Platelets and platelet-leukocyte interactions in infectious diseases

Area of Science:

• Immunology
• Hematology
• Infectious Diseases

Background:

• Platelets are critical immune cells involved in host defense.
• Their roles in infectious diseases are complex, influencing both protective and pathological outcomes.
• Understanding these roles is vital for developing effective treatments.

Purpose of the Study:

• To review recent findings on platelet involvement in immune responses to infectious diseases.
• To elucidate the mechanisms and consequences of platelet activation and interactions in infection.
• To highlight platelet contributions in globally impactful diseases like COVID-19 and HIV-1.

Main Methods:

• Literature review of recent data on platelets in infectious diseases.
• Compilation of evidence on platelet activation, aggregation, and interactions with pathogens and leukocytes.
• Focus on specific infectious diseases including viral, bacterial, and parasitic infections.

Main Results:

• Platelets recognize and respond to diverse pathogens, contributing to immune response assembly.
• Platelet activation and platelet-leukocyte aggregate formation are observed in infected individuals and models.
• Platelets mediate both protective immunity and pathological responses, including pathogen clearance and immune evasion.
• Evidence highlights platelet roles in COVID-19, HIV-1, viral hemorrhagic fevers, sepsis, and parasitic infections.

Conclusions:

• Platelets regulate innate and adaptive immunity through activation and direct pathogen interaction.
• They contribute to both protective and pathological immune responses in infectious diseases.
• Despite recent advances, further investigation into platelet mechanisms in infection is warranted.