Induction of tissue resident memory T cells by measles vaccine vector

Area of Science:

• Immunology
• Vaccinology
• Cellular Biology

Background:

• Measles live attenuated vaccine (MV) effectively controls measles via systemic immune memory.
• MV serves as a versatile platform for developing new vaccines.
• Understanding tissue-specific memory responses is crucial for vaccine design.

Purpose of the Study:

• To investigate the induction and persistence of resident memory T cells (Trm) in the lungs and liver following MV vaccination.
• To evaluate the impact of different immunization routes on Trm generation.
• To assess the functional activity of MV-induced Trm.

Main Methods:

• Mice were immunized with MV, and MV-specific Trm were analyzed in lung and liver tissues.
• Different immunization routes (including intranasal) were compared for their efficacy in inducing Trm.
• Functional assays were performed on CD8+ and CD4+ Trm to assess effector functions.
• Human lymphocytes were analyzed for homing receptor expression to confirm tissue tropism.

Main Results:

• A single dose of MV rapidly induced MV-specific Trm in both the liver and lungs, irrespective of administration route.
• Intranasal immunization resulted in a higher number of Trm in the lungs compared to other routes.
• MV-specific Trm exhibited functional activity, with CD8+ Trm secreting granzyme B and CD4+ Trm secreting IFN-γ and TNF-α.
• Human lymphocytes showed overexpression of homing receptors, indicating tissue tropism for inflamed and epithelial sites.

Conclusions:

• MV vaccination effectively generates functional Trm in key tissues like the lungs and liver.
• The intranasal route shows promise for inducing robust pulmonary immune responses.
• Inducing Trm at specific tissue sites is a promising strategy for improving vaccine efficacy and platform selection.