Implication of interfering antibody formation and apoptosis as two different mechanisms leading to variable duration of adenovirus-mediated transgene expression in immune-competent mice

This study explores the genetic and immunologic factors involved in the differences in duration of transgene expression following in vivo transduction with recombinant adenoviruses. Different strains of mice (C3H/HeJ [C3H], C57BL/6J [B6], BALB/cJ [Balb/c], C. B10-H2(b)/LiMcdJ [Balb.B], CB6F1/J [(Balb/c x B6)F1], B6C3F1/J [(B6 x C3H)F1], and BALB/cj SCID) received 5 x 10(9) PFU of the first-generation adenovirus, which expresses human alpha1-antitrypsin (Ad/RSVhAAT). While all strains studied showed similar patterns of anti-adenovirus antibody formation, only Balb/c and C3H mice developed significant levels of anti-hAAT antibodies by 8 weeks posttransduction. In addition, while all strains had quantitatively comparable amounts of adenovirus genomes and hAAT mRNA transcripts in the liver 9 days posttransduction, only Balb/c mice had undetectable adenovirus vector genomes and hAAT mRNA in the liver 40 days posttransduction. Terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling staining of liver sections from control and Ad/RSVhAAT-infected mice 5, 9, and 40 days posttransduction suggested that apoptosis was involved in the rapid elimination of transduced hepatocytes in Balb/c mice. Persistent expression of hAAT protein observed in BALB/cj SCID mice suggests that antigen-dependent immunity was essential for this apoptotic process in transduced Balb/c hepatocytes. In contrast to Balb/c mice, the loss of expression in C3H mice did not correlate with the loss of vector genomes or hAAT mRNA. Instead, the anti-hAAT antibodies in C3H but not Balb/c mice were found to interfere with detection of hAAT in the serum. In Balb. B and B6 mice, vector genome, hAAT mRNA transcripts, and hAAT protein levels persisted for at least 40 days posttransduction. This persistence correlated with poor anti-hAAT antibody formation and minimal hepatocyte toxicity. The expression of hAAT in (Balb/c x B6)F1 pups was found to be intermediate between the duration observed in the parental strains, while in (C3H x B6)F1 pups hAAT expression was similar to that seen in the B6 parents, which together support polygenic control of the immune responses in these mice. In summary, these findings suggest that there are three different profiles and at least two defined immune system-mediated mechanisms resulting in the loss of hAAT expression in mice and that different strains differ in the capacity to utilize these mechanisms.

Cytokines and inflammatory mediators do not indicate acute infection in cystic fibrosis

Various treatment regimens and difficulties with research design are encountered with cystic fibrosis (CF) because no standard diagnostic criteria exist for defining acute respiratory exacerbations. This study evaluated the role of serial monitoring of concentrations of selected cytokines and inflammatory mediators in serum and sputum as predictors of respiratory exacerbation, as useful outcome measures for CF, and to guide therapy. Interleukin-8 (IL-8), tumor necrosis factor alpha (TNF-alpha), neutrophil elastase-alpha-1-protease inhibitor complex (NE complex), protein, and alpha-1-protease inhibitor (alpha-1-PI) were measured in serum and sputum collected from CF patients during respiratory exacerbations and periods of well-being. Levels of NE complex, protein, and alpha-1-PI in sputum rose during respiratory exacerbations and fell after institution of antibiotic therapy (P = 0.078, 0.001, and 0.002, respectively). Mean (+/- standard error of the mean) levels of IL-8 and TNF-alpha were extremely high in sputum (13,780 +/- 916 and 249.4 +/- 23.5 ng/liter, respectively) but did not change significantly with clinical deterioration of the patient (P > 0.23). IL-8 and TNF-alpha were generally undetectable in serum, and therefore these measures were unhelpful. Drop in forced expiratory volume in 1 s was the only clinical or laboratory parameter that was close to being a determinant of respiratory exacerbation (P = 0.055). This study provides evidence of intense immunological activity occurring continually within the lungs of adult CF patients. Measurement of cytokines and inflammatory mediators in CF sputum is not helpful for identifying acute respiratory exacerbations.

Sustained secretion of human alpha-1-antitrypsin from murine muscle transduced with adeno-associated virus vectors

Recombinant adeno-associated virus (AAV) vectors have been used to transduce murine skeletal muscle as a platform for secretion of therapeutic proteins. The utility of this approach for treating alpha-1-antitrypsin (AAT) deficiency was tested in murine myocytes in vitro and in vivo. AAV vectors expressing the human AAT gene from either the cytomegalovirus (CMV) promoter (AAV-C-AT) or the human elongation factor 1-alpha promoter (AAV-E-AT) were examined. In vitro in C2C12 murine myoblasts, the expression levels in transient transfections were similar between the two vectors. One month after transduction, however, the human elongation factor 1 promoter mediated 10-fold higher stable human AAT expression than the CMV promoter. In vivo transduction was performed by injecting doses of up to 1.4 x 10(13) particles into skeletal muscles of several mouse strains (C57BL/6, BALB/c, and SCID). In vivo, the CMV vector mediated higher levels of expression, with sustained serum levels over 800 micrograms/ml in SCID and over 400 micrograms/ml in C57BL/6 mice. These serum concentrations are 100,000-fold higher than those previously observed with AAV vectors in muscle and are at levels which would be therapeutic if achieved in humans. High level expression was delayed for several weeks but was sustained for over 15 wk. Immune responses were dependent upon the mouse strain and the vector dosage. These data suggest that recombinant AAV vector transduction of skeletal muscle could provide a means for replacing AAT or other essential serum proteins but that immune responses may be elicited under certain conditions.

Inhibition of NF-kappaB activation in combination with bcl-2 expression allows for persistence of first-generation adenovirus vectors in the mouse liver

NF-kappaB is a key regulator of the innate antiviral immune response, due in part to its transcriptional activation of cytokines and adhesion molecules, which, in turn, function in chemotaxis and activation of inflammatory cells. We reported earlier that viral gene expression in hepatocytes transduced with first-generation (E1-deleted) adenoviruses induced NF-kappaB activation, elevation of serum cytokines, and hepatocellular apoptosis during the first days postinfusion. These events did not occur in mice infused with an adenovirus vector deleted for E1, E2, E3, and late gene expression. In the present study, we used an adenovirus expressing an IkappaBalpha supersuppressor (Ad.IkappaBM) and bcl-2 transgenic mice to unravel the role of virus-induced NF-kappaB activation and apoptosis in the clearance of recombinant adenovirus vectors from the liver. The combined action of IkappaBM and Bcl-2 allowed for vector persistence in livers of C57BL/6 x C3H mice. In the absence of Bcl-2, IkappaBM expression in mouse livers significantly reduced NF-kappaB activation, cytokine expression, leukocyte infiltration, and the humoral immune response against the transgene product; however, this was not sufficient to prevent the decline of vector DNA in transduced cells. Infusion of Ad.IkappaBM caused extended apoptosis predominantly in periportal liver regions, indicating that NF-kappaB activation may protect transduced hepatocytes from apoptosis induced by adenovirus gene products. To confer vector persistence, bcl-2 transgene expression was required to block virus-induced apoptosis if NF-kappaB protection was inactivated by IkappaBM. Expression of gene products involved in early stages of apoptotic pathways was up-regulated in response to virus infusion in bcl-2 transgenic mice, which may represent a compensatory effect. Our study supports the idea that the suppression of innate defense mechanisms improves vector persistence.

Improved hepatic and pancreatic localisation of the equine alpha-1-proteinase inhibitor family of serpins using an antigen enhancement technique and a monoclonal antibody

Equine alpha-1-proteinase inhibitor (API) consists of three, occasionally four, serum glycoproteins. This study investigated the immunohistochemical localisation of equine API in paraformaldehyde fixed, paraffin embedded equine tissue samples of liver, lung, stomach, pancreas, jejunum and colon in five horses using affinity purified sheep polyclonal and protein A purified mouse monoclonal antibodies, whose specificities were verified by Western blotting. Exposing tissue sections to boiling citrate buffer greatly enhanced antigen recovery and improved immunostaining with both antibodies, resulting in discovery of novel tissue distribution patterns for the horse. In the horses studied, all hepatocytes showed some degree of cytoplasmic staining, many having perinuclear intense granular inclusions. This finding is contrary to findings in human studies where hepatocytes of Pi MM phenotype have proven difficult to stain for human API, despite evidence at the molecular level suggesting hepatocytes as the major source of serum API. This discrepancy may be due to the use of different tissue fixation and antigen recovery techniques. In all other tissues examined, the distribution of equine API was similar to human studies.

