Altered cytokine production and accessory cell function after HIV-1 infection

We investigated cytokine production and accessory cell function in human macrophage hybridoma cell lines and primary monocytes after infection with HIV-1. HIV-1 infection induced IL-10 production in the macrophage hybridoma cell line with loss of IL-12 1 wk after infection. There were also significant increases in production of IL-10 (537 +/- 521 vs 687 +/- 625 pg/ml) while there was a reduction in IL-12 (6.3 +/- 3.1 vs 1.2 +/- 1.0 pg/ml, p = 0.021) in the primary monocytes 5 days after HIV-1 infection. In addition, the hybridoma cell lines and primary monocytes failed to support PHA, Con A, PWM, or anti-CD3- induced T cell proliferation 1 wk after infection. The viability of the T cells cocultured with the HIV-1-infected macrophage cell lines or the primary monocytes as determined by propidium iodide staining was unaltered and there was no increase in apoptosis-specific DNA strand breaks or increased expression of Bcl-2 in the T cells. No soluble suppressor factor was present, since UV-inactivated supernatants from the hybridoma cell line and primary monocytes failed to inhibit mitogen- and anti-CD3-induced T cell proliferation. Early events in T cell activation, including calcium flux and phosphotyrosine kinase activity, were intact in the T cells cocultured with the HIV-1- infected hybridomas and monocytes but there was reduced IL-2 production. Addition of exogenous IL-2 restored the proliferative responses. Taken together, these data suggest that alteration of cytokine production and accessory cell function for mitogens and anti-CD3-induced T cell proliferation independent of induction of apoptosis, suppressor factor production, or inhibition of T cell signaling occurs very early after HIV-1 infection and may contribute to the global immunosuppression observed in AIDS.

Altered cytokine production and accessory cell function after HIV-1 infection

We investigated cytokine production and accessory cell function in human macrophage hybridoma cell lines and primary monocytes after infection with HIV-1. HIV-1 infection induced IL-10 production in the macrophage hybridoma cell line with loss of IL-12 1 wk after infection. There were also significant increases in production of IL-10 (537 +/- 521 vs 687 +/- 625 pg/ml) while there was a reduction in IL-12 (6.3 +/- 3.1 vs 1.2 +/- 1.0 pg/ml, p = 0.021) in the primary monocytes 5 days after HIV-1 infection. In addition, the hybridoma cell lines and primary monocytes failed to support PHA, Con A, PWM, or anti-CD3- induced T cell proliferation 1 wk after infection. The viability of the T cells cocultured with the HIV-1-infected macrophage cell lines or the primary monocytes as determined by propidium iodide staining was unaltered and there was no increase in apoptosis-specific DNA strand breaks or increased expression of Bcl-2 in the T cells. No soluble suppressor factor was present, since UV-inactivated supernatants from the hybridoma cell line and primary monocytes failed to inhibit mitogen- and anti-CD3-induced T cell proliferation. Early events in T cell activation, including calcium flux and phosphotyrosine kinase activity, were intact in the T cells cocultured with the HIV-1- infected hybridomas and monocytes but there was reduced IL-2 production. Addition of exogenous IL-2 restored the proliferative responses. Taken together, these data suggest that alteration of cytokine production and accessory cell function for mitogens and anti-CD3-induced T cell proliferation independent of induction of apoptosis, suppressor factor production, or inhibition of T cell signaling occurs very early after HIV-1 infection and may contribute to the global immunosuppression observed in AIDS.

The antiinflammatory and antiviral effects of hydroxychloroquine in two patients with acquired immunodeficiency syndrome and active inflammatory arthritis

OBJECTIVE

To report the antiinflammatory and antiviral effects of hydroxychloroquine (HCQ) treatment in 2 patients with AIDS and inflammatory arthritis.

METHODS

Two patients with AIDS and inflammatory arthritis were treated with HCQ, which was given in a loading dose of 600 mg/day. The maintenance dosage was calculated to remain below 6.5 mg/kg/day. Both patients had initial T cell subset studies; 1 patient, had serum and plasma collected before and after 1 year of HCQ treatment. Assays were performed for T cell subsets, recoverable human immunodeficiency virus type 1 (HIV-1) RNA, mitogen- and antigen-specific proliferation, and interleukin-6 (IL-6) levels. New studies on the use of HCQ as an anti-HIV-1 agent are reviewed.

RESULTS

Both patients had a dramatic decrease in their arthritis activity. Neither patient required immunosuppressive therapy or developed an opportunistic infection. In the patient who was studied after 1 year of therapy, there was a 1-log decrease in recoverable HIV-1 RNA, improved mitogen- and antigen-specific immune responses, and a large decrease in the IL-6 level while taking HCQ. Recent in vitro and in vivo assays in patients with HIV infection have shown similar antiviral and antiinflammatory effects from HCQ.

CONCLUSION

HCQ may exert simultaneous anti-inflammatory and antiviral effects in patients with HIV infection and inflammatory arthritis. If larger studies confirm this observation, it may be the drug of choice in this population of patients.

