CECR1-mediated cross talk between macrophages and vascular mural cells promotes neovascularization in malignant glioma.

Glioblastomas (glioblastoma multiforme, GBM) are most malignant brain tumors characterized by profound vascularization. The activation of macrophages strongly contributes to tumor angiogenesis during GBM development. Previously, we showed that extracellular adenosine deaminase protein Cat Eye Syndrome Critical Region Protein 1 (CECR1) is highly expressed by M2-like macrophages in GBM where it defines macrophage M2 polarization and contributes to tumor expansion. In this study, the effect of CECR1 in macrophages on tumor angiogenesis was investigated. Immunohistochemical evaluation of GBM tissue samples showed that the expression of CECR1 correlates with microvascular density in the tumors, confirming data from the TCGA set. In a three-dimensional co-culture system consisting of human pericytes, human umbilical vein endothelial cells and THP1-derived macrophages, CECR1 knockdown by siRNA and CECR1 stimulation of macrophages inhibited and promoted new vessel formation, respectively. Loss and gain of function studies demonstrated that PDGFB mRNA and protein levels in macrophages are modulated by CECR1. The proangiogenic properties of CECR1 in macrophages were partially mediated via paracrine activation of pericytes by PDGFB-PDGFRß signaling. CECR1-PDGFB-PDGFRß cross-activation between macrophages and pericytes promoted pericyte migration, shown by transwell migration assay, and enhanced expression and deposition of periostin, a matrix component with proangiogenic properties. CECR1 function in (M2-like) macrophages mediates cross talk between macrophages and pericytes in GBM via paracrine PDGFB-PDGFRß signaling, promoting pericyte recruitment and migration, and tumor angiogenesis. Therefore, CECR1 offers a new portent target for anti-angiogenic therapy in GBM via immune modulation.

Elevated IP-10 and IL-6 from bronchoalveolar lavage cells are biomarkers of non-cavitary tuberculosis.

BACKGROUND: Active TB disease can destroy lung parenchyma leading to cavities. Immune responses that predispose or protect individuals from lung damage during TB are poorly defined. OBJECTIVE: To sample lung immune cells and assay bronchoalveolar lavage (BAL) cell cytokine production. DESIGN: Enrolled subjects (n = 73) had bilateral infiltrates and underwent BAL. RESULTS: All had sputum culture demonstrating Mycobacterium tuberculosis and 22/73 (30%) had cavities on their chest radiograph. Those with cavities at presentation had a higher percentage of polymorphonuclear neutrophils (PMN) in BAL as well as lower inducible protein (IP) 10 (P < 0.01) and interleukin (IL) 6 (P = 0.013) in BAL cell supernatants compared to those without cavities. There was no correlation between cavities and other BAL or serum cytokines. IP-10 was negatively associated with BAL PMN. IP-10 and IL-6 expression above median reduces the odds of cavities by 79% and 78% in logistic regression models. IP-10 and IL-6 clustered with interferon-gamma and tumour necrosis factor-alpha in a principal component analysis, while IL-4 clustered with PMN. CONCLUSION: Increasing IP-10 and IL-6 production by BAL cells is associated with non-cavitary TB in patients who present with radiographically advanced TB. IP-10 and IL-6 may reflect an effective T-helper 1 immune control pathway for TB, attenuating tuberculous lung destruction.

The impact of the World Trade Center attack on FDNY firefighter retirement, disabilities, and pension benefits.

