Frequent detection of HIV-1-specific mRNAs in infected individuals suggests ongoing active viral expression in all stages of disease

It has been shown that only a small fraction of CD4+ T cells are infected with human immunodeficiency virus type 1 (HIV-1) in vivo, particularly early in the course of infection. An even smaller proportion of cells have been shown to be expressing virus. Recent studies suggest that plasma viremia in asymptomatic HIV-infected individuals, representing active viral replication, is more common than was previously believed (range 23-100% of patients). To determine the in vivo state of HIV expression, samples of peripheral blood of 49 HIV-infected individuals at all stages of disease were examined. All subjects were positive for viral DNA by standard polymerase chain reaction (PCR), and a modified PCR was utilized to detect HIV-specific mRNAs (gag, major splice junction, env, and tat/rev). Patient's plasma was also assayed for p24 antigen and viremia. The results were as follows: (formula: see text) Overall, the findings suggest that active viral expression occurs at all stages of HIV infection. In particular, the presence of gag mRNA was determined in only 2 of 14 patients with T4% greater than 30% but in 20 of 35 patients with T4% less than or equal to 30% (p less than 0.05), demonstrating a direct association between the presence of message for a structural protein, and more advanced immunosuppression. Determination of the expression of certain HIV-specific messages from within a patient's cells adds a new dimension to understanding the pathogenesis of HIV infection. The presence of HIV-specific mRNAs, and in particular gag message, in many healthy seropositives may further argue for early initiation of antiviral therapy.

Surgical pathology of the lung in Wegener's granulomatosis. Review of 87 open lung biopsies from 67 patients

We report the pulmonary pathologic features in 87 open lung biopsies from 67 patients with Wegener's granulomatosis (WG) who were treated at a single institution from 1968 to 1990. At the time of open lung biopsy, 48 patients (72%) had classical WG with renal involvement; 19 (28%) had limited WG without renal involvement. The pathologic features were divided into major and minor manifestations. In the 82 specimens demonstrating no infectious organism, the three major pathologic manifestations of classical WG observed were also useful diagnostic criteria and included: (a) parenchymal necrosis, (b) vasculitis, and (c) granulomatous inflammation accompanied by an inflammatory infiltrate composed of a mixture of neutrophils, lymphocytes, plasma cells, histiocytes, and eosinophils. Parenchymal necrosis was found in 84% of biopsy specimens either as neutrophilic microabscesses (65% of specimens) or as large (67%) or small (69%) areas of geographic necrosis. Areas of geographic necrosis were usually surrounded by palisading histiocytes and giant cells. Additional granulomatous lesions consisted of microabscesses surrounded by giant cells (69%), poorly formed granulomas (59%), and scattered giant cells (79%). Sarcoid-like granulomas were uncommon (4%), and in only one specimen (1%) appeared within an inflammatory lesion of WG. Vascular changes were identified in 94% of biopsy specimens. Vascular inflammation was classified as chronic (37% arterial, 64% venous), acute (37% arterial, 29% venous), non-necrotizing granulomatous (22% arterial, 9% venous), and necrotizing granulomatous (22% arterial, 10% venous). Fibrinoid necrosis was relatively uncommon (11% arterial, 6% venous). Cicatricial changes were found in arteries in 41% of biopsy specimens and in veins in 16%. Capillaritis was present in 31% of specimens. Minor pathologic lesions were commonly observed in biopsy specimens associated with classical WG lesions, but they were usually inconspicuous and not useful diagnostic criteria. These included interstitial fibrosis (26%), alveolar hemorrhage (49%), tissue eosinophils (100%), organizing intraluminal fibrosis (70%), endogenous lipoid pneumonia (59%), lymphoid aggregates (37%), and a variety of bronchial/bronchiolar lesions including acute and chronic bronchiolitis (51% and 64%), follicular bronchiolitis (28%), and bronchiolitis obliterans (31%). These minor lesions were often found at the periphery of typical nodules of WG. However, in 15 specimens (18%) a minor pathologic feature represented the dominant or major finding: pulmonary fibrosis (six specimens, 7%), diffuse pulmonary hemorrhage (six specimens, 7%), lipoid pneumonia (one specimen, 1%), acute bronchopneumonia (one specimen, 1%), and chronic bronchiolitis, bronchiolitic obliterans with organizing pneumonia (BOOP), and bronchocentric granulomatosis (one specimen, 1%).(ABSTRACT TRUNCATED AT 400 WORDS)

Transforming growth factor beta suppresses human immunodeficiency virus expression and replication in infected cells of the monocyte/macrophage lineage

