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Biomedical subjects

F Spinozzi

Publications and source records attributed to F Spinozzi.

At least 91 records · Page 5Linked to original sources

Activation of cord T lymphocytes. I. Evidence for a defective T cell mitogenesis induced through the CD2 molecule.

A study was carried out on cord blood T cell activation via the CD2-mediated pathway. Despite similar percentages of circulating CD3+ and CD2+ cells in adult and cord blood, the proliferation of cord PBMC to the anti-CD3 mAb and cord T cells to anti-CD2 mAb were defective. The T cell CD3-surface structure was normally able to control CD2-mediated activation, as its modulation by a non-mitogenic anti-CD3 mAb blocked cord PBMC proliferation induced by anti-CD2 mAb. CD2-stimulated cord T cells did not proliferate and did not produce a significant amount of IL-2 in culture, although they expressed the IL-2R. This observation was confirmed by the optimal proliferation of CD2-induced cord T cells when rIL-2 was added. Despite the alternative T cell activation pathway is monocyte-independent in adults, the defective cord T cell activation via the CD2 molecule could also be bypassed by the addition of PMA, small amounts of either autologous or allogeneic adult and cord AC or simply rIL-1 alone. Our findings provide evidence for an intrinsic functional defect in cord CD2-mediated T cell activation, which is linked to an impaired increase of free cytoplasmic calcium, as confirmed by the effectiveness of calcium ionophore A23187 in restoring a good CD2-induced cord T cell proliferation and by measurement of cellular calcium uptake after activation via the CD2 molecule. The characteristics of cord T cells revealed by this study recall the thymocyte functional pattern and may represent functional expression of the previously described phenotypic immaturity of cord T cells.

Antibodies, Monoclonal↗

X-ring Turner's syndrome with combined immunodeficiency and selective gonadotropin defect.

A rare association of chromosomal, immunological and endocrine defects is described in a young woman with short stature, recurrent pulmonary infections and primary amenorrhea. Cytogenetic studies showed a 45, X karyotype in 65% of peripheral blood lymphocytes and 46,Xr(X) (p22q27) karyotype in the remaining 35%. Severe immunodeficiency was revealed by phenotypical and functional studies and a selective gonadotropin defect was disclosed by endocrinological investigations. An attempt is made to explain the coexistence of the three abnormal pictures.

Adult↗

Helper inducer T cells in the lungs of sarcoidosis patients. Analysis of their pathogenic and clinical significance.

Phenotypic analysis of helper CD4+TQ1- cell population, the major helper T-cell subset for B-cell responses, was carried out in BAL fluid of sarcoidosis patients. Most of the BAL CD4+ cells lacked TQ1 membrane antigen. A correlation between the number of helper CD4+TQ1- cells and IgM and IgA levels was observed in 27 sarcoidosis patients' BAL. A role of CD4+TQ1- cells in modulating lung B-cell immunoglobulin secretion in sarcoidosis was confirmed by the fact that BAL IgG level and helper T-cell number correlated well in patients with low-intensity alveolitis. Results showed an inverse correlation between symptom duration and BAL IgM levels and CD4+TQ1- cell number. The number of helper cells was above normal in patients who had symptoms for less than 12 months and within normal range in those who had symptoms for more than that. The pathogenic and clinical relevance of these data is discussed.

Adult↗

Analysis of CD4-positive T cell subpopulation in sarcoidosis.

Double-labelling immunofluorescence analysis within the CD4+ cell subset was carried out in 27 bronchoalveolar lavage fluids and 11 peripheral blood samples of sarcoidosis patients with anti-TQ1, anti-2H4 and anti-4B4 monoclonal antibodies. Helper/inducer CD4+TQ1-/4B4+ cells were strongly increased in the lung and slightly, but significantly, decreased in the blood of sarcoidosis patients with respect to normal controls. No differences were found in the number of both lung and blood CD4+2H4+ cells between sarcoidosis patients and controls. The findings are further evidence for a compartmentalization of T cell subsets in sarcoidosis.

Adult↗

Phenotypic and functional abnormalities of T lymphocytes in pathological hyperprolactinemia.

