Antigen presentation in cancer: insights into tumour immunogenicity and immune evasion

Area of Science:

• Immunology
• Oncology
• Cancer Research

Background:

• Immune checkpoint blockade (ICB) therapy has revolutionized cancer treatment by blocking inhibitory T cell signals.
• However, ICB efficacy is limited, with only a subset of patients responding positively.
• CD8+ T cell responses, crucial for ICB success, primarily target tumor-specific mutations known as neoantigens.

Purpose of the Study:

• To review tumor-derived factors that modulate dendritic cell (DC) function.
• To summarize mechanisms of immune evasion related to antigen presentation in tumors.
• To discuss how tumors evade Natural Killer (NK) cell recognition despite antigen presentation defects.

Main Methods:

• Review of existing literature on tumor immunology and cancer immune evasion.
• Analysis of mechanisms by which tumors modulate antigen expression and presentation.
• Examination of tumor strategies to evade both T cell and NK cell-mediated immunity.

Main Results:

• Tumors employ diverse strategies to evade immune recognition, including modulating antigen expression and Human Leukocyte Antigen class I (HLA-I) surface levels.
• Alterations in antigen processing and presentation machinery within tumor cells are key evasion tactics.
• Tumors can present defective antigen presentation while still evading NK cell detection.

Conclusions:

• Understanding tumor immune evasion mechanisms is critical for improving ICB therapy efficacy.
• Targeting tumor antigen presentation and HLA-I pathways could enhance anti-tumor immune responses.
• Further research is needed to overcome tumor resistance to immunotherapy and broaden patient benefit.