The pleiotropic immunoregulatory cytokine transforming growth factor beta (TGF-beta) potently suppresses production of the human immunodeficiency virus (HIV), the causative agent of the acquired immunodeficiency syndrome, in the chronically infected promonocytic cell line U1. TGF-beta significantly (50-90%) inhibited HIV reverse transcriptase production and synthesis of viral proteins in U1 cells stimulated with phorbol myristate acetate (PMA) or interleukin 6 (IL-6). Furthermore, TGF-beta suppressed PMA induction of HIV transcription in U1 cells. In contrast, TGF-beta did not significantly affect the expression of HIV induced by tumor necrosis factor alpha (TNF-alpha). These suppressive effects were not mediated via the induction of interferon alpha (IFN-alpha). TGF-beta also suppressed HIV replication in primary monocyte-derived macrophages infected in vitro, both in the absence of exogenous cytokines and in IL-6-stimulated cultures. In contrast, no significant effects of TGF-beta were observed in either a chronically infected T cell line (ACH-2) or in primary T cell blasts infected in vitro. Therefore, TGF-beta may play a potentially important role as a negative regulator of HIV expression in infected monocytes or tissue macrophages in infected individuals.

Experience with surgical treatment of Takayasu's disease

We reviewed 28 patients with Takayasu's disease to determine the incidence of stroke and its relationship to the involvement of the thoracic aortic arch and its branches. We describe surgical experiences with 10 of the 28 patients who required 21 vascular surgical procedures for critical thoracic aortic arch arterial stenoses, upper and lower extremity ischemia, and renal artery stenoses. Four of the 28 patients initially had a stroke caused by occlusion of one or more thoracic aortic arch arteries. Six of the 10 patients underwent 7 bypass procedures for critical thoracic arch stenoses. All have remained free of stroke for 5 or more years. Four patients had five anastomotic stenoses or graft occlusions in late follow-up; the development of these stenoses did not relate to disease activity at the time of the operative procedure. All bypass grafts originating from the subclavian axillary artery developed anastomotic stenoses; no anastomotic stenoses occurred in bypass grafts originating from the ascending aorta. In contrast to other reports, no anastomotic false aneurysms occurred. Occlusions of major aortic arch arteries in Takayasu's disease cause stroke. Bypass of critically stenoses aortic arch arteries protects against stroke and is best performed with grafts originating from the ascending aorta. Anastomotic stenoses but not anastomotic aneurysms are common. This study suggests that aggressive surgical treatment can be performed with good results.

Suppression of human immunodeficiency virus expression in chronically infected monocytic cells by glutathione, glutathione ester, and N-acetylcysteine

The effects of glutathione (GSH), glutathione ester (GSE), and N-acetyl-L-cysteine (NAC) on the induction of human immunodeficiency virus (HIV) expression were investigated in the chronically infected monocytic U1 cell line, a previously described cellular model for HIV latency. U1 cells constitutively express low levels of virus, which can be increased by phorbol 12-myristate 13-acetate (PMA), tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), and other inducers. GSH, GSE, and NAC suppressed in a dose-dependent fashion the induction of HIV expression mediated by PMA, TNF-alpha, and IL-6, in the absence of cytotoxic or cytostatic effects. Reverse transcriptase activity, inducible by PMA, TNF-alpha, or IL-6, was decreased by 80-90% after pretreatment with GSH, GSE, or NAC. The induction of total HIV protein synthesis was also decreased appreciably after pretreatment with GSH, GSE, or NAC. The accumulation of HIV mRNA was substantially suppressed after pretreatment with NAC but to a lesser extent after pretreatment with GSH or GSE. Although PMA induces the expression of TNF-alpha in U1 cells, the suppressive effect of GSH, GSE, and NAC on PMA-induced HIV expression in U1 cells was not associated with the inhibition of TNF-alpha expression. The present findings, which elucidate relationships between cellular GSH and HIV expression, suggest that therapy with thiols may be of value in the treatment of HIV infection.

Wegener's granulomatosis

Wegner's granulomatosis is a clinicopathologic syndrome of unknown etiology characterized by granulomatous vasculitis of the upper and lower respiratory tracts and glomerulonephritis. During the period covered by this review several articles were published describing the clinical and pathologic features of Wegner's granulomatosis. Specifically, two large series are discussed reviewing the pulmonary manifestations of the disease and the histopathology of the head and neck disease associated with Wegner's granulomatosis. The majority of publications related to Wegner's granulomatosis concern anti-neutrophil cytoplasmic antibodies and their role in the diagnosis, management, and pathogenesis of Wegner's granulomatosis. In the period covered by this article, no new reports on the therapy of Wegner's granulomatosis were reviewed. However, two articles that address the efficacy of cyclophosphamide pulse therapy in Wegner's granulomatosis have recently been published with conflicting conclusions. The data from these articles are mentioned but will be reviewed in more detail in a subsequent article.