The phenotype and function of T cells circulating in patients with pathological hyperprolactinemia were analyzed and compared to those in sex- and age-matched control subjects. Two-color immunofluorescence study revealed an increased number of CD4+ TQ1+ cells and the presence of phenotypically immature CD1+ T cells, also exhibiting transferrin surface receptor, in peripheral blood of the hyperprolactinemic patients. After chronic treatment with the dopamine agonist bromocriptine, T-cell abnormalities disappeared. In addition, some untreated patients showed enhanced T-cell suppressor activity in an in vitro pokeweed mitogen-driven B-cell transformation assay. These immunological findings confirm a link between neuroendocrine and immune systems in humans.

Antigens, Differentiation, T-Lymphocyte↗

Thymic hormone modulation of CD38 (T10) antigen on human cord blood lymphocytes.

We studied the in vitro effect of three different thymic factors on the expression of CD38 (T10) antigen on cord T-lymphoid cell surface. The results showed that cord mononuclear cell populations contain variable percentages of CD38+ cells. The CD38 molecule was expressed on cord T and B lymphocyte and monocyte surfaces. Incubation with thymic agents induced a significant increases in the CD38+ cell percentage only in the samples with low CD38 antigen expression, and this modulation was mainly attributable to the T-cell subset. The effect seems to be specific and not correlated with the known high spontaneous DNA synthesis rate of cord mononuclear cells.

ADP-ribosyl Cyclase↗

Immunoregulatory T cells in alcoholic liver disease: phenotypical dissection of circulating Leu3+/T4+ inducer T-lymphocytes.

Alcoholic liver disease (ALD) patients had normal absolute lymphocyte counts, increased percentage of Leu3+/T4+ cells (p less than 0.001) and raised T4/T8 ratio (p less than 0.01). Double-colour immunofluorescence analysis using isotype-specific goat anti-mouse immunoglobulins, fluorescein or rhodamine-conjugated, demonstrated that the rise in inducer (Leu3+/T4+) T-cells was almost entirely represented by an expanded population of T4+TQ1- and 5/9+ true helper lymphocytes. T4+ cells also expressed IL2 receptors, as detected by the anti-Tac monoclonal antibody (range 1-18%). On the other hand, the percentage of Leu3+/T4+ cells which bind the K562 cell-line or co-express NK markers on their surface, such as Leu7 (HNK-1), was within the normal range in the majority of ALD patients. Functional studies on patients' cultured total or B-enriched lymphocytes in a pokeweed-mitogen-driven B-cell differentiation assay showed an enhanced plasma cell generation even in unstimulated cultures. Co-culture experiments with normal enriched-B lymphocytes demonstrated that both irradiated and non-irradiated patient T cells led to an increased plasma cell generation. These findings indicate that helper T cells and B cells are all simultaneously activated in vivo, and that the suppressor T lymphocyte function is normal in ALD.

Adult↗

Immunologic studies of peripheral blood from patients with idiopathic dilated cardiomyopathy.

Immune function, T-lymphocyte subsets, serum quantitative immunoglobulin levels, serum lysozyme levels, and circulating immune complex levels were analyzed in patients with idiopathic dilated cardiomyopathy (IDCM). The percentage of helper/inducer T cells (OKT4) was higher and the percentage of suppressor/cytotoxic T cells (OKT8) was lower in IDCM patients than in healthy controls and in patients with ischemic heart disease. IDCM patients, in addition, have higher 5/9+ T cells, a T-cell subset known to give maximal helper activity in B-cell differentiation assays. Peripheral blood mononuclear cells (PBMC) from IDCM patients demonstrated a statistically greater ability to induce B-cell differentiation (helper T-cell function) into plasma cells and a hypofunctioning suppressor T-cell population in an in vitro pokeweed nitrogen (PWN)-driven B-cell differentiation assay. Serum immunoglobulin IgM levels were higher in IDCM patients, but serum lysozyme levels and serum immune complex levels in IDCM patients were normal. These data verify that an immunoregulatory defect exists in IDCM.

Adult↗

Phenotypic dissection of cord blood immunoregulatory T-cell subsets by using a two-color immunofluorescence study.

