PubMed Health⌕ Search

Biomedical subjects

C Agostini

Publications and source records attributed to C Agostini.

At least 19 recordsLinked to original sources
PubMed1992

Release of granulocyte-macrophage colony-stimulating factor by alveolar macrophages in the lung of HIV-1-infected patients. A mechanism accounting for macrophage and neutrophil accumulation.

In this paper, the release of granulocyte-macrophage colony-stimulating factor (GM-CSF) in the lung of patients with HIV-1 infection was evaluated. This cytokine has well recognized effects on granulocyte and macrophage growth and differentiation and plays some role in the mechanisms leading to the accumulation of alveolar macrophages (AM) in patients with interstitial lung disease. Detectable levels of GM-CSF (up to 10 pg/ml) were demonstrated in unconcentrated bronchoalveolar lavage fluid retrieved from HIV-1-seropositive patients, thus suggesting that the GM-CSF is released in vivo in the lung during HIV-1 infection. A statistically significant correlation was demonstrated between the bronchoalveolar lavage concentrations of GM-CSF and the absolute numbers of AM and lung neutrophils. Cell-free supernatants obtained from unstimulated 24-h cultured AM isolated from HIV-1-infected patients contained discrete amounts of GM-CSF, as demonstrated by an immunoenzymatic assay. AM lost the capability of releasing GM-CSF after 72 h of culture, thus suggesting that the production of GM-CSF is not constitutive in AM. After exposition of AM with LPS, the release of GM-CSF and the expression of its mRNA significantly increased with respect to the baseline values; interestingly, the amount of GM-CSF released by LPS-stimulated AM was more than 10-fold higher in HIV-1-infected patients than in healthy subjects. As demonstrated by flow cytometry analysis, more than 70% of freshly isolated AM efficiently bound phycoerythrin-GM-CSF, thus indicating that they express the receptor for GM-CSF. Determination of AM in G1, S, and G2+M by flow cytometry showed that, after 48 h of culture with GM-CSF, 5.5 to 7% of AM entered the proliferative phase of the cell cycle. Taken together, these findings suggest that AM might represent an important source of GM-CSF production in HIV-1 infection. In particular, the hypothesis is formulated that pulmonary opportunists might trigger AM to synthesize GM-CSF in situ. The local overproduction of this cytokine is likely to play a role in the pathogenic events leading to the local proliferation of AM and recruitment of neutrophils in AIDS-associated interstitial lung disease.

AIDS-Related Complex↗
PubMed1992

Role of tumor necrosis factor-alpha and its specific 55-Kd and 75-Kd receptors in patients with lymphoproliferative disease of granular lymphocytes.

The role of tumor necrosis factor-alpha (TNF-alpha) in the development of in vitro proliferative and cytotoxic abilities of granular lymphocytes (GL) in patients with lymphoproliferative disease of GL (LDGL) has been investigated. To this aim, taking advantage of the recent generation of specific monoclonal antibodies (MoAbs) reacting with the p55 and p75 TNF receptors (TNF-R) (htr-9 and utr-1 MoAb, respectively), we evaluated the expression and the functional role of each TNF-R in freshly isolated highly purified GL from a series of 10 LDGL patients (six CD3+ T-lineage GL and four CD3- natural killer [NK]-lineage GL). The expression of TNF-alpha transcripts and the release of TNF-alpha in the culture medium at resting conditions and following cell activation were also studied. Our data indicate that at resting conditions both CD3+ and CD3- GL express only the p75 TNF-R. Accordingly, a specific inhibition of phycoerythrin (PE)-conjugated TNF-alpha binding was demonstrated by the anti-p75 TNF-R utr-1 MoAb, but not by the anti-p55 htr-9 MoAb. Following activation with interleukin-2 (IL-2), anti-CD3, or anti-CD16 MoAbs, an increased expression of the p75 TNF-R and a slight induction of the p55 TNF-R was observed. Weak expression of specific TNF-alpha transcripts was detected at resting conditions and on unstimulated cells, whereas both IL-2 or anti-CD3 MoAb induced TNF-alpha mRNA. Under these in vitro conditions, detectable amounts of this cytokine were demonstrated in the culture supernatant of GL. The cytotoxic and proliferating activities mediated by IL-2 or anti-CD3 MoAb were dampened by anti-TNF-alpha antibody, suggesting a role for endogenous TNF-alpha in these functions. Both utr-1 and htr-9 MoAbs showed a moderate inhibition of proliferative activity, whereas cytotoxicity was not reduced. Taken together, our results suggest that TNF-alpha plays a role in the mechanisms leading to CD3+ and CD3- GL in vitro activation in patients with LDGL.

