A CD4-like molecule can be expressed in vivo in human parathyroid.

The expression of several epitopes of CD4, a molecule usually restricted to a subset of T-lymphocytes, was observed after immunofluorescent labeling of frozen-cut sections of human parathyroid. Seven samples obtained from three subjects presenting adenomas and from seven renal insufficiency patients with secondary or tertiary hyperplasia were found to express this molecule. Dot enzyme-linked immunosorbent assay, polyacrylamide gel electrophoresis, and Western blotting were used to characterize this peptide in cytosol and membrane fractions of these glands. These studies confirmed, in the parathyroids found positive in immunofluorescence, the presence of a protein with a mol wt similar to that of lymphocyte-derived CD4.

Immunohistological studies of surface antigen on colonic lymphoid cells in normal and inflamed mucosa. Comparison of follicular and lamina propria lymphocytes.

Mucosal samples from 16 patients with idiopathic inflammatory bowel disease were examined immunohistologically using several monoclonal antibody combinations, and the results were compared with those obtained in other colonic inflammatory disorders and in normal mucosa. Within and around lymphoid follicles, most T cells expressed the restricted common leucocyte antigen (CD45R, displayed by unprimed T cells). Conversely, most lamina propria T cells were negative for CD45R but stained positively with UCHL1 (a monoclonal antibody recognizing an antigen displayed by primed T lymphocytes). The proportions of T-lymphocyte subpopulations in normal and inflamed mucosa were similar, except that CD6-negative, CD7-positive cells were significantly more frequent in inflammatory bowel disease. A characteristic feature of ulcerative colitis and Crohn's colitis was marked infiltration by CD45R+ lymphoid cells that did not coexpress T- or B-cell surface antigens; some stained positively with plasma cell reagents, suggesting that they may be activated B cells. The observations in the colitis sections are consistent with the interpretation that T and B cells alter their surface antigen expression as they emerge from follicles and enter the inflamed lamina propria.

Molecular analysis of T cell receptor and CD3 genes in CD3- large granular lymphocytes (LGLs): evidence for the existence of CD3- LGLs committed to the T cell lineage.

Seven patients with CD3- lymphoproliferative disorder of granular lymphocytes (LDGL) were analyzed for rearrangement of the T cell receptor (TCR) delta and alpha as well as gamma and beta genes. Among those patients six showed the germline configuration of all known rearranging TCR genes. Two analyzed patients of them lacked CD3-gamma transcripts and expressed nonfunctional TCR-beta transcripts. Meanwhile, TCR-delta gene rearrangement accompanied by expression of full-length TCR-delta transcripts was observed in one patient with CD3- LDGL. In addition, the cells from this patient transcribed the CD3-gamma gene which is one of the earliest events restricted to cells committed to the T cell lineage. These findings indicate that CD3- LGLs include not only cells belonging to the NK cell lineage but also precursor cells committed to the T cell lineage.

cAMP regulation of IL-2 receptor expression. Selective modulation of the p75 subunit.

As previous experiments have shown that IL-2 activity is abrogated by cAMP, its effect on IL-2R expression by normal and leukemic T lymphocytes was evaluated in detail. The exposure of murine or human T cells to dibutyryl cAMP or the cAMP-elevating drug, forskolin, resulted in a decrease in high affinity IL-2 binding. Equilibrium binding analyses revealed that elevation of cAMP for 4 to 5 h produced a 40 to 50% decrease in the number of detectable receptors, whereas the affinity of the IL-2R interaction remained unchanged. The effect of cAMP could be attributed to a selective effect on the 75-kDa chain of the IL-2R (p75) subunit of the 55-kDa chain of the IL-2R/p75 heterodimer. The mechanism for the decreased expression of high affinity IL-2R appears to be due to a dual effect of cAMP, which functions to both increase the rate of IL-2R internalization, and to decrease the rate of expression of new receptors. Moreover, the effect of cAMP on IL-2 binding to p75 subunits is post-transcriptional, because the steady state levels of p75 mRNA expression are not altered within a time interval that produced nearly a 50% reduction in p75 binding.

Local infiltration of T-lymphocyte subsets as a prognostic indicator in patients with nasopharyngeal carcinoma.

We studied tumor-host interactions in 47 patients with NPC. The local infiltration of T-lymphocyte subsets was investigated by an immunoperoxidase technique using monoclonal antibodies. Biopsy specimens of patients without cervical metastasis showed more T-lymphocyte (T11) infiltration. The amount of Leu-3a (helper/inducer) and T8 (cytotoxic/suppressor) cell infiltration did not correlate with the age, sex, clinical stage, and peripheral blood T4 and T8 cells of the patients. A higher incidence of Leu-3a cell infiltration was found in patients with high serum IgA antibody titers to EBV VCA. A trend of better prognosis was revealed in those cases with no or slight stromal T8 cell infiltration. A local immune response was found to exist which may prevent the spread of NPC to the cervical nodes, but this needs further study to evaluate the local infiltration of T-lymphocyte subsets as a prognostic indicator.

Detection in non-erythroid cells of a factor with the binding characteristics of the erythroid cell transcription factor EF1.