BACKGROUND: Our goal was to examine the effect of the World Trade Center (WTC) attack and subsequent New York City Fire Department (FDNY) rescue/recovery activities on firefighter retirements. We also analyzed the financial impact associated with the increased number and proportion of service-connected "accidental" disability retirements on the FDNY pension system. METHODS: A total of 7,763 firefighters retired between 9/11/1994 and 9/10/2008. We compared the total number of retirements and the number and proportion of accidental disability retirements 7 years before and 7 years after the WTC attack. We categorized WTC-related accidental disability retirements by medical cause and worked with the New York City Office of the Actuary to approximate the financial impact by cause. RESULTS: In the 7 years before 9/11 there were 3,261 retirements, 48% (1,571) of which were accidental disability retirements. In the 7 years after 9/11, there were 4,502 retirements, 66% (2,970) were accidental disability retirements, of which 47% (1,402) were associated with WTC-related injuries or illnesses. After 9/11, the increase in accidental disability retirements was, for the most part, due to respiratory-related illnesses. Additional increases were attributed to psychological-related illnesses and musculoskeletal injuries incurred at the WTC site. Pension benefits associated with WTC-related accidental disability retirements have produced an increased financial burden of over $826 million on the FDNY pension system. CONCLUSIONS: The WTC attacks affected the health of the FDNY workforce resulting in more post-9/11 retirements than expected, and a larger proportion of these retirees with accidental disability pensions.

Hela /-CaD undergoes a DNA replication-associated switch in localization from the cytoplasm to the nuclei of endothelial cells/endothelial progenitor cells in human tumor vasculature.

Caldesmon (CaD) is a major actin-binding protein distributed in a variety of cell types. So far no diversity in functions of the different isoforms were found in in vitro studies. The low molecular weight isoform (Hela /-CaD) was detected in the vasculature of a variety of tumor types in our previous study. Proliferation of endothelial cells/endothelial progenitor cells (ECs/EPCs) is a crucial event for formation of new blood vessels. Here we report the intranuclear translocation of Hela /-CaD in cell cycle activated ECs/EPCs in the vasculature of human tumors. The nuclear translocation coincides with phosphorylation of the molecule and the activation of intranuclear protein kinase p34(cdc2). These findings point to a function of this molecule relating to DNA synthesis which is triggered by cell-cycle signalling pathways. The data challenge and update the generally accepted concept that CaD is a pure cytoplasmic protein in vitro study. It suggests that nuclear translocation of Hela /-CaD serves as an additional regulatory step in the control of mitotic initiation and triggers further investigations in the role of this protein in the regulation of nuclear investigations in the role of this protein in the regulation of nuclear functions.

Differential expression of Hela-type caldesmon in tumour neovascularization: a new marker of angiogenic endothelial cells.

Caldesmon (CaD) is a major actomyosin-binding protein found in various cell types. There are at least two high-molecular-weight isoforms (h-CaD) and four low-molecular-weight isoforms (l-CaD) produced by alternative splicing. The alternatively spliced variants of the l-CaD class are further differentiated by inclusion (Hela l-CaD) or exclusion (WI-38 l-CaD) of exon 1. Currently, nothing is known about differential expression of the Hela l-CaD in tumour neovascularization. In a previous study, expression of the Hela-type transcripts was found in glioma blood vessels but not in the normal cerebral vasculature. To investigate whether the differentially expressed transcripts are translated into protein, a specific antibody against the peptide encoded by exon 1 was raised. Initially, exclusive expression of the protein in glioma vasculature was confirmed. To determine further whether these findings are generalizable to neovascularization in a wide variety of other tumour types, a large cohort of cancers derived from various organs, including breast, lung, kidney, colon, stomach, ovary, uterus, prostate, thyroid, liver, giving a total of 180 cases, were examined. Expression of the Hela l-CaD was restricted to tumour vasculature and was not found in normal blood vessels. Hela l-CaD was preferentially expressed in the early stage of tumour neovascularization and the Hela l-CaD+ endothelial cells (ECs) were frequently enlarged, multinucleated, and developed elongated cell projections or free fragments of cytoplasm, correlating with the features of motile cells. In the Hela l-CaD+ ECs, disassembly of focal adhesion and the formation of podosome-like structures was observed. Therefore, the findings support the notion that quiescent ECs undergo activation of motility, necessary for ubiquitous tumour-associated neovascularization. The data indicate that Hela l-CaD can be considered as a marker for angiogenic ECs during the early stages of tumour neovascularization.

