Abstract
Tissue-resident memory T cells (TRM) are different from effector memory T cells (TEM) and central memory T cells (TCM) and contribute to the protective immunity against local challenges. Currently, we found that CD4+ and CD8+ TRM cells in the nasal mucosa, trachea, lungs, and lavage fluids were heterogeneous on the expression of CD69 and CD103 as well as the production of cytokines including IFN-γ, IL-2, and TNF-α. After intranasal vaccination of mice with BCG, respiratory tissues expressed higher levels of the chemokine CXCL16 and TRM cells expressed CXCR6 to CXCL16. In addition, antigen-specific CD4+ and CD8+ TRM cells expressed cytokines following the stimulation with BCG and persisted in the nasal mucosa, trachea, and lungs for more than a hundred days. At the same time, mice were infected intranasally with live BCG and the results showed that vaccinated mice cleared up live BCG faster than nonvaccinated mice in the respiratory system. Taken together, our data demonstrated that intranasal vaccination of mice with BCG could induce antigen-specific CD4+ and CD8+ TRM cells in the respiratory system and have the ability to provide protection against pulmonary reinfection.
Highlights
Recent studies have demonstrated that both circulating memory T cells and tissue-resident memory T cells (TRM) abundant in peripheral tissues play a central role to elicit protective immunity [1, 2]
The cells in the lavage fluids, nasal mucosa, trachea, lungs, and blood were stained with antiCD3, anit-CD4, and anti-CD8 mAbs; live and singlet CD45− lymphocytes from nasal mucosa, trachea, lung tissues and CD45+ lymphocytes from blood were gated and subsequently analyzed on CD3+, CD4+, and CD8+ T cells by flow cytometry (Figure 2(b))
The results showed that expression of IFN-γ, IL-2, and TNF-α by CD3+, CD4+, and CD8+ T cells in the lavage fluids, nasal mucosa, trachea, and lungs is significantly higher in the Bacille calmette-guerin (BCG) group than the control group (Table 3)
Summary
Recent studies have demonstrated that both circulating memory T cells and tissue-resident memory T cells (TRM) abundant in peripheral tissues play a central role to elicit protective immunity [1, 2]. TRM cells are resident in mucous membranes and induced by vaccination to provide rapid and effective protective immunity against infection and are the basis for successful vaccination [9, 13]. We established the murine model of BCG immunization to compare the difference in phenotype and function of TRM cells in lavage fluid, nasal mucosa, trachea, and lung tissues and explored the similarities and differences in function and regulation. The results indicated that the BCG could induce the expression of IFN-γ, TNF-α, and IL2 by TRM cells in lavage fluids, nasal mucosa, trachea, and lung tissues. BCG-specific TRM cells were persisted for a long time in lavage fluids, nasal mucosa, trachea, and lung tissues and had the ability to provide protection against pulmonary reinfection. The study will reveal the immunology characteristics of TRM cells in the respiratory system and provide a new theoretical basis for the prevention and treatment of respiratory infections and allergic diseases
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