Acute allergic reaction and demonstration of specific IgE antibodies against alpha-1-protease inhibitor

A 44 yr-old female with severe pulmonary emphysema and reduced alpha-1-protease inhibitor (alpha1-PI) serum levels developed an acute anaphylactic reaction following the third intravenous infusion of human alpha1-PI which was administered to prevent the progression of pulmonary emphysema. Specific immunoglobulin E-antibodies against human alpha1-PI could be demonstrated in the patient's serum using an enzyme allergosorbent test. Because of the risk of further severe anaphylactic reaction, the replacement therapy with alpha1-PI was discontinued. Physicians should be aware of this rare complication.

Automated sample introduction for an imaged capillary isoelectric focusing instrument via high-performance liquid chromatography sampling devices

Sample introduction of an imaged capillary isoelectric focusing (cIEF) instrument is fully automated by using commercially available high-performance liquid chromatography (HPLC) injection valves and autosamplers. Sample carryover can be controlled to under 1% when the valve and separation column are washed for 1 min between sample runs. The standard deviation of peak areas for 20 injections is 3.5%, which includes deviations created by the absorption imaging detector and the isoelectric focusing process inside the 75 microm I.D. column. Sample throughput is up to 10 samples per hour. The instrument has been applied to fast analysis of many proteins including monoclonal antibodies.

Comparison of IgA-alpha1-antitrypsin levels in rheumatoid arthritis and seronegative oligoarthritis: complex formation is not associated with inflammation per se

Serum complexes between IgA and alpha1-antitrypsin (IgA alpha1AT) have been found at raised levels in early rheumatoid arthritis (RA), where they appear to be associated with more erosive disease. We have now measured the levels of these complexes in the sera and synovial fluid of patients with RA and seronegative oligoarthritis to determine whether there is a relationship between complex levels and joint inflammation, and if bacterial stimulation of the mucosa is associated with complex formation in seronegative oligoarthritis. IgA-alpha1AT complexes were measured in patients with RA (n = 75) and seronegative oligoarthritis, with or without definite reactive arthritis (n = 28), using a newly developed sandwich ELISA. The results were compared with serum levels from healthy volunteers (n = 30). IgA and alpha1AT were also measured using ELISA and radial immunodiffusion (RID) techniques, respectively. IgA-alpha1AT complex levels in the sera of RA patients [mean = 25.6 arbitrary units (au)] were significantly higher (P = 0.0034) than those in patients with seronegative oligoarthritis (mean = 12.36 au) and healthy controls (mean = 8.08 au). There was no evidence for the inflamed joint being the source of IgA-alpha1AT complexes since synovial fluid levels were lower than corresponding serum levels, although higher amounts were found in RA than seronegative oligoarthritis (12.84 au vs 4.11 au, P = 0.01). Serum levels of IgA and alpha1AT were similar in RA and seronegative oligoarthritis patients, and were higher than in normals. There was a significant correlation between complex and serum IgA levels in RA (r = 0.49, P < 0.001) and seronegative oligoarthritis (r = 0.53, P < 0.001) patients, although no relationship was found with alpha1AT levels. There was no correlation with other markers of the acute-phase response (C-reactive protein, erythrocyte sedimentation rate), nor with any clinical markers. In RA patients, serum complex levels were significantly higher in seropositive than seronegative patients (30.75 vs 16.48 au, P = 0.03), and we have demonstrated that a small amount of alpha1AT may be complexed with IgA rheumatoid factor. Our data suggest that the formation of IgA-alpha1AT complexes is not associated with inflammation per se, and does not appear to be related to bacterial stimulation of the mucosal immune system in patients with seronegative oligoarthritis.

Alpha-1-antitrypsin phenotyping in ANCA-associated diseases: one of several arguments for protease/antiprotease imbalance in systemic vasculitis

The vasculitic lesions observed in Wegener's granulomatosis may be partly the consequence of proteases released following activation of neutrophils by ANCA. The activity of these proteases, including proteinase 3 (PR3) and elastase, is normally closely restricted to the inflammation site by a large excess of circulating alpha-1-antitrypsin (alpha1AT). Patients with ANCA-positive systemic vasculitis may exhibit a protease/antiprotease imbalance either genetically determined in the rare patients with deficient alpha1AT phenotypes, or more often acquired through both alpha1AT inactivation in various pathological conditions and possible inhibition of PR3/alpha1AT complexation by anti-PR3 ANCA. This imbalance may at least contribute to disease spreading or aggravation.

Constitutive expression of murine CTLA4Ig from a recombinant adenovirus vector results in prolonged transgene expression

The administration of soluble muCTLA4Ig around the time of adenovirus vector mediated gene transfer into murine hepatocytes has been shown to markedly prolong transgene expression, diminish the formation of adenovirus neutralizing antibody, decrease T cell proliferative response and infiltration into the liver without causing irreversible systemic immunosuppression. In this study, an E1/E3-deleted adenovirus vector constitutively expressing murine CTLA4Ig (Ad.RSV-muCTLA4Ig) was constructed in order to determine if production of muCTLA4Ig from within transduced cells (i.e. hepatocytes) would provide a more specific/localized interference with the CD28/B7-1 and B7-2 signaling pathways, and thus result in prolonged transgene expression in vivo at nonimmunosuppressive serum concentrations. In contrast to C3H mice receiving a control adenovirus, transduction with 6 x 10(9) p.f.u. of Ad.RSV-muCTLA4Ig and a reporter adenovirus (2 x 10(9) p.f.u. of Ad.PGK-hAAT) resulted in prolonged reporter gene expression, reduced anti-adenovirus and anti-hAAT antibody production, and attenuated T cell proliferation and IFN-gamma production in response to adenoviral vector. Mice given a constant total amount of adenovirus with diminishing amounts of Ad.RSV-muCTLA4Ig and a constant amount of reporter virus (2 x 10(9) p.f.u. of Ad.PGK-hAAT) demonstrated prolonged reporter gene expression and decreased anti-adenovirus and anti-hAAT antibody production only when high serum levels of muCTLA4Ig were produced. Taken together, these findings suggest that a certain threshold of muCTLA4Ig must be achieved to alter the immune responses and prolong transgene expression from adenoviral vectors.

Adenovirus vector-infected cells can escape adenovirus antigen-specific cytotoxic T-lymphocyte killing in vivo

The recent findings that prolonged expression of certain adenovirus (Ad) vector-encoded proteins, including human alpha1-antitrypsin (huAAT), mouse erythropoietin (EPO), and human factor IX, can be achieved in animals that do not mount an immune response to the reporter protein were obtained with mouse strains which have been shown to be capable of mounting a cellular immune response against Ad vector antigens. This suggests either that Ad vectors expressing nonimmunogenic transgenes fail to elicit a cellular immune response or that an Ad-specific cellular immune response does develop but is ineffective against cells expressing nonimmunogenic transgenes. Here we demonstrate that an Ad vector expressing huAAT administered by intravenous injection does stimulate an Ad-specific cellular immune response but that this response fails to abolish vector-directed gene expression in vivo. Moreover, expression of huAAT remained stable in animals stimulated by concurrent and multiple administrations of different Ad vectors or viruses. We also demonstrate prolonged expression of huAAT in CD1 mice transgenic for the huAAT gene, indicating that long-term expression is not restricted to C57BL/6 mice. These results demonstrate that under some circumstances, an Ad vector can direct prolonged expression of a nonimmunogenic transgene despite the presence of a robust Ad-specific cellular immune response.