The erythroid transcription factor erythroid factor-1 (EF1) plays a critical role in the transcription of erythroid-specific genes. Here we report the presence of a factor with the mobility and sequence-specific DNA-binding characteristics of EF1 at low abundance in a wide variety of non-erythroid cell types. This is the first report of an EF1-like activity in non-erythroid cells and indicates that this factor may play a role in the regulation of genes expressed in such cells.

Immune activation and autoantibodies in humans with long-term inhalation exposure to formaldehyde.

Four groups of patients with long-term inhalation exposure to formaldehyde (HCHO) were compared with controls who had short-term periodic exposure to HCHO. The following were determined for all groups: total white cell, lymphocyte, and T cell counts; T helper/suppressor ratios; total Ta1+, IL2+, and B cell counts; antibodies to formaldehyde-human serum albumin (HCHO-HSA) conjugate and autoantibodies. When compared with the controls, the patients had significantly higher antibody titers to HCHO-HSA. In addition, significant increases in Ta1+, IL2+, and B cells and autoantibodies were observed. Immune activation, autoantibodies, and anti-HCHO-HSA antibodies are associated with long-term formaldehyde inhalation.

Nonneoplastic and nonhyperplastic thymus in myasthenia gravis. An immunohistochemical study with double immunoenzymatic labeling of basement membrane and cellular components.

Histologically normal thymus (type A) in patients with myasthenia gravis (MG) was immunohistochemically compared with hyperplastic MG thymus (type B) and normal non-MG thymus. In formalin-fixed, paraffin-embedded sections of ten type A, ten type B, and eight non-MG cases, the thymic epithelium and other cellular components were stained in conjunction with the basement membrane by a double immunoenzymatic method. This technique demonstrated a moderate architectural disturbance in type A thymus, with distended perivascular space (PVS), elongated medullary epithelium, and disrupted basement membrane. These changes were more prominent in type B thymus but were minimal to lacking in non-MG thymus. Compared with those in non-MG thymus, the myoid cells in MG thymuses of both types tended to cluster around the Hassall's corpuscles, with a slight decrease in number in type B but not in type A. B-lymphocytes were present in type B, type A, and non-MG thymuses in that order of abundance; the cells were confined to the medullary parenchyma in the non-MG group but were numerous both in the PVS and medulla in the MG groups. T-lymphocytes were increased in the expanded PVS of type A and B MG thymuses. The number of interdigitating reticulum cells was similar in the three groups, but the cellular distribution was more dispersed in MG thymuses of both types. These findings, although previously described in type B thymus, have not been well recognized in type A thymus. They support the view that a common abnormality (presumably chronic thymitis), differing in degree only, underlies MG thymuses regardless of the presence of follicular hyperplasia.

Lamins A and C are not expressed at early stages of human lymphocyte differentiation.

Lamins are major proteins of the nuclear envelope that are members of the intermediate filament protein family. In vertebrates, nuclei from differentiated tissues usually contain both lamins of the A and B subtypes, while embryonic tissues contain the B-type lamin only. We have examined the composition of the nuclear lamina in human B and T lymphocytes representative of distinct stages of lymphoid differentiation. We show here that, in both cell lineages, while lamin B is constitutively expressed at all stages of differentiation, A-type lamin expression is restricted to later developmental stages.

Distribution of lymphocytes bearing TCR gamma/delta in cutaneous lymphocytic infiltrates.

A monoclonal antibody to the recently characterized T lymphocyte expressing a T cell receptor bearing gamma and delta chains (TCR gamma/delta) was applied to 60 biopsy specimens spanning a wide range of diagnoses and containing a variable number of T lymphocytes. TCR gamma/delta+ cells were not enriched in the tissues examined, representing between 0-5% of the total CD3 positive T lymphocyte population. TCR gamma/delta+ cells were identified in 27 cases (45%). The distribution of the TCR gamma/delta-bearing cells was remarkable for preferential stratification at upper cutaneous levels, within the epidermis and papillary dermis in some cases of mycosis fungoides. Benign infiltrates lacked a similar pattern. The role of TCR gamma/delta+ cells is uncertain. The data do not reveal a consistent number or distribution of these cells in cutaneous infiltrates.

Interaction of cellular proteins with the human T-cell leukemia virus type I transcriptional control region. Purification of cellular proteins that bind the 21-base pair repeat elements.

Nuclear extracts of cultured human cells contain multiple proteins that recognize specific sequence elements within the transcriptional control region of the human retrovirus, human T-cell leukemia virus type I (HTLV-I). Here we report the purification of host expression factor 1T (HEF-1T), a DNA-binding protein from human T-lymphocytes that binds to each of the three 21-base pair repeat enhancer elements in the proviral long terminal repeats of HTLV-I and the related virus, HTLV-II. HEF-1T is composed of two polypeptides of 41 and 59 kDa. We show that HEF-1T is distinct from a second protein, present in non-lymphoid cells, that binds to overlapping sites in and near the 21-base pair repeats. This second protein is composed of a single 47-kDa polypeptide and appears to be identical to the previously described transcription factor AP-2. A third protein, also distinct from HEF-1T, binds within the first repeat. The present results suggest that there may be multiple modes of HTLV-I promoter recognition involving distinct sets of cellular proteins.

