Compromised T Cell Immunity Links Increased Cutaneous Papillomavirus Activity to Squamous Cell Carcinoma Risk

Area of Science:

• Immunology
• Oncology
• Virology

Background:

• Cutaneous squamous cell carcinoma (cSCC) is a prevalent cancer, particularly in immunosuppressed individuals.
• Beta-human papillomavirus (β-HPV) is implicated in cSCC due to observed higher viral loads and seropositivity in patients.
• T cell immunity against β-HPV may protect against skin cancer, with its loss potentially increasing cSCC risk.

Purpose of the Study:

• To investigate the role of T cell immunity in the link between β-HPV and cSCC.
• To determine if compromised T cell immunity affects β-HPV viral load and seropositivity in a skin carcinogenesis model.

Main Methods:

• Utilized a mouse model colonized with mouse papillomavirus type 1 (MmuPV1).
• Administered a skin carcinogenesis protocol to the MmuPV1-colonized mice.
• Depleted CD8+ T cells to assess their impact on viral load and antibody response.

Main Results:

• CD8+ T cell depletion led to increased MmuPV1 viral load in the skin.
• Depletion of CD8+ T cells resulted in higher seropositivity for anti-MmuPV1 antibodies.
• These outcomes suggest a role for T cell immunity in controlling MmuPV1 infection during skin carcinogenesis.

Conclusions:

• Compromised T cell immunity, specifically CD8+ T cells, is linked to increased β-HPV viral load in the skin.
• Impaired T cell responses may represent the connection between elevated β-HPV detection and the heightened risk of cSCC.
• Maintaining robust T cell immunity could be crucial for preventing β-HPV-associated skin cancers.