Differential expression of splicing variants of the human caldesmon gene (CALD1) in glioma neovascularization versus normal brain microvasculature.

Caldesmon is a cytoskeleton-associated protein which has not yet been related to neoplastic angiogenesis. In this study we investigated the expression of the caldesmon gene (CALD1) splicing variants and the protein expression level in glioma microvessels versus normal brain microvasculature. To exclude sources of splice variant expression from non-vascular components all possible cellular components present in control and glioma samples were pre-screened by laser-capture microdissection followed by RT-PCR before the cohort study. We discovered differential expression of the splicing variants of CALD1 in the tumor microvessels in contrast to normal brain microvasculature. Missplicing of exons 1, 1 + 4, and 1' + 4 of the gene is exclusively found in glioma microvessels. To exclude the possibility that this missplicing results from splice-site mutations, mutation scanning was performed by a coupled in vitro transcription/translation assay (IVTT). No premature stop mutations were traced by the IVTT. The transcriptional changes consequently resulted in up-regulation at the protein expression level. The up-regulated expression of caldesmon was coincident with the down-regulated expression of tight junction proteins (occludin and ZO-1). The results support the notion that missplicing of the CALD1 gene in glioma microvasculature is an independent epigenetic event regulated at the transcriptional level. The event coexists with tight junction (TJ) breakdown of the endothelial cells in glioma microvasculature. The data reveal a novel mechanism contributing to dysfunctionality of glioma neovascularization.

Surface complexation of ferrous iron and carbonate on ferrihydrite and the mobilization of arsenic.

Surface complexation models are commonly used to predict the mobility of trace metals in aquifers. For arsenic in groundwater, surface complexation models cannot be used because the database is incomplete. Both carbonate and ferrous iron are often present at a high concentration in groundwater and will influence the sorption of arsenic, but the surface complexation constants are absent in the database of Dzombak and Morel. This paper presents the surface complexation constants for carbonate and ferrous iron on ferrihydrite as derived for the double-layer model. For ferrous iron the constants were obtained from published data supplemented by new experiments to determine the sorption on the strong sites of ferrihydrite. For carbonate the constants were derived from experiments by Zachara et al., who employed relatively low concentrations of carbonate. The double-layer model, optimized for low concentrations, was tested against sorption experiments of carbonate on goethite at higher concentration by Villalobos and Leckie, and reasonable agreement was found. Sorption was also estimated using linear free energy relations (LFER), and results compared well with our derived constants. Model calculations confirm that sorption of particularly carbonate at common soil and groundwater concentrations reduces the sorption capacity of arsenic on ferrihydrite significantly. The displacing effect of carbonate on sorbed arsenate and arsenite has been overlooked in many studies. It may be an important cause for the high concentrations of arsenic in groundwater in Bangladesh. Sediments containing high amounts of sorbed arsenic are deposited in surface water with low carbonate concentrations. Subsequently the sediments become exposed to groundwater with a high dissolved carbonate content, and arsenic is mobilized by displacement from the sediment surface.

[Tuberculosis in patients with acquired immune deficiency syndrome].

