of EAE. This methods paper presents an alternative protocol to induce EAE in C57BL/6 mice using a modified incomplete Freund&#39;s adjuvant containing the heat-killed Mycobacterium avium subspecies paratuberculosis strain K-10.
M. paratuberculosis, a member of the Mycobacterium avium complex, is the causative agent of Johne&#39;s disease in ruminants and has been identified as a risk factor for several human T-cell-mediated disorders, including multiple sclerosis. Overall, mice immunized with Mycobacterium paratuberculosis showed earlier onset and greater disease severity than mice immunized with CFA containing the strain of M. tuberculosis H37Ra at the same doses of 4 mg/mL. The antigenic determinants of Mycobacterium avium subspecies paratuberculosis (MAP)&#160;strain K-10 were able to induce a strong Th1 cellular response during the effector phase, characterized by significantly higher numbers of T-lymphocytes (CD4+ CD27+), dendritic cells (CD11c+ I-A/I-E+), and monocytes (CD11b+ CD115+) in the spleen compared to mice immunized with CFA. Furthermore, the proliferative T-cell response to the MOG peptide appeared to be highest in M. paratuberculosis-immunized mice. The use of an encephalitogen (e.g., MOG35-55) emulsified in an adjuvant containing M. paratuberculosis in the formulation may be an alternative and validated method to activate dendritic cells for priming myelin epitope-specific CD4+ T-cells during the induction phase of EAE.

Here, we present an alternative protocol to actively induce experimental autoimmune encephalomyelitis in C57BL/6 mice, using the immunogenic epitope myelin oligodendrocyte glycoprotein (MOG)35-55 suspended in incomplete Freund's adjuvant containing the heat-killed Mycobacterium avium subspecies paratuberculosis.

Experimental autoimmune encephalomyelitis (EAE) induced by myelin oligodendrocyte glycoprotein (MOG) requires immunization by a MOG peptide emulsified in ...