Expression of TQ1(Leu8) and 2H4 antigens on human cord blood T-cell subsets was evaluated by a double immunofluorescence analysis. In normal adult blood all of the helper function for B-cell differentiation is confined to the smaller OKT4+TQ1-(Leu8-) cell subset, while the OKT4+TQ1+(Leu8+) cell subpopulation includes a subset of suppressor inducer 2H4+(JRA+) cells. Our results indicated that the OKT4+TQ1-(Leu8-) cell subpopulation was decreased and the reciprocal OKT4+TQ1+(Leu8+) cell subset was markedly increased in cord blood E-rosetting OKT3+ cell population. A rise in the number of cord OKT4+2H4+ cells was also found. In addition, TQ1 antigen was present on OKT3+E-, a less mature, cord T-cell subset, not present in adult blood. These findings may not only be of help in understanding lymphoid cell development during ontogeny, but also may agree with the reported strong-suppressor and weak-helper activities exerted by the T-cell subsets circulating in human cord blood.

Adult↗

Immunological studies in patients with alcoholic liver disease: evidence for the in vivo activation of helper T cells and of the monocyte-macrophage system.

Immunologic parameters were evaluated in 22 patients with alcoholic liver disease (ALD). Patients with ALD had increased levels of circulating immune complexes (CIC) and serum immunoglobulins, particularly IgA. The classical complement pathway was preferentially activated in CIC-positive patients. There was no increase in total lymphocyte or total T lymphocyte counts, but a significant rise in both the helper/inducer population (OKT4) and helper/suppressor cell ratio (T4/T8) was noted. The presence of interleukin-2 receptors and HLA-DC/DS and HLA-DR antigens suggested in vivo activation of ALD patients' T cells. The rate of differentiation of B cells to plasma cells was high in both pokeweed mitogen-stimulated and unstimulated cultures of ALD patients' B cells, whereas plasma cell generation doubled when patient T lymphocytes were added to enriched normal B cells. The above data support a role for activated helper (T4+) T cells in the immune response initiated by alcoholic hepatitis. Serum angiotensin-converting enzyme levels and lysozyme levels were increased in ALD patients, and cultured adherent mononuclear cells from ALD patients secreted more lysozyme in vitro than normal cells, suggesting the presence of an activated monocyte-macrophage system in ALD.

Adult↗

Phenotypic heterogeneity within the circulating human neonatal T4-positive T cell subset.

An indirect immunofluorescence staining technique was employed to evaluate the TQ1 and 5/9 monoclonal antibody lymphocyte reactivity in 10 cord blood mononuclear cell (MC) preparations enriched of E-rosette-forming cells (E+). Ten adult E+ MC populations were used as controls. Unfractionated T4+ cord and adult MC positively selected by panning procedure were also assayed. The results of these experiments, taken together, suggest that there is an overexpanded neonatal T cell subset which displays a previously unrecognized immunophenotype (T4+, TQ1+, 5/9+). Whether these lymphocytes are involved in the wellknown fetal-maternal immunosuppressive mechanisms of whether they are a further example of neonatal phenotypic immaturity remains to be elucidated.

Adult↗

Catecholamines and pituitary function. IV. Effects of low-dose dopamine infusion and long-term bromocriptine treatment on the abnormal thyrotroph (TSH) dynamics in patients with pathological hyperprolactinaemia.

In order to gain further insight into the role of dopamine (DA) in the control of TSH release and to investigate whether an increased or defective DA inhibition on pituitary thyrotrophs may be considered responsible for the abnormal TSH dynamics in pathological hyperprolactinaemia, we examined the effect of low-dose DA infusion on TRH stimulated TSH secretion in normally cycling women and in patients with pathological hyperprolactinaemia. The effect of long-term bromocriptine therapy on TSH dynamics was also evaluated in a selected group of hyperprolactinaemic women. Fifty-two hyperprolactinaemic patients with no other signs of pituitary or thyroid dysfunction had significantly higher mean TSH serum concentrations and mean TSH peak values after TRH administration than 75 healthy controls. Furthermore, the TSH rises induced by the DA-synthesis inhibitor alpha-methyl-p-tyrosine (AMPT, 500 mg orally) were enhanced in both prolactinoma and 'idiopathic hyperprolactinaemia' patients as compared with controls. There was a positive correlation between the TRH- and AMPT-induced TSH rises in the hyperprolactinaemic group. Low-dose DA infusion (0.1 microgram/kg X min) reduced TSH response to TRH in both regularly cycling women and patients with hyperprolactinaemic amenorrhoea. Longterm bromocriptine therapy (2.5 mg tid over 60-150 days) not only normalized serum Prl levels, but also reduced the TSH response to TRH in 7 hyperprolactinaemic women who had presented exaggerated TSH responses to the basal TRH test.(ABSTRACT TRUNCATED AT 250 WORDS)

Bromocriptine↗

Acute infectious lymphocytosis: phenotype of the proliferating cell.