Immune responses to reporter proteins and high viral dose limit duration of expression with adenoviral vectors: comparison of E2a wild type and E2a deleted vectors

Experiments designed to evaluate the effect of deletion of E2a on duration of expression using adenoviral vectors led to a series of observations regarding host responses to adenoviral vectors and reporter proteins. In studies using human alpha1-antitrypsin (hAAT) as a reporter gene, we found that the duration of expression is very brief for C3H/J and CBA/J mice but is prolonged for C57BL/6J mice, that disappearance of hAAT from the blood is correlated with the appearance of antibodies, and that immunization against hAAT can prevent appearance of the protein in the blood after administration of an adenoviral vector. Deletion of E2a in hAAT vectors did not prolong expession in C3H/J or CBA/J mice and did not shorten duration of expression in C57BL/6J mice. Using similar vectors expressing Escherichia coli beta-galactosidase (beta-Gal) in immunocompetent mice, short duration of expression with a beta-Gal reporter was remarkably different from the long expression with an identical vector expressing hAAT in C57BL/6J. In the case of vectors expressing hAAT, adenoviral sequences persisted in the liver, and inflammatory responses were minimal compared to vectors expressing beta-Gal, where adenoviral sequences disappeared from the liver concomitant with a prominent inflammatory response. The duration of expression of beta-Gal in hepatocytes was increased in transgenic mice expressing the reporter in keratinocytes, indicating that host immune responses to the reporter can limit duration of expression. Dosage studies indicated that persistence of expression of hAAT can be markedly decreased by administration of high doses of vector in a manner consistent with a nonimmune-mediated toxicity following injection. These experiments indicate that host responses to reporter genes rather than host responses to adenoviral proteins can be the primary determinant of duration of expression under many experimental conditions.

[Identification physico-chemical properties and immunochemical characteristic of prostate specific antigen and its complexes with protease inhibitors]

The study of the PSA complexes with the protease inhibitors has confirmed the opinion of possible existence the complexes of the PSA with a2-macroglobulins and a1-antihymotripsines in blood serum. The immunoenzyme analysis of the PSA and its complexes has made it possible to establish the normal level of the PSA corresponding complexes in donors blood serum. There are reasons to suppose, that the quantitative analysis of the PSA and its complexes with the protease inhibitors can be used for the early diagnosis of PC and its differential diagnosis with the prostate benign hyperplasia. In our opinion, the effect of the complex approach can be more informative than the ordinary PSA detection.

Evidence for the systemic delivery of a transgene product from salivary glands

The aim of this study was to assess the feasibility of using gene transfer to salivary glands to direct the systemic delivery of therapeutic proteins in vivo. We used a replication-deficient recombinant adenovirus vector (Ad alpha 1AT) that encodes human alpha 1-antitrypsin (h alpha 1-AT), which we used as a marker protein. Ad alpha 1AT (5 x 10(9) pfu) was administered by retrograde ductal instillation to the submandibular glands of male rats. The amount of h alpha 1-AT found in the salivary glands, saliva, serum, and other tissues was analyzed by a sensitive enzyme-linked immunosorbent assay (ELISA). Maximal levels of the marker protein were detected at 24-48 hr post-virus administration for glands (274 ng/mg protein), saliva (approximately 313 ng/ml), and serum (approximately 5 ng/ml). Serum levels remained elevated for 96 hr, whereas the measured half-life for the marker protein was approximately 2 hr. Generally little to no h alpha 1-AT was detectable in most other organs. However, we were able to measure low levels of marker protein in tissues immediately surrounding infected glands. In all animals studied, levels of h alpha 1-AT were higher in the glandular venous effluent than in arterial blood. Similar results were found with parotid glands. The aggregate data demonstrate that salivary glands may be a target for the nonsurgical, systemic delivery of transgene-encoded therapeutic proteins for diseases that require relatively low circulating protein levels.

Substitution of carbonate by acetate buffer for IgG coating in sandwich ELISA

The first step of sandwich ELISA, namely adsorption of antibodies to plastic microtiter plates, was studied as a function of the pH of the coating buffer. Coating efficiency was assessed in terms of maximum signal (absorbance) observed in ELISA and also estimated by measuring the amount of functional antibodies adsorbed to the plate. While goat antibodies displayed better results after coating with acetate pH 5 buffer, rabbit IgGs generally worked well at pH 7.4. On average, the classical carbonate pH 9.6 buffer was only 50% as efficient.

Prospective study of the clinical value of determining circulating IgA-alpha 1-antitrypsin complex using a prototype ELISA kit in patients with rheumatoid arthritis

OBJECTIVE

To evaluate the clinical value of determining circulating IgA-alpha 1-antitrypsin (IgA-AT) complex in rheumatoid arthritis.

METHODS

The IgA-AT complex was assayed by a prototype ELISA kit using a specific monoclonal antibody against the complex.

RESULTS

The median level of serum IgA-AT complex in rheumatoid patients (2.26 AU ml-1) was significantly higher than in osteoarthritis patients (1.37 AU ml-1, P < 0.05) and healthy volunteers (1.03 AU ml-1, P < 0.001). The concentration of IgA-AT complex in rheumatoid arthritis patients at baseline was correlated with the number of painful joints (P < 0.05), number of swollen joints (P < 0.01), erythrocyte sedimentation rate (P < 0.05), and modified Lansbury index (P < 0.01). The median serum level of IgA-AT complex in rheumatoid patients at baseline was higher than that at three months (P < 0.01), six months (P < 0.01), and 12 months (P < 0.01) after the start of treatment. The difference and ratio of IgA-AT complex levels before and after treatment were significantly associated with radiographic progression.

CONCLUSIONS

The findings validate the usefulness of determining IgA-AT complex using ELISA in the management of rheumatoid arthritis.

Characterization of plasmid DNA transfer into mouse skeletal muscle: evaluation of uptake mechanism, expression and secretion of gene products into blood

The expression of naked plasmid DNA coding for firefly luciferase (pRSVluc) or a secreted protein, human-alpha-1-antitrypsin (pRcCMVhAAT) in mouse skeletal muscle was characterized following administration by an improved intramuscular injection technique. Injection guided by intense illumination along the longitudinal axis of the mouse quadriceps muscle and parallel to the myofibers yielded 200-fold higher levels of luciferase expression than perpendicular injection. Luciferase expression was inhibited by an excess of non-coding DNA or dextran sulfate suggesting that muscle DNA uptake mechanism(s) can be saturated. Injected plasmid DNA was rapidly eliminated from the muscle as evidenced by tissue distribution studies of radiolabeled hAAT plasmid and Southern analysis. However, PCR analysis demonstrated that hAAT cDNA persisted in the muscle for at least 1 month after injection. Immunohistochemistry techniques indicated that the hAAT gene was expressed by the muscle fibers. ELISA analysis of serum samples collected from intramuscularly injected mice demonstrated that secreted hAAT protein concentration peaked in serum by day 7, started to decline by day 14 and was barely detectable 21 days post-injection. RT-PCR analysis demonstrated that hAAT transcript persisted at the site of injection for at least 1 month indicating that the decline of serum hAAT concentration 21 days post-injection was not due to the absence of hAAT transcript. However, the decline of hAAT protein concentration in the serum was inversely correlated with accumulation of murine anti-hAAT antibodies in circulation.

Activation of circulating polymorphonuclear leukocytes in preterm infants with severe idiopathic respiratory distress syndrome

We have studied activation of circulating polymorphonuclear leukocytes (PMN) in plasma of preterm infants with severe idiopathic respiratory distress syndrome (IRDS group, n = 15) and without IRDS (reference group, n = 15) during the first 5 postnatal days. We have observed lower median PMN counts in the IRDS group than in the reference group from d 2 (1.4 x 10(9)/L versus 4.8 x 10(9)/L in the reference group, p < 0.001) to d 4 to 6 (1.6 x 10(9)/L versus 4.0 x 10(9)/L, p < 0.01). Lower PMN counts in the IRDS infants were accompanied by lower median plasma elastase-alpha1-proteinase inhibitor (PI) concentrations (53.6 ng/mL versus 128.0 ng/mL in the reference group on d 2, p < 0.05). Simultaneously, median elastase-alpha1-PI/PMN ratios of these infants were significantly higher (40.8 ng/10(6) PMN versus 21.8 ng/10(6) PMN on d 2, p < 0.05), indicating activation of circulating PMN. Activation of circulating PMN in the IRDS group is associated with platelet-activating factor (PAF) release and complement activation from within 6 to 12 h of birth but not with release of tumor necrosis factor-alpha. PAF release was represented by significantly reduced inhibiting capacity (58% of normal human plasma, p < 0.01) and complement activation by higher median plasma C3a des-Arg concentrations (1680 ng/mL versus 325 ng/mL in the reference group, p < 0.001). We conclude that circulating PMN are activated in preterm infants with severe IRDS, which might be caused by systemic PAF release and complement activation. This activation process may play a role in the pathogenesis of the IRDS by influx of activated PMN into the lungs.

