Circulating, Mycobacterium tuberculosis-specific lymphocytes from PPD skin test-negative patients with tuberculosis do not secrete interferon-gamma (IFN-gamma) and lack the cutaneous lymphocyte antigen skin-selective homing receptor

Individuals with a negative intradermal reaction to tuberculin PPD have long been described in the Mycobacterium tuberculosis exposed, immune-competent population. Here, we studied PPD-specific blood T lymphocytes from these subjects for phenotypic markers relevant to skin migration, including the expression of the skin-selective homing receptor, the cutaneous lymphocyte-associated antigen (CLA). Out of 82 patients with active tuberculosis we identified four subjects who were repeatedly PPD skin test-negative. CD4 T lymphocytes specific to mycobacterial antigens were derived from these individuals, which (i) proliferated in vitro to M. tuberculosis antigens comparably to those from PPD+ patients; (ii) secreted comparable amounts of IL-2 but lower amounts of IFN-gamma; (iii) were confined within the CLA-negative T cell subset. We conclude that the negative tuberculin reaction in a small subset of patients exposed to mycobacteria is associated with impaired production of IFN-gamma by circulating PPD-specific T cells that are lacking CLA expression. On this basis in vitro proliferation to PPD can discriminate bona fide non-responders from infected patients with a deficit in the margination of M. tuberculosis-specific T lymphocytes.     

Peripheral T-cell lymphomas: a clinicopathological and immunological study of 10 cases

Diagnosis and classification of T-cell lymphomas is notoriously difficult. Existing classification schemes are insufficient. Some clinicopathologically well defined T-cell lymphomas exist (mycosis fungoides, Sézary's syndrome, and T-lymphoblastic lymphomas) but the remaining tumours, frequently called peripheral T-cell lymphomas, are a heterogeneous group, clinically, morphologically and immunologically. The data on 10 peripheral T-cell lymphomas are presented and compared to data from the literature. Patients were elderly, had a high frequency of extranodal localizations (notably the skin 75%) and had a poor prognosis: five of 10 patients have died, median survival 22 months. Morphologically and immunophenotypically the group is very heterogeneous. The variety of blast cell morphology is emphasized. No correlations were found between immunophenotype and prognosis, or immunophenotype and morphology.     

Keratinocyte expression of intercellular adhesion molecule 1 (ICAM-1) correlated with infiltration of lymphocyte function associated antigen 1 (LFA-1) positive cells in evolving allergic contact dermatitis reactions

Adhesion molecules are considered to have an important role in inflammatory reactions. We investigated the kinetics of ICAM-1 expression on keratinocytes and correlated this with the numbers of lymphocytes expressing LFA-1 in the dermis and epidermis of evolving allergic contact dermatitis reactions. In nickel-sensitive individuals, after application of a nickel patch, increased expression of ICAM-1 on keratinocytes was observed as early as 3 h and reached a maximum at 48 h. The number of lymphocytes expressing LFA-1 in the dermis and epidermis was greatest at 48 h. The LFA-1 cells were observed to be in close proximity to keratinocytes expressing ICAM-1, thus supporting the hypothesis that T-lymphocytes attach to keratinocytes via LFA-1/ICAM-1 molecules.     

Interleukin-12 alone can not enhance the expression of the cutaneous lymphocyte associated antigen (CLA) by superantigen-stimulated T lymphocytes

It has been reported that bacterial superantigens induce interleukin (IL)-12 dependent expression of the cutaneous lymphocyte associated antigen (CLA) and that this may be relevant to the association between certain skin diseases and infections including psoriasis and streptococcal tonsillitis. We have confirmed that the streptococcal pyrogenic superantigen C (SpeC) increases CLA expression by both CD4+ and CD8+ T cells when PBMCs are incubated in medium enriched with fetal calf serum (FCS). However, such an increase could not be induced in medium enriched with human serum (HS) even when recombinant IL-12 was added to the PBMCs cultures. Strikingly, CD4+ T cells incubated with SpeC in HS showed a marked reduction in CLA expression, which was not due to apoptosis. In contrast, SpeC did induce T cell proliferation and expression of CD25, CD54 and CD103 in the presence of HS indicating that the absence of SpeC induced CLA expression in HS was not due to SpeC inhibitors. Although addition of low amounts of lipopolysaccharide endotoxin (LPS) caused a highly significant increase in CLA expression in the absence of SpeC in cultures enriched with HS, a combination of LPS and SpeC did not increase CLA expression beyond that induced by LPS alone. The superantigen-induced CLA expression in FCS was partially inhibited by anti-IL-12 but not by anti-IL-18 or antibodies to transforming growth factor (TGF)-beta. It is concluded that IL-12 alone can not increase CLA expression but requires the help of other factor(s) present in FCS but not in HS. Although LPS can induce CLA expression it does not seem to be the factor that interacts with IL-12 to induce superantigen-mediated CLA expression in cultures enriched with FCS.     

