CD4+ T-cell depletion is not associated with alterations in survival, bacterial clearance, and inflammation after cecal ligation and puncture

• Published in: Shock (Augusta, Ga.) Vol. 29; no. 1; p. 56
• Main Authors: Enoh, Victor T, Lin, Scott H, Etogo, Anthony, Lin, Cheng Y, Sherwood, Edward R
• Format: Journal Article
• Language: English
• Published: United States 01.01.2008
• Subjects: Animals; Bacteria - immunology; Bacteria - isolation & purification; CD4 Antigens - genetics; CD4 Antigens - metabolism; CD4-Positive T-Lymphocytes - immunology; Colony Count, Microbial; Cytokines - biosynthesis; Female; Inflammation - immunology; Killer Cells, Natural - immunology; Lymphocyte Depletion; Mice; Mice, Inbred C57BL; Mice, Knockout; Sepsis - immunology; Sepsis - microbiology
• ISSN: 1073-2322; 1540-0514
• DOI: 10.1097/shk.0b013e318070c8b9

Our recent studies indicate that mice depleted of T cells that bear the alphabeta T-cell receptor (alphabeta T cells) show less inflammation, less physiological dysfunction, and improved survival after cecal ligation and puncture (CLP) compared with control mice. Classic CD4(+) and CD8(+) T cells comprise most of the alphabeta T-cell population. We previously showed that CD8(+) T cells, in conjunction with natural killer (NK) cells, participate in CLP-induced inflammation. However, the contribution of CD4(+) T cells to the early inflammatory response caused by CLP is largely undefined. In the present study, we evaluated CLP-induced mortality, bacterial clearance, and inflammation in mice that were depleted of CD4(+) T cells. Compared with control mice, CD4 knockout mice and wild-type mice treated with anti-CD4 did not show significant differences in survival, cytokine production, and systemic bacterial counts. The combined depletion of CD4(+) T and NK cells resulted in improved survival and decreased cytokine production compared with mice possessing a full lymphocyte complement, especially when CD4(+) T and NK cell-deficient mice were treated with imipenem. These improvements were nearly identical to those observed in mice depleted only of NK cells. These studies show that CD4(+) T cells do not seem to play a critical role in facilitating the early inflammatory response caused by CLP.