Macrophage presentation of endogenous self-protein: the MHC class II presentation pathway is not accessible to intracellular C5 or alpha 1-antitrypsin

This paper addresses the question of whether macrophages can present biosynthesized protein in a class II-restricted manner using the endogenous rather than the exogenous pathway of presentation. Two distinct self-antigens, the fifth component of complement (C5) and alpha 1-antitrypsin, were studied. Both antigens are serum proteins synthesized by hepatocytes and macrophages. To direct synthesis exclusively to macrophages chimeras were constructed by transfer of bone marrow from donors expressing the self-antigen into irradiated hosts deficient for the respective self-antigen. Macrophages from such mice were unable to present biosynthesized C5 to class II-restricted T cells, even when preactivated in vivo. While C5 production by macrophages is low and may not reach critical levels of intracellular protein required to access the class II presentation pathway, human alpha 1-antitrypsin, expressed as a transgene in mice, was synthesized at 600-fold higher levels than C5. Nevertheless, macrophage-synthesized alpha 1-antitrypsin in bone marrow chimeras was not presented in the context of class II--even in a mutant form which is sequestered in high amounts in the endoplasmic reticulum. We conclude that macrophages are unable to use the endogenous class II presentation pathway for these two model self-antigens. As a consequence MHC class II-restricted T cells specific for C5 and alpha 1-antitrypsin remain ignorant of the presence of self-antigen within macrophages and are neither tolerized nor rendered autoimmune.

Intramolecular mimicry. Identification and analysis of two cross-reactive T cell epitopes within a single protein

The recognition of peptide Ags by T cells through the TCR has exquisite specificity. Cross-reactive T cell responses have been described; however, the structural basis for these responses is not known. We show that two peptides derived from the same protein can exhibit sufficient structural homology, despite minimal structural identity, to elicit cross-reactive T cell responses. In addition, we explore the structural basis for cross-reactivity. T cell hybridomas recognizing PiM and PiZ allelic forms of human alpha 1-antitrypsin (hAAT) each recognized both PiM 205-220 and PiM 335-350. These two peptides possessed primary sequence identity at only two of 16 amino acid residues. Cross-reactive peptides also exhibited homology at the bulk T cell level because lymph node T cells primed with one peptide proliferated to the other peptide in vitro. Critical amino acids for the responding T cells were determined, and the core was transferred into the less reactive peptide in an attempt to increase homology by increasing sequence identity. Interestingly, as identity increased, homology decreased: peptides with the least primary sequence identity appeared most homologous to the T cells. These results have important implications for understanding the development of autoimmune diseases, and imply that minimal obvious primary sequence identity may be sufficient to initiate cross-reactive T cell responses. The ability of structurally dissimilar peptides to mimic each other when bound to a class II MHC molecule may also be important to the understanding of T development and autoimmunity.

Screening for asymptomatic celiac sprue in families

We evaluated the reliability of IgA and IgG antigliadin antibodies (AGA-A, AGA-G), antireticulin antibody (ARA), endomysial antibodies (EmA), and alpha 1-antitrypsin clearance (alpha 1-AT CL) in the detection of celiac sprue (CS) in 59 first-degree asymptomatic relatives of celiac patients who had duodenal biopsy. Twenty-four relatives who had normal results of screening tests were selected at random for biopsy; 35 relatives with at least one abnormal test result were biopsied. Eleven relatives were noted to have villous atrophy at biopsy; the diagnosis of celiac sprue was confirmed by histological improvement after gluten-free diet in six. AGA-G, alpha 1-AT CL, and EmA had sensitivities of 73%, 73%, and 64%, respectively, with very high levels of specificity. Sensitivity was improved by the combination of two serological markers (AGA-G + alpha 1-AT CL = 91%; AGA-G + EmA = 82%; EmA + ARA = 82%). Furthermore, combination of EmA and ARA has shown the best specificity and positive predictive value. AGA-G, alpha 1-AT CL, and EmA are reliable individual markers for the detection of asymptomatic celiac sprue. However, a combination of two of them, including ARA, was more sensitive than the individual tests.

Autoantibodies to cryptic epitopes of C-reactive protein and other acute phase proteins in the toxic oil syndrome

Toxic oil syndrome (TOS) was caused by the consumption of rapeseed oil contaminated with derivatives of aniline. Many persons who survived the acute phase developed a puzzling, multi-year chronic disease considered to be inflammatory or autoimmune in nature. In attempting to characterize their autoantibodies, we found that 74% of TOS patients with chronic disease had IgG antibodies to C-reactive protein (CRP). This activity was detectable only when CRP was chemically or physically denatured and behaved like a previously described antibody produced by immunization with the CRP monomer. Significant antibody reactivities to other acute phase proteins, especially alpha 1-antitrypsin and fibrinogen (P < 0.025) and ceruloplasmin (P < 0.05) were also observed. IgG antibodies to cryptic epitopes in CRP and other major serum proteins that increase during the acute phase response may reflect an earlier toxin-mediated insult to the liver that included abnormal biosynthesis of and/or damage to acute phase proteins.

Antineutrophil cytoplasmic autoantibodies, autoantigens, and systemic vasculitis

Antineutrophil cytoplasmic antibodies (ANCA) encompass a heterogeneous group of autoantibodies targeting antigens in neutrophils (PMN), monocytes, and endothelial cells. ANCA are routinely detected by the indirect immunofluorescence technique (IFT) and at least three different patterns of fluorescence can be distinguished which have been assigned the acronyms cANCA, pANCA and aANCA. cANCA is mostly induced by proteinase 3 (PR3) antibodies (PR3-ANCA), and pANCA by myeloperoxidase (MPO) antibodies (MPO-ANCA), while aANCA has unidentified subspecificity. Over the past decade, ANCA have been the subject of extensive investigation. They have proved to be of significant value both as diagnostic tools and for follow-up in several forms of systemic vasculitis (e.g. Wegener's granulomatosis, WG; microscopic polyarteritis, MPA; Churg-Strauss syndrome, CSS) which are now termed 'ANCA-associated vasculitides'. Furthermore, it is suspected that the presence of ANCA is an important factor in the pathogenesis of these disease groups. Data regarding the detection of ANCA and their diagnostic value and role in the pathogenesis of vasculitic disorders will be discussed in this review. Growing evidence points to a pathophysiological and diagnostic relevance of the distribution of the ANCA target antigens PR3 and MPO (presence in the circulation, on cell membranes, and in tissue extracellularly). An autoimmune process has been implicated in the pathogenesis of ANCA-associated vasculitis, but it is uncertain which mechanism underlies the induction of the ANCA-related immunoresponse. In this paper mechanisms such as antigenic cross-reactivity between human PMN proteins and extrinsic antigens by molecular mimicry, idiotypic immunoglobulin regulation, and T-cell reactivity to PR3 and MPO will be discussed.

Tumor necrosis factor, natural killer activity and other measures of immune function and inflammation in elderly men with heart failure

OBJECTIVE

To determine the status of tumor necrosis factor (TNF) and other measures of immunity and inflammation in chronic heart failure (CHF) in the elderly.

DESIGN

Comparative survey study of subjects with heart failure and age-matched controls.

SETTINGS

University affiliated tertiary care VA Medical Center, Heart Failure Clinic.

PATIENTS

Twenty men with New York Class II and III heart failure and 17 age-matched controls.

INTERVENTIONS

None.

MAIN OUTCOME MEASURE

Levels of lymphocyte mitogenesis, TNF, natural killer (NK) cell activity, elastase-alpha 1-antitrypsin (E/alpha) and cross-linked fibrin D-dimers (XDP).

RESULTS

TNF levels (p = 0.27), NK activity (p = 0.56), and lymphocyte mitogenesis (p = 0.67) were similar in patients and controls. E/alpha levels were somewhat lower in CHF patients (p = 0.05) and XDP were similar (p = 0.59). However, TNF levels were significantly related to NK activity and to E/alpha activity in elderly men with heart failure but not controls. XDP were positively related to NK in heart failure patients but not controls.

CONCLUSION

TNF and other measures of immune function and inflammation do not appear to be significantly elevated in elderly patients with heart failure of moderate severity. However, significant relationships exist between TNF, NK activity, XDP and E/alpha in the heart failure patients only, suggesting that immune activation and subclinical inflammation does exist in these patients.