Aged↗
PubMed1992

Expression and functional role of the p75 interleukin 2 receptor chain on leukemic hairy cells.

Hairy cell leukemia is a chronic lymphoproliferative disorder characterized by the expansion of neoplastic B-cells expressing the p55 chain of the interleukin 2 receptor (IL-2R) system that is recognized by anti-CD25 monoclonal antibodies (mAb) and binds interleukin 2 (IL-2) with low affinity. In the present study we investigated leukemic hairy cells (HC) for the presence of the p75 IL-2R chain which binds IL-2 with intermediate affinity and plays a crucial role in transducing the message to the cell. For this purpose, we tested highly enriched leukemic HC from six hairy cell leukemia patients for the presence of IL-2R transcripts and for the expression of the p55 and p75 IL-2R chains on their surface membrane by flow cytometry and immunoprecipitation analyses. The functional role of IL-2 in the regulation of HC proliferation was also investigated. Our results indicate that freshly isolated HC express detectable messages for both the p75 IL-2R and the p55 IL-2R. Flow cytometry analysis demonstrated detectable levels of p75 IL-2R on the HC from all patients tested. A mixture of two specific mAb was able to immunoprecipitate detectable amounts of p75 IL-2R from leukemic HC. When leukemic HC were cultured in the presence of several concentrations of IL-2 a low proliferative response was observed. Moreover, the IL-2-driven proliferation of HC was markedly inhibited by anti-p75 IL-2R mAb and to a lesser extent by anti-p55 IL-2R mAb. These findings provide direct evidence of the expression of different IL-2 receptors on leukemic HC and suggest that these molecules might play a role in leukemic cell growth.

Adult↗
PubMed1992

Expression of a functional p75 interleukin-2 receptor on lung lymphocytes from patients with human immunodeficiency virus type 1 (HIV-1) infection.

Lung involvement in patients affected by HIV-1 infection is characterized by an alveolitis sustained by the accumulation of CD8+ T lymphocytes. To investigate whether in situ T cell growth plays a relevant role in the pooling of CD8+ lymphocytes, we have analyzed the activity of two lymphokines involved in the mechanisms of T cell proliferation, i.e., interleukin-2 (IL-2) and interleukin-4. To this aim, following appropriate triggering and blocking, the expression and the functional role of IL-2 receptors (IL-2R) (both p55 and p75 chains) and IL-4 receptors have been analyzed on T lymphocytes obtained from the bronchoalveolar lavage (BAL) of 16 HIV-1+ patients. Molecular and phenotypic studies we performed demonstrated that CD8+ lymphocytes from the BAL of HIV-1 + patients strongly expressed the p75 chain of IL-2 receptor, while neither p55 mRNA nor its surface membrane product (Tac antigen) was detectable; in addition, there was no expression of IL-4 receptors. IL-2 stimulation was able to induce T cell growth in a dose-dependent manner, whereas IL-4 did not. Finally, using mAbs which specifically block the p55 or p75 IL-2R, we showed that both subunits of IL-2R were involved in the proliferative activity of lung lymphocytes. The results obtained in the present study directly demonstrate that BAL T lymphocytes of HIV-1 + patients express a fully functional IL-2 receptor apparatus, pointing to the role for this lymphokine in maintaining the alveolitis taking place in the lungs of AIDS patients.

Adult↗
PubMed1992

Phenotypic and functional characterization of cytotoxic cells derived from endomyocardial biopsies in human cardiac allografts.

