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Phenotypic and functional analysis of lamina propria mononuclear cells from colonoscopic biopsy specimens in patients
J Haruta1, K Kusugami, A Kuroiwa
1First Department of Internal Medicine, Nagoya University School of Medicine, Japan.
Insights
In active ulcerative colitis (UC), T lymphocytes show in vivo activation. However, intestinal lymphokine-activated killer (LAK) cell activity is reduced due to fewer CD56+ cells during active inflammation.
Area of Science:
- Immunology
- Gastroenterology
- Cell Biology
Background:
- Ulcerative colitis (UC) is a chronic inflammatory bowel disease.
- Immune cell dysregulation in the colonic mucosa is implicated in UC pathogenesis.
- Understanding immune cell phenotypes and functions in UC is crucial.
Purpose of the Study:
- To investigate the phenotype and function of lamina propria mononuclear cells (LPMCs) in patients with active UC.
- To compare immune cell activation markers and cytotoxic activity between active UC and control groups.
- To explore the role of CD56+ cells and lymphokine-activated killer (LAK) cell activity in UC.
Main Methods:
- Phenotypic and functional analysis of LPMCs isolated from colonoscopic biopsies of 27 UC patients and controls.
- Flow cytometry to assess T lymphocyte activation markers (HLA-DR, IL-2 receptor, transferrin receptor).
- Measurement of lymphokine-activated killer (LAK) cell activity and CD56+ cell proportions.
Main Results:
- A higher proportion of T lymphocytes expressing HLA-DR, IL-2 receptor, and transferrin receptor was observed in active UC.
- No significant differences in activation markers after in vitro culture with IL-2 or phytohemagglutinin.
- Lower CD56+ cell proportion and reduced LAK cell activity in active UC LPMCs.
- Depletion of CD56+ cells from control LPMCs significantly reduced LAK cell activity.
Conclusions:
- Mucosal T lymphocytes exhibit in vivo activation during active UC inflammation.
- Decreased intestinal LAK cell activity in active UC may be associated with a reduction in CD56+ cells.
- These findings highlight immune cell alterations in the colonic mucosa of UC patients.
Abstract:
Phenotypic and functional analysis was performed with lamina propria mononuclear cells (LPMCs) isolated from colonoscopic biopsies in 27 patients with ulcerative colitis (UC). The proportion of T lymphocytes displaying HLA-DR antigens, interleukin 2 (IL-2) receptor, and transferrin receptor was greater in active UC than in control diseases. When LPMCs were cultured with IL-2 or phytohemagglutinin for 72 h, there were no significant differences in the proportion of cells bearing these activation markers between active UC and controls. The proportion of CD56+ cells and lymphokine-activated killer (LAK) cell activity was lower in LPMCs from active UC than in control cells, and depletion of CD56+ cells from control lamina propria cells essentially eliminated LAK cell activity. Mucosal T lymphocytes may be activated in vivo during active inflammation in UC, and lower levels of intestinal LAK cell activity may be related to the decrease of CD56+ cells under these conditions.