Hydroxychloroquine treatment of patients with human immunodeficiency virus type 1

Hydroxychloroquine (HCQ), an antimalarial agent used to treat patients with autoimmune diseases, has been shown to suppress human immunodeficiency virus type 1 (HIV-1) replication in vitro in T cells and monocytes by inhibiting posttranscriptional modification of the virus. These in vitro observations have been expanded into an in vivo study of HCQ as a potential anti-HIV-1 agent in HIV-1-infected patients. A randomized, double-blind, placebo-controlled clinical trial was conducted in 40 asymptomatic HIV-1-infected patients who had CD4+ counts between 200 and 500 cells/mm3. Patients were randomly assigned to receive either HCQ 800 mg/d or placebo for 8 weeks. Virologic and immunologic parameters, including HIV-1 ribonucleic acid (RNA) via use of polymerase chain reaction, viral culture, antigen and mitogen responses, and proinflammatory cytokine levels were measured at the beginning and end of the study. The amount of recoverable HIV-1 RNA in plasma declined significantly in the HCQ group over the 8-week period (P = 0.022), while it increased in the placebo group. The percentage of CD4+ T cells remained stable in the HCQ-treated group (18.1 +/- 9.2% before treatment vs 18.6 +/- 10.5% after treatment) and fell significantly in the placebo group (21 +/- 7% before treatment vs 19.3 +/- 6.3% after treatment; P = 0.032). However, this was not reflected as a change in absolute CD4+ counts for either group (HCQ, 262.8 +/- 166 cells/mm3 vs 251 +/- 163 cells/mm3; placebo, 312 +/- 121 cells/mm3 vs 321 +/- 124 cells/mm3). Mitogen- and antigen-specific responses remained constant in the HCQ group while T cell proliferative responses to Candida decreased in the placebo group (4.8 +/- 3.6 x 10(3) SI [stimulation index] vs 3.0 +/- 3.0 x 10(3) SI; P = 0.032). Lastly, serum interleukin 6 levels declined in the HCQ group (14.3 +/- 13.5 U/mL vs 12.0 +/- 16.7 U/mL; P = 0.023) but not in the placebo group (11.3 +/- 8.8 U/mL vs 7.0 +/- 11.7 U/mL); this was coincident with a decrease in serum immunoglobulin (Ig)G (2563 +/- 1352 mg/mL vs 2307 +/- 1372 mg/dL; P = 0.032), compared with the placebo group (2733 +/- 1473 mg/dL vs 2709 +/- 1501 mg/dL). No other parameters, including serum p24 and beta-2 microglobulin levels, were altered by HCQ therapy. HCQ thus may be useful in the treatment of patients with HIV-1 infection.

Cytokine secretion induced by superantigens in peripheral blood mononuclear cells, lamina propria lymphocytes, and intraepithelial lymphocytes

Superantigens are potent inducers of T-cell proliferation and induce a broad range of cytokines, including tumor necrosis factor (TNF), gamma interferon, and interleukin 2 (IL-2). In the present study, we compared the abilities of different staphylococcal superantigens (staphylococcal enterotoxin B [SEB], staphylococcal enterotoxin E [SEE], and toxic shock syndrome toxin 1 [TSST-1]) to stimulate distinct cytokine profiles in peripheral blood mononuclear cells (PBMC), lamina propria lymphocytes (LPL), and intraepithelial lymphocytes (IEL). One million PBMC, LPL, and IEL were stimulated with various concentrations of superantigen (10 to 0.001 ng/ml) for 24, 48, and 72 h. Maximum cytokine production by PBMC, LPL, and IEL was observed for all three superantigens at 48 h at a concentration of 1 ng/ml. In PBMC, SEE and TSST-1 stimulated more IL-2 and gamma interferon than SEB. SEE and TSST-1 also stimulated more TNF and IL-4 production than SEB. In contrast, SEB stimulated more IL-6 than either SEE or TSST-1. In LPL, there was no SEE-induced IL-2 or IL-4 production, but IL-6, TNF, and gamma interferon were induced. SEB similarly induced no IL-2 or gamma interferon from the LPL, but IL-4, IL-6, and TNF were detected. TSST-1 stimulation of LPL resulted in IL-2 and TNF production but no IL-4, IL-6, or gamma interferon. In IEL, SEE induced no IL-2, IL-4, or gamma interferon but produced IL-6 and TNF, while SEB stimulation resulted in no IL-2 or gamma interferon but did result in detectable IL-4, IL-6, and TNF. Taken together, these data indicate that there are significant differences in the cytokine profiles induced by superantigens in LPL and IEL compared with those in PBMC, and these differences may relate to differences in activation requirements.