A case of acute infectious lymphocytosis in an otherwise healthy 2-year-old child is reported. Marker analysis of the expanded blood lymphocytes showed that they were predominantly T cells and that there was a considerable increase in the helper/inducer phenotype (OKT4+) population. However, the lymphocyte response to polyclonal T-cell activators was low. This is the first report on T-cell subset distribution in acute infectious lymphocytosis.

Acute Disease↗

Sézary's syndrome: a case with blood T-lymphocytes of helper phenotype, elevated IgE levels and circulating immune complexes.

A patient with Sézary's syndrome is described. Surface marker analysis of her peripheral blood lymphocytes exhibit a phenotype characteristic of mature helper T cells (OKT3+, OKT4+, OKT8-, OKT6-). Serological studies revealed a polyclonal hyperimmunoglobulinemia with large amounts of IgE and IgA and circulating immune complexes that activate the complementary system via alternative pathway. The patient's cells showed a helper activity on normal B cell differentiation after a 7-day co-culture with pokeweed mitogen. The relevance of this helper phenotype and the function on in vivo polyclonal B cell activation is discussed.

Aged↗

Monoclonal antibody-defined T-cell phenotypes and phytohemagglutinin reactivity of E-rosette-forming circulating lymphocytes from untreated chronic myelocytic leukemia patients.

T-cell phenotypes, as defined by murine monoclonal antibodies, (OKT3, OKT4, OKT8, OKIa1), and phytohemagglutinin (PHA) reactivity, were evaluated in E-rosette forming cells (T-cells) from 10 untreated chronic myelocytic leukemia patients. The proportion of T4+ cells was lower in patients than in controls (41.6 versus 61.7%, P less than 0.02); whereas the proportion of T8+ cells was similar in patients and controls. The decrease in T4+ cells in CML resulted in a decrease in circulating T4+/T8+ ratio (P less than 0.02). The Ia1+ T-cells were increased in most CML (8 of 9) patients, while control subjects never displayed Ia1+ T-lymphocytes (P less than 0.01). The PHA reactivity of E-rosette forming lymphocytes was significantly impaired in CML patients with respect to controls (P less than 0.02). The presence of Ia antigen on T-cells was positively correlated with the T8+ cell phenotype (P less than 0.001) and inversely correlated with the T4+ (helper) cell phenotype (P less than 0.05). Furthermore, there was a trend towards an inverse correlation between the PHA response and the level of Ia1+ or T8+ cells, there is no correlation between PHA reactivity and T4+ phenotype. The results suggest that the T-lymphocyte population from untreated CML patients is intrinsically abnormal.

Adult↗

A mature thymocyte-like phenotypic pattern on human cord circulating T-lymphoid cells.

Cord blood samples from healthy full-term newborns were tested with antimature and antiimmature lymphoid-cell monoclonal antibodies, as well as more traditional markers, in order to identify the phenotype of circulating precursor cells. The results demonstrated that human cord blood contains a lower number of OKT3+, E-rosetting mature T cells than adult blood, very high levels of OKT10+ cells, and few OKT9+, OKT8+ OKT3-, and OKT4+ OKT3- cells. Although the finding of OKT9+ and OKT10+ cord circulating cells could be indicative of cell activation, double marker studies in newborn blood pointed to phenotypically immature lymphoid subsets at different stages of maturation, according to Reinherz's hypothesis. In addition, the absence of nuclear Tdt-positive and hot-rosetting cells, together with the fact that most of these are OKT3+, OKT10+, OKT4+, or OKT8+ cells, suggests that the surface phenotype of newborn lymphocytes is similar to that of mature thymocytes.

Antibodies, Monoclonal↗