Prolonged expression of MHC class I - peptide expression in bone marrow derived retrovirus transfected matured dendritic cells by continuous centrifugation in the presence of IL-4.

Background & objectives: Dendritic cells (DCs) are potent antigen presenting cells which proceed from immature to a mature stage during their differentiation. There are several methods of obtaining long lasting mature antigen expressing DCs and different methods show different levels of antigen expressions. We investigated bone marrow derived DCs for the degree of maturation and genetically engineered antigen presentation in the presence of interleukin-4 (IL-4) as a maturity enhancer. Methods: DCs and transfected retrovirus were cultured together in the presence of granulocyte-macrophage colony stimulating factor (GMCSF)-IL4, GMCSF +IL4, lipopolysaccharide (LPS). B 7.1, B7.2 and CD11c were measured by the degree of immune fluorescence using enhanced green fluorescent protein (EGFP) shuttled retrovirus transfected antigen. Degree of MHC class I molecule with antigen presentation of antigen was also evaluated by fluorescence activated cell sorting. The antigen presenting capacity of transfected DCs was investigated. Bone marrow DCs were generated in the presence of GMCSF and IL-4 in vitro. Dividing bone marrow cells were infected with EGFP shuttled retrovirus expressing SSP2 by prolonged centrifugation for three consecutive days from day 5, 6 and 7 and continued to culture in the presence of GMSCF and IL-4 until day 8. Results: IL-4 as a cytokine increased the maturation of retrovirus transfected DCs by high expression of B 7-1 and B 7-2. Also, IL-4 induced DC enhanced by the prolonged centrifugation and it was shown by increased antigen presentation of these dendric cells as antigen presenting cell (APC). Cytolytic effects were significantly higher in cytotoxic T cell response (CTLs) mixed with transfected DCs than CTLs mixed with pulsed DCs. Interpretation & conclusions: There was an enhanced antigen presentation by prolonged expression of antigen loaded MHC class I receptors in DCs in the presence of IL-4 by prolonged centrifugation.

CD4 and CD8 T cell response to the rHSP60 from Klebsiella pneumoniae in peripheral blood mononuclear cells from patients with ankylosing spondylitis / Respuesta de linfocitos T CD4 y CD8 contra la rHSP60 de Klebsiella pneumoniae en células mononucleares de sangre periférica de pacientes con espondilitis anquilosa

Objective. To determine the processing pathways used by peripheral blood mononuclear cells (PBMC) and present the rHSP60Kp, and the T cell subpopulations involved in the response, in patients with ankylosing spondylitis (AS) Methods. The lymphoproliferative response to the rHSP60Kp in PBMC from 14 HLA-B27 + AS patients and 15 B27 healthy controls was assessed by ³H-TdR incorporation. The processing pathways for the rHSP60Kp were analyzed by ³H-TdR incorporation in fresh PBMC from patients using homologous PBMC preincubated with the antigen and specific inhibitors: chloroquine, N-acetyl-L-leucil-L-leucil-L-nor-leucinal (LLnL) or brefeldin A (BFA), fixed with p-formaldehyde (fixed APC). The CD4+/CD8+ T cell subpopulation activated with the antigen was determined by three colours flow cytometry in PBMC from patients. Results. Eight out of fourteen patients showed positive lymphoproliferative responses to the rHSP60Kp while none of the healthy controls responded (p < 0.012). In five patients S.I. was above 4.0. In these patients lymphoproliferation was lower when chloroquine and LLnL was used and it became negative with BFA, indicating that both pathways are used. CD4+ and CD8+ T cells populations expressed CD69 when activated by the rHSP60Kp. Conclusions. Our results suggest that CD4 and CD8 T cells participate in the response to the rHSP60Kp in B27+ AS patients.

Objetivo.Determinar las vías utilizadas por las células mononucleares de sangre periférica (CMSP) de pacientes con espondilitis anquilosante para procesar a la rHSPGO de Klebsiella pneumoniae (rHSPGOKp) y las subpoblaciones de linfocitos T involucrados en la activación. Métodos. Se determinó la respuesta linfoproliferativa, por incorporación de ³H-TdR en CMSP, en presencia de la rHSPGOKp, en 14 pacientes con EA HLA-B27+y en 15 sujetos sanos HLA-B27-. La ruta de procesamiento y presentación de la rHSPGOKp se determinó por incorporación de ³H-TdR en las CMSP de los pacientes utilizando como células presentadoras a las CMSP homologas, preíncubadas con el antígeno y los inhibidores específicos: cloroquína, brefeldína A y N-acetil-L-leucil-L-leucil-L-nor-leucinal (LLnL), y fijadas con p-formaldehído. Se evaluaron las subpoblaciones de linfocitos T CD4+ y CD8+ que expresaron CD69, frente al antígeno, por citometría de flujo. Resultados. Ocho de los 14 pacientes y ninguno de los sujetos sanos, tuvo respuesta linfoproliferativa positiva (IE > 3.0) contra la rHSPGOKp (p < 0.012). En cinco de los pacientes el I.E. fue superior a 4.0. En estos pacientes la linfoproliferación disminuyó cuando se utilizó cloroquína y LLnL, y se hizo negativa cuando se utilizó BFA, lo que indica que ambas vías son empleadas. Las subpoblaciones de linfocitos T (CD4+ y CD8+) expresaron CD69 frente al antigeno. Conclusiones. Nuestros resultados sugieren que ambas poblaciones de linfocitos T: CD4+ y CD8+ participan en la respuesta a la rHSPGOKp.

Ketotifen inhibits allergen-specific T lymphocytes' responses by suppressing antigen presentation with concomitant decrease of HLA-DQ antigen on macrophages.

Allergen activates T lymphocytes responsive to interleukin 2 (IL-2) in allergic patients but not in normal individuals. This response was suppressed by anti-allergic agent, Ketotifen (4-(1-methyl-4-piperidylidene)-4H-benzo [4, 5] cyclohepta [1, 2-b] thiophen-10 (9H)-one hydrogen (fumarate). Prolonged culture of antigen-presenting adherent cells impaired the ability to present Dermatophagoides farinae (Df) antigen to T cells, whereas stimulation of adherent cells with recombinant interferon-gamma (IFN-gamma) restored the antigen-presenting capability. The maintained antigen presenting ability of adherent cells treated with IFN-gamma was also suppressed by Ketotifen. Fluorescence activated cell sorter (FACS) analysis disclosed that Ketotifen selectively reduced the expression of HLA-DQ antigen, crucial restriction elements in Df antigen-related responses, on macrophages but not on B cells, even in the presence of IFN-gamma. Collectively, Ketotifen prevented macrophages from inducing allergen-activated T lymphocytes' responsiveness to IL-2 at least in part by decreasing the expression of HLA-DQ antigen.