Morphological and immunohistochemical characteristics of T-cell malignant lymphomas in the west of Scotland

Sixteen cases of T-cell malignant lymphoma are described. They represent the experience of a single pathology department in recent years and serve to illustrate several of the reasons why recognition of T-cell differentiation is important in the classification of lymphomas.     

Polymerase chain reaction (PCR) amplification demonstrates the absence of human T-cell lymphotrophic virus (HTLV)-I specific pol sequences in peripheral T-cell lymphomas

HTLV-I seronegative patients in nonendemic areas have been described with T-cell proliferations the DNA of which contains specific HTLV-I viral sequences. We have looked for the presence of HTLV-I DNA sequences in 27 HTLV-I seronegative patients with peripheral T-cell lymphomas, distinct from adult T-cell leukemia (ATL), and four HTLV-I seropositive patients, three with an ATL and one with a tropical spastic paraparesis. Using HTLV-I pol specific primers, the genomic DNA from peripheral blood mononuclear cells and lymph nodes massively infiltrated by tumor cells was analyzed by the enzymatic gene amplification procedure. In contrast to the peripheral blood lymphocytes from the four HTLV-I seropositive patients, the peripheral T-cell lymphoma samples did not harbor HTLV-I pol sequences. The data show that the detection of HTLV-I nucleotide sequences by the polymerase chain reaction correlates with serologic analysis in this series.     

Prognostic significance of the therapeutic targets histone deacetylase 1, 2, 6 and acetylated histone H4 in cutaneous T-cell lymphoma

Aims:  Aberrant histone acetylation has been associated with malignancy and histone deacetylase (HDAC) inhibitors are currently being investigated in numerous clinical trials. So far, the malignancy most sensitive to HDAC inhibitors has been cutaneous T-cell lymphoma (CTCL). The reason for this sensitivity is unclear and studies on HDAC expression and histone acetylation in CTCL are lacking. The aim of this study was to address this issue.
Methods and results:  The immunohistochemical expression of HDAC1, HDAC2, HDAC6, and acetylated H4 was examined in 73 CTCLs and the results related to histological subtypes and overall survival. HDAC1 was most abundantly expressed ( P  < 0.0001), followed by HDAC2; HDAC6 and H4 acetylation were equally expressed. HDAC2 ( P  = 0.001) and H4 acetylation ( P  = 0.03) were significantly more common in aggressive than indolent CTCL subtypes. In contrast, no differences were observed for HDAC1 and HDAC6. In a Cox analysis, elevated HDAC6 was the only parameter showing significant influence on survival ( P  = 0.04).
Conclusions:  High expression of HDAC2 and acetylated H4 is more common in aggressive than indolent CTCL. HDAC6 expression is associated with a favorable outcome independent of the subtype.     

Cytotoxic protein expression in natural killer cell lymphomas and in αβ and γδ peripheral T-cell lymphomas