Impairment of monocytic function after influenza virus infection

In order to analyze the immunosuppression associated with influenza virus infection, we investigated monocytic function in macrophage hybridoma cell lines 5 weeks after infection with two strains of influenza virus. Clones 30 and 63, chosen for stability in long-term culture, were infected with two strains of influenza virus, X-31 and PR-8. Uniform infection of both cell lines was confirmed by intracytoplasmic staining with the antihemagglutinin strain-specific monoclonal antibodies PY 102 and PY 206. One week after infection, clones 30 and 63 lost their ability to stimulate tetanus toxoid-specific major histocompatibility complex (MHC)-matched responder T cells. Coincident with the inability to stimulate MHC-matched T cells, there was diminished surface expression of class II MHC antigens and LFA-1-alpha and LFA-3 compared with that in uninfected cells: DR, 2.5 versus 10.6% (mean channel 0.3 versus 1.5); DQ, 1.6 versus 15.6% (mean channel 0.3 versus 3.0); DP, 5.0 versus 30.9% (mean channel 0.3 versus 2.0). LFA-1-alpha expression was reduced (13.1 versus 20.0%; mean channel 1.5 versus 2.0) while LFA-3 expression remained the same (22.2 versus 324%; mean channel 3.0 versus 3.3). Class I MHC surface antigen expression was unaltered. Cytokine secretion was also perturbed, as interleukin 1-alpha (IL-1-alpha) and IL-1-beta production was lost 1 week after infection. Production of IL-12 and IL-10 was unchanged, while IL-6 production was increased. The viability of the T cells cocultured with 63Flu was unaltered, demonstrating that the inability of the MHC-restricted T cells to proliferate in response to tetanus toxoid was not due to a toxic effect of 63Flu. Interestingly, other accessory functions, including the ability to support mitogen- and anti-CD3-mediated T-cell proliferation, remained intact. These data suggest that alteration of macrophage function relating to viral infection occurs at multiple levels and may contribute to the immunosuppression observed following influenza virus infection.

Detection of a novel macrophage-derived mucus secretagogue (MMS-68) in bronchoalveolar lavage fluid of patients with asthma

BACKGROUND

We have previously described a novel high-molecular-weight macrophage-derived mucus secretagogue (MMS-68) that causes mucuslike glycoconjugate release from cultured airways, nasal explants, and the Ishikawa adenocarcinoma cell line. We have generated monoclonal antibodies against MMS-68 and have developed an antigen-capture ELISA to measure MMS-68 levels in biologic fluids. Using this ELISA, we have demonstrated elevated levels of MMS-68 in the bronchoalveolar lavage fluid (BALF) of smokers and persons chronic bronchitis, in a patient with asthma and bronchorrhea, and in nasal lavage from patients with allergic rhinitis challenged with histamine and methacholine. We have also demonstrated that both spontaneous and lipopolysaccharide induced MMS-68 production is increased in the culture supernatants of monocytes from patients with steroid-dependent asthmas compared with those from normal control subjects.

METHODS

To delineate further a role for MMS-68 in the regulation of mucus secretion in asthma, we measured MMS-68 levels in the BALF of 37 patients with non-steroid-dependent asthma and of 16 control subjects.

RESULTS

There were 21 men and 16 women in the asthma group (age range, 17 to 62 years; mean, 33.8 years) and 11 men and five women in the control group (age range, 18 to 42 years; mean, 27.8 years). There were no statistical differences in either total cell count (145.5 x 103 +/- 75.7 cells/mm3 x 10(3) cells/mm3 vs 134 x 103 +/- 65.9 x 10(3) cells/mm3, p < 0.234) or numbers of alveolar macrophages (103.7 x 10(3) +/- 71.7 x 10(3)/mm3 vs 98.7 x 10(3) +/- 65 x 10(3) cells/mm3, p < 0.244) when the asthmatic group was compared with the control group. The MMS-68 level in the asthmatic group was 2.1 +/- 0.25 micrograms MMS-68 per milligram protein compared with 2.09 +/- 0.26 micrograms MMS-68 per milligram protein (p < 0.256) in the control group.

CONCLUSIONS

There was no correlation between MMS-68 levels and total protein content, numbers of alveolar macrophages, or the production of other macrophage-derived cytokines including interleukin-1, interleukin-6, or tumor necrosis factor in the asthmatic BALF. Mild asthma, which is clinically not associated with mucus hypersecretion, was not associated with elevated levels of MMS-68. We believe that direct correlation exists between mucus hypersecretion and MMS-68 levels.

Effectiveness of a specialized asthma clinic in reducing asthma morbidity in an inner-city minority population

Asthma is the most common chronic disease of childhood and a leading cause of morbidity in adults. Despite significant advances in medical therapy, asthma morbidity and mortality rates have risen dramatically over the past two decades, especially in minority and socioeconomically disadvantaged populations. Numerous intervention programs have been designed in an attempt to reduce asthma morbidity but few have targeted poor or minority populations. The purpose of this study was to assess whether an outpatient intervention program specifically targeted at a high-minority population in East Harlem, in New York City, was successful in reducing asthma morbidity. A retrospective chart review of 84 patient records was conducted. The patients were divided into two groups, an intervention group (n = 45), who were followed by an asthma specialist (allergist/immunologist), and a nonintervention group, followed by a general internist or pediatrician. Outcome variables including clinic walk-in visits, emergency room visits, and hospitalizations were determined and compared in the pre- and postintervention period in both groups. Patients in the intervention group had reduced total walk-in visits (73 vs. 27, p < 0.001), emergency room visits (30 vs. 5, p < 0.001), and hospitalizations (16 vs. 2, p < 0.001). In contrast, patients in the nonintervention group had no change in total walk-in visits (88 vs. 72), increased emergency visits (7 vs. 22, p < 0.05), and no change in hospitalizations (5 vs. 2), respectively. The outpatient intervention program has been successful in reducing asthma morbidity in the high-risk minority community of East Harlem. Future larger studies are warranted to extend this pilot program to other high-risk minority populations.

