Prolactin as an Adjunct for Type 1 Diabetes Immunotherapy

Area of Science:

• Immunology
• Endocrinology
• Regenerative Medicine

Background:

• Type 1 diabetes involves autoimmune destruction of insulin-producing beta-cells.
• Current immunotherapies can halt immune attack but often fail to restore sufficient beta-cell function for normoglycemia.
• Prolactin (PRL) shows potential as a growth factor to boost beta-cell mass and function.

Purpose of the Study:

• To investigate if prolactin (PRL) enhances the efficacy of anticluster of differentiation 3 monoclonal antibody (aCD3) immunotherapy in treating autoimmune diabetes.
• To determine if PRL improves beta-cell mass and function in conjunction with aCD3 therapy.

Main Methods:

• Diabetic nonobese diabetic (NOD) mice received a 5-day course of aCD3 with or without a concurrent 3-week course of PRL.
• Evaluated diabetes reversal rates, beta-cell proliferation, islet size, insulin content, and glucose-stimulated insulin secretion.
• Utilized lineage tracing to assess beta-cell neogenesis and analyzed T-cell populations and insulitis.

Main Results:

• Combined aCD3 and PRL therapy resulted in a higher proportion of diabetes remission compared to aCD3 alone.
• The combination group exhibited increased beta-cell proliferation, a larger beta-cell fraction, larger islets, and higher insulin content.
• Enhanced glucose-stimulated insulin secretion and a greater proportion of insulitis-free islets were observed in the combined therapy group.
• Beta-cell neogenesis contributed minimally to new beta-cell formation.

Conclusions:

• Combining prolactin (PRL) with aCD3 immunotherapy is a promising strategy for treating autoimmune diabetes.
• This combined approach effectively boosts beta-cell mass and function, leading to improved diabetes remission.
• The findings suggest a novel therapeutic paradigm for autoimmune diabetes by combining growth factor support with immunotherapy.