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Notes: Immunohistological techniques were used to identify activated T lymphocytes within the synovial membrane of patients with rheumatoid arthritis, using the monoclonal antibody (MoAb) RFT2, which identifies a 40-k dalton molecule preferentially expressed by T blasts or activated cells. Using this reagent together with a monoclonal ‘cocktail’ that stains all T cells, cell counts on consecutive sections of rheumatoid synovium revealed that up to 50% T lymphocytes were RFT2+ (range 9.3-50.2%, mean 25.4). Subsequent analysis using combination immunofluorescence demonstrated that over 90% of these activated cells were of the T4+ subset. Furthermore all these cells appeared to be Leu8-. suggesting that the activated population were exclusively ‘true helpers’ and not suppressor inducers. Studies indicated that 50% of the RFT2+ cells were positive with anti-Tac MoAb. Comparisons with tissues from other arthropathies demonstrated that this relatively high proportion of RFT2+ cells was a feature restricted to rheumatoid arthritis, although biopsies from patients with psoriatic arthritis and ankylosing spondylitis also contained activated cells. Biopsies of Reiter's syndrome, osteo-arthritis, and pigmented villonodular synovitis contained no activated cells, no were any seen in sections of normal synovium. The presence in rheumatoid synovial membrane of activated T cells which are only of the T4+, Leu8+ subset adds weight to the suggestion that local immunoregulatory dysfunction contributes to the chronic inflammation of rheumatoid arthritis.

Notes: To determine whether dendritic cells (DC) are a consistent feature of lesions of sarcoidosis. we have used monoclonal antibodies to identify the HLA-DR-expressing populations of cells in cryostat sections of 15 lymph node, pulmonary and cutaneous lesions. The commonest HLA-DR positive cells in granulomas were epithelioid and giant cells, although lymphocytes within granulomas and tissue macrophages around them were also positive. Dendritic eells with Langerhans cells (NA1/34+=OKT6+) and interdigitating cell (RFD1+) phenotype were consistency associated with granulomas only in skin lesions. In lymph nodes, interdigitating cells (NA1/34-/RFD1 +/HLA-DR++) were confined to paracortical zones as in normal nodes, although a small area of NA1/34+/RFD1+ cells was found in one of three nodes. In lung lesions NA1/34+/RFDI+ dendritie eells were uneommon or absent, except in one chronic case. We conclude that while sometimes present in extracutaneous sites. DC are not an essential feature of sarcoid lesions, and that cells of the classical macrophage group are the most signifieant HLA-DR-expressing population. We suggest that the presence ol DC in lesions of sarcoidosis may indicate an immunologieal response distinct from that causing granulomas to form. The variability of their involvement may have immunoregulatory significance.

Notes: Two monoclonal antibodies (MoAb), RFD1 and RFD7, have been used to investigate whether human macrophages and dendritic cells represent phenotypically distinct cell types. RFD7 recognizes a 77 kd antigen, and is specific for acid phosphatase positive tissue macrophages, while RFD1 recognizes a unique Class II antigen, which is associated with dendritic cells. With immunohistological/cytological methods it was found that neither of these reagents reacted with granulocytes, monocytes, or lymphocytes, with the exception that a small proportion (〈20%) of B cells were stained with RFD1. In tissues, RFD7 reacted with mature macrophages only and did not stain Langerhans cells in the skin or the interdigitating (dendritic) cells of the T-cell zones of lymphoid tissue and the thymic medulla. Conversely, RFD1 appeared specific for the interdigitating (dendritic) cells and did not react with macrophage populations identified morphologically, geographically, and histochemically in any tissue studied. When peripheral blood monocytes (RFD1−, RFD7−) were matured in vitro, two distinct populations of RFD1+ RFD7− and RFD7+ RFD1− cells emerged. It is concluded that in normal tissues these two reagents identify phenotypic differences between macrophages and dendritic cells that may have functional significance.