Patterns of asthma death and near-death in an inner-city tertiary care teaching hospital

Although the pathophysiology of asthma is increasingly understood, asthma deaths continue to increase, especially among non-Caucasians in inner-city urban areas including East Harlem, which has the highest mortality rate in the United States. The cause for this increase is uncertain, but several factors, including poor access to appropriate medical management, the overuse of beta agonists, environmental precipitants, or more severe disease, have been proposed as contributing factors. The Mount Sinai Hospital is a 1300-bed, tertiary care university hospital located at the juncture of East Harlem, an inner-city, predominantly Hispanic and African-American neighborhood, and Carnegie Hill, an affluent, predominantly Caucasian residential area. We examined asthma deaths (13) and near-deaths (20) at the Mount Sinai Hospital from 1986 to 1992 to determine risk factors and compared them to an age- and demographically matched control group. All of the information was based on retrospective patient chart reviews, and the parameters considered included ethnicity, insurance status, poverty level, and medications including the use of beta agonists. All of the asthma deaths and near-deaths except 1 occurred in low-income African-American and Hispanic patients (x = 16.9) However, steroid and beta-agonist usage were comparable in the adverse outcome group compared to the control group. Our results confirm that adverse outcome asthma in East Harlem occurred predominantly among non-Caucasians of low socioeconomic status. We conclude that ethnicity and socioeconomic status play an important role in asthma death and near-death at our institution.(ABSTRACT TRUNCATED AT 250 WORDS)

Impairment of monocytic function during Trypanosoma cruzi infection

During acute infection, Trypanosoma cruzi, the etiologic agent of Chagas' disease, causes immunosuppression by mechanisms that are not fully delineated. Since mononuclear phagocytes are major target cells in trypanosomiasis, we investigated monocytic function during acute T. cruzi infection. A series of human monocyte and macrophage hybridomas, which represent clonal expansions of subpopulations of human macrophages and possess many normal monocytic functions, were successfully infected with T. cruzi. Clones 63 and 53, chosen for stability in long-term culture, were studied extensively after infection with T. cruzi. Following infection of clone 63, the trypomastigote did not transform into the amastigote multiplicative form, suggesting that clone 63 did not support the entire T. cruzi life cycle. The typical life cycle was completed in clone 53, and thus, clone 53 was used in subsequent studies. Following infection, clone 53 lost expression of class II antigens compared with uninfected cells (DR of 2.2% versus 29.3% and mean channel fluorescence intensity [mean channel] of 4.1 versus 30.5, DQ of 2.3% versus 15.6% and mean channel of 5.4 versus 11.4, and DP of 6.3% versus 27.2% and mean channel of 10.3 versus 33.4). The expression of Class I antigens (87.9% versus 82.8%; mean channel, 20 versus 120) and the adhesion molecules LFA-1 (72.9% versus 28.7%; mean channel, 50.7 versus 23.7) and LFA-3 (10.8% versus 0.7%; mean channel, 20.7 versus 15.1) was increased in infected cells compared with that in uninfected cells. Production of interleukin-1 alpha was decreased and interleukin-6 production was increased in infected clone 53 compared with those in the uninfected cells, while production of tumor necrosis factor alpha was increased.(ABSTRACT TRUNCATED AT 250 WORDS)

In vivo detection of a novel macrophage-derived protein involved in the regulation of nasal mucus-like glycoconjugate secretion

BACKGROUND

We recently described a novel 68 kd mucus secretagogue (MMS-68) derived from human monocytes, pulmonary macrophages, and a macrophage hybridoma, clone 63. We detected MMS-68 in monocyte culture supernatants from patients with steroid-dependent asthma and in bronchoalveolar lavage fluid from patients with chronic bronchitis by antigen capture ELISA and in normal lung tissue by immunohistochemistry.

METHODS

To determine a role for MMS-68 in the regulation of nasal mucus, we labeled human nasal turbinates with tritiated glucosamine and assayed for the ability of the previously purified MMS-68 (stock solution) to induce mucus-like glycoconjugate release (MLGC). We also performed immunohistochemistry stains with an anti-MMS-68 antibody (1-D-10) on frozen sections (n = 5) of nasal turbinates from patients with allergic and nonallergic rhinitis who were undergoing rhinoplasty and measured MMS-68 levels in nasal lavages from patients who were undergoing topical nasal histamine or methacholine challenge.

RESULTS

MMS-68 is a potent nasal MLGC secretagogue causing a dose-dependent increase in MLGC release in vitro. Staining revealed a subepithelial distribution for MMS-68. Antigen capture ELISA of nasal lavages demonstrated mean MMS-68 levels from saline control challenge of 0.9 +/- 0.5 micrograms MMS-68 per milligram of protein (n = 5), 8.6 +/- 1.4 micrograms MMS-68 per milligram of protein from histamine challenge and 20.7 +/- 2.3 micrograms MMS-68 per milligram of protein (n = 5) after methacholine challenge.

CONCLUSION

Taken together these data suggest that MMS-68 may play a role in the normal regulation of mucus secretion.

