B-cell activation in patients with irritable bowel syndrome (IBS).

• Patients with irritable bowel syndrome (IBS) may have a low grade immune activation. However, little is known about the properties of B cells of IBS patients. We therefore investigated activation level and antigen presenting phenotype of blood B cells of IBS patients. We also examined B-cell responses to lipopolysaccharide (LPS) and probiotic bacteria. Blood samples were obtained from 74 IBS patients and 30 healthy subjects. Peripheral blood mononuclear cells were isolated and stimulated with LPS or an UV-light inactivated bacterial cocktail consisting of the probiotic Gram-positive strains; Lactobacillus paracasei ssp. paracasei 19, Lactobacillus acidophilus La5, Bifidobacterium lactis B612. The phenotype of CD19(+) B cells was investigated by flow cytometry before and after 72 h cell culture. Furthermore, IBS symptom severity was assessed. B cells isolated from blood of IBS patients displayed an amplified activation level as demonstrated by increased cell surface expression of IgG, and also the costimulatory molecules CD80 and CD86. Expression of antigen presenting HLA-DR and costimulatory molecule CD40 on B cells was, however comparable in IBS patients and controls. B cells of IBS patients displayed an impaired ability to increase expression of CD80, but not CD86, in response to both LPS as well as probiotic bacteria stimulations. To conclude, blood B cells of IBS patients have an increased activation level. Bacterial component induced expression of the costimulatory molecule CD80, regarded as important for tolerance induction, is impaired. These data suggest that B-cell antigen presentation in IBS patients is associated with altered capacity of providing costimulation to T cells.

Ämnesord

MEDICIN OCH HÄLSOVETENSKAP  -- Klinisk medicin -- Gastroenterologi (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Clinical Medicine -- Gastroenterology and Hepatology (hsv//eng)

MEDICIN OCH HÄLSOVETENSKAP  -- Medicinska och farmaceutiska grundvetenskaper -- Immunologi inom det medicinska området (hsv//swe)

MEDICAL AND HEALTH SCIENCES  -- Basic Medicine -- Immunology in the medical area (hsv//eng)

Nyckelord

Adult

Antigen-Presenting Cells

physiology

Antigens

CD40

biosynthesis

Antigens

CD80

biosynthesis

Antigens

CD86

biosynthesis

B-Lymphocytes

immunology

metabolism

physiology

Cells

Cultured

Female

Flow Cytometry

Gram-Positive Bacteria

immunology

HLA-DR Antigens

biosynthesis

Humans

Immunoglobulin G

biosynthesis

genetics

Integrin beta Chains

biosynthesis

Irritable Bowel Syndrome

immunology

physiopathology

Leukocyte Count

Lymphocyte Activation

immunology

physiology

Male

Middle Aged

Phenotype

Probiotics

Stimulation

Chemical

Young Adult

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)