Bronchoalveolar lavage analysis in Wegener's granulomatosis. A method to study disease pathogenesis

A prospective analysis of bronchoalveolar lavage (BAL) in 13 patients with Wegener's granulomatosis (WG), 20 disease control subjects with idiopathic pulmonary fibrosis (IPF), and 24 normal control subjects was conducted to (1) evaluate the quality of the alveolar inflammatory response associated with active WG; (2) determine whether antineutrophil cytoplasmic antibody (ANCA) is present in alveolar fluid and produced in the lungs of patients with WG; and (3) determine whether inhaled particles or infectious agents may play an etiologic role in WG. BAL in untreated active WG had a marked increase in neutrophils (mean = 42% of total WBC count), and usually in eosinophils (mean = 4%) compared with that in normal control subjects (1.6% neutrophils, 0% eosinophils), and untreated WG in remission (5.9% neutrophils, 0% eosinophils). Disease control subjects with IPF, a process known to be associated with neutrophilic alveolitis, had an increased population of neutrophils (15.4%) and eosinophils (2.7%) in BAL. Leukocyte remnants, as well as intact leukocytes, could be identified within BAL macrophages in the patients with WG and IPF, and rarely in the normal control subjects. Normal subjects and control patients with IPF were all negative for ANCA in serum, whereas ANCA was found in serum and BAL in all patients with active WG who had generalized disease. Protein analysis of BAL revealed a disproportionate increase in the IgG to albumin ration compared with serum values (IgG index) in patients with active untreated disease. The increase in the IgG index suggests that IgG with ANCA reactivity is produced by pulmonary lymphoid tissue. An infectious agent in BAL was not identified by any of the techniques applied in this study.(ABSTRACT TRUNCATED AT 250 WORDS)

Human immunodeficiency virus (HIV) infection in CD4+ T lymphocytes genetically deficient in LFA-1: LFA-1 is required for HIV-mediated cell fusion but not for viral transmission

In the present study, we demonstrated that expression of the LFA-1 molecule is necessary for cell fusion and syncytia formation in human immunodeficiency virus (HIV)-infected CD4+ T lymphocytes. In contrast, the lack of expression of LFA-1 does not influence significantly cell-to-cell transmission of HIV. In fact, LFA-1- T lymphocytes obtained from a leukocyte adhesion deficiency patient were unable to fuse and form syncytia when infected with HIV-1 or HIV-2, despite the fact that efficiency of HIV infection (i.e., virus entry, HIV spreading, and levels of virus replication) was comparable with that observed in LFA-1+ T lymphocytes. In addition, we provide evidence that LFA-1 by mediating cell fusion contributes to the depletion of HIV-infected CD4+ T lymphocytes in vitro.

Selective autoregulation of endothelins in primary astrocyte cultures: endothelin receptor-mediated potentiation of endothelin-1 secretion

Observations that primary rat astrocytes express high-affinity binding sites for endothelins and, in addition, are capable of producing not only endothelin-3 but also endothelin-1 prompted the investigation of a possible relation between endothelin peptides and receptors in these cells. Sarafotoxin S6b, an endothelin receptor agonist, was used as a tool to study endothelin receptor-mediated changes in the secretion of endothelin-1 and -3. The effects of sarafotoxin S6b and endothelin-1 in stimulating inositolphospholipid turnover as well as in inducing AP1 in primary astrocyte cultures were found to be similar. A low cross-reactivity of sarafotoxin S6b with endothelin-1 and -3 in the endothelin radioimmunoassays used here, along with a distinctly different elution position in high-performance liquid chromatography, allowed a clear discrimination between sarafotoxin and endothelins in the culture media. Stimulation of primary rat astrocytes with 10(-7) M sarafotoxin S6b for 1 hour resulted in a substantial increase in endothelin-1 immunoreactivity in the medium. This immunoreactivity reached a peak at 3 hours and showed no further increase after 8 and 24 hours. Treatment of our cultures with phorbol myristate acetate, lipopolysaccharide, tumor necrosis factor alpha, and norepinephrine for 24 hours led to only a moderate elevation of endothelin-1 immunoreactivity. Immunoreactive endothelin-3 was not affected by any of the treatments tested. Thus, our data suggest that endothelins in primary rat astrocytes are subject to selective autoregulation, as demonstrated by the potentiation of endothelin-1 secretion after activation of glial endothelin receptors.