Variation in the composition of gingival inflammatory cell infiltrates.

Biopsy specimens were taken at gingivectomy from 18 adult patients undergoing treatment for chronic marginal periodontitis. They were embedded so that the cut surface of the gingiva was parallel to the top of the block to obtain a comprehensive view in a transversal plane of the inflammatory cell infiltrate near the bottom of the pocket. Sections were stained with HES or with toluidine blue for histological description, and acid alpha-naphthyl acetate esterase (ANAE) was used to differentially stain T lymphocytes, plasma cells and monocytes/macrophages. Sections stained with HES showed that the density and size of the cell infiltrates varied along the circumference of a tooth over very short distances and on various surfaces on neighbouring teeth. Differential counts of cells stained for ANAE demonstrated great variation in the composition of the cell infiltrates, particularly along the pocket epithelium. The predominating ANAE positive cell type in this area was T lymphocytes, while in the central connective tissue, plasma cells predominated. There was no systematic covariation between the localization of the gingiva (i.e. mesial, facial, etc.) and the composition of the cell infiltrates. The local variation in the composition of the cellular infiltrate most likely reflects local variability in the noxious substances (i.e. plaque composition) within the periodontal pocket, and in the resulting local inflammatory response.

Characterization of peripheral blood and salivary gland lymphocytes in Sjögren's syndrome.

Primary Sjögren's syndrome (SS) is an autoimmune disease resulting from lymphocyte infiltration of lacrimal and salivary glands (SG). This study was designed to investigate the peripheral blood (PBL) and SG lymphocytes in 14 patients with primary SS and control subjects. With the use of monoclonal antibodies, cells were stained to identify T-cells and T-cell subsets (T-helper and T-suppressor) and cells positive for HLA-DR antigen, whereas B cells were determined by the Smlg (surface membrane immunoglobulin) method. Lymphocytes in SG biopsy specimens were characterized by means of monoclonal antibodies and the immunoperoxidase technique. In the peripheral blood lymphocytes, there was a significant reduction in T cells and suppressor T cells. T lymphocytes and mostly helper T cells were predominant around the ducts and within the lymphocytic infiltrates in the minor SG biopsy samples of patients with SS. Suppressor T cells and B cells were found in fewer numbers, HLA-DR(+) cell populations had increased, and IgG- and IgA-bearing plasma cells were also present within the infiltrates. These results may contribute to our understanding of the immunopathogenesis of primary SS.

T cell receptor-bearing cells among rat intestinal intraepithelial lymphocytes are mainly alpha/beta+ and are thymus dependent.

Rearrangement of both the beta and gamma chain T cell receptor (TcR) genes was detected in intestinal intraepithelial lymphocytes (IEL) from normal euthymic rats. Flow cytometric analyses showed that about 73% of the IEL were CD3+ (1F4) and that 67% were TcR alpha/beta+ (R73). About 5% of the IEL were found to be CD3+, TcR alpha/beta- in double-labeling experiments suggesting that a small fraction of IEL in the rat express the alternative TcR gamma/delta. More than 70% of the IEL were granular implying that many CD3+ IEL are granular. In IEL from athymic nude rats no rearrangement of either the TcR beta or gamma chain genes or surface expression of CD3 or TcR alpha/beta was detected despite the fact that about 95% of the cells were granular and morphologically similar to those in normal rats. Taken together our data suggest that the majority of IEL in the rat express the conventional TcR alpha/beta and that TcR-bearing cells in the gut epithelium are thymus dependent.

Flow cytometry resonance energy transfer suggests an association between low-affinity interleukin 2 binding sites and HLA class I molecules.

Using flow cytometry energy transfer we have studied the sterical proximity of interleukin 2 receptors and the heavy chain of the major histocompatibility complex at the surface of normal lymphocytes. Our data suggest that class I molecules may be part of a low-affinity interleukin 2 receptor multimolecular complex, where the MHC class I heavy chain is in close proximity to the actual interleukin 2 binding site, in contrast to the light chain (beta 2-microglobulin).

Cell-type-specific control elements of the lymphotropic papovavirus enhancer.

Lymphotropic papovavirus (LPV) exhibits a highly restricted host range, in which only cells of primate B-lymphocyte origin are permissive for infection. Its enhancer element contributes to this tropism, since transcriptional potentiation is confined to cells of the hematopoietic lineage. Nuclear extracts from B and T cells, but not from HeLa cells, contain protein factors that interact specifically with the LPV 63-base-pair enhancer repeat, as demonstrated by DNase I footprinting and gel retardation experiments. Within the repeat three sequence motifs were identified: the core motif, the Pu box, and a novel element named T motif. Functional analysis demonstrated that these motifs as well as some sequences upstream of the repeat contribute to the optimal activity of the enhancer. There are clear differences between the patterns of binding of the B and T lymphocyte nuclear proteins to the enhancer which are also reflected in the transcriptional activity of the enhancer in both cell types. Furthermore, the activity of the LPV enhancer and its interaction with nuclear proteins seem to be regulated during B-cell differentiation.