5 research outputs found
A Biodegradable Nanoparticle Platform for the Induction of Antigen-Specific Immune Tolerance for Treatment of Autoimmune Disease
Targeted immune tolerance is a coveted therapy for the treatment of a variety of autoimmune diseases, as current treatment options often involve nonspecific immunosuppression. Intravenous (iv) infusion of apoptotic syngeneic splenocytes linked with peptide or protein autoantigens using ethylene carbodiimide (ECDI) has been demonstrated to be an effective method for inducing peripheral, antigen-specific tolerance for treatment of autoimmune disease. Here, we show the ability of biodegradable poly(lactic-<i>co</i>-glycolic acid) (PLG) nanoparticles to function as a safe, cost-effective, and highly efficient alternative to cellular carriers for the induction of antigen-specific T cell tolerance. We describe the formulation of tolerogenic PLG particles and demonstrate that administration of myelin antigen-coupled particles both prevented and treated relapsing-remitting experimental autoimmune encephalomyelitis (R-EAE), a CD4 T cell-mediated mouse model of multiple sclerosis (MS). PLG particles made on-site with surfactant modifications surpass the efficacy of commercially available particles in their ability to couple peptide and to prevent disease induction. Most importantly, myelin antigen-coupled PLG nanoparticles are able to significantly ameliorate ongoing disease and subsequent relapses when administered at onset or at peak of acute disease, and minimize epitope spreading when administered during disease remission. Therapeutic treatment results in significantly reduced CNS infiltration of encephalitogenic Th1 (IFN-γ) and Th17 (IL-17a) cells as well as inflammatory monocytes/macrophages. Together, these data describe a platform for antigen display that is safe, low-cost, and highly effective at inducing antigen-specific T cell tolerance. The development of such a platform carries broad implications for the treatment of a variety of immune-mediated diseases
B and T cell frequency in therapeutic model of Rituximab administration.
<p>Cells from each organ were pooled from at least three mice per group
and counted. Cell counts were then normalized by dividing the total
counts by the numbers of mice in each group and then multiplied by
the percentage of each cell type as identified by flow cytometry.
Total leukocytes were identified by CD45+ events within FSC and
SSC gates. B cells were identified using gates for CD19 and B220. T
cells were identified by expression of CD3 and either CD4 or CD8.
Numbers in parenthesis indicate the percent change in cell counts in
the hCD20Tg mice as compared to WTLM controls.</p
Rituximab administration alters MOG-specific recall responses.
<p><b>Panels A–E</b>. WTLM and hCD20Tg mice were treated with
Rituximab daily for 3 days (Day -3,-2,-1) followed by immunization with
MOG<sub>1–125</sub> on Day 0. On day 20 post-immunization,
bulk draining lymph node cells (LNC) were isolated and recall response
determined. <b>Panels A and B</b>. Identification of MOG-reactive
T cells by tetramer staining. Bulk LNC were cultured for 3 days in the
presence of MOG<sub>1–125</sub> prior to labeling with antibodies
to CD3, CD4 and I-Ab tetramers to either human (A)
CLIP<sub>103–117</sub> or (B) MOG<sub>38–48</sub>.
Numbers above boxes indicate percentages of T cells in the tetramer
positive gate. <b>Panel C</b>. Secondary T cell proliferative
responses were determined by CFSE dilution assay. LNC were labeled with
CFSE and placed in culture with 20 µg/ml MOG<sub>1–125</sub>
and proliferation determined by flow cytometry on day 6 of culture.
Results shown are gated on CD4+ events. Numbers indicate the
percentage of total cells that diluted CFSE from WTLM and hCD20Tg mice.
<b>Panels D and E</b>. 48-hour supernatants from the Panel C
experiments were examined for the presence of IL-17 (D) or IFNγ (E)
by ELISA. Asterices indicate a significant decrease in IL-17 production
(p<0.05). Results are representative of at least 2 independent
experiments.</p
B and T cell dynamics following Rituximab treatment.