Immunoglobulin G antineutrophil cytoplasmic antibodies are produced in the respiratory tract of patients with Wegener's granulomatosis

Wegener's granulomatosis (WG) is a small-vessel vasculitis of unknown etiology that usually involves the upper and lower respiratory tract and the kidneys. Recently, an association has been made between the presence of serum antineutrophil cytoplasmic antibodies (ANCA) and WG. Because WG frequently involves the lung, we sought to evaluate bronchoalveolar lavage (BAL) fluids obtained from 14 patients with WG for the presence of ANCA. Immunoglobulin (Ig) G ANCA was found in the BAL with the same staining patterns as observed in the serum. Patients with active disease had the highest serum and BAL IgG ANCA titers. IgA or IgM ANCA was not detected in the serum or BAL of these patients. Protein analysis of BAL fluid revealed that patients with active, untreated WG had approximately a fourfold elevation in total protein (41.3 versus 10.5 mg/dl), with a disproportionately greater increase in the ratio of IgG to albumin (BAL IgG index = 1.49, normal = 0.74; p = 0.027). The increase of the IgG index in patients with active WG suggests that local production of IgG ANCA occurs in the lungs.

A vasoactive peptide, endothelin-3, is produced by and specifically binds to primary astrocytes

Primary rat astrocytes were found by immunohistochemistry to display positive staining for endothelin-3, located predominantly in the perinuclear area. The ability of these cells to produce and release endothelin-3 was confirmed by a combination of reverse-phase HPLC and radioimmunoassay, specific for endothelin-3, which demonstrated immunoreactive peptide in cellular extracts and astrocyte-conditioned medium. In addition, astrocytes were shown to possess a single class of binding sites for endothelin with comparable high affinity for endothelin-1, -2 and -3. These results suggest that astrocytes, by virtue of their ability to produce and secrete endothelin-3, serve as a potential extravascular source of intracerebral vasoregulation capable of influencing regional cerebral blood flow.

cDNA cloning of the B cell membrane protein CD22: a mediator of B-B cell interactions

We have cloned a full-length cDNA for the B cell membrane protein CD22, which is referred to as B lymphocyte cell adhesion molecule (BL-CAM). Using subtractive hybridization techniques, several B lymphocyte-specific cDNAs were isolated. Northern blot analysis with one of the clones, clone 66, revealed expression in normal activated B cells and a variety of B cell lines, but not in normal activated T cells, T cell lines, Hela cells, or several tissues, including brain and placenta. One major transcript of approximately 3.3 kb was found in B cells although several smaller transcripts were also present in low amounts (approximately 2.6, 2.3, and 1.6 kb). Sequence analysis of a full-length cDNA clone revealed an open reading frame of 2,541 bases coding for a predicted protein of 847 amino acids with a molecular mass of 95 kD. The BL-CAM cDNA is nearly identical to a recently isolated cDNA clone for CD22, with the exception of an additional 531 bases in the coding region of BL-CAM. BL-CAM has a predicted transmembrane spanning region and a 140-amino acid intracytoplasmic domain. Search of the National Biological Research Foundation protein database revealed that this protein is a member of the immunoglobulin super family and that it had significant homology with three homotypic cell adhesion proteins: carcinoembryonic antigen (29% identity over 460 amino acids), myelin-associated glycoprotein (27% identity over 425 amino acids), and neural cell adhesion molecule (21.5% over 274 amino acids). Northern blot analysis revealed low-level BL-CAM mRNA expression in unactivated tonsillar B cells, which was rapidly increased after B cell activation with Staphylococcus aureus Cowan strain 1 and phorbol myristate acetate, but not by various cytokines, including interleukin 4 (IL-4), IL-6, and gamma interferon. In situ hybridization with an antisense BL-CAM RNA probe revealed expression in B cell-rich areas in tonsil and lymph node, although the most striking hybridization was in the germinal centers. COS cells transfected with a BL-CAM expression vector were immunofluorescently stained positively with two different CD22 antibodies, each of which recognizes a different epitope. Additionally, both normal tonsil B cells and a B cell line were found to adhere to COS transfected with BL-CAM in the sense but not the antisense direction.(ABSTRACT TRUNCATED AT 400 WORDS)

Activated B lymphocytes from human immunodeficiency virus-infected individuals induce virus expression in infected T cells and a promonocytic cell line, U1

