Cervical cancer cells suppress effector functions of cytotoxic T cells through the adenosinergic pathway

Area of Science:

• Immunology
• Oncology
• Virology

Background:

• CD73 expression on tumor cells promotes adenosine production, which inhibits anti-tumor immune cells.
• Adenosine (Ado) is a key immunosuppressive molecule in the tumor microenvironment.

Purpose of the Study:

• To investigate the role of CD73 and adenosine production in HPV-positive (HPV+) versus HPV-negative (HPV-) cervical cancer (CeCa).
• To determine the impact of HPV on CD73 expression and its effect on CD8+ T cell functions.

Main Methods:

• Analysis of CD73 expression and adenosine production in HPV+ (CaSki, SiHa, HeLa, RoVa) and HPV- (C33A, ViBo) CeCa cell lines.
• Assessment of the inhibitory effects of these cells on CD8+ T cell proliferation, activation, and cytotoxicity.
• Investigation of the role of HPV E6/E7 oncoproteins by silencing their expression in CeCa cells.

Main Results:

• HPV+ CeCa cells exhibited significantly higher membrane CD73 expression and produced greater amounts of adenosine compared to HPV- CeCa cells.
• Increased CD73 and adenosine in HPV+ CeCa cells led to stronger inhibition (>50%) of CD8+ T cell functions via the A2A adenosine receptor.
• Silencing HPV E6/E7 expression in CeCa cells markedly reduced CD73 levels and adenosine production.

Conclusions:

• HPV infection is associated with increased constitutive CD73 expression in cervical neoplasia.
• This elevated CD73 contributes to immune suppression in cervical cancer through excessive adenosine production.
• Targeting CD73 or adenosine pathways could be a therapeutic strategy for HPV-driven cervical cancers.