T lymphocytes in acute bacterial infection: increased prevalence of CD11b(+) cells in the peripheral blood and recruitment to the infected site

Immunology. 2008 Dec;125(4):503-9. doi: 10.1111/j.1365-2567.2008.02863.x. Epub 2008 May 13.

Abstract

T-cell activation, particularly of CD8(+) cells, is invariably associated with viral infections. We now provide evidence for the activation of T cells in patients with localized bacterial soft tissue infections. During acute disease we detected in the peripheral blood of these patients, small though conspicuous populations of CD4(+) CD28(+) CD11b(+) and CD8(+) CD28(+) CD11b(+) cells, indicative of an expansion of effector T cells. Moreover, we identified CD4(+) and CD8(+) cells at the infected site, in addition to highly activated polymorphonuclear neutrophils (PMN). In keeping with their role as first-line defence, PMN were preponderant, but T cells amounted to 20% of the infiltrated cells. The majority of the infiltrated T cells expressed CXCR6, a homing receptor for non-lymphoid tissue. The infiltrated T cells produced interferon-gamma (IFN-gamma), while the peripheral blood cells obtained at the same time did not. In conclusion, in response to localized bacterial infections, T cells are activated and recruited to the infected site. We propose that these T cells, e.g. by producing IFN-gamma, enhance the efficiency of the infiltrated phagocytic cells, particularly of the PMN, thereby supporting the local host defence.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acute Disease
  • Adult
  • Aged
  • Bacterial Infections / immunology*
  • CD11b Antigen / immunology*
  • CD24 Antigen / immunology
  • CD4-Positive T-Lymphocytes / immunology
  • CD8-Positive T-Lymphocytes / immunology
  • Case-Control Studies
  • Chemotaxis, Leukocyte
  • Coculture Techniques
  • Flow Cytometry / methods
  • Humans
  • Interferon-gamma / immunology
  • Lymphocyte Activation
  • Middle Aged
  • Neutrophils / immunology
  • Receptors, CXCR6
  • Receptors, Chemokine / analysis
  • Receptors, Virus / analysis
  • Soft Tissue Infections / immunology*
  • T-Lymphocytes / immunology*
  • Young Adult

Substances

  • CD11b Antigen
  • CD24 Antigen
  • CXCR6 protein, human
  • Receptors, CXCR6
  • Receptors, Chemokine
  • Receptors, Virus
  • Interferon-gamma