Gene gun-based nucleic acid immunization: elicitation of humoral and cytotoxic T lymphocyte responses following epidermal delivery of nanogram quantities of DNA

Particle-mediated (gene gun) DNA transfer to the epidermis was evaluated for its ability to elicit humoral and cytotoxic T lymphocyte responses using decreasing quantities of plasmid DNA-based antigen expression vectors. Using plasmids encoding human growth hormone, human alpha-1-antitrypsin, and influenza virus nucleoprotein, strong immune responses were observed in mice following immunization with as little as 16 ng of DNA using an electric discharge gene delivery system. Significant antibody titers were observed against these antigens following a primary immunization, with responses rising dramatically following a boost. Increasing the DNA dose above 16 ng per immunization had little beneficial effect. In contrast to particle-mediated DNA delivery, intramuscular or intradermal inoculation required greater than 5000-fold more DNA to achieve comparable results. Data are also presented demonstrating that a simple, hand-held version of the Accell DNA delivery system, employing compressed helium as the particle motive force, achieves immune responses comparable to the traditional electric discharge device.

Analysis of allele-specific contact sites of natural HLA-DR17 ligands

The sequence motif of peptide ligands naturally associated with DR17 has indicated conserved residues at the relative positions P1-P4-P6-P 8.9 or 10. Eight naturally processed DR17 ligands were synthesized to study the role of conserved residues in DR17 binding. In their majority, they showed an excellent ability to bind to purified DR17 molecules. Binding experiments with variant peptides confirmed aspartate as the DR17-specific contact site at P4. In addition, hydrophobic or aromatic residues at P1 and P9, probably interacting with the NH2- and COOH-terminal pockets, and lysine or chemically related amino acids at P6 were important for binding. A core peptide of 10 amino acids, bordered by the terminal contact sites, is sufficient, although the ability to bind is reduced approximately 10-fold compared with the binding capacity of the natural ligand. Ala substitution of flanking stretches at either end completely restores the binding capacity to that of the natural ligand. This suggests that regions flanking the peptide core contribute to the binding strength nonspecifically, i.e., by forming H-bonds to MHC molecules. Natural DR1 and DR12 ligands like HLA-A2 (103-117) and transferrin receptor (140-156) failed to bind to DR17 molecules. However, substituting leucine for aspartate at P4 transformed DR1 and DR12 ligands into excellent DR17 binders. This conversion, enabled by a single amino acid substitution, emphasizes the importance of aspartate as the DR17-specific contact site and suggests that terminal contact residues are shared among DR1, DR12, and DR17 ligands. In contrast, additional aspartates introduced next to the contact site at P4 impaired the binding capacity. Regarding this specific role of asparate we expect that DR17-specific ligands will be rarely found among "promiscuous" peptides binding to several different DR molecules.

Intraperitoneal in vivo gene therapy to deliver alpha 1-antitrypsin to the systemic circulation

The utility of replication-deficient recombinant adenovirus vector-mediated transfer and expression of the alpha 1-antitrypsin (alpha 1AT) cDNA to peritoneal mesothelial tissues was evaluated as a means of delivering alpha 1AT to the systemic circulation. Preliminary studies with Ad.RSV beta gal, an adenovirus vector expressing the Escherichia coli lacZ gene (beta-galactosidase), showed that intraperitoneal injection of 10(9) plaque-forming units (pfu) to cotton rats resulted in beta-galactosidase activity in mesothelial cells lining the peritoneal cavity. After intraperitoneal administration of 10(9) pfu of Ad alpha 1AT (an adenovirus vector containing the human alpha 1AT cDNA), human alpha 1AT was detectable in serum for up to 24 days, with a maximal level of 3.4 micrograms/ml at 4 days. Expression of the exogenous gene was localized to the peritoneal mesothelium as PCR analyses detected no evidence of expression of the exogenous gene in any other tissues evaluated. Anti-adenovirus vector antibodies were detectable in serum after intraperitoneal administration of the recombinant vectors, including antibodies with neutralizing activity. Repeat administrations of adenovirus vectors to the peritoneal cavity at 1 wk and 1 mo after the initial dose failed to show gene expression, but repeat administration 3 mo after demonstrated measurable gene transfer and expression. Together these observations suggest replication-deficient adenovirus-mediated gene transfer to the peritoneal mesothelium offers a promising means to transfer alpha 1AT to the systemic circulation, although immunity induced against the adenovirus may limit frequent repetitive dosing.

The immunohistochemical heterogeneity of atheroma macrophages: comparison with lymphoid tissues suggests that recently blood-derived macrophages can be distinguished from longer-resident cells

We studied the antigenic markers of macrophages (Mphs) in atherosclerotic human arteries by immunohistochemistry and compared them with the patterns in Mph subpopulations of tonsil and lymph node, which are also described. The staining of atheroma intimal Mphs was assessed semiquantitatively in the subendothelial, mid, and outer intima. Three patterns of reactivity with Mph antibodies were recognized. (a) Pan-Mph (antibodies HAM56, EBM11, and CD14 group). Staining was maximal in the mid-intimal zone. (b) Subendothelial Mphs (anti-muramidase, anti-alpha-1-antitrypsin and MAC387). In lymphoid tissue, sinusoidal Mphs and a few inflammatory Mphs were stained, as well as blood monocytes. This group of antibodies recognizes Mphs that are likely to be recently blood-derived (RBD-Mphs). (c) Antibodies reactive with various histiocyte populations in lymphoid tissues (anti-Factor XIII; anti-HLA Class II and LN2) also gave maximal staining in the mid-intimal zone, but differences between lesion types suggest that they are recognizing heterogeneous subpopulations of Mphs. These observations demonstrate the heterogeneity of tissue Mphs and suggest that an insight into the dynamics of tissue Mphs can be obtained from the cell phenotype. They indicate that all stages of atherosclerosis can have an outward traffic of Mphs from the blood through the arterial intima.

Nitrogen dioxide reactivity with proteins: effects on activity and immunoreactivity with alpha-1-proteinase inhibitor and implications for NO2-mediated peptide degradation

Nitrogen dioxide (NO2), an air pollutant produced by burning fossil fuels and a component of cigarette smoke, is thought to contribute to the pathogenesis of pulmonary diseases, such as emphysema. In order to gain information on the mechanism by which NO2 damages the lung and proteins vital to its function, as well as its reaction with proteins in general, in vitro exposures of alpha-1-proteinase inhibitor (alpha 1PI), elastin, poly-L-lysine, and poly-L-arginine were performed. The ability of alpha 1PI to inhibit its natural physiological target, human neutrophil elastase (HNE), declined with exposure to 54% of the control value at molar ratios of NO2:alpha 1PI of 400:1 and greater. Exposure of alpha 1PI to NO2 resulted in a 50% loss of immunoreactivity with either monoclonal or polyclonal antibodies in an enzyme-linked immunosorbent assay at molar ratios of NO2:alpha 1PI of 100:1 and greater. The results of parallel O-phthalaldehyde and bicinchoninic acid protein assays as well as amino acid analysis on control and NO2-exposed alpha 1PI suggested a reactivity of NO2 with lysine residues. Elastin and poly-L-lysine were labeled by reductive methylation of amino groups with [3H]HCHO prior to treatment with NO2 in aqueous solutions at physiological pH. NO2 exposure of elastin resulted in the solubilization of 84% of the associated radioactivity of which 79% was identified as [3H]methyllysine by amino acid analysis. After NO2 exposure of poly-L-[3H]lysine, gel filtration chromatography revealed that the 50,000 M(r) poly-L-[3H]lysine had been degraded to small peptides of 1-3000 M(r). Similarly, after NO2 exposure of unlabeled poly-L-arginine, gel filtration chromatography, and total peptide analysis revealed that the 47,500 M(r) peptide was also partially degraded to peptides. These results suggest that NO2 reacts with the epsilon-amino groups of Lys residues (primary amines) and with the amide nitrogen (secondary amines) of surface-exposed Lys and Arg residues in the peptide backbone to result in peptide bond cleavage. These findings are the first indication of NO2-mediated peptide degradation and provide additional data on the potential of NO2 to damage proteins vital to the function of the lung in an in vitro exposure system.