Progressive impairment of monocytic function in HIV-1-infected human macrophage hybridomas

Using human macrophage hybridomas infected with HIV-1, we investigated monocyte function over a 5-week period after HIV-1 infection. Two clones, 63 and 30, were infected with HIV-1IIIB. Infection was documented by RT activity (15 x 10(6) cpm/ml), intracytoplasmic staining with an anti-p24 antibody, in situ hybridization with an HIV-1-specific riboprobe, and electron microscopy showing intracytoplasmic virus. Two weeks after infection, clones 63 and 30 lost expression of all class II antigens (DR, 81.7 vs. 0%; DQ, 15.6 vs. 0%; and DP, 76.9 vs. 0%) while retaining expression of class I (87.4 vs. 84.1%), LFA-1 (82.4 vs. 83.1%), and LFA-3 (79.1 vs. 74.7%) antigens when compared to uninfected cells. When tested for functional integrity, infected but not uninfected clone 63 cells failed to stimulate a tetanus-specific MHC-restricted T cell proliferative response 2 weeks after infection. Cytokine secretion and antigen processing were also perturbed as production of IL-1 was abolished 2 weeks after infection (although IL-6 secretion was augmented) and infected clone 63 cells failed to process exogenous antigen. Last, the viability of T cells cocultured with infected clone 63 was dramatically decreased 35 days after infection (85 vs. 15%). There was no evidence of transmission of HIV-1 to T cells, suggesting a toxic effect of infected clone 63. Taken together, these data suggest that altered macrophage function in our system occurs at multiple levels, which may account for the early immunological defects described in HIV-1 infection.

Prevalence of atopy in an inner-city asthmatic population

Seventy-three patients at The Mount Sinai Hospital Emergency Room were investigated to determine the prevalence of atopy in asthma in a predominantly black and Hispanic inner-city population. Serum IgE levels and radioallergosorbent tests (RASTs) to eight common inhalant allergens were measured in both the asthmatic group and a nonasthmatic emergency-room control group. The mean total IgE level for the asthma group was 263.8 IU/mL compared to 63.8 IU/mL in the control group (p = 0.032), and 60% of the asthmatics had IgE levels in the atopic range (> 100 IU/mL). Increases in IgE were associated with age under 50 years but did not reach statistical significance. Cockroach, dust mite, cat, and dog were the most common RASTs in the asthmatic group; there were no positive RASTs in the control group. There was a correlation (p = 0.04) between age (less than 50 years) and increased numbers of positive RASTs. These results are similar to those of other studies that have associated atopy with asthma in rural and suburban populations. These data demonstrate that atopy is common in the asthmatic patients seen in The Mount Sinai Hospital Emergency Room and strongly suggest that management of atopic factors should become routine in the care of adult asthmatic patients.

A novel human macrophage-derived intestinal mucin secretagogue: implications for the pathogenesis of inflammatory bowel disease

BACKGROUND

A novel 68-kilodalton macrophage-derived protein (MMS-68) stimulating mucin release from respiratory epithelial cells has previously been described. In this study, the effect of MMS-68 on mucin release from intestinal epithelial cells was determined.

METHODS

Colonic epithelial cells isolated from normal colon, ulcerative colitis, Crohn's colitis, and cells from three colon cancer cell lines were labeled with [3H]-glucosamine and stimulated with MMS-68. High molecular weight glycoproteins were precipitated and counted.

RESULTS

In all of the cells tested, MMS-68 enhanced mucin secretion by 1.46-2.0-fold above control values, comparable to the level achieved with carbachol (10(-5) mol/L). Coincubation with anti-MMS-68 monoclonal antibody 1D-10 blocked this bioactivity. Freshly isolated intestinal macrophages reacted with monoclonal antibody 1D-10. Immunofluorescent staining of frozen sections revealed the presence of MMS-68-producing cells (macrophages) in the lamina propria of normal colon and Crohn's colitis, with weaker expression in ulcerative colitis mucosa.

CONCLUSIONS

Intestinal macrophages produce a novel mucin secretagogue, which is as potent as carbachol for stimulating mucin secretion from colonic epithelial cells. This factor may explain, in part, the alterations in mucin secretion often seen in inflammatory bowel disease.

Selective regulation of cytokine secretion by hydroxychloroquine: inhibition of interleukin 1 alpha (IL-1-alpha) and IL-6 in human monocytes and T cells

To study the effect of hydroxychloroquine on cytokine production by monocytes and T cells, cells were pretreated with varying concentrations of hydroxychloroquine and stimulated with lipopolysaccharide (monocytes), phytohemagglutinin or anti-CD-3 monoclonal antibodies (T cells). Interleukin 1 alpha (IL-1-alpha), IL-6 and tumor necrosis factor alpha (TNF-alpha) production were measured from the stimulated monocytes and IL-2, IL-4 and gamma interferon (IFN-gamma) were measured from the stimulated T cells. Hydroxychloroquine inhibited production of IL-1-alpha (monocytes) and IL-6 (T cells and monocytes). In contrast IL-2, IL-4, TNF-alpha and IFN-gamma production were not affected. Preferential inhibition of IL-1-alpha production by monocytes and IL-6 production by T cells and monocytes may contribute to its antiinflammatory effect in autoimmune diseases.

