CD48 controls T-cell and antigen-presenting cell functions in experimental colitis.

Area of Science:

• Immunology
• Cell Biology
• Gastroenterology

Background:

• CD48 is a lipid-anchored cell-surface receptor found on antigen-presenting cells and T cells.
• CD2 and 2B4 are known ligands for CD48, involved in hematopoietic cell interactions.

Purpose of the Study:

• To investigate the role of CD48 in the development of chronic experimental colitis.
• To determine how CD48 influences adaptive and innate immune functions in this model.

Main Methods:

• Adoptive transfer of wild-type or CD48(-/-) T cells into Rag-2(-/-) or CD48(-/-) x Rag-2(-/-) mice.
• Assessment of colitis via disease activity index, histology, and interferon-gamma production.
• In vitro examination of CD48(-/-) T cell proliferation and macrophage function.
• Evaluation of anti-CD48 antibody efficacy in preventing or treating colitis.

Main Results:

• CD48(-/-) T cells did not induce colitis in CD48(-/-) x Rag-2(-/-) mice, unlike wild-type T cells.
• Impaired in vitro proliferation of CD48(-/-) T cells stimulated by CD48(-/-) macrophages.
• CD48(-/-) macrophages showed reduced TNF-alpha and IL-12 production and impaired bacterial clearance.
• Anti-CD48 antibody treatment ameliorated colitis development, even post-induction.

Conclusions:

• CD48-dependent activation of macrophages and T cells sustains the inflammatory response in experimental colitis.
• Amelioration of T cell-induced colitis requires CD48 absence in both T cells and antigen-presenting cells.
• Anti-CD48 antibody therapy shows potential for treating inflammatory bowel disease.