Lymphomas with T-cell phenotype represent a heterogeneous group of diseases differing in histopathology, tumour site, and cell origin. They include peripheral T-cell lymphomas (PTCLs) derived from αβ cells, but also some recently recognized entities such as γδ hepatosplenic lymphomas and natural killer (NK) cell lymphomas. Only a few studies have investigated the possibility that at least some PTCLs could be derived from lymphocytes with cytotoxic potential. In order to investigate this possibility, 60 cases of PTCL, including 27 cases expressing the αβ T-cell receptor (TCRαβ), 15 TCRγδ cases and 18 cases expressing neither TCR (TCR silent), as well as 14 cases of NK-cell lymphomas, were studied by immunohistochemistry for the expression of TIA-1, perforin, and granzyme B proteins. Expression of TIA-1 is characteristic of cytotoxic cells regardless of their activation status, whereas expression of perforin and granzymes is highly increased in activated cytotoxic cells and correlates with the induction of cytolytic activity. All NK-cell lymphomas (11 sinonasal, three systemic cases) expressed TIA-1, perforin, and granzyme B in most tumour cells. All γδ PTCLs (15 cases) expressed TIA-1 protein in most tumour cells, with a different cytotoxic antigen profile in hepatosplenic γδ PTCL (TIA-1+, perforin−, granzyme B−) and in non-hepatosplenic γδ PTCLs (three nasal, one skin, one lung), the latter expressing the three cytotoxic proteins. Of the 45 cases of αβ and TCR silent PTCL, 15 (33 per cent) were considered to be derived from cytotoxic lymphocytes with expression of at least one cytotoxic protein (TIA-1, 15/45; perforin, 10/41; granzyme B, 14/38) in tumour cells. This cytotoxic protein expression appeared to be related to the site of localization, since 7/13 (54 per cent) extranodal and only 8/32 (25 per cent) nodal αβ and TCR silent PTCLs expressed TIA-1, and to histology, since this pattern was observed in a proportion of anaplastic (6/8, 75 per cent) and pleomorphic (8/17, 47 per cent) lymphomas, but not in AILD-type NHL (0/16). Taken together, our data suggest that NK-cell lymphomas and non-hepatosplenic γδ PTCLs represent tumours of activated cytotoxic NK cells and γδ T cells, respectively; that hepatosplenic γδ PTCLs represent tumours of non-activated cytotoxic γδ T cells; and that a small proportion of αβ and TCR silent PTCLs, mostly extranodal cases, or nodal anaplastic lymphomas, represent tumours of cytotoxic T cells. © 1997 John Wiley & Sons, Ltd.     

The ontogeny of human lymphocyte recirculation: high endothelial cell antigen (HECA-452) and CD44 homing receptor expression in the development of the immune system

In the present report we have studied the expression of a lymphocyte homing receptor, the CD44 antigen, and of HECA-452, a high endothelial-specific antigen, during the development of the human immune system. We found that prothymocyte immigrants of the thymus already expressed the CD44 antigen. Similarly, the first peripheral T lymphocytes in fetal lymph nodes, tonsils and gut-associated lymphoid tissue were also CD44+. Cortical thymocytes and germinal center cells were CD44-. CD44 antigen expression was, thus, not limited to mature recirculating lymphocytes. This suggests that CD44 may not only be involved in recirculation of mature lymphocytes but also in the migration of prothymocytes to their site of maturation, i.e. the thymus. High endothelial venules (HEV) were not demonstrable at the early onset of lymphocyte immigration into the developing lymphoid organs. However, when large-scale influx of lymphocytes occurred, it paralleled HEV development. HECA-452 antigen expression preceded the morphological transformation of endothelium into a HEV phenotype. Expression of this antigen therefore, independently reflected the specialized nature of high endothelium. In a patient with complete DiGeorge's syndrome normal HEV developed, indicating that the presence of T lymphocytes is not a requirement for HEV development. Interestingly, a subpopulation of venules located in the thymic medulla near the cortico-medullary junction expressed the HECA-452 antigen. These vessels, which had flat or intermediately high endothelium, are probably involved in lymphocyte migration to the thymus.     