HIV-1 infection is a major cause of worldwide epidemic of tuberculosis. In Japan, the cumulative number of the patients reported is 131 by the end of 1999 with 10 to 20 annual new cases. Most of Japanese cases are advanced AIDS patients with low CD4 number less than 100/microliter. The peak age of Japanese patient is 40 to 60 years old, whereas that of foreigners is 20-30 years old, suggesting that most Japanese cases are recurrent tuberculosis. There is increasing clinical evidence that coinfection with M. tuberculosis accelerates progression of AIDS. We found that, in vivo, HIV-1 load and mutation increase in involved lung segments in patients with pulmonary tuberculosis. We also reported that Mycobacterium tuberculosis stimulates HIV-1 replication by enhancing transcription on the 5' LTR in a macrophage cell line, THP-1, in vitro. In contrast, HIV-1 replication is suppressed by M. tuberculosis infection of monocytes derived macrophages (MDM) or differentiated monocytic THP-1 cells. We observed that HIV-1 5' LTR function was repressed in PMA differentiated THP-1 cells after co-infection with M. tuberculosis. Point mutations in C/EBP-beta binding domains of the HIV-1 LTR negative regulatory element (NRE) abolished promoter repression. Monocyte-derived macrophages and differentiated THP-1 cells increased expression of the 16 kDa inhibitory from of C/EBP-beta after M. tuberculosis coinfection. Bronchoalveolar lavage cells obtained from normal controls and alveolar macrophages from uninflamed lung of tuberculosis patients also expressed the 16 kDa inhibitory form of C/EBP-beta. However, alveolar macrophages from lung segments involved with pulmonary tuberculosis had markedly reduced C/EBP-beta expression. These data suggest that 16 kDa isoform of C/EBP-beta plays an important role for the control of HIV-1 replication in macrophages. We propose derepression of HIV-1 LTR mediated transcription as one mechanism for enhanced HIV-1 replication observed in pulmonary tuberculosis.

Differentiation of monocytes to macrophages switches the Mycobacterium tuberculosis effect on HIV-1 replication from stimulation to inhibition: modulation of interferon response and CCAAT/enhancer binding protein beta expression.

HIV-1 replication is inhibited in uninflamed lung macrophages and is stimulated during tuberculosis. Attempts to recapitulate activation of HIV-1 replication in primary monocytes and macrophages ex vivo and in the untreated and PMA-treated THP-1 cell line model in vitro have produced opposite results depending on the state of differentiation of the cells. After infection with Mycobacterium tuberculosis, monocytes enhanced HIV-1 replication and produced a stimulatory 37-kDa CCAAT/enhancer binding protein beta (C/EBPbeta) transcription factor, whereas macrophages suppressed HIV-1 replication and produced an inhibitory 16-kDa C/EBPbeta transcription factor. IFN-beta induced inhibitory 16-kDa C/EBPbeta in macrophages, but had no effect on C/EBPbeta expression in monocytes. Macrophages, but not monocytes, were able to activate IFN-stimulated gene factor-3 (ISGF-3), a transcription factor composed of STAT-1, STAT-2, and IFN regulatory factor (IRF)-9, after infection with M. tuberculosis or stimulation with type I IFN. Macrophages expressed IRF-9 DNA-binding activity, but monocytes did not, and addition of the IRF-9 component reconstituted ISGF-3 in extracts of IFN-treated monocytes. Modulation of IFN responsiveness upon differentiation occurred at least in part through a post-transcriptionally regulated increase in IRF-9 expression. Both monocytes and macrophages maintained IFN responsiveness, activating STAT-1 homodimer formation and transcription of the STAT-1 gene after IFN stimulation. In addition, both monocytes and macrophages were able to activate NF-kappaB upon infection with M. tuberculosis. These results show that induction of ISGF-3, expression of the inhibitory 16-kDa C/EBPbeta, and suppression of HIV-1 replication via a transcriptional mechanism are macrophage-specific responses to infection with M. tuberculosis.

Aberrant expression of immunoglobulin heavy chain genes in Epstein-Barr virus-negative, human immunodeficiency virus-related lymphoid interstitial pneumonia.