Freshly isolated B lymphocytes from patients infected with human immunodeficiency virus (HIV), in contrast to B cells from normal controls, were shown to induce viral expression in two cell lines: ACH-2, a T cell line, and U1, a promonocytic cell line, which are chronically infected with HIV, as well as in autologous T cells. In 10 out of 10 HIV-infected individuals with hypergammaglobulinemia, spontaneous HIV-inductive capacity was found with highly purified peripheral blood B cells, whereas peripheral blood or tonsillar B cells from six healthy, HIV-negative donors did not induce HIV expression unless the cells were stimulated in vitro. The induction of HIV expression was observed in direct coculture experiments of B lymphocytes and HIV-infected cells, and could also be mediated by supernatants from cultures of B cells. Significantly higher amounts of interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) were detected in the B cell culture supernatants from HIV-infected patients with hypergammaglobulinemia (IL-6: mean = 536 pg/ml; TNF-alpha: mean = 493 pg/ml), as compared with normal uninfected controls (IL-6: mean = 18 pg/ml; TNF-alpha: mean = 23 pg/ml). Antibodies against these cytokines abolished the HIV-inductive capacity of B cells. We conclude that in vivo activated B cells in HIV-infected individuals can upregulate the expression of virus in infected cells by secreting cytokines such as TNF-alpha and IL-6, and, therefore, may play a role in the progression of HIV infection.

Functional studies examining the subpopulation of human B lymphocytes responding to high molecular weight B cell growth factor

Mature human B lymphocytes perform many functions including antibody secretion, Ag presentation, preservation of memory for Ag, and lymphokine secretion. Individual resting B cells receive multiple sequential signals that determine the function(s) that will be performed by those cells. Activation signals such as Ag or Staphylococcus aureus Cowan I (Sac) stimulate overlapping but different subpopulations of B cells. After activation, B cells may be induced to proliferate by a variety of B cell growth factors (BCGF) including IL-2, IL-4, TNF-alpha, low molecular weight BCGF (LMW-BCGF), and high molecular weight BCGF (HMW-BCGF). Little information exists to explain why so many different BCGFs are involved with human B cell proliferation. The current studies were designed to examine the role HMW-BCGF plays in selecting B cells for particular functions. HMW-BCGF but not LMW-BCGF was found to inhibit Ig secretion when it was included in culture with Sac-activated B cells and B cell differentiation factors (BCDFs) including IL-6. Sorting resting B lymphocytes into surface IgD+ and IgD- populations and then stimulating each population with anti-mu revealed that the cells most responsive to HMW-BCGF resided in the surface IgD- sorted population. Sorting activated B lymphocytes into BA5 (HMW-BCGFR)+ and BA5- populations revealed that BA5+ B cells stimulated with BCDF (in the absence of HMW-BCGF) produced predominantly IgG, whereas the BA5- population produced both IgG and IgM. Finally, expansion of peripheral B cells from tetanus toxoid-immunized donors with either HMW-BCGF or LMW-BCGF revealed that the HMW-BCGF-expanded population produced predominantly IgG tetanus-specific antibody in the presence of BCDF (in the absence of HMW-BCGF), whereas the LMW-BCGF-expanded population produced IgM much greater than IgG tetanus-specific antibody. Thus, HMW-BCGF may function to expand a subpopulation of B cells for memory B cell functions.

Functional studies examining the subpopulation of human B lymphocytes responding to high molecular weight B cell growth factor

Mature human B lymphocytes perform many functions including antibody secretion, Ag presentation, preservation of memory for Ag, and lymphokine secretion. Individual resting B cells receive multiple sequential signals that determine the function(s) that will be performed by those cells. Activation signals such as Ag or Staphylococcus aureus Cowan I (Sac) stimulate overlapping but different subpopulations of B cells. After activation, B cells may be induced to proliferate by a variety of B cell growth factors (BCGF) including IL-2, IL-4, TNF-alpha, low molecular weight BCGF (LMW-BCGF), and high molecular weight BCGF (HMW-BCGF). Little information exists to explain why so many different BCGFs are involved with human B cell proliferation. The current studies were designed to examine the role HMW-BCGF plays in selecting B cells for particular functions. HMW-BCGF but not LMW-BCGF was found to inhibit Ig secretion when it was included in culture with Sac-activated B cells and B cell differentiation factors (BCDFs) including IL-6. Sorting resting B lymphocytes into surface IgD+ and IgD- populations and then stimulating each population with anti-mu revealed that the cells most responsive to HMW-BCGF resided in the surface IgD- sorted population. Sorting activated B lymphocytes into BA5 (HMW-BCGFR)+ and BA5- populations revealed that BA5+ B cells stimulated with BCDF (in the absence of HMW-BCGF) produced predominantly IgG, whereas the BA5- population produced both IgG and IgM. Finally, expansion of peripheral B cells from tetanus toxoid-immunized donors with either HMW-BCGF or LMW-BCGF revealed that the HMW-BCGF-expanded population produced predominantly IgG tetanus-specific antibody in the presence of BCDF (in the absence of HMW-BCGF), whereas the LMW-BCGF-expanded population produced IgM much greater than IgG tetanus-specific antibody. Thus, HMW-BCGF may function to expand a subpopulation of B cells for memory B cell functions.