Inhibition of human immunodeficiency virus type 1 replication by hydroxychloroquine in T cells and monocytes

Chloroquine and its analogue hydroxychloroquine (HCQ) have been shown to inhibit a variety of viral infections including influenza and adenovirus through blockade of viral entry via inhibition of endosomal acidification. We have extended these observations to human immunodeficiency virus type 1 (HIV-1) infection utilizing primary T cells and monocytes, a T cell line (CEM), and a monocytic cell line (U-937). HCQ inhibited HIV-1 replication (> 75%), as measured by reverse transcriptase activity, in the primary T cells and monocytes as well as the T cell and monocytic cell lines. HCQ itself had no anti-reverse transcriptase activity and was not toxic to the cells at concentrations inhibitory to viral replication. Intracytoplasmic staining with an anti-p24 antibody, 24 h after infection, revealed the presence of intracytoplasmic virus, suggesting that the drug does not block viral entry. The production of steady-state HIV-1 mRNA was not affected by HCQ in that comparable levels of HIV-1 mRNA could be detected by Northern blot analysis and by in situ hybridization in both the HCQ-treated and untreated cells. However, HCQ does appear to affect production of infectious HIV-1 virions because viral isolates from HCQ-treated cells could not infect target CEM cells. These data suggest that HCQ may be useful adjunctive therapy in the treatment of HIV-1 infection.

In vivo detection of a novel macrophage-derived protein involved in the regulation of mucus-like glycoconjugate secretion

We previously described a novel 68,000 D macrophage-derived protein (MMS-68) that can stimulate mucus-like glycoconjugate (MLGC) secretion from cultured human airways, respiratory epithelial cells, and the ishikawa adenocarcinoma cell line. To better characterize this mucus secretagogue, we generated monoclonal antibodies against MMS-68 by injecting crushed SDS-PAGE gel slices containing this protein into Balb-C mice followed by fusion with SP2/0, a nonsecreting mouse myeloma cell line. A panel of monoclonal antibodies was produced that identified the 68,000 D MMS by immunoblot analysis and immunoprecipitation. The monoclonal antibodies detected MMS-68 in normal peripheral blood monocytes and pulmonary macrophages by cytofluorographic analysis and in human airways as determined by immunohistochemistry. Utilizing the monoclonal antibodies, an antigen-capture ELISA assay was developed. Statistically significant elevations in levels of MMS-68 were detected in bronchoalveolar lavage fluid (BALF) of chronic bronchitic subjects and cigarette smokers and in monocyte culture supernatants from steroid-dependent asthmatic patients compared to normal control subjects. The 68,000 D MMS is a potent secretagogue and may play an important role in the regulation of mucus secretion, especially in chronic bronchitis and steroid-dependent asthma.

Productive nonlytic human immunodeficiency virus type 1 replication in a newly established human leukemia cell line

We have isolated a lymphoid cell line, MDS, from the pleural exudate of a patient with chronic myelomonocytic leukemia. The cells are biphenotypic, containing various T-cell and myeloid markers, and are surface negative for CD4 and CD8 but have low CD4 mRNA. The cells grow in suspension with a doubling time of 15 hr, have been karyotyped as trisomy 21, are negative for human immunodeficiency virus type 1 (HIV-1), and are tumorigenic in the nude mouse. We have isolated two stable HIV-1-producing cell lines, MDS-T, by transfecting MDS cells with pHXBc2, and MDS-I, by infecting MDS cells with HIV-1IIIB. In 24 hr, 1 x 10(5) MDS-T or MDS-I cells produce 46 ng of p24 per ml and reverse transcriptase that is capable of incorporating 0.2 pmol of [32P]TTP into oligo(dT).poly(A). Ultrastructural studies showed numerous mature viral particles in MDS-T and MDS-I cells that are capable of infecting T cells. HIV-1 infection could be inhibited by 25% in the MDS cells with the anti-CD4 antibody Leu 3a. For over a year MDS-T and MDS-I cells have been producing high concentrations of HIV-1 in culture. A subclone derived from the MDS cells behaves like the parent cells when transfected or infected with HIV-1. In contrast to other T-cell lines, neither phorbol 12-myristate 13-acetate nor tumor necrosis factor alpha stimulated the replication of HIV-1, whereas bromoadenosine 3',5'-cyclic monophosphate or interferon alpha caused 50% and 80% inhibition of reverse transcriptase production, respectively. These chronically infected T-cell lines are a useful model system to study the effect of anti-HIV agents and cellular factors required for HIV-1 replication.

Inhibition of HIV-1 productive infection in hepatoblastoma HepG2 cells by recombinant tumor necrosis factor-alpha

OBJECTIVE

To evaluate the role of liver cells in and the effect of tumor necrosis factor-alpha (TNF-alpha) on HIV-1 replication.

METHODS

Human hepatoblastoma HepG2 cells were infected with various strains of HIV-1 and the effect of TNF-alpha treatment, either before or after infection, was monitored by p24 antigen assays. Northern blot analysis and gel retardation assays were performed to determine the expression of CD4 and HIV-1 trans-acting region (TAR)-binding proteins in these cells, respectively.

RESULTS

HepG2 cells are CD4+ and support active HIV-1 replication, producing infectious virions, as measured by both p24 production and ability to infect T-cell lines with the virus produced by HepG2 cells. In contrast to the stimulatory effect of TNF-alpha on HIV-1 replication in T-cells and monocytes, up to 200 U/ml TNF-alpha treatment, at various times, either before or after HIV-1 infection, substantially inhibited p24 antigen production in HepG2 cells without causing any remarkable cytotoxicity. Gel-retardation assay revealed enhancement of a DNA-binding protein in TNF-alpha-treated HepG2 cells that binds to a specific sequence of the HIV-1 TAR, compared with the untreated control.