Changes of immunoreactivity in alpha 1-antitrypsin in patients with autoimmune diseases

Recent studies from this laboratory have shown that a monoclonal antibody prepared against a specific epitope on alpha 1-antitrypsin is a valuable diagnostic marker for autoimmune conditions. In the present study we have further characterized this monoclonal antibody and reassessed its diagnostic value in screening samples from patients with various autoimmune conditions. alpha 1-Antitrypsin was micropurified from patients with selected autoimmune conditions and from normal donors. The purified alpha 1-antitrypsin isolated from patients with autoimmune conditions and normal donors was deglycosylated using both a mixture of exoglycosidases and endoglycosidase F. The immunoreactivity of the native and deglycosylated alpha 1-antitrypsin was examined using both a monoclonal antibody and a polyclonal antibody in enzyme linked immunosorbent assay (ELISA) and radioimmunoassay (RIA), respectively. It was noted that alpha 1-antitrypsin isolated from patients with autoimmune diseases generated a displacement curve dissimilar to alpha 1-antitrypsin purified from normal donors or alpha 1-antitrypsin from patients with autoimmune diseases subjected to deglycosylation when these samples were examined by ELISA using the monoclonal antibody. However, when the polyclonal antibody was used for these studies, no difference was found between the native and deglycosylated alpha 1-antitrypsin suggesting that the monoclonal antibody recognized an epitope not detectable by the polyclonal antibody.(ABSTRACT TRUNCATED AT 250 WORDS)

Inactivation of alpha 1-proteinase inhibitor by alveolar inflammatory cells from smoking patients with or without emphysema

The aim of this study was to evaluate the ability of alveolar inflammatory cells recovered by bronchoalveolar lavage from the lower respiratory tract of 17 smoking patients with or without emphysema to inactivate alpha 1-proteinase inhibitor (alpha 1-Pl). The presence of emphysema was determined and quantified using CT scan and was evidenced in 8 patients (Group 1), whereas 9 patients exhibited a normal CT scan (Group 2). Patients with emphysema had lower values of FEV1, DLCO, and resting PO2 and higher values of RV/TLC ratio than patients without emphysema. BAL analysis showed a higher percentage of neutrophils and of myeloperoxidase (MPO) in BAL fluid in Group 1 than in Group 2. Alveolar inflammatory cells stimulated or not with phorbol myristate acetate (PMA) were incubated for 45 min with purified alpha 1-Pl, and the results were expressed as a percentage of inactivation of alpha 1-Pl as evaluated by its inhibitory activity against porcine pancreatic elastase or human neutrophil elastase. In Group 2, unstimulated alveolar inflammatory cells inactivated only 3.3 +/- 0.7% alpha 1-Pl and stimulated cells inactivated only 5.4 +/- 1.1% alpha 1-Pl. In marked contrast, in Group 1, a significant loss of the antielastase function of alpha 1-Pl was observed (p < 0.001) when alpha 1-Pl was incubated with unstimulated cells (24.2 +/- 8.9%) or stimulated cells (35 +/- 8.9%) from Group 1. The addition of catalase to the cell suspension was associated with a significant decrease in the inactivation of alpha 1-Pl (from 35 +/- 8.9 to 10.2 +/- 1.2%, Group 1).(ABSTRACT TRUNCATED AT 250 WORDS)

Peptide-induced memory (IgG) response, cross-reactive with native proteins, requires covalent linkage of a specific B cell epitope with a T cell epitope

In order to raise antibodies synthetic peptides are often coupled to a carrier protein to provide the necessary T cell determinants. Alternatively, a short synthetic determinant with a distinct sequence motif which can be presented by major histocompatibility complex (MHC) class II to T cells, can be linked directly to a B cell epitope. Recently, it has been suggested that covalent linkage between a class II-presentable T helper peptide and a B cell epitope is not required to induce antibodies against a B cell determinant (Sarobe et al., Eur. J. Immunol. 1991. 21: 1555). Therefore, we investigated the ability of an H-2d-restricted T cell determinant (AA 111-120 FERFEIFPKEK) from the influenza virus hemagglutinin, to support B cell responses to different proven B cell determinant peptides, derived from human alpha 1-antitrypsin. Antibodies against B cell epitopes crossreactive with native alpha 1-antitrypsin could be raised only when these B epitope peptides were covalently coupled to the T cell determinant through a peptide bond. No antibodies were raised against the B cell epitope when the free peptides (T and B cell epitopes) were just mixed or when the T cell epitope was conjugated via m-maleimidobenzoyl succinimide ester or bis-maleimidohexane to the B cell determinant. Antibodies against the T cell determinant were raised in all cases, regardless of the mode of presentation: just mixed with or covalently coupled to the B cell determinant. The results indicate that a covalent bond between T cell and B cell determinants in general is needed to induce anti B cell determinant antibodies cross-reactive with the native protein.

Isolation of a protein complex from purulent sputum consisting of proteinase-3 and alpha 1-antitrypsin reactive with anti neutrophil cytoplasmic antibodies

The detection of ANCA (anti-neutrophil cytoplasmic antibodies) is of importance in the diagnosis of Wegener's granulomatosis (WG) and solid-phase assays for the detection of c-ANCA have been set up by various groups, using purified proteinase-3 (PR-3) in an ELISA or RIA. For the isolation of PR-3 large numbers of PMNs are needed. We therefore examined the possibility of isolating PR-3 from the purulent sputum of patients with chronic bronchitis or cystic fibrosis, since large numbers of PMNs and their degranulation products are present in such material. By a three-step chromatographic procedure (4-phenylbutylamine affinity chromatography, Biorex 70 cation exchange chromatography and monoclonal antibody anti-PR-3 affinity chromatography) we isolated a 53 kDa protein that was recognized on immunoblot by MoAbs directed against PR-3 and alpha 1-antitrypsin (alpha 1AT). We show that the 53 kDa protein is a complex of PR-3 and alpha 1AT. This complex is reactive with a selected set of c-ANCA positive sera from patients with Wegener's granulomatosis.

T cell antigen receptor immune complexes demonstrating biologic and proteolytic activity

An elastase-like protease, recently recognized as a specific product of murine T cells, may functionally associate with the classical TCR. T cell elastase, found in combination with the natural elastase inhibitor alpha 1-antitrypsin (alpha 1-protease inhibitor, alpha 1-PI), is produced by both CD4+ and CD8+ T lymphocytes. T cell elastase and alpha 1-PI are found chemically associated with the TCR in an antigen-specific complex reminiscent of the Ig-complement 'immune complexes'.

D-penicillamine and rheumatoid factor

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Adverse effects of neutrophils on the lung

Studies of both emphysema and adult respiratory distress syndrome (ARDS) support the premise that lung injury is due to unregulated host defense mechanisms. A major mediator of host defense and injury is the neutrophil, which is relatively incapable of regulating its own function. Accordingly, defects in regulatory mechanisms allow neutrophils to damage the lungs. Emphysema serves as a prime example of this link between host defense and injury. Hereditary emphysema is caused by a deficiency in alpha 1-antitrypsin (alpha 1-AT), a protease inhibitor. The decreased levels of this enzyme in affected individuals result in inadequate protection against neutrophil elastase and other proteolytic enzymes, leading to lung damage. Patients with acquired emphysema, associated with cigarette smoking, have normal levels of alpha 1-AT in their lungs. However, the alpha 1-AT in these patients has a reduced ability to associate with and inhibit the action of neutrophil elastase. Thus, both types of emphysema involve an alteration in the balance between proteases and antiproteases. The lung damage observed in patients with ARDS also appears to involve neutrophils, but in this case elastase may not be the culprit. In these patients, neutrophil elastase appears to be inactivated by high levels of alpha 1-AT, thus preventing excess protease action. It is hoped that a more complete understanding of the mechanisms involved in host defense and injury will enable the development of specific therapeutic interventions, such as the alpha 1-AT replacement therapy that is being used to treat patients with hereditary emphysema.