This study was undertaken to characterize the phenotype and function of lymphocytes derived from endomyocardial biopsies in heart transplant patients. To this aim, tissue infiltrating lymphocytes were derived from seven heart transplant patients and were analyzed for the expression of a panel of markers, including CD3, CD4, CD8, CD16, CD56, CD45RA, CD45RO, alpha/beta and gamma/delta T cell receptor, and for their ability to lyse a series of targets, including NK-sensitive K-562 targets, NK-resistant Raji targets, donor related, and unrelated normal splenocytes. Our data show that the majority of cultured lymphocytes expressed the CD3+ phenotype and the alpha/beta T cell receptor. The CD4 and CD8 molecules were heterogeneously expressed among T cell lines tested. Concerning cytotoxic related markers, a significant percentage of cells were CD56+. The evaluation of CD45 isoforms showed that both "naive" and "memory" cells were present among heart TIL. Cytotoxic in vitro studies demonstrated that all our T cell lines showed an efficient cytotoxic machinery when tested against NK-sensitive targets. A marked lysis of donor-related splenocytes was demonstrated in all patients tested. To investigate the role of CD3 and HLA class I molecules in the cytotoxic mechanisms taking place in human heart allograft rejection mechanisms, TIL were assessed for their lytic activity against different targets in the presence of anti-CD3 and anti-HLA class I monoclonal antibodies (mAbs). Although donor-specific cytotoxicity was considerably inhibited by the anti-CD3 mAb, no inhibitory effect was displayed by this antibody on TIL-mediated cytotoxicity against donor-unrelated splenocytes. Anti-HLA class I mAb was able to inhibit both allospecific and nonallospecific cytotoxicity. These data suggest that different types of cytotoxic cells may be propagated from biopsy specimens of heart transplant patients.

Adult↗
PubMed1992

Immunophenotypic characterization of the cell infiltrate in five cases of sinus histiocytosis with massive lymphadenopathy (Rosai-Dorfman disease).

Little is known about the nature of the large intrasinusoidal cells exhibiting cytophagocytosis, which are the histologic hallmark of sinus histiocytosis with massive lymphadenopathy (SHML) (Rosai-Dorfman disease). Using a broad panel of monoclonal and polyclonal antibodies, we analyzed the immunophenotype of the cell infiltrates in seven lymph node biopsy specimens from five cases of SHML. The SHML cells constantly expressed the S-100 protein, concanavalin agglutinin and peanut agglutinin lectins, and monocyte-macrophage-associated antigens CD 11c, CD 14, CD 33, CD 68, and LN 5. Labeling with other antimacrophage antibodies was extremely variable, with some (MAC 387, lysozyme) restricted to clusters of SHML cells and others (CD11b, CD 36, alpha-1-antichymotrypsin) staining only scattered cells. The CD 1a antigen was found on some cells in only one case, whereas HLA-DR and the HLA-DR-associated invariant chains were absent. The heterogeneity of SHML cell marker expression might be related to the local content of factors (eg, cytokines) capable of modulating the phenotype of monocytes and derived cells. All cases presented with huge amounts of medium-sized mononuclear cells accumulated in the sinuses and intersinusoidal tissue. These cells expressed the S-100-/CD 11b+/CD 11c+/CD 14+/CD 16+/CD 33+/CD 36+/lysozyme+/MAC 387+/HLA-DR+ phenotype. These recently immigrated monocytes might represent the immediate precursors of SHML cells.

Adolescent↗
PubMed1992

Spontaneous production of interleukin-6 by alveolar macrophages from human immunodeficiency virus type 1-infected patients.

To test the hypothesis that the lung represents a source of interleukin (IL)-6 in human immunodeficiency virus type 1 (HIV-1)-positive subjects, alveolar macrophages (AM) obtained from the bronchoalveolar lavage (BAL) fluid of 10 HIV-1-positive patients were investigated for the expression of IL-6 mRNA and the ability to release IL-6. The presence of IL-6 in BAL fluid was also investigated. It has been demonstrated that freshly recovered AM from HIV-1-positive patients show a strong IL-6 mRNA signal. The message for IL-6 increases following culture with LPS. Supernatants obtained from AM cultured in medium alone contain high amounts of IL-6; the values are three to four times higher following culture with LPS. IL-6 has also been detected in the BAL fluid from 5 of 8 HIV-1-positive patients. Results of immunoblotting analysis were consistent with those given above. These findings suggest that the lung represents a source of IL-6 production in HIV-1-infected subjects with lung disorders.

Acquired Immunodeficiency Syndrome↗
PubMed1992

Suppurative granulomatous lymphadenitis. Immunohistochemical evidence for a B-cell-associated granuloma.

The cellular composition of suppurative granulomas was investigated by the application of monoclonal and polyclonal antibodies to paraffin sections and compared with nonsuppurative, hypersensitivity-type granulomas. Macrophages, T cells, and dendritic cells showed a similar distribution in both types of granulomas. In addition to the presence of granulocytes, a major difference between suppurative granulomas and hypersensitive-type granulomas concerned their relationship with B lymphocytes. Hypersensitive-type granulomas were surrounded by small mantle B cells, but they did not contain any B lymphocytes. In contrast, variable numbers of B cells were found either at the periphery or in the center of suppurative granulomas. In view of their morphology (medium size, pale cytoplasm, irregular nuclear shape) and phenotype (L26 +/LN1 -/MB2 +/MT2 +) these B lymphocytes closely resembled monocytoid B cells. The monocytoid B cells might have a role in the recruitment of polymorphonuclear granulocytes and in the development of the necrosis, which occur within suppurative granulomas.