CONCLUSIONS

These results indicate the importance of cellular factor(s) in HIV-1 infection and suggest that cytokines in different tissues can induce opposite effects. TAR-binding protein may act as an inhibitory factor for HIV-1 replication in the HepG2 cell line.

Persistent infection of human adenovirus type 5 in human monocyte cell lines

Adenovirus infection of human monocyte hybridoma cell lines and the fusion partner U937 was investigated. Adenovirus adsorbed poorly to these cells as well as primary human alveolar macrophages. The virus-binding experiments showed a 100-fold reduction in apparent viral binding to these cells compared to the permissive HeLa cells. Adsorption of adenovirus to these cells could be enhanced by preincubation of adenovirus with its antiserum. Following entry into the cells amplification of adenovirus DNA was detected starting at 2 days postinfection but few mature virus particles were produced. The infected cultures survived the infection and continued to grow for more than a year. In these chronically infected cultures, linear adenovirus DNA persisted up to 200 copies per cell and a small amount of mature virus was produced. Infectious center assay and cell cloning experiments showed that the majority of the cells in the chronically infected cultures harbor adenovirus genome. These results indicate that restriction of replication of human adenovirus type 5 at the late phase results in persistent infection of U937 and the human monocyte hybridoma cell lines.

Positive Kveim test in patients with coexisting sarcoidosis and human immunodeficiency virus infection

We present two cases of sarcoidosis complicated by HIV infection. Each case had a different level of sarcoidosis activity and coexisted with either an AIDS-related infection or a HIV-positive state. Manifestations of sarcoidosis were not apparent in the patient with the AIDS-defining opportunistic infection, but were active in the patient with asymptomatic HIV infection. Both patients had granulomatous reactions to Kveim antigen, and one had such a reaction following an AIDS-defining infection. These findings suggest that non-T-cell mechanisms may be involved in granuloma formation in sarcoidosis.

Activation of the human immunodeficiency virus type 1 long terminal repeat by vaccinia virus

A variety of DNA viruses are known to activate gene expression directed by the long terminal repeat (LTR) of human immunodeficiency virus type 1 (HIV-1). In light of the proposed use of recombinant vaccinia virus for HIV-1 vaccines, evaluation of the role of vaccinia virus in HIV-1 activation is warranted. To investigate whether vaccinia virus induces HIV LTR-directed gene expression, transient expression assays in Jurkat cells persistently infected with vaccinia virus (Jvac) using plasmid DNA containing the LTR linked to the bacterial chloramphenicol acetyltransferase (CAT) gene were performed. CAT activity in Jvac cells was always recorded, although the level appears to fluctuate independently of virus titers. Dual intracytoplasmic staining and fluorescence-activated cell sorter analysis showed that CAT activity was expressed in the infected cells. CAT expression was not due to plasmid replication, since plasmid DNA extracted from Jvac cells 48 h after transfection was restricted only by enzymes which recognize methylated sequences, indicating a prokaryotic source for the DNA. These findings suggest that a factor(s) present in vaccinia virus-infected cells is capable of activating the LTR of HIV-1.

Stimulation of lymphokines in Jurkat cells persistently infected with vaccinia virus

The response of the human CD4+ T-cell line Jurkat to infection with vaccinia virus was investigated. Virus titers peaked approximately 3 to 4 days after infection, while cell growth paralleled that of uninfected cells, indicating that growth rates were not appreciably affected by viral infection. Results from plaque assays and fluorescence-activated cell sorter (FACS) analyses of virus antigens demonstrated that a persistent infection in which the percentage of infected cells and the virus titers fluctuated from passage to passage was established. Further characterization of the persistent infection revealed that the virus influences cellular functions. Induction of interleukin-2 (IL-2) and IL-2 receptor alpha (IL-2R alpha) in Jvac cells was shown by enzyme-linked immunosorbent assay and FACS analysis, respectively. Hybridization of cellular RNA with cloned probes confirmed the increased IL-2 expression and demonstrated that Jvac cells also expressed more IL-6 but not gamma interferon (IFN-gamma) or IL-1 beta. Dual-antibody staining and FACS analysis for vaccinia virus antigens and IL-2R alpha indicated that IL-2R alpha expression was restricted to the infected cells. Jvac cells were also resistant to superinfection, an additional proof that persistent infection elicited phenotypic changes in the cell population.