上海地区正常人群中TAP多态性调查

报告一组无血缘关系的上海地区正常人中抗原处理相关转运蛋白（ＴＡＰ）的分布。在８８名正常人中共观察到３种ＴＡＰ１和４种ＴＡＰ２等位基因，其中包括罕见的ＴＡＰ２Ｈ等位基因。并将上海人群中ＴＡＰ的分布与日本人和白种人中ＴＡＰ的分布作了比较。     

Mucosal lymphocyte subsets and HLA-DR antigen expression in paediatric Helicobacter pylori-associated gastritis

Paediatric studies may provide important insights into the immunopathology of Helicobacter pylori-associated gastritis, as mucosal changes reflect different stages of the immunoinflammatory response. We characterized, by quantitative immunohistochemistry, gastric mucosal lymphocyte phenotype and HLA-DR antigen expression and evaluated correlation with histopathology, in H. pylori-infected (Hp+ve) and uninfected children (Hp-ve). In the infected group, lamina propria CD3+ and IgA plasmocyte cell numbers were significantly higher and a trend for predominance of CD8+ over CD4+ was observed both in epithelium and lamina propria. A correlation of inflammation score with lamina propria CD3+ and CD4+ cell numbers and of CD45RO+ T lymphocytes with density of colonization was observed. The proportion of epithelial cells expressing HLA-DR antigen was significantly higher in the Hp+ve group and furthermore, glandular HLA-DR expression correlated with lamina propria CD3+ cell numbers, emphasizing the potential role of epithelial cells as antigen-presenting cells at this stage of infection.     

Quantitative analysis of cell-free Epstein-Barr virus DNA in the plasma of patients with peripheral T-cell and NK-cell lymphomas and peripheral T-cell proliferative diseases

BACKGROUND: The level of circulating EBV DNA is a prognostic marker in patients with some EBV-associated malignant diseases. OBJECTIVES: To investigate the presence and nature of Epstein-Barr virus (EBV) DNA in the plasma and to evaluate the correlation of plasma concentrations of EBV DNA with the EBV genomic status in peripheral blood T-cells and neoplastic cells and with the clinical outcome of patients with peripheral T-cell and NK-cell lymphomas (PTCL) and peripheral T-cell proliferative diseases (PTPD). STUDY DESIGN: EBV DNA in the plasma of 45 patients and 45 controls was measured using real-time PCR. The presence of the EBV genome in the isolated peripheral blood lymphocytes (CD3+ and CD3- cells) was analysed by PCR. Detection of EBV-encoded early RNA (EBER) in corresponding tumor tissues was carried out using in situ hybridization. DNase I digestion was applied to plasma samples to detect naked EBV DNA. RESULTS: Cell-free EBV DNA was detected in 32/38 (84%) of PTCL patients and 5/7 (71%) of PTPD patients, but not in the controls. Patients with EBV genome in peripheral blood CD3+ cells and EBV genome (EBER) in the tumor cells, compared to those without these findings, had significantly higher plasma EBV DNA levels. The majority of circulating EBV DNA molecules was naked form. The plasma EBV DNA levels were not related to survival. CONCLUSIONS: The concentration of EBV DNA in the plasma was not a prognostic marker in PTCL and PTPD patients.     

Cutaneous lymphocyte antigen expression on human effector B cells depends on the site and on the nature of antigen encounter

In contrast to T cells, information on skin-homing B cells expressing the cutaneous lymphocyte antigen (CLA) is sparse. CLA expression on human B cells was investigated among circulating immunoglobulin-secreting cells (ISC) and among antigen-specific antibody-secreting cells (ASC) elicited by parenteral, oral or rectal primary immunization, or by parenteral or oral secondary immunization with Salmonella typhi Ty21a. CLA expression was examined by combining cell sorting with an enzyme-linked immunospot assay. Among all ISC, the proportion of CLA(+) cells was 13-21%. Parenteral immunization induced antigen-specific ASC of which 13% were CLA(+), while oral and rectal immunizations were followed by only 1% of CLA(+) ASC (p<0.001). Oral re-immunization was followed by an up-regulation of CLA (34-48%) regardless of the route of priming. Parenteral re-immunization elicited ASC of which 9-14% were CLA(+). In conclusion, the expression of CLA on human effector B cells depends on the site of antigen encounter: intestinal stimulation elicits cells with no CLA, while parenteral encounter elicits significant numbers of CLA(+) cells. Even though primary antigen encounter in the intestine failed to stimulate CLA expression, up-regulation of CLA was found upon intestinal antigen re-encounter. These findings may be of relevance in the pathogenesis of some cutaneous disorders.     