Astrocyte-conditioned medium stimulates HIV-1 expression in a chronically infected promonocyte clone

Human promonocytic cells chronically infected with human immunodeficiency virus-1 (HIV-1) (clone U1.1.5) were grown in the presence of media conditioned by primary rat cortical astrocytes and HIV-1 expression was assessed by measuring reverse transcriptase activity. Media conditioned by non-stimulated and lipopolysaccharide (LPS)-stimulated astrocytes induced the expression of HIV-1 2.1-fold and 4.1-fold, respectively. LPS alone, media conditioned by the uninfected parental cell line of U1.1.5 (U937), and culture media from four other cell lines, had no effect on viral expression. The magnitude of induction was time- and dose-dependent. Tumor necrosis factor alpha (TNF-alpha) was detected in LPS-stimulated astrocyte-conditioned medium and the HIV-inducing capability of the medium was neutralized, in part, by an antibody to recombinant murine TNF-alpha. These results suggest a role for astrocytes in the induction of HIV expression and thus in the pathogenesis of HIV-1 infection in brain.

Endothelins, peptides with potent vasoactive properties, are produced by human macrophages

Endothelins are peptides, originally isolated from endothelial cells, with potent vasoactive and mitogenic properties. In this study, we demonstrate that human macrophages synthesize and secrete endothelins. Cultured human macrophages were found by immunocytochemistry to stain positively for endothelin 1 and endothelin 3. Their capability to produce and release these peptides was confirmed by a combination of reverse-phase high-performance liquid chromatography and radioimmunoassays, specific for endothelin 1 and 3, respectively. Immunoreactive peptides were identified both in cellular extracts and in macrophage-conditioned medium. The secretion of endothelin 1, but not of endothelin 3, from macrophages could be stimulated 6-10-fold by lipopolysaccharide or phorbol myristate acetate (PMA). Northern blot analysis of total macrophage RNA using an endothelin 1 cDNA probe revealed induction of endothelin mRNA in PMA-treated macrophages. Furthermore, immunoreactive endothelin 1 and 3 were found in U937 cells, a human promonocytic line, and in freshly isolated human monocytes. In contrast, no immunoreactive endothelin was detected in cell extracts from human neutrophils and lymphocytes. The expression of endothelins in tissue macrophages was demonstrated in paraffin sections of human lung using immunohistochemistry. In conclusion, the finding that human macrophages produce endothelins suggests an important role for these peptides in the microenvironment of tissue macrophages. Macrophage-derived endothelins may have an essential function in blood vessel physiology, and aberrant production may contribute to vessel pathology.

Circulating CD8+ cytotoxic T lymphocytes specific for HTLV-I pX in patients with HTLV-I associated neurological disease

The human T-lymphotropic virus type I (HTLV-I), the first human retrovirus to be characterized, is associated with adult T-cell leukaemia and a chronic progressive disease of the central nervous system termed tropical spastic paraparesis, or HTLV-I-associated myelopathy. Only 1% of individuals infected with HTLV-I develop clinical disease however. The various manifestations of an HTLV-I infection may be related to differences in the genetic backgrounds of individuals, infection with variant strains of HTLV-I, differences in viral tropism or host immune response to the virus. Whereas the humoral response to HTLV-I is well characterized, little is known about the human cellular immune response, such as the production of cytotoxic T lymphocytes. Here we report the presence of high levels of circulating HTLV-I-specific cytotoxic T lymphocytes in patients with HTLV-I associated neurological disease but not in HTLV-I seropositive individuals without neurological involvement. These cytotoxic T lymphocytes are CD8+, HLA class I- restricted and predominantly recognize the HTLV-I gene products encoded in the regulatory region pX. These findings suggest that HTLV-I-specific cytotoxic T lymphocytes may contribute to the pathogenesis of associated neurological disorders associated with HTLV-I.

Treatment of Wegener's granulomatosis with intermittent high-dose intravenous cyclophosphamide

PURPOSE

Concerns regarding the long-term toxicity of daily cyclophosphamide (CP) therapy for the systemic vasculitides have led us to evaluate alternative approaches to treatment in an attempt to achieve comparable efficacy with less toxicity. This study sought to determine the efficacy, toxicity, and immunologic effects of glucocorticoids (GC) and intermittent high-dose intravenous CP ("pulse" CP) in the treatment of 14 patients with Wegener's granulomatosis (WG).

PATIENTS AND METHODS

The diagnosis of active WG was supported by a typical clinical presentation and histopathologic findings of vasculitis, granulomatous inflammation, and tissue necrosis. GC treatment was initially provided on a daily basis and later tapered to an alternate-day schedule if vasculitis remained inactive. Pulse CP treatment was initially administered once a month for 6 months. If after 6 months remission had been attained and GC therapy had been discontinued, then pulse CP treatment was given at less frequent intervals thereafter. Treatment and evaluation were provided for participants as inpatients in a clinical research center (National Institutes of Health).