The two-step polymerase chain reaction (PCR) and sequencing analysis was used to analyze the immunoglobulin heavy chain variable (Ig V(H)) genes of open-chest biopsy or autopsy samples from five patients with Epstein-Barr virus-negative human immunodeficiency virus (HIV)-related lymphoid interstitial pneumonia (LIP), and the results were compared with those for Ig V(H) genes from five HIV-negative LIP patients. The findings of this study are consistent with the different immunological situations of HIV-related and HIV-negative LIP. (a) The Ig V(H)3 subgroup was underexpressed in three of five cases of HIV-related LIP. In contrast, none of the HIV-negative cases showed this abnormality. Because the Ig V(H)3 subgroup encodes the largest portion of Ig V(H) genes, a depletion of B cells expressing Ig V(H)3 genes reflects a major alteration in the B-cell compartment. (b) All HIV-related LIP cases demonstrated two or three oligoclonal populations. HIV-negative cases showed minor monoclonal or polyclonal populations, but not oligoclonal ones. These oligoclonal populations suggest the coexistence of several occult clonal B-cell populations in HIV-related LIP. (c) Some oligoclonal clones in HIV-related LIP showed mutated framework regions not demonstrated in HIV-negative clones. This degree of variation exceeds the usual mutation rate for frameworks, suggesting a role for framework residues in antigen binding. (d) The frequency of D-D fusions of minor oligoclonal clones (HIV-related LIP) is higher than that of minor monoclonal clones (HIV-negative LIP). Such D-D fusions may enhance the probability of expression of antibodies capable of binding HIV glycoproteins.

Effects of fire fighting uniform (modern, modified modern, and traditional) design changes on exercise duration in New York City Firefighters.

Fire departments have replaced traditional uniforms with modern, more thermal protective gear. Although the new uniforms afford superior burn protection, they may reduce work time. Our purpose was to determine if exercise time was (1) reduced by wearing the modern versus traditional uniform, and (2) increased by a design change to a modified modern uniform (T-shirt and short pants rather than a shirt and long pants under the outer uniform). Male firefighters (n = 23; age 27 to 59) performed a maximum exercise test in gym clothes (maximal oxygen consumption = 46 +/- 9 ml/kg/min) and then returned on separate days to exercise using a moderately high intensity, constant work rate treadmill protocol while wearing fire fighting breathing apparatus and each of three uniforms. Firefighters exceeded anaerobic threshold by 1 minute and eventually reached or exceeded maximum heart rate and maximal oxygen consumption. Exercise time in modern (15 +/- 3 min) was significantly less than in traditional (18 +/- 5 min) uniform. Exercise time in modified modern (17 +/- 5 min) was significantly greater than in modern and not significantly different than in traditional uniforms. The rate of change in oxygen consumption and water loss were significantly affected by uniform type, with faster rates in modern compared with modified modern or traditional uniforms. These findings show the impact that design changes have on energy demands and exercise duration.

Identification of a homozygous deletion at 8p12-21 in a human prostate cancer xenograft.

One of the most frequent genetic abnormalities in prostate cancer is loss of the complete or part of the short arm of chromosome 8, indicating the localization of one or more tumor suppressor genes on this chromosomal arm. Using allelotyping, a frequently deleted region in prostate cancer in a genetic interval of approximately 17 cM between sequence tagged sites D8S87 and D8S133 at chromosome arm 8p12-21 was previously detected. A detailed physical map of this region is now available. Using known and novel polymorphic and nonpolymorphic sequence tagged sites in this interval, a search for homozygous deletions in DNAs from 14 prostate cancer-derived cell lines and xenografts was carried out. In DNA from xenograft PC133, the presence of a small homozygously deleted region of 730-1,320 kb was unambiguously established. At one site, the deletion disrupts the Werner syndrome gene. Data from allelotyping were confirmed and extended by fluorescence in situ hybridization analysis of PC133 chromosome spreads using centromere, YAC, and PAC chromosome 8 probes.

Type I interferon induces inhibitory 16-kD CCAAT/ enhancer binding protein (C/EBP)beta, repressing the HIV-1 long terminal repeat in macrophages: pulmonary tuberculosis alters C/EBP expression, enhancing HIV-1 replication.

