BACKGROUND:Human tumor necrosis factor-like molecule 1A(hTL1A) is a strong T helper cell type 1(Th1) co-stimulator.Guillain-Barre syndrome(GBS) is an autoimmune disorder of the nervous system,which is mediated by Th1 cells. OBJECTIVE:To determine hTL1A expression in peripheral blood T lymphocytes of acute GBS children and the effects of hTL1 A on secretion of interferon-γ. DESIGN,TIME AND SETTING:A randomized,controlled,neuroimmunological in vitro study was performed at the Central Laboratory of First Hospital of Jilin University,China from November 2005 to November 2007. MATERIALS:Venous blood samples were obtained from 6 healthy donors,aged 6-12 years(all routine blood examination items were normal),and 6 additional children with acute GBS,aged 6-12 years.The GBS children fell ill within 1 week and were not treated with hormones or immunoglobulin. Purified recombinant human soluble tumor necrosis factor-like molecule 1A(rhsTL1A,1 mg/mL, relative molecular mass 22 000,6×His tag,soluble form) was supplied by the Central Laboratory of First Hospital of Jilin University,China. METHODS:Peripheral blood mononuclear cells were isolated from healthy donors using the standard Ficoll gradient centrifugation and were incubated in 96-well culture plates.The cells were assigned to the following groups:control(2μg/mL phytohemagglutinin),2μg/mL phytohemagglutinin + 25,100 and 400 ng/mL rhsTL1A.T cell proliferation was quantified using the tritiated thymidine(~3H-TdR) method.Serum interferon-γlevels in acute GBS children were detected by enzyme-linked immunosorbent assay(ELISA).The ratio of hTL1 A-positive T cells to CD3-positive T cells in peripheral blood of acute GBS children was determined using flow cytometry. Following in vitro pre-activation of peripheral blood mononuclear cells by 2μg/mL phytohemagglutinin,the peripheral blood mononuclear cells were treated with 400 ng/mL exogenous rhsTL1A.Finally,peripheral blood mononuclear cell-secreted interferon-γlevels were measured by ELISA. MAIN OUTCOME MEASURES:The following parameters were measured:rhsTL1A stimulation index to stimulate proliferation of T cells;the serum interferon-γlevels in acute GBS children;the ratio of hTL1A-positive cells to CD3-positive cells;the levels of interferon-γsecreted by peripheral blood mononuclear cells in acute GBS children,as well as rhsTL1A-stimulated interferon-γlevels. RESULTS:T cell proliferation assay revealed that the stimulation index in each rhsTL1A group was greater than the control group.The stimulation index of the 400 ng/mL rhsTL1A group was the greatest.Serum interferon-γlevels in acute GBS children were significantly greater than the control group(P<0.05).The ratio of hTL1 A~+ CD3~+ T cells to CD3~+ T cells in acute GBS children was significantly greater than the control group(P<0.01).Phytohemagglutinin stimulated peripheral blood mononuclear cells to a greater extent than 400 ng/mL rhsTL1A in the acute GBS group,and the secreted interferon-γlevels were significantly increased(P<0.05). CONCLUSION:In T cells pre-activated with 2μg/mL phytohemagglutinin,proliferation was effectively increased with 400 ng/mL rhsTL1A treatment.Expression of hTL1 A was increased in activated T cells from peripheral blood of acute GBS children,followed by increased interferon-γsecretion.These mechanisms are considered to be part of the pathological process that induces the secretion of inflammatory cytokines in GBS syndrome. BACKGROUND: Human tumor necrosis factor-like molecule 1A (hTL1A) is a strong T helper cell type 1 (Th1) co-stimulator. Guillain-Barre syndrome (GBS) is an autoimmune disorder of the nervous system, which is mediated by Th1 cells . OBJECTIVE: To determine hTL1A expression in peripheral blood T lymphocytes of acute GBS children and the effects of hTL1 A on secretion of interferon-γ. DESIGN, TIME AND SETTING: A randomized, controlled, neuroimmunological in vitro study was performed at the Central Laboratory of First Hospital of Jilin University, China from November 2005 to November 2007. MATERIALS: Venous blood samples were obtained from 6 healthy donors, aged 6-12 years (all routine blood examination items were normal), and 6 additional children with acute GBS, aged 6-12 years. The GBS children fell ill within 1 week and were not treated with hormones or immunoglobulin. Purified recombinant human soluble tumor necrosis factor-like molecule 1A (rhsTL1A, 1 mg / mL, relative molecular mass 22 000, 6 × His tag, solu ble form) was supplied by the Central Laboratory of First Hospital of Jilin University, China. METHODS: Peripheral blood mononuclear cells were isolated from healthy donors using the standard Ficoll gradient centrifugation and were incubated in 96-well culture plates. The cells were assigned to the following groups: control (2 μg / mL phytohemagglutinin), 2 μg / mL phytohemagglutinin + 25,100 and 400 ng / mL rhsTL1A.T cell proliferation was quantified using the tritiated thymidine (~ 3H-TdR) were detected by enzyme-linked immunosorbent assay (ELISA). The ratio of hTL1 A-positive T cells to CD3-positive T cells in peripheral blood of acute GBS children was determined using flow cytometry. Following in vitro pre-activation of peripheral blood mononuclear cells by 2 μg / mL phytohemagglutinin, the peripheral blood mononuclear cells were treated with 400 ng / mL exogenous rhsTL1A.Finally, peripheral blood mononuclear cell-secreted interferon-γlevels were m easuredby ELISA. MAIN OUTCOME MEASURES: The following parameters were measured: rhsTL1A stimulation index to stimulate proliferation of T cells; the serum interferon-γlevels in acute GBS children; the ratio of hTL1A-positive cells to CD3-positive cells; the levels of interferon -γsecreted by peripheral blood mononuclear cells in acute GBS children, as well as rhsTL1A-stimulated interferon-γlevels. RESULTS: T cell proliferation assay revealed that the stimulation index in each rhsTL1A group was greater than the control group. The stimulation index of the 400 ng / mL rhsTL1A group was the greatest. Serum interferon-γlevels in acute GBS children were significantly greater than the control group (P <0.05). The ratio of hTL1 A ~ + CD3 ~ + T cells to CD3 ~ + T cells in acute GBS children were significantly greater than the control group (P <0.01). Phytohemagglutinin stimulated peripheral blood mononuclear cells to a greater extent than 400 ng / mL rhsTL1A in the acute GBS group, and the secreted interferon-γ levels were In T cells pre-activated with 2 μg / mL phytohemagglutinin, proliferation was effectively increased with 400 ng / mL rhsTL1A treatment. Expression of hTL1 A was increased in activated T cells from peripheral blood of acute GBS children, followed by increased interferon-γsecretion.These mechanisms are considered to be part of the pathological process that induces the secretion of inflammatory cytokines in GBS syndrome.