Notes: This study investigates the distribution of immunocompetent cells in the ectocervix, and cytokine and immunoglobulin (Ig) levels in cervicovaginal secretions to determine whether they are altered in asymptomatic human immunodeficiency virus (HIV) infection. Ectocervical biopsies from 10 HIV+ and 10 presumed HIV-ve women were studied by immunocytochemistry. Levels of Igs in cervicovaginal secretions were quantified by radial immunodiffusion (RID) and cytokine levels by ELISA. HIV+ women had significantly increased numbers of CD8+ lymphocytes resulting in reversal of the CD4:CD8 ratio. There was a significant increase in the proportion of activated CD8+ HLA-DR+ and CD4+ HLA-DR + lymphocytes, but not in CD8+ TIA-1+ cells. The epithelium of the cervix from HIV+ subjects showed a significant increase in both numbers of macrophages (CD68+) and proportions of activated macrophages (CD68+ HLA-DR+) compared to normal. The stroma contained increased proportions of inductive (D1+) and suppressive (D1+ D7+) macrophages but a decrease in effector phagocyte (D7+) proportions and Langerhans' cells. Significantly lower tumour necrosis factor (TNF)-α levels were observed in cervicovaginal secretions from HIV+ subjects. IgG levels were 4 times higher and IgM levels twice higher in cervicovaginal secretions from HIV+ women, compared to results from normal subjects. These results suggest a response within the CD8+ cells in HIV+ women, yet these cells may have a low cytolytic capacity. The raised proportions of HLA-DR+ and D1+ CD4+ macrophages could act as antigen-presenting cells (APC) for CD4+ CD45RO+ lymphocytes, and represent a local acquired response. However, the close juxtaposition of these cells offers the potential for them to act as a local reservoir of virus and promote its proliferation. The increase of IgG over sIgA in secretions of HIV+ subjects provides evidence suggesting a dysregulation of local humoral immunity.

Notes: This study investigates local alterations in T-cell and macrophage subsets that occur in cervical epithelial neoplasia (CIN), in the presence and absence of human immunodeficiency virus (HIV) infection. Ectocervical biopsies from 10 women with CIN who were infected with HIV, and 10 women with CIN but no HIV infection were studied by immunocytochemistry.Significantly increased proportions of activated CD8+ T cells were seen in all CIN biopsies, and these proportions were further increased in the presence of HIV infection. Levels of CD8+TIA-1+ cells were particularly increased in the CIN+HIV+ group. There was a lack of expression of CD28 on the CD8+ cells of the epithelium of CIN+HIV+ samples. A significant reduction in the proportion of epithelial inductive D1+ macrophages and an increase in D1+D7+-suppressive cells were observed in the CIN+HIV+ cohort.The lack of expression of CD28 on the CD8+ cells of the epithelium of CIN+HIV+ samples in combination with the reduced CD4+ T-cell numbers seen in the presence of HIV infection may contribute to the development of higher grade CIN in this susceptible group. This may be aggravated by the reduction in the D1+ epithelial inductive macrophages, which might reflect recruitment of more suppressive D1+D7+ cells. This would further compromise the ability of the local T-cell system to respond to antigens and thus contribute to the development of neoplasia at this site. These results suggest that the increase in activated CD8+ T cells is a consequence rather than a cause of CIN.

Notes: Background The importance of TH2-type T cell cytokines in atopic disease is widely accepted. CD30, a member of the TNF/NGF receptor superfamily, is expressed on a proportion of activated CD45RO+ T cells and has been proposed as a marker for TH2 phenotype. CD30 ligand-CD30 interaction has been shown to positively influence development of the TH2 phenotype, and serum levels of soluble CD30 (sCD30) have been used as prognostic markers in HIV, SLE, Epstein-Barr Virus infection and Hodgkin's Lymphoma but not as yet in allergic disease.Objectives To establish if serum levels of sCD30 are elevated in atopic asthma and determine whether allergen-induced proliferation/activation of PBMCs from atopic asthmatics promotes CD30 expression on CD4+ T lymphocytes. Further, to determine if expression of CD30 and sCD30 correlate with disease severity.Methods Eighteen atopic asthmatics were each assigned a symptomatic disease score based on symptoms and bronchodilator rescue usage. Serum sCD30 was measured in peripheral blood by ELISA. PBMCs from atopic asthmatics were analysed with flow cytometry to obtain the proportions of CD4 T cells expressing CD45RO and CD30. The cells were then cultured for 10 days with IL-2 with or without house dust mite antigen. A proliferation index was recorded and expression of CD30 and CD45RO retested. As a control, stimulation with PHA was used. Results with patients’ PBMCs were compared with results of a parallel analysis of PBMCs from non-atopic healthy controls.Results Serum sCD30 was elevated in the 18 atopic asthmatics compared with a group of normal subjects but levels did not correlate with symptomatic disease activity. CD4CD45RO expression was low (14%) in atopic asthmatic peripheral blood but increased to 41% after 10 days culture with allergen. The CD4:CD8 ratio increased after Der p stimulation. A significant rise in the percentage of CD44 T cells expressing surface CD30 (29%) was seen along with increased mean fluorescence intensity. Both these results correlated with symptomatic disease severity score. Non-specific PHA stimulation failed to significantly affect CD30 expression.Conclusions There is a specific response to allergen in atopic asthma which causes significant increases in CD30 expression. This may correlate with disease severity.