Do the lungs deliver naïve CD4 T cells to draining nodes? (95.13)

• Published in: The Journal of immunology (1950) 2009-04, Vol.182 (1_Supplement), p.95-95.13
• Main Authors: Caucheteux, Stephane M, Paul, William E
• Format: Article
• Language: English
• ISSN: 0022-1767; 1550-6606
• DOI: 10.4049/jimmunol.182.Supp.95.13

~80% of lung CD4 T cells express low levels of CD44, high levels of CD62L, CD45RB, CCR7 and CD127 consistent with their being naïve. When Rag2-/- TCR transgenic cells are transferred to syngeneic mice, naïve phenotype transgenic cells are found in the lung. These cells disappear rapidly upon treatment with FTY-720 but are still found in mice treated with anti-CD62L, implying they are part of the recirculating pool but do not require L-selectin to enter the lung. Upon intranasal immunization with low (1 μg) antigen dose, the response is limited to the nodes draining the airways. When these low antigen doses are used, responses are not efficient as shown by the persistence of naïve antigen-specific CD4 T cells in the non-draining nodes. Nonetheless, "naïve" antigen-specific cells are lost from the lung; they reappear as activated cells at about 2.5 days after immunization, a response that is inhibited by FTY720. These results indicate that primary responses occur in the organized draining lymphoid tissue, as would be expected, but imply that the afferent lymphatics may be an important source for the delivery of naive CD4 T cells from tissues to the responding lymph nodes.