Acid Phosphatase↗
PubMed1991

General practitioner referral to specialist psychiatric services: a comparison of practices in north- and south-Verona.

Specialist psychiatric services run by the Italian National Health Service are mainly hospital-based in North-Verona and community-based in South-Verona. Ninety-two GPs from both areas participated in a one-day survey of their provision of psychiatric care, and this paper focuses on socio-demographic and clinical variables associated with specialist psychiatric referral. The one-day prevalence figure for GP referral to specialist psychiatric services was 7.3% (17.6/10,000): the figures did not differ between the sexes or between the two areas. Whereas in North-Verona 49% of the patients referred were sent to the two local hospital-based public services and 51% to other agencies (mainly to private psychiatrists), in South-Verona 71% of referrals were to the community-based public service. Log-linear analysis showed that past psychiatric history, psychological presenting complaint, social problems and GPs' psychiatric diagnosis exerted positive joint main effects on GP referral to specialist psychiatric services, and that diagnosed organic illness had a negative effect in this regard. In the presence of a psychological complaint, a psychiatric diagnosis proved to be quite unimportant, so that those without a psychiatric diagnosis were just as likely to be referred as those with one. However, in the absence of a psychological complaint a GP diagnosis of depression greatly increased the risk of referral. Though the type of psychiatric service proved not to be an important determinant of GP referral to specialist psychiatric services it influenced the GPs' choice of referral agency.

Adolescent↗
PubMed1991

Shedding of the soluble form of the CD8 complex by CD8+/HLA-DR+ cells in HIV-1-infected patients.

High levels of the soluble form of the CD8 molecule (sCD8) are detectable in the serum of HIV-1-infected patients. To investigate the mechanisms accountable for the release of this molecule we evaluated the presence of sCD8 in the supernatants obtained from in vitro cultures of highly purified CD8 cells isolated from 20 HIV-1-infected patients. At resting conditions cultured CD8 cells from HIV-1-infected patients released low amounts of sCD8; no statistically significant differences were observed between unstimulated cultures from HIV-1-seropositive patients and from HIV-1-seronegative subjects at risk for HIV-1 infection or normal healthy controls. Following in vitro activation of highly purified CD8 cells with a series of stimulatory agents, including phorbol myristate acetate, phytohemagglutinin (PHA) and recombinant interleukin-2, CD8 cells of HIV-1-infected patients significantly increased the shedding of sCD8. By expressing the results of activation-related release index (ARRI = sCD8 levels detected in the cultures with stimulatory agent/sCD8 levels detected in the unstimulated cultures), significantly higher values were observed upon PHA stimulation in HIV-1-infected patients than in control subjects. In order to identify the cell subset responsible for the enhanced release of sCD8 by PHA-stimulated cultures, we correlated the amounts of sCD8 detected in the supernatants with the phenotypic profile of CD8+ cells recovered from the cultures. A significant relationship was demonstrated between the percentage of CD8+/HLA-DR+ lymphocytes and sCD8 levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Alveolar macrophages from patients with AIDS and AIDS-related complex constitutively synthesize and release tumor necrosis factor alpha.

To verify the hypothesis that alveolar macrophages (AMs) from patients infected with HIV-1 could synthesize and release TNF alpha, AMs recovered from the BAL fluid of 11 patients with seropositive HIV-1 (six with AIDS and five with ARC) were tested in vitro for their ability to destroy TNF alpha-susceptible targets. Furthermore, the presence of TNF alpha was assessed in AM-conditioned supernatants on the basis of their cytotoxic activity and by using an immunoenzymatic test and immunoblotting. Transcription of the TNF alpha gene in AMs was also studied by means of the Northern blot analysis. AMs freshly recovered from patients infected with HIV-1 exhibited high levels of cell-mediated cytotoxicity against U937 targets, and the addition of a polyclonal anti-TNF alpha antibody resulted in a significant inhibition of the target lysis. Cell-free supernatants conditioned by unstimulated AMs exerted high levels of cytotoxic activity against TNF alpha-sensitive targets, whereas duplicate, neutralization experiments performed in the presence of an anti-TNF alpha antibody proved that the observed cytotoxic activity was mostly mediated by TNF alpha. The presence of high amounts of TNF alpha in the conditioned media was confirmed by the immunoenzymatic test. In addition, the immunoblot analysis showed that the TNF alpha released by AMs has a Mr 17,000 band, identical to a standard preparation of recombinant TNF alpha. The Northern blot demonstrated that unstimulated AMs express detectable levels of mRNA transcripts for TNF alpha. Taken together, our data support the concept that AMs from patients with HIV-1 infection constitutively release TNF alpha.(ABSTRACT TRUNCATED AT 250 WORDS)