Production of monoclonal antibodies against inactivated alpha 1-antitrypsin. Cross-reactivity with complexed alpha 1-antitrypsin and application in an assay to determine inactivated and complexed alpha 1-antitrypsin in biological fluids

15 different monoclonal antibodies (mcAbs) have been raised against the cleaved (inactive) form of the serpin alpha 1-antitrypsin (AT). In initial experiments these mcAbs were analysed for their ability to bind the native and the cleaved form of this inhibitor: eight of the 15 mcAbs appeared to react predominantly with cleaved AT. Additional experiments with mixtures of purified native AT, AT complexed to neutrophilic elastase and inactivated AT revealed that all mAbs that preferentially reacted with inactivated AT also bound to complexed AT. Using two of the mcAbs against inactivated AT a quantitative and sensitive sandwich-type radioimmunoassay was developed to determine levels of proteolytically inactivated AT in biological fluids. With this assay increased levels of inactivated AT were found in synovial fluid from patients with rheumatoid arthritis corresponding to about 2.4% (range 0.3-11%) of total AT. Approximately 10% of this inactivated AT appeared to consist of AT complexed to neutrophil elastase. The mcAbs described here further illustrate the structural resemblance between the complexed and cleaved forms of AT. In addition, these mcAbs appear to be useful tools for the study of AT in human disease.

Complement C4-derived monocyte-directed chemotaxis-inhibitory factor. A molecular mechanism to cause polymorphonuclear leukocyte-predominant infiltration in rheumatoid arthritis synovial cavities

To reveal the mechanism of the lesser infiltration of monocytes in synovial cavities with rheumatoid arthritis despite the presence of chronic inflammation, the synovial fluid from 15 rheumatoid arthritis patients was analyzed with respect to leukocyte chemotaxis. The synovial fluid possessed strong chemotactic activity to polymorphonuclear leukocytes but rather suppressed one to monocytes. The synovial fluid contained two different inhibitory activities in monocyte chemotaxis. One, which also suppressed polymorphonuclear leukocyte chemotaxis, was identified as alpha 1 protease inhibitor. The other, with molecular weight of 8 kd, possessed the specificity to monocytes and shared the antigenicity with complement C4 but not with C3 or C5. A similar inhibitor was generated in normal human plasma when the classical pathway of the complement system was initiated with aggregated human IgG, while it was not when alternative pathway was initiated with zymosan. The small size factor in the synovial fluid, apparently derived from C4, seemed to be a cyto-directed factor that might block an early part of signal transduction system of monocytes in the chemotaxis. After removal of the small-size inhibitor, the synovial fluid exhibited chemotactic ability to monocytes. Therefore the apparent C4-derived factor might play a key role in the polymorphonuclear leukocyte-predominant infiltration in the synovial fluid of rheumatoid arthritis.

Undifferentiated (embryonal) sarcoma of the liver. Clinical and pathologic study of 16 cases with emphasis on immunohistochemical features

Undifferentiated (embryonal) sarcoma of the liver is a primitive mesenchymal neoplasm with predilection for individuals in the first 2 decades of life. In this study (10 boys, 6 girls), children in the age range of 6-10 years were most commonly affected (63%). Clinical features most frequently noted on presentation were abdominal pain or a palpable mass. In two cases there was cardiac involvement caused by invasion of the inferior vena cava with extension into the right atrium and ventricle; both children died of progressive dyspnea from tumor embolization to the lungs. One patient was a member of a kindred with the cancer family syndrome (Li-Fraumeni syndrome). There were 13 tumor-related deaths (86% mortality); on child was alive with recurrent tumor in the upper abdomen. Complete surgical resection was attempted in 10 of 15 children who underwent exploratory laparotomy; 2 were alive and well 1 and 5 years later, whereas 1 patient had a recurrence in the upper abdomen 3 years after diagnosis. Ultrastructural study (five cases) and immunohistochemistry (11 cases) supported a mesenchymal origin for the tumor, but failed to identify any diagnostic immunophenotype or specific line of differentiation. Coexpression of vimentin and cytokeratin was seen in three cases. Prompt detection of this aggressive tumor with complete surgical resection is the key to a successful outcome, but this is very difficult to achieve. Recent experience suggests that aggressive adjuvant chemotherapy may improve survival in some cases.

Histopathologic, immunophenotypic, and genotypic analysis of Ki-1 anaplastic large cell lymphomas that express histiocyte-associated antigens

CD30/Ki-1 antigen expression in 243 cases of malignant lymphomas was examined using Ber-H2 monoclonal antibody. Among them 20 cases were categorized as Ki-1 anaplastic large cell lymphoma. In two of these cases histiocyte-associated markers were also expressed. In these cases histopathologic and extensive in situ immunophenotypic analyses were used with genotypic studies in the determination of cell lineage. A sinusoid histologic pattern of involvement with partial lymph node infiltration by pleomorphic neoplastic cells was noticed in the nodes from both patients. Solid areas of node replacement resembling metastatic carcinoma were seen in Patient 1. Immunohistologically, tumor cells of both cases were positive for CD30, CD25, CD71, LN3 (HLA-DR), EMA, CD45, CD74, vimentin, alpha-1-antichymotrypsin, and CD68. Patient 1 was also CD45RO+, CD43+, whereas Patient 2 was positive for alpha-1-antitrypsin and CD4 tumor cells. Genotypic studies revealed that TCR beta and TCR gamma chain genes were clonally rearranged in Patient 1, whereas no rearrangements were detected in Patient 2. This study supports the view that some Ki-1 anaplastic large cell lymphomas may express multiple histiocyte-associated antigens and confirms that this group of neoplasms have immunophenotypic heterogeneity. The results of genotypic analyses used with immunophenotyping does not exclude that the tumor cells in these cases may be of true histiocytic origin despite the Ki-1-positive phenotype.

Prognostic significance of alpha-1-antitrypsin in early stage of colorectal carcinomas

We have previously shown that human colorectal carcinoma cell lines, RCM-1 and CoCM-1, synthesize alpha-1-antitrypsin (alpha 1-AT) in culture. We have studied immunohistochemically the incidence of alpha 1-AT on histologic sections from paraffin-embedded tissues of surgically resected colorectal carcinomas and their metastatic foci, polypectomized adenomas, and normal mucosae. alpha 1-AT was detected in 89 (61%) of 145 carcinomas (including 14 carcinomas in adenoma), and 12 (39%) of 31 adenomas. But only 2 (4%) of 55 normal colorectal mucosae were positive for alpha 1-AT. In metastatic tumor cells of colorectal carcinomas in lymph nodes and other organs, alpha 1-AT positivity was 60% and 82%, respectively. The incidence of alpha 1-AT was markedly higher in advanced adenocarcinomas than in early ones and more frequent in adenocarcinomas of right side (including transverse colon) than those of left side and rectum, regardless of their histological malignancy grades. In mucinous carcinomas the frequency was greater (8 of 9 cases) than in conventional adenocarcinomas. Clinical follow-up of the patients with colorectal carcinomas suggested that alpha 1-AT positivity in Dukes' stage A/B tends to correlate with unfavorable prognosis irrespective of the grade of histologic differentiation of carcinoma, but there is no significant relation in Dukes' stage C/D. Our findings suggest that alpha 1-AT in colorectal carcinoma is related to the invasive and metastatic capacity. It may thus serve as a biologic marker for prognosis of colorectal carcinomas at relatively early stages (Dukes' stage A/B).

Development of an enzyme-linked immunosorbent assay with a monoclonal antibody prepared against alpha 1-antitrypsin for diagnostic screening of inflammatory disorders

A monoclonal antibody, designated A2a18b8, of IgG1 class prepared against human alpha 1-antitrypsin, cross-reacts with alpha 1-antitrypsin in the serum of rat and baboon, but not with alpha 1-antitrypsin in serum of rabbit, pig, hamster, guinea pig, dog, or turtle. We used A2a18b8 in an enzyme-linked immunosorbent assay (ELISA) developed for human alpha 1-antitrypsin. Preliminary ELISA screening of 247 serum samples from patients with various inflammatory disorders indicated that the concentration of a specific epitope(s) on alpha 1-antitrypsin recognized by this monoclonal antibody was increased significantly in patients with active systemic lupus erythematosus, mixed connective tissue disease, and rheumatoid arthritis, but not in patients with sclerodermic disorders or Sjögren's syndrome. Evidently, A2a18b8 has diagnostic value in that it selectively recognizes a specific epitope(s) on alpha 1-antitrypsin that is (are) apparently exposed during selective inflammatory disorders.

