Immunologic effector cells in head and neck cancer

Area of Science:

• Immunology
• Oncology
• Molecular Biology

Background:

• Tumor-infiltrating lymphocytes (TIL) and lymph node lymphocytes (LNL) in head and neck cancer (HNC) patients often exhibit reduced functional responses.
• Impaired cytokine production by these lymphocytes may contribute to their functional incompetence.

Purpose of the Study:

• To investigate the spontaneous and induced production of key cytokines (IL-2, IL-1β, TNF-α, IFN-γ) by TIL, LNL, and peripheral blood lymphocytes (PBL) in HNC patients.
• To determine the in situ expression of cytokine mRNA and IL-2 receptor components in tumor tissues and lymph nodes.

Main Methods:

• Measurement of cytokine production by TIL, LNL, and PBL.
• In situ hybridization to detect cytokine and IL-2 receptor mRNA in tumor tissues and lymph nodes.
• Analysis of lymphocytes from tumor-involved and tumor-free lymph nodes.

Main Results:

• TIL and PBL produced IL-1β and TNF-α, while LNL did not produce measurable levels of these cytokines.
• LNL produced lower levels of IFN-γ compared to PBL.
• TIL and LNL near the tumor expressed mRNA for IL-2, IFN-γ, IL-1β, TNF-α, and IL-2 receptor chains.
• LNL adjacent to the tumor expressed TGF-β mRNA, whereas LNL distant from the tumor did not.

Conclusions:

• Lymphocytes in the tumor microenvironment of HNC patients exhibit distinct cytokine expression profiles.
• LNL near the tumor are activated and express immunosuppressive factors like TGF-β, potentially contributing to local immune evasion.
• Functional impairment of lymphocytes in HNC may be linked to the tumor microenvironment's influence on cytokine production.