Transient B-Cell Depletion with Anti-CD20 in Combination with Proinsulin DNA Vaccine or Oral Insulin: Immunologic Effects and Efficacy in NOD Mice

Abstract

A recent type 1 diabetes (T1D) clinical trial of rituximab (a B cell-depleting anti-CD20 antibody) achieved some therapeutic benefit in preserving C-peptide for a period of approximately nine months in patients with recently diagnosed diabetes. Our previous data in the NOD mouse demonstrated that co-administration of antigen (insulin) with anti-CD3 antibody (a T cell-directed immunomodulator) offers better protection than either entity alone, indicating that novel combination therapies that include a T1D-related autoantigen are possible. To accelerate the identification and development of novel combination therapies that can be advanced into the clinic, we have evaluated the combination of a mouse anti-CD20 antibody with either oral insulin or a proinsulin-expressing DNA vaccine. Anti-CD20 alone, given once or on 4 consecutive days, produced transient B cell depletion but did not prevent or reverse T1D in the NOD mouse. Oral insulin alone (twice weekly for 6 weeks) was also ineffective, while proinsulin DNA (weekly for up to 12 weeks) showed a trend toward modest efficacy. Combination of anti-CD20 with oral insulin was ineffective in reversing diabetes in NOD mice whose glycemia was controlled with SC insulin pellets; these experiments were performed in three independent labs. Combination of anti-CD20 with proinsulin DNA was also ineffective in diabetes reversal, but did show modest efficacy in diabetes prevention (p = 0.04). In the prevention studies, anti-CD20 plus proinsulin resulted in modest increases in Tregs in pancreatic lymph nodes and elevated levels of proinsulin-specific CD4+ T-cells that produced IL-4. Thus, combination therapy with anti-CD20 and either oral insulin or proinsulin does not protect hyperglycemic NOD mice, but the combination with proinsulin offers limited efficacy in T1D prevention, potentially by augmentation of proinsulin-specific IL-4 production.

The mechanism of anti-CD20–mediated B cell depletion revealed by intravital imaging

“…To model anti-CD20 therapy, we treated mice with a depleting mouse anti-CD20 Ab (9). After 16 hours, the percentage of B cells was reduced in all organs analyzed, a phenomenon that was strictly dependent on activating Fc receptors (Supplemental Figure 1; supplemental material available online with this article; doi:10.1172/JCI70972DS1).…”

The microRNA-212/132 cluster regulates B cell development by targeting Sox4

“…4, A-C). To further understand the contribution of miR-212/132 to pro-B cell development, we challenged WT and miR-212/132 / mice with an anti-CD20 antibody to deplete all mature B cells (Sarikonda et al, 2013) and track B cell development under nonhomeostatic conditions. We observed a rapid depletion decrease in the frequency of both pre-B cells (Hardy Fr.…”

Targeted immune interventions for type 1 diabetes

“…In some cases autoantigen therapy prevented or reversed diabetes and thus provided the justification for clinical trials. (53-55) A number of medium- to large-scale trials have been conducted evaluating insulin, Hsp60, and GAD on the progression of T1D. In the case of insulin, this has been tested by the oral, intranasal, and parenteral routes with no significant effect.…”