<p><b>Panels A and E</b>. Expression of human CD20 by hCD20Tg B cells
and hCD20Tg T cells. Splenocytes from WTLM and hCD20Tg mice were stained
with antibodies to human CD20, CD4 and CD19 and flow cytometry
performed. Results shown are gated on CD19+CD4− events to
identify B cells or gated on CD19−CD4+ events to identify T
cells. <b>Panels B/C/D/F/G</b>. WTLM and hCD20Tg mice received
three daily injections of Rituximab (100 µg) beginning on day 0.
At 144 hours after Rituximab treatment was initiated, tissues were
harvested for flow cytometry analysis. <b>Panel B</b>. Peripheral
B cells are rapidly depleted following Rituximab treatment. <b>Panel
C</b>. Splenic B cells are depleted following Rituximab
treatment. <b>Panel D</b>. B cells in the LN (Axilary, Brachial
and Inguinal) are depleted following Rituximab treatment. <b>Panel
E</b>. CD4 T cells do not express human CD20. <b>Panel
F</b>. Splenic CD4 T cells are reduced following Rituximab
treatment. <b>Panel G</b>. CD4 T cells in the LN (Axilary,
Brachial and Inguinal) are reduced following Rituximab treatment.
<b>Panel H</b>. Rituximab administration does not prevent
priming of inflammatory T-effector cells. WTLM and hCD20Tg mice were
treated with Rituximab daily for 3 days (Day -3,-2,-1), followed by
immunization with MOG<sub>1–125</sub> on Day 0. On day 10
post-immunization, DTH responses were elicited by subcutaneous injection
of MOG<sub>1–125</sub> (10 µg) in the ear. The net ear
swelling responses were determined at 24 hours. Results shown indicate
the mean ear swelling in mmX10E-3 (background subtracted) +/−
SEM. Significant differences were detected by unpaired t-test (*,
p<0.05; **, p<0.01). These results are representative of
at least two independent experiments.</p
Disruption of EAE pathogenesis by B cell depletion.
<p><b>Panel A</b>. EAE severity is similar in WTLM and hCD20Tg mice.
EAE onset and severity were monitored using a 5-point scale on WTLM and
hCD20Tg mice immunized with MOG<sub>1–125</sub>. These results are
representative of at least two independent experiments. <b>Panels
B–D</b>. Rituximab administration prevents the induction of
EAE. WTLM or hCD20Tg mice were either left untreated or were injected
with 100 µg Rituximab daily for three days (Day -3,-2,-1). On Day
0, EAE was induced by immunization with MOG<sub>1–125</sub>.
<b>Panel B</b>. Disease course of WTLM and hCD20Tg mice, EAE
onset and severity was monitored using a 5-point scale. Shown are the
mean clinical score +/− SEM. <b>Panel C</b>. B cell
depletion results in reduced levels of anti-MOG IgG in the serum. Serum
was harvested on day 21 post-immunization and MOG-specific IgG levels
were determined by ELISA. Results shown are the mean IgG concentration
+/− SEM. Asterix indicates significant decrease as compared
to Rituximab-treated WTLM mice. <b>Panel D</b>. Rituximab
administration results in rapid depletion of B cells in the peripheral
blood. Blood was taken from WTLM or hCD20Tg mice 3 days following the
final dose of Rituximab (day 2 post-immunization). B cells were
identified by flow cytometry using gates to identify lymphocytes and
CD19 expressing cells. Results shown are the mean percentages of
CD19+ B cells +/−SEM (*, p<0.01). <b>Panels
E/F</b>. Treatment with Rituximab reduces EAE severity. EAE was
initiated in WTLM and hCD20Tg mice on Day 0. Upon the appearance of
clinical signs of EAE, Rituximab (100 µg) was administered daily
for three treatments. <b>Panel E</b>. Disease course of WTLM and
hCD20Tg mice, EAE onset and severity was monitored using a 5-point
scale. Shown are the mean clinical score +/− SEM. <b>Panel
F</b>. B cell depletion in peripheral blood on day 20.
Significant differences were determined using an unpaired t-test (*,
p<0.05; **, p<0.01). These results are representative of
at least two independent experiments with Rituximab and two experiments
using the 1F5 anti-human CD20 mAb (data not shown).</p