Prophylactic Injection of Recombinant Alpha-Enolase Reduces Arthritis Severity in the Collagen-Induced Arthritis Mice Model
Abstract
Objective
To evaluate the ability of the glycolytic enzyme alpha-enolase (ENO1) or its immunodominant peptide (pEP1) to reduce the severity of CIA in DBA/1 mice when injected in a prophylactic way.
Methods
Mice were treated with mouse ENO1 or pEP1 one day prior to collagen II immunization.
Clinical assessment was evaluated using 4 parameters (global and articular scores, ankle
thickness and weight). Titers of serum anti-ENO1, anti-cyclic citrullinated peptides (antiCCP) and anti-CII (total IgG and IgG1/IgG2a isotypes) antibodies were measured by ELISA
at different time-points. Disease activity was assessed by histological analysis of both anterior and hind paws at the end of experimentation.
Results
Prophylactic injection of 100 μg of ENO1 reduced severity of CIA. Serum levels of anti-CII
antibodies were reduced in ENO1-treated mice. Concordantly, ENO1-treated mice joints
presented less severe histological signs of arthritis. ENO1 did not induce a shift toward a
Th2 response since IgG1/IgG2a ratio of anti-CII antibodies remained unchanged and IL-4
serum levels were similar to those measured in the control group.
Conclusions
Pre-immunization with ENO1 or its immunodominant peptide pEP1 reduces CIA severity at
the clinical, immunological and histological levels. Effects of pEP1 were less pronounced. This immunomodulatory effect is associated with a reduction in anti-CII antibodies production but is not due to a Th1/Th2 shift.