We have previously observed that HIV-1 replication is suppressed in uninflamed lung and increased during tuberculosis. In vitro THP-1 cell-derived macrophages inhibited HIV-1 replication after infection with Mycobacterium tuberculosis. Suppression of HIV-1 replication was associated with inhibition of the HIV-1 long terminal repeat (LTR) and induction of ISGF-3, a type I interferon (IFN)-specific transcription factor. Repression of the HIV-1 LTR required intact CCAAT/enhancer binding protein (C/EBP) sites. THP-1 cell-derived macrophages infected with M. tuberculosis, lipopolysaccharide, or IFN-beta induced the 16-kD inhibitory C/EBPbeta isoform and coincidentally repressed HIV-1 LTR transcription. C/EBPbeta was the predominant C/EBP family member produced in THP-1 macrophages during HIV-1 LTR repression. In vivo, alveolar macrophages from uninflamed lung strongly expressed inhibitory 16-kD C/EBPbeta, but pulmonary tuberculosis abolished inhibitory C/EBPbeta expression and induced a novel C/EBP DNA binding protein. Therefore, in vitro, proinflammatory stimulation produces an IFN response inhibiting viral replication by induction of a C/EBPbeta transcriptional repressor. THP-1 cell-derived macrophages stimulated with type I IFN are similar to alveolar macrophages in the uninflamed lung in vivo. In contrast, the cellular immune response in active pulmonary tuberculosis disrupts this innate immunity, switching C/EBP expression and allowing high level viral replication.

Adhesion molecules in iris biopsy specimens from patients with uveitis.

BACKGROUND/AIMS: Earlier studies on intraocular tissue have demonstrated that T lymphocytes play a major role in the pathogenesis of uveitis. Adhesion molecules are immunoregulatory molecules for the interaction between T lymphocytes and vascular endothelium and they play an important role in the recruitment of specific T lymphocytes from the circulation into inflamed tissue. In uveitis an increased expression of some of these adhesion molecules may be expected. METHODS: The presence of adhesion molecules was investigated in iris biopsy specimens from 11 patients with uveitis and eight controls (patients with primary open angle glaucoma) immunohistochemically with a panel of monoclonal antibodies: LECAM (CD 62L), ICAM-1 (CD 54), LFA-1 (CD 11a/18), VCAM-1 (CD 106), VLA-4 (CD 49d), and HECA-452, a marker for high endothelial venules. RESULTS: Positive staining for ICAM-1, LFA-1 and VCAM-1 was found in the iris in a significantly higher number of uveitis patients than in controls. The remaining adhesion molecules were also found in a higher number of uveitis patients than in controls, but this difference did not reach statistical significance. CONCLUSION: An increased expression of adhesion molecules was found in the iris of patients with uveitis, indicating an immunoregulatory function for adhesion molecules in the pathogenesis of uveitis.

Application of biomarkers for exposure and effect of polyhalogenated aromatic hydrocarbons in naturally exposed European otters (Lutra lutra).

In the serious decline of European otters (Lutra lutra) over the last decades, polychlorinated biphenyls (PCBs) are considered to be one of the major factors. As no experiments can be conducted with otters, an eco-epidemiological study was performed to derive no observed effect concentrations (NOECs) for PCBs in the otter. A strong negative correlation was found between hepatic vitamin A and polychlorinated biphenyl (PCB) concentrations expressed as TCDD-equivalents (TEQs), coinciding with a higher incidence of infectious diseases. The no-effect concentration for vitamin A reduction was 2 ng TEQ/g lipid, 10-fold reduction was already found in animals with 5 ng TEQ/g lipid. The TEQ-levels measured with a reporter gene assay based on chemical-activated luciferase expression (the CALUX assay) correlated well with the TEQ levels calculated based on non- and mono-ortho PCB concentrations. The TEQ levels in blood and liver correlated well when expressed on a lipid basis. In living captive otters blood plasma TEQ levels (either measured based on gas chromatography (GC) or CALUX measurement) were lower than in the feral otters, and positively correlated with plasma total and free thyroid hormone but not with plasma retinol levels. Hepatic vitamin A concentration was found to be a physiologically relevant effect parameter. The NOEC for hepatic vitamin A reduction was translated into TEQ levels in fish and sediment. The CALUX response in 50-500 µl blood plasma proved to be a sensitive non-destructive biomarker for quantification of internal TEQ levels.