RESULTS

Thirteen of 14 patients (93%) initially experienced unequivocal improvement with pulse CP therapy, and seven of 14 (50%) achieved remission within 4 months. However, treatment was associated with significant toxicity in two patients and later relapses in nine patients, so that a total of 79% either failed to achieve sustained remission or were unable to continue therapy. Three of 14 (21%) patients have achieved sustained remissions with the pulse CP protocol and one additional patient (who had a limited exacerbation of WG) continues to receive that therapy after 14 to 22 months (mean 17 months).

CONCLUSIONS

The use of pulse CP and GC therapy in 14 patients with WG was associated with a high initial response rate. However, failure to respond initially to treatment, to sustain improvement, or to tolerate continued treatment was noted in 79% of patients within a period of 1 to 22 months. These observations indicate that this particular pulse CP protocol does not achieve a high degree of lasting efficacy.

Evidence for susceptibility of intrathymic T-cell precursors and their progeny carrying T-cell antigen receptor phenotypes TCR alpha beta + and TCR gamma delta + to human immunodeficiency virus infection: a mechanism for CD4+ (T4) lymphocyte depletion

Individuals infected by the human immunodeficiency virus type 1 (HIV-1) demonstrate progressive depletion and qualitative dysfunction of the helper T4 (CD4+) cell population. Mechanisms proposed for attrition of CD4+ T cells include direct cytopathicity of these mature cells following infection as well as infection of early T-lymphocyte progenitors. The latter mechanism could lead to failure to regenerate mature functioning CD4+ T cells. The present study determines the susceptibility of thymocytes at various stages of maturity to infection with HIV-1. Various normal thymocyte populations were inoculated with HIV-1, including unfractionated (UF), CD3- CD4- CD8- ["triple negative" (TN)], CD4+ CD8+ ["double positive" (DP)] thymocytes, and thymocyte populations obtained by limited dilution cloning. Cultures were studied for the presence of HIV-1 DNA by polymerase chain reaction in addition to examination for reverse transcriptase activity. We determined that transformed T-cell and thymocyte cell lines completely lacking CD4 were not susceptible to infection by HIV-1, whereas all of the following lines were: UF thymocytes (70-90% CD4hi+); DP thymocytes (99% CD4hi+); TN thymocytes (0% CD4hi+); and TCR alpha beta +, TCR gamma delta +, or CD16+ CD3- (natural killer) thymocyte clones expressing variable levels of CD4 and representing the progeny of TN thymocytes. [TCR alpha beta + and TCR gamma delta + refer to the chains of the T-cell antigen receptor (TCR), and CD4hi refers to a strong rightward shift (greater than 30 linear channels) of the CD4 curve on flow cytometric analysis compared with control.] Monoclonal antibodies (mAbs) to CD4 (T4a epitope) but not to CD3 (T3) were capable of blocking infection of mature and immature CD4hi+ thymocytes. Moreover, anti-CD4(T4a) mAbs also inhibited infection of CD4hi- TN thymocytes, indicating that these T-cell precursors--despite their apparent "triple negativity" (CD3- CD4hi- CD8-)--expressed sufficient CD4 molecules to become infected. Cell sorter analysis with a panel of CD4 mAbs demonstrated a mean shift of the mean fluorescence channel (MFC) with CD4 mAbs on TN thymocytes of 6 +/- 4 MFC units. Thus, intrathymic T-cell precursors and their progeny representing many stages of T-cell ontogeny are susceptible to infection by HIV-1, including early TN thymocytes, which express very low levels of CD4. Infection of multiple stages and multiple subsets of the T-cell lineage in man, mediated via the CD4 molecule, may explain the inability of the T-cell pool to regenerate in the setting of progressive HIV infection.

Increasing viral burden in CD4+ T cells from patients with human immunodeficiency virus (HIV) infection reflects rapidly progressive immunosuppression and clinical disease

OBJECTIVE

To determine over time the relation between viral burden and immunologic decline in patients with asymptomatic human immunodeficiency virus (HIV) infection.

DESIGN

Blind analysis of cell samples from matched cohorts for HIV proviral DNA by polymerase chain reaction, retrospective analysis of clinical data on patients, and prospective follow-up of patients seropositive for the human immunodeficiency virus type 1 (HIV-1).

SETTING

National research clinic and academic medical centers.