Trypsin inhibitors in guinea pig plasma: isolation and characterization of contrapsin and two isoforms of alpha-1-antiproteinase and acute phase response of four major trypsin inhibitors

Contrapsin and two isoforms, F (fast) and S (slow), of alpha-1-antiproteinase (also called alpha-1-proteinase inhibitor) were isolated in an apparently homogeneous state from plasma of inflamed guinea pigs. Contrapsin inactivated trypsin, but did not significantly affect chymotrypsin, pancreatic elastase, or pancreatic kallikrein. On the other hand, both isoforms of alpha-1-antiproteinase inhibited trypsin, chymotrypsin, and elastase, but not plasma or pancreatic kallikrein. The S isoform of alpha-1-antiproteinase was present in barely detectable amounts in healthy animals, but increased markedly when the acute-phase reaction was induced by subcutaneous injection of turpentine. On the other hand, the plasma levels of the F isoform, contrapsin, and alpha-macroglobulin showed moderate (1.5 to 2.3-fold) elevation during the acute-phase reaction. In contrast to the previous findings that rats and rabbits contain two different alpha-macroglobulins, one of which is an acute-phase reactant while the other is not, inflamed guinea pigs contained only one species of alpha-macroglobulin. Murinoglobulin, the most prominent acute-phase negative protein in both mice and rats, showed no significant change in guinea pigs. These results indicate that guinea pig plasma contains four major trypsin inhibitors, i.e., contrapsin, alpha-1-antiproteinase, alpha-macroglobulin, and murinoglobulin, the properties of which are very similar to those of the respective mouse homologues, but that the acute-phase response of these inhibitors differs greatly from that of the homologous proteins in rats or mice.

Circadian variations in blood coagulation parameters, alpha-antitrypsin antigen and platelet aggregation and retention in clinically healthy subjects

Ten clinically healthy subjects (5 men and 5 women), 31 +/- 11 yrs of age, were studied at six timepoints (0800, 1200, 1600, 2000, 0000, 0400) distributed over a 1-week span. Circadian rhythms in platelet aggregation in response to adenosine diphosphate (ADP) and adrenalin (A), platelet adhesiveness measured as retention in a glass bead column, prothrombin time (PT), activated partial thromboplastin time (APTT), thrombin time (TT), fibrinogen, Factor VIII activity and alpha-1-antitrypsin antigen showed circadian rhythms. The plasma concentrations of plasminogen, alpha-2-macroglobulin, and antithrombin III (AT III) antigen, Factor V and fibrinogen degradation products showed no circadian rhythm by ANOVA or cosinor analysis. The phase relations of the rhythms of different coagulation parameters are of interest in the physiology and pathobiology of the coagulation-fibrinolytic system. The extent of the circadian rhythm (range of change) described is not of a magnitude to lead to diagnostic problems in the clinical laboratory. The timing of these rhythms, however, may determine transient risk states for thromboembolic phenomena, including myocardial infarction and stroke. Several but not all coagulation parameters suggest a transient state of hypercoagulability during the morning hours. The recognition of these rhythmic, and thus in the time of the occurrence predictable temporary risk states for thromboembolic phenomena, may lead to timed treatment and/or effective prevention.

[Alpha 1-antitrypsin in clinical diagnosis of primary hepatic carcinoma--an appraisal of monoclonal antibody-rate nephelometry]

This study was undertaken to evaluate the use of serum alpha 1-antitrypsin (alpha 1AT) in clinical diagnosis of primary hepatic carcinomas with monoclonal antibody-rate nephelometry. BALB/c mice were injected with human alpha 1AT. Spleen cells of the immunized mice and SP2/0 myeloma cells were hybridized in vitro. Monoclonal antibodies against alpha 1AT so obtained were used as detection agents in immuno-chemical monitor system (ICS). In 50 healthy individuals, serum alpha 1AT was 209 +/- 46.04 mg/dl. Serum alpha 1AT was determined in 49 patients with primary hepatic carcinoma, 26 with chronic active hepatitis and 26 with cirrhosis. Their positive rates were 43%, 3.8% and 0, respectively. Serum alpha 1AT level was significantly higher in primary hepatic carcinoma than in chronic active hepatitis and cirrhosis patients (P less than 0.001). No difference was found in alpha 1AT between patients with benign liver diseases and healthy adults (P greater than 0.05). The results indicate that alpha 1AT is useful in the diagnosis of primary hepatic carcinomas.

[Immunoaffinity purification of alpha 1-protease inhibitor from human plasma]

A single-step procedure is described for isolation of alpha 1-inhibitor of proteases (alpha 1-IP) from human blood plasma using affinity chromatography on immunosorbent containing monoclonal antibodies against alpha 1-IP. Activity of the alpha 1-IP preparation, estimated by means of specific trypsin inhibition, was increased 61.1-fold after the chromatography, with a yield of the end product 20%. The preparation of alpha 1-IP obtained exhibited electrophoretic and immunochemical homogeneity.

Immunohistochemistry of vacuoles occurring in rat hepatocytes after retinol administration

The vacuoles occurring in rat hepatocytes after intraportal injection of retinol (33 or 67 micrograms) were examined immunohistochemically using respective antibodies against rat albumin, human retinol-binding protein, human ceruloplasmin, human alpha 1-antitrypsin, human transferrin, and human prealbumin as representative plasma proteins. The occurrence of the vacuoles reached a numerical maximum 30 min after injection of 67 micrograms retinol, followed by a temporal decrease. Hepatocytes from control rats, which had been intraportally injected with either blood plasma diluted to 2/3 concentration or with retinol palmitate solvent (castor oil) dissolved in blood plasma, showed immunoreactive fine granules without the occurrence of vacuoles in the cytoplasm. Identical vacuoles in serial sections appeared immunohistochemically either immunoreactive or non-immunoreactive for all the antibodies used, with rare exceptions. The occurrence of several rare exceptions suggested that 2 kinds of vacuoles might be formed in different cytoplasmic compartments. A zonal distribution of vacuoles was apparent in the hepatic laminae (or acini) within the liver lobules. The vacuoles were predominantly distributed in zone 2, and to a lesser extent in zone 3 and zone 1 in that order.

Alpha-1-antitrypsin and lysozyme. Their limited significance in fibrohistiocytic tumors

A wide range of tumors were immunohistochemically analyzed for alpha-1-antitrypsin (AAT) and lysozyme in order to evaluate their specificity as histiocytic markers and their significance in the diagnostic and histogenetic evaluation of fibrohistiocytic tumors. Besides histiocytic lesions, AAT immunoreactivity was commonly found in different types of carcinomas and sarcomas, and strong immunoreactivity was found in carcinoid tumors, malignant melanomas, and schwannomas, which, however, had negative results for lysozyme. The AAT immunoreactivity could be abolished with the absorption of the antibody with purified AAT also in nonhistiocytic tumors. The neoplastic pleomorphic cells in malignant fibrous histiocytomas (MFHs) usually had strongly positive results for AAT, whereas only entrapped histocytes had positive results for lysozyme and for two monoclonal antibodies to histomonocytic cells. The results show that AAT has a relatively low specificity as a histiocytic marker, and one should be careful in concluding the histiocytic nature of tumors, such as MFHs, based on AAT immunostaining. It seems also questionable whether AAT can be used as a diagnostic marker for MFH. The reason for the widespread AAT immunoreactivity in various tumors may be that AAT is taken up from serum to various types of nonhistiocytic tumor cells.

Patterns of antigen expression in hepatoblastoma and hepatocellular carcinoma in childhood

Two hepatocellular carcinomas and six hepatoblastomas were examined for the presence of 13 antigens using immunoperoxidase, avidin-biotin, staining techniques. Primary antibodies were directed against alpha-fetoprotein (AFP), alpha-1-antitrypsin (AAT), lysozyme (LYS), carcinoembryonic antigen (CEA), human chorionic gonadotropin (HCG), glial fibrillary acidic protein (GFAP), neuron specific enolase (NSE), epithelial membrane antigen (EMA), hepatitis B surface antigen (HbSA), lactoferrin (LF), desmin (DES), vimentin (VIM), and keratin (KER). Except for HbSA, the antigen staining pattern was unable to differentiate between hepatoblastoma and hepatocellular carcinoma. Both neoplasms where positive for AFP, AAT, CEA, EMA, and KER; however, neither stained for GFAP, NSE, LYS, LF, HCG, or DES. Vimentin was weakly positive in those hepatoblastomas where mesenchymal tissue was present in the tumor. Only the tissue adjacent to hepatocellular carcinomas stained positively for HbSA and correlated with the elevated serum levels of HbSA.