Cytokeratin and laminin immunostaining in the diagnosis of cutaneous neuro-endocrine (Merkel cell) tumours

Nine cutaneous neuro-endocrine tumours have been immunostained with monoclonal antibodies to low molecular weight cytokeratin (CAM 5.2) and neurofilament. Polyclonal antisera to neurone-specific enolase, calcitonin and laminin were also used. All nine cases showed paranuclear, dot-like positive staining with CAM 5.2 and diffuse cytoplasmic staining for neurone-specific enolase. Neurofilament and calcitonin immunoreactivity could not be demonstrated. All tumours were negative for laminin immunoreactivity. The limitations of staining for neurone-specific enolase are discussed and the value of CAM 5.2 in the differential diagnosis of cutaneous neuro-endocrine tumours is emphasized. The histogenetic implications of the absence of laminin staining are considered.     

An evaluation of the staining of lymphomas and normal tissues by the rabbit polyclonal antibody to protein gene product 9.5 following non-enzymatic retrieval of antigen

We have previously described the staining of normal follicle centre lymphoid cells by the rabbit polyclonal antibody to protein gene product 9.5 (PGP9.5), following an antigen unmasking step employing heat pretreatment. Applying this finding to a range of lymphomas to determine whether this phenomenon could have a role in identifying lymphomas of follicle centre origin revealed no relationship between type or grade of lymphoma and staining of neoplastic cells. Testing a range of normal tissues following antigen retrieval displayed increased sensitivity and a greater range of tissue positivity. Immunoblots of gel electrophoresed tonsil and brain extract were performed. Although subjecting these blots to antigen unmasking increased sensitivity, no novel epitopes, in terms of additional bands, appeared. This suggested that antibody specificity remained unaltered.     

Identification of a previously unrecognized polypeptide associated with lymphocyte function associated antigen one (LFA-1)

In lymphocyte function associated antigen one (LFA-1) preparations from metabolically labeled lymphocytes we have observed a new polypeptide component of 86-kilodalton additional to the already described - and β-chains. This chain is cosynthesized with the - and β-chains and can be covalently cross-linked with them, resulting in a three-chain complex. This complex is recognized by the H35–89.9 anti-LFA-1 monoclonal antibody. Cleveland peptide mapping analysis indicates that the new chain is structurally different from the - and β-chains of the LFA-1 complex. The chain has been observed in B-cells as well as in T-cells. Labeling properties of the 86-kilodalton chain suggest that this molecule is not exposed on the membrane.     

Skin disease-related T cells bind to endothelial selectins: expression of cutaneous lymphocyte antigen (CLA) predicts E-selectin but not P-selectin binding

Cutaneous lymphocyte antigen (CLA), defined by the HECA-452 antibody, is a cell surface glycoprotein found on a subset of T cells in peripheral blood that binds specifically to E-selectin. This marker is present on the majority of T cells at sites of cutaneous inflammation and immune responses. Based upon such evidence, an association between T cell CLA expression and skin homing has been proposed. To understand better this relationship, we asked whether putative disease-related, antigen-specific T cells expressed CLA. In this study, we employed T helper type 2 (TH2) T cell clones specific for house dust mite (Dermatophagoides pteronyssinus) antigens. These cells were derived from challenged skin of an individual known to react positively to epicutaneous challenge with this agent. In this study, we show that these cloned T cells showed very high homogeneous expression of CLA (nearly 500-fold higher than T cell clones derived from peripheral blood) and bound specifically to recombinant E-selectin. The CLA molecule on these cells was identified not only by HECA-452, but also by CSLEX-1, indicating that it contained sialyl-Le^x (S-Le^x) determinants. T cells cloned under similar conditions from peripheral blood were CLA negative or low and bound poorly to E-selectin. Surprisingly, both skin and blood clones bound comparably to P-selectin. This binding was independent of S-Le^x or CLA expression. We conclude that in sensitized individuals, antigen-specific T cells expressing high levels of CLA localize in skin promptly after epicutaneous challenge. This localization is likely to involve the interaction of S-Le^x determinants on the CLA molecule with E-selectin on the dermal microvasculature. We further conclude that T cells can interact with P-selectin on endothelium and that S-Le^x does not appear to be necessary for this interaction.