PATIENTS

Cohort 1 included 12 healthy HIV-1-seropositive patients (average follow-up, 14 months): Six patients had stable disease and 6 developed rapidly progressive disease. Cohort 2 included 15 healthy HIV-1-seropositive patients from the Multi-center AIDS Cohort Study (average follow-up, 32 months): Eight patients had stable disease and 7 developed rapidly progressive disease. LABORATORY STUDIES: Quantitative polymerase chain reaction was done to determine the HIV-1 viral burden in sort-purified CD4+ T cells obtained from patients at various timepoints.

MEASUREMENTS AND MAIN RESULTS

In patients who remained asymptomatic, frequencies of HIV-infected CD4+ T cells were low (less than 1/10,000 to 1/1000) at study entry and increased only minimally (none higher than 1/1000). In contrast, among patients who developed HIV-related symptoms including the acquired immunodeficiency syndrome (AIDS) despite having similar CD4 counts, frequencies of HIV-infected CD4+ T cells were higher at entry (greater than 1/1000) and increased substantially (greater than 1/100) in most within 3 months of developing progressive disease. This increase in HIV burden coincided with a significant decline over time in the percent of T4 cells (31% to 16%), whereas the percent of T4 cells was unchanged in persons who remained asymptomatic (33% to 34%).

CONCLUSIONS

Increasing viral burden in peripheral blood CD4+ T-cells is directly associated with a progressive decline in CD4+ T cells and deteriorating clinical course in HIV-infected patients.

Direct and cytokine-mediated activation of protein kinase C induces human immunodeficiency virus expression in chronically infected promonocytic cells

The chronically infected promonocytic clone U1 expresses low-to-undetectable constitutive levels of human immunodeficiency virus (HIV). Virus replication in these cells can be increased up to 25-fold by phorbol esters (phorbol-12-myristate-13-acetate), recombinant cytokines such as tumor necrosis factor-alpha, and cytokine-enriched mononuclear cell supernatants. We have tested specific activators of protein kinases (PK) and PK inhibitors (isoquinolinesulfonamide derivatives), as well as calcium-mobilizing agents, for their effect on constitutive and induced virus expression in U1 cells. Virus expression was measured by reverse transcriptase, Western blot, and nuclear run-on analysis. Activation of PKC by 1-oleyl,2-acetylglycerol, a synthetic analog of the natural ligand 1,2-diacylglycerol, and bryostatin 1 (a recently described specific PKC activator) resulted in a two- to eightfold increase in virus production. In contrast, activators of cyclic-nucleotide-dependent PKs were not effective in inducing virus expression. PK inhibitors were tested for their effect on HIV upregulation by cytokines and other inducing agents. The isoquinolinesulfonamide derivative H7, a potent inhibitor of PKC activation, effectively blocked (70 to 90%) HIV induction by cytokines and phorbol-12-myristate-13-acetate. The derivative HA1004, which is more selective for cyclic-nucleotide-dependent kinases, did not suppress viral induction. In addition, increases in intracellular calcium levels dramatically enhanced HIV production induced by both specific PKC activators and cytokines. These results indicate that activation of PKC is a common pathway involved in the upregulation of HIV expression in chronically infected cells stimulated by cytokines and other inducing agents.

Induction of nuclear factor-kappa B and the human immunodeficiency virus long terminal repeat by okadaic acid, a specific inhibitor of phosphatases 1 and 2A

We have used a specific phosphatase inhibitor, okadaic acid, to examine the role of two phosphatases, PP1 and PP2A, in the induction of NF-kappa B and the long terminal repeat of the human immunodeficiency virus type 1 (HIV-LTR). Treatment of Jurkat cells with okadaic acid induced NF-kappa B in nuclear extracts. The rate of induction by okadaic acid was delayed compared to the induction of NF-kappa B by phorbol myristate acetate (PMA). The induction of NF-kappa B by okadaic acid was enhanced by cycloheximide or phytohemagglutinin (PHA). In contrast to PMA, okadaic acid appeared to induce NF-kappa B independently of protein kinase C (PKC). That the NF-kappa B induced by okadaic acid was functional was demonstrated by the marked increase in CAT activity that occurred in Jurkat, BJA-B, and U251 cells that were transfected with HIV-LTR-CAT and treated with okadaic acid. The increase in CAT activity triggered by okadaic acid was dependent on the presence of the NF-kappa B sites in the long terminal repeat of HIV as assessed by deletion and mutation analysis. Similarly to its effect on the induction of NF-kappa B, PHA added together with okadaic acid resulted in a further increase in CAT activity. Somewhat surprisingly, the addition of PMA inhibited the increase in CAT activity in response to okadaic acid, which suggests that the activation of PKC may also induce inhibitory factors.(ABSTRACT TRUNCATED AT 250 WORDS)