CD45 is required for type I IFN production by dendritic cells

Area of Science:

• Immunology
• Cell Biology
• Virology

Background:

• CD45, a leukocyte tyrosine phosphatase, is crucial for immune responses.
• Dendritic cells (DCs) are key antigen-presenting cells in immunity.
• The role of CD45 in DC function during viral infections is not fully understood.

Purpose of the Study:

• To investigate the function of splenic dendritic cells lacking CD45 expression.
• To determine the impact of CD45 deficiency on DC response to lymphocytic choriomeningitis virus (LCMV) infection.
• To evaluate the restorative effects of CD45RABC and CD45RO transgenes on CD45-deficient DCs.

Main Methods:

• Comparative analysis of splenic dendritic cells from wild-type (CD45+/+), CD45-deficient (CD45-/-), and transgenic (CD45RABC, CD45RO) mice.
• Assessment of dendritic cell numbers, including plasmacytoid dendritic cells.
• Evaluation of dendritic cell response to LCMV infection, including MHC and costimulatory molecule expression.
• Measurement of type I interferon production by dendritic cells in response to LCMV infection in vivo.

Main Results:

• CD45-/- mice exhibited increased numbers of plasmacytoid dendritic cells.
• Dendritic cells from all mouse groups showed upregulation of MHC and costimulatory molecules upon LCMV infection.
• Dendritic cells from CD45-/- mice demonstrated impaired type I interferon production following LCMV infection in vivo.
• CD45RABC and CD45RO transgenes largely restored the function of CD45-deficient dendritic cells.

Conclusions:

• Lack of CD45 expression in dendritic cells significantly affects their function, particularly in type I interferon production during viral infections.
• CD45 plays a critical role in regulating dendritic cell responses to LCMV infection.
• CD45RABC and CD45RO transgenes can rescue the impaired function of CD45-deficient dendritic cells, highlighting the importance of specific CD45 isoforms.