Isolation and characterization of a macrophage-derived high molecular weight protein involved in the regulation of mucus-like glycoconjugate secretion

Pulmonary macrophages release a variety of mediators that are involved in inflammatory processes and probably are involved in respiratory mucus secretion. Conditioned media obtained from activated pulmonary macrophages were found to contain a protein that functioned as a secretagogue for mucus-like glycoconjugate (MLGC) in an in vitro bioassay. A human macrophage-derived hybridoma cell line, HB-63, exhibited the same properties and was very useful in obtaining large amounts of the protein for purification and characterization. With ultrafiltration membranes and gel electrophoresis, the protein isolated from the conditioned media of zymosan- or lipopolysaccharide-treated cells was found to have a molecular weight of approximately 68 kd. The purified protein obtained from hybridoma cells and from pulmonary macrophages exhibited strong biologic activity when it was used to stimulate MLGC secretion, both in human airway explants and in an in vitro human secretory epithelial cancer cell line. The proteins from both sources were found to have similar amino acid compositions. Preliminary results indicate the presence of the 68 kd protein in the bronchoalveolar lavage fluid of a patient with severe chronic bronchitis and mucus hypersecretion. The role of this novel protein in the lungs is, so far, speculative. The 68 kd protein may be a useful tool for studying the biosynthesis and regulation of MLGC secretion and hypersecretion.

Stimulation of distinct T cell subsets in MLR using human macrophage hybridomas differentially expressing class II antigens

Recognition of class II antigens by alloreactive T cells is thought to be the major mechanism by which tissues undergo rejection. However, the specific role of the various class II antigens in the stimulation of these alloreactive cells remains to be elucidated. We have recently generated a series of human monocyte hybridomas that express distinct patterns of class II antigen expression. HLA-DR+ as well as HLA-DR-DP+DQ+ hybrids were capable of promoting T cell proliferation in a unidirectional mixed lymphocyte reaction. T cells stimulated by the HLA-DR+ clone 16.1 were predominantly of the CD4 (helper/inducer) phenotype. In contrast, T cells stimulated by the HLA-DR-DP+DQ+ clone 13 appear to reside in the CD8+ T cell subpopulation. Functional assessment of the T cell blasts generated in these cultures demonstrated a predominant helper T cell effect by those T cells stimulated by the HLA-DR+ clone 16.1, while suppressor cell activity was exhibited by T cells stimulated with the HLA-DR-DP+DQ+ clone 13. These data suggest that there may be a differential role for distinct class II molecules in the stimulation of T cell subpopulations.

The role of atopy in asthma

Allergy plays an important role in chronic asthma. Aeroallergens, both indoor and outdoor, provide a constant source of bronchial inflammation that increases bronchial hyperreactivity. This increased reactivity lowers the threshold of response to nonspecific triggers of asthma flares such as viral infections, pollutants, and cold air. Asthma is a chronic inflammatory disease in much the same way that the rheumatic diseases are. In that respect, therapy should be directed at reducing inflammation, as it is in the rheumatic diseases. Along these lines, newer approaches to asthma therapy should emphasize steroids as first-line treatment. In this way, therapy is targeted against the underlying inflammation that causes the bronchial obstruction, rather than treating with bronchodilators such as theophylline and B agonists. The effect of such continuous antiinflammatory therapy is decreased airway hyperresponsiveness, which has obvious clinical benefit.

Cytokines in Alzheimer's disease

1. Human astrocytoma cells produced biologically active interleukin-6 when treated with a variety of agents including bacterial lipopolysaccharides, viruses, and interleukin-1. 2. Both human recombinant IL-6 and IL-6 produced by stimulated astrocytes promoted differentiation of cultured neuronal cells and reduced survival time in culture. 3. Interleukin-6 and interleukin-1 stimulated the synthesis of the Alzheimer's disease beta-amyloid precursor protein. 4. Cytokines may be involved in stimulation of dystrophic neuritic sprouting, neuronal death, and amyloid deposition noted in the brains of Alzheimer's disease patients.

Identification of subpopulations of human macrophages through the generation of human macrophage hybridomas

We have generated a series of human macrophage hybridomas by fusing an HGPRT-deficient promonocytic cell line, U937, with macrophages obtained by allowing monocytes to mature into macrophages in teflon bags. The fusions were documented as true hybrids by the acquisition of donor class I molecules, as well as donor derived macrophage surface antigens. The hybridomas represent clonal expansion of individual macrophages, retaining the surface antigen expression and functional capacity of the normal donor cells including cytokine production and stimulation in a mixed lymphocyte reaction. These cell lines differentially express Vmax antigens found on normal macrophages, potentially identifying subpopulations of macrophages. These lines may be useful not only to study normal macrophage function but may be relevant to a variety of disease states where expansion of subpopulations of macrophages identified by Vmax antigens may be important in disease pathogenesis.

Surface expression of CD-4 does not predict susceptibility to infection with HIV-1 in human monocyte hybridomas

In contrast to T-cell lines, where CD-4 expression may predict susceptibility to HIV infection, in monocyte hybridomas, presence or absence of surface CD-4 does not appear to be the determining factor of susceptibility to HIV infection. One clone, 20, was documented to be CD-4 negative by surface immunofluorescence as well as by immunoprecipitation. Both CD-4+ and CD-4- human monocyte hybridomas, representative of peripheral blood monocytes were readily infected with HIV (strains IIIB and BR-1 and a variety of patient isolates) as assessed by p24 Ag secretion reverse transcriptase activity and in situ hybridization. Infection occurred in the absence of antibody to HIV suggesting a non Fc mediated process as had been previously described. These data suggest that alternative mechanisms, such as non-specific phagocytosis, may exist for entry of HIV into peripheral blood monocytes. Given these findings, treatment for AIDS, such as the use of soluble CD-4, may not be effective long term, as monocyte infection may still occur and serve as a reservoir for subsequent viral infection of T cells.