AIDS-Related Complex↗
PubMed1991

Prognostic significance of the evaluation of bronchoalveolar lavage cell populations in patients with HIV-1 infection and pulmonary involvement.

To investigate the prognostic utility of the morphologic and immunologic evaluation of BAL cell populations in determining mortality risk, we analyzed BAL data obtained from 115 patients infected with HIV-1. Forty fatal outcomes occurred within 73 patients with OI. The OI patients who died showed a significant increase in neutrophils with respect to surviving patients. Furthermore, the finding of a BAL neutrophilia in HIV-1-infected patients with OI strongly correlated with a high risk of death. Among 42 cases without OI, 11 patients died. Patients without OI who had a fatal outcome showed an increase in CD3+ and CD8+ BAL lymphocytes with respect to the survivors. The presence of a lymphocytic alveolitis was associated with a significant increase in the mortality rate. Taken together our data suggest that the evaluation of the BAL cell populations might be useful in predicting the risk of fatal outcome in patients with HIV-1 infection.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Tumor necrosis factor-alpha and B-cell growth factor induce leukemic hairy cells to proliferate in vitro.

To clarify the mechanisms accounting for the hairy cell proliferation, in five patients with hairy cell leukemia (HCL), we evaluated the ability of neoplastic cells to proliferate in vitro in response to tumor necrosis factor-alpha (TNF-alpha), B-cell growth factor (BCGF), and interleukin 4 (IL-4). In addition, supernatants recovered from cultures of unstimulated hairy cells were tested for the capability to induce the proliferation of allogeneic hairy cells. We demonstrated that TNF-alpha and BCGF were able to induce the in vitro growth of hairy cells (stimulation index (SI) ranging, at different concentrations, from 1.6 to 10.7 and from 1.6 to 25.1 for TNF-alpha and BCGF, respectively). IL-4 did not show any proliferative effect on hairy cells. When unstimulated hairy cell supernatants were tested for the proliferative activity on allogeneic hairy cells, we demonstrated a low proliferative effect that was not inhibited by an anti-TNF-alpha antibody. Our findings demonstrate that unstimulated hairy cells proliferate in vitro in response to TNF-alpha and BCGF, thus suggesting that these cytokines could be involved in an autocrine model of cell proliferation.

Cell Division↗
PubMed1991

Different mechanisms of activation of proliferating CD3+ cells in patients with lymphoproliferative disease of granular lymphocytes.

To investigate the role of p55 and p75 chains of interleukin-2 receptor (IL-2R) on the activation of granular lymphocytes (GL) in patients with lymphoproliferative disease of granular lymphocytes (LDGL), the cells obtained from 11 LDGL patients (belonging to the CD3+ group) were studied for (a) the surface expression and (b) mRNA transcripts of the p55 and p75 IL-2R after activation with anti-CD3 monoclonal antibody (mAb) or interleukin-2 (IL-2). The effects of mAbs specifically blocking the p55 and p75 IL-2R on the generation of proliferative and cytotoxic functions were studied following anti-CD3 mAb stimulation. A significant difference was observed in the expression of p55 and p75 antigens on LDGL cells under resting conditions: a low number of p55 IL-2R+ (mean 1.2 +/- 0.4%) and high values of p75 IL-2R+ cells (54.9 +/- 7.4%). Accordingly, a barely detectable message for the p55 IL-2R and a strong signal for the p75 IL-2R mRNA were demonstrated. Following activation with anti-CD3 or IL-2, different patterns of IL-2R expression were observed. Anti-CD3 mAb induced an increase in the expression of the p55 IL-2R both at the mRNA and antigen level, whereas the p75 values remained consistently raised. In contrast, IL-2 induced the expression of p55 IL-2R mRNA associated with only a slight expression of this antigen. This finding was associated with a decrease in the cell expression of the p75 IL-2R, whereas the amount of p75 mRNA was unchanged. Both anti-CD3 mAb and IL-2 induced cell proliferation and cytotoxicity against the K-562 target cells. Anti-p55 IL-2R mAb did not affect the cytotoxic activity mediated by anti-CD3, but it markedly inhibited cell proliferation. Anti-p75 mAb did not inhibit either lytic function or cell proliferation mediated by anti-CD3 mAb, suggesting that only the high affinity IL-2R (p55 plus p75) is involved in anti-CD3 mediated cell activation in LDGL patients. This mechanism is different from that responsible for the IL-2 activation of CD3+ GL in LDGL patients, which is achieved through the p75 IL-2R alone. These results provide new insights into the pathophysiology of proliferating GL in LDGL patients and may also contribute to further characterization of the normal CD3+ GL population.

