Manipulation of costimulatory molecules by intracellular pathogens: veni, vidi, vici!!

Area of Science:

• Immunology
• Pathogen Biology
• Molecular Medicine

Background:

• Successful human pathogens, including Mycobacterium tuberculosis (Mtb), HIV, and Leishmania donovani, establish chronic infections and pose significant global health threats.
• These pathogens employ sophisticated immune evasion strategies, such as antigenic variation, interference with antigen processing, subversion of phagocytosis, and manipulation of immune regulatory pathways.
• Costimulatory molecules are crucial for initiating and maintaining immune responses, and pathogens exploit their functions to undermine host defenses.

Purpose of the Study:

• To review how various pathogens manipulate costimulatory molecules to establish and maintain chronic infections.
• To summarize the convergent strategies pathogens use to modulate the immune system via costimulatory pathways.
• To highlight the potential of exploiting costimulatory pathways for developing novel immunotherapeutic interventions against intracellular pathogens.

Main Methods:

• Literature review focusing on host-pathogen interactions and immune evasion mechanisms.
• Analysis of how pathogens interfere with costimulatory molecule signaling.
• Synthesis of information on pathogen manipulation of immune checkpoints and costimulatory signals.

Main Results:

• Pathogens like Mtb, HIV, and Leishmania sp. effectively manipulate costimulatory molecules to evade immune surveillance and establish chronic infections.
• Impairment of costimulatory molecule signaling by pathogens leads to defective T-cell responses, allowing pathogen proliferation.
• Pathogens utilize convergent molecular mechanisms to tune and suppress host immune responses through costimulatory pathways.

Conclusions:

• Pathogen manipulation of costimulatory molecules is a key factor in establishing chronic infections.
• Understanding these host-pathogen interactions at the molecular level is vital for developing effective treatments.
• Targeting costimulatory pathways presents a promising avenue for developing immunotherapies to eradicate intracellular pathogens.