CD11b (Mac-1): a marker for CD8+ cytotoxic T cell activation and memory in virus infection
Department of Pathology
Medical Subject Headings
Animals; Antigens, CD8; Cell Separation; Flow Cytometry; *Immunity, Cellular; *Immunologic Memory; Interleukin-2; *Lymphocyte Activation; Lymphocytic Choriomeningitis; Macrophage-1 Antigen; Male; Mice; Mice, Inbred Strains; Receptors, Lymphocyte Homing; T-Lymphocyte Subsets; T-Lymphocytes, Cytotoxic
Life Sciences | Medicine and Health Sciences
We have found that CD11b, a cell surface integrin of macrophages, granulocytes, and NK cells, is expressed by a subset of CD8+ T cells that include both the active virus-specific CTL and the virus-specific memory CTL populations. CD8+CD11b+ cells comprise less than 3% of naive mouse splenocytes, but after lymphocytic choriomeningitis virus (LCMV) infection increase by 9- to 12-fold by the peak (day 8) of the virus-specific CTL response. Depletion of day-8 splenocytes with anti-Mac-1 and C' or enrichment by sorting for CD11b+ or CD8+CD11b+ spleen cells demonstrated that LCMV-specific CTL are CD11b+. The CD11b+ subpopulation also contained the bulk of the IL-2-responsive CD8+ cells. MEL-14, a homing marker down-regulated on activated T cells, was down-regulated on the majority of CD8+ cells that became CD11b+. Less than 1% of LCMV-immune splenic lymphocytes expressed CD11b. Antibody and C' depletion of this population severely impaired the ability of immune splenocytes to respond to in vitro secondary stimulation with LCMV-infected peritoneal macrophages, but did not affect the generation of a primary allospecific CTL response in MLC. Mixing of CD8-depleted and CD11b-depleted LCMV-immune splenocytes failed to restore the ability of these cells to mount a virus-specific memory CTL response, indicating that a cell coexpressing CD8 and CD11b is essential for this response. As determined by limiting dilution analysis, the precursors for the LCMV-specific memory CTL response were enriched in the CD11b+ population of LCMV-immune splenocytes. CD11b stained far fewer CD8+ splenocytes from naive mice than did CD44 (Pgp-1), and among immune splenocytes it identified a small subpopulation of CD44hi cells, indicating that CD11b may be the best single marker available for discriminating between naive and memory CD8+ T cells.
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Citation: J Immunol. 1992 Aug 15;149(4):1326-33.
Journal of immunology (Baltimore, Md. : 1950)
McFarland, Hugh I.; Nahill, Sharon R.; Maciaszek, Joseph Walter; and Welsh, Raymond M., "CD11b (Mac-1): a marker for CD8+ cytotoxic T cell activation and memory in virus infection" (1992). GSBS Student Publications. 827.