Adult↗
PubMed1990

Cell membrane expression and functional role of the p75 subunit of interleukin-2 receptor in lymphoproliferative disease of granular lymphocytes.

The cell membrane expression and functional role of the interleukin-2 receptor (IL-2R) was analyzed in nine patients with lymphoproliferative disease of granular lymphocytes (LDGL) using monoclonal antibodies (MoAbs) specific for the p75 (TU27) and the p55 (anti-Tac) subunits of IL-2R. Four patients were characterized by the proliferation of CD3+CD8+ granular lymphocytes (GL) expressing the alpha/beta T-cell receptor (T alpha beta) and one case by the proliferation of CD3+CD4-CD8- GL expressing the gamma/delta T-cell receptor (T gamma delta); in four additional cases proliferating cells were CD3 negative GL. Consistent with data observed on normal GL, phenotypic analysis demonstrated that patients' GL lack the expression of the p55 IL-2R, whereas the p75 subunit is constitutionally expressed by expanding GL of both T-cell (either T alpha beta and T gamma delta) and natural killer (NK) origin in variable proportions (11% to 94% of cells). The analysis of the cytotoxic and proliferative activity demonstrated that the anti-p55 MoAb failed to inhibit IL-2-mediated activation, whereas a marked inhibition of both cytotoxicity and proliferation were obtained using the anti-p75 chain specific MoAb. These data indicate that the p75 chain of IL-2R is responsible for IL-2 signal transduction in both CD3+ and CD3- LDGL patients' GL.

Adult↗
PubMed1990

Mechanisms accounting for lymphocytic alveolitis in hypersensitivity pneumonitis.

Hypersensitivity pneumonitis (HP) is a lung disorder characterized by an exaggerated accumulation of CD8+ T lymphocytes in the pulmonary parenchyma. To investigate the mechanisms accounting for the T cell alveolitis taking place in the lung of HP patients and their pattern of growth, cells recovered from the bronchoalveolar lavage (BAL) of seven patients were evaluated for: 1) the expression of activation markers, including IL-2R (p55 and p75 subunits), HLA-DR and VLA-1 Ag; 2) the ability of IL-2 and IL-4 to induce in vitro proliferation; 3) the capability to synthesize and release IL-2 by determining the levels of IL-2 in BAL cell-free supernatants and by evaluating the presence of mRNA transcripts for IL-2; and 4) the molecular configuration of the beta- and gamma-genes of the TCR. This study demonstrates that a high number of BAL lymphocytes recovered from the lungs of HP patients express activation markers including the p75 chain of IL-2R, VLA-1, and HLA-DR Ag. These cells express the CD3+,CD8+,CD16-,CD56+ phenotype and proliferate in vitro in the presence of IL-2 but do not release this cytokine. Furthermore, IL-2 transcripts could not be detected in BAL resting T lymphocytes. No proliferation was observed in the presence of IL-4. The analysis of the configuration of the TCR beta- and gamma-genes showed a polyclonal pattern, with the exception of one case in which extra bands were observed following digestion with BamHI and EcoRI restriction enzymes. Taken together, our data suggest that the IL-2 system may play a central role in the mechanisms accounting for lymphocytic alveolitis in HP patients. Although the pattern of growth is usually polyclonal, such polyclonal recruitment seems to be biased toward cells that have rearranged and possibly expressed particular V beta or V gamma genes, thus leading to the hypothesis that the events that take place in the lung of these patients may occasionally elicit an oligoclonal expansion of the cells proliferating in lung parenchyma.

Adult↗