Mycobacterium tuberculosis enhances human immunodeficiency virus-1 replication in the lung.

We investigated the in vivo effect of coinfection of Mycobacterium tuberculosis on human immunodeficiency virus type 1 (HIV-1) replication using bronchoalveolar lavage (BAL) of 11 HIV-1-infected patients with pulmonary tuberculosis and 10 patients with no lung disease. Lung segments involved with pulmonary tuberculosis had significantly elevated HIV-1 branched DNA (bDNA) levels and p24 in BAL compared with lung segments uninvolved with tuberculosis or with BAL from patients with no lung disease. The BAL viral burden was higher than plasma HIV-1 in tuberculosis patients, indicating local production of virus. BAL HIV-1 bDNA declined over the course of treatment for tuberculosis in three patients who underwent serial bronchoscopies. Tumor necrosis factor-alpha (TNF-alpha) and HIV-1 bDNA particles were strongly correlated (r2 = 0.9, p < 0.01) in lung segments involved with tuberculosis. The deduced amino acid sequence of HIV-1 gp120 V3 region from involved segments of three patients with pulmonary tuberculosis showed basic substitutions associated with altered viral phenotype. Phylogenetic analysis of V3 sequences demonstrated that BAL HIV-1 RNA had diverged from plasma. These data support the conclusion that pulmonary tuberculosis enhances local HIV-1 replication in vivo.

Tuberculosis in HIV-positive patients: cellular response and immune activation in the lung.

The host response to Mycobacterium tuberculosis is dependent on the accumulation and activation of cytotoxic and memory CD4+ T cells, resulting in granuloma formation and delayed type hypersensitivity. We characterized the cellular response of radiographically involved lung segments from 17 HIV-positive and 11 HIV-negative patients with acute tuberculosis (TB) using bronchoalveolar lavage (BAL) and compared the response to uninvolved segments, normal control subjects and peripheral blood. In both HIV-positive and HIV-negative patients, radiographically involved segments had significantly increased numbers of total cells per milliliter, percent of neutrophils recovered, and percent of lymphocytes recovered compared with uninvolved segments or normal control subjects, but HIV-positive patients had a lower proportion of lymphocytes in the involved segments than HIV-negative patients with tuberculosis (19 +/- 5% versus 33 +/- 5%; p < 0.05). Lymphocyte subset analysis demonstrated that HIV-positive patients had markedly reduced percentages of CD4+ lymphocytes (CD4+ lymphocytes in HIV-positive TB involved site 25 +/- 6%; HIV-negative TB involved site 73 +/- 2%; p < 0.01) and an increase in the percentage of CD8+ lymphocytes (HIV positive involved site 61 +/- 6% versus HIV negative involved site 19 +/- 3%; p < 0.01). Immunohistochemistry of lung biopsy tissue in five HIV-negative patients showed similar lymphocyte subset profiles as BAL, indicating that BAL reflects cell populations in tissue granulomas. BAL lymphocytes from four HIV-positive and four HIV-negative tuberculosis patients demonstrated immune activation by staining with a murine antibody to TIA-1, a cytoplasmic protein associated with cytotoxicity and apoptosis (HIV positive 48 +/- 6%, HIV negative 31 +/- 7%, normals 11 +/- 5%). Steady state mRNA for gamma-interferon was decreased in four HIV-positive patients when compared with four HIV-negative patients. IL-8 production was comparable in HIV-negative and HIV-positive patients with focal disease but reduced in two patients with miliary tuberculosis. We conclude that HIV-positive patients with+ tuberculosis have a reduced enrichment and activation of immune cells in the lung, and this failure of a CD4+ alveolitis limits an effective immune response.