C1q receptors: Opportunities for selectively regulating protective and detrimental responses

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complement suppressing post ischemic myocardial inflammationand necrosis. Science 249:146, 1990. 12. Higgins PJ, Ko J-L, Lobell R, Sardonini C, Alexxi MK, Yeh CG: A soluble chimeric complement inhibitory protein that possesses both decay-accelerating and factor I cofactor activities. J Immunol 158:2872, 1997. 13. Bach FH, Ferran C, Soares M, WrightonCJ, Anrather J, Winkler H, Robson SC, Hancock WW: Modification of vascular responses in xenotransplantation: inflammation and apoptosis. Nat Med 3:944, 1997. 14. Cooper NR: Complementevasion strategies of microorganisms. Immunol Today 12:327, 1991. 15. Fishelson Z: Complement-related proteins in pathogenic organisms. Springer Semin

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Immunopathol 15:345, 1994. 16. TedderTF, Inaiko M, Sato S: The CD19-CD21 complex regulates signal transductionthresholds governing humoral immunityand autoimmunity. Immunity6:107, 1997. 17. Molina H, Holers VM, Li B, Fang Y-F Mariathasan, S, Goellner J, StraussSchoenberger J, W. Karr R, Chaplin DD: Markedly impaired humoral immune response in mice deficient in complementreceptors 1 and 2. Proc Natl Acad Sci USA 93:3357, 1996. 18. Krych M, ClemenzaL, Howdeshell D, Hauhart R, Hourcade D, Atkinson JP: Analysis of the functional domains of complementreceptor type 1 (C3b/C4breceptor; CD35) by substitution mutagenesis. J Biol Chem 269:13273, 1994. 19. ThomasTC, Rollins SA, Rother RE Giannoni

MA, Hartman SL, Elliott EA, Nye SH, Matis LA, Squinto SP, Evans MJ: Inhibition of complement activity by humanized anti-C5 antibodyand single-chain Fv. Mol Immunol 33:1389, 1996. 20. WangY, Hu Q, Madri JA, Rollins SA, Chodera A, Matis LA: Amelioration of lupus-like autoimmane disease in NZB/W F1 mice after treatment with a blocking monoclonalantibody specific for complement componentC5. Proc Natl Acad Sci USA 93:8563, 1996. 21. Chert S, Frederickson RC, Brunden KR: Neuroglial-mediated immunoinflamrnatory responses in Alzheimer's disease: complement activation and therapeutic approaches. Neurobiol Aging 17:781, 1996.

C l q Receptors: O p p o r t u n i t i e s for S e l e c t i v e l y R e g u l a t i n g Protective a n d D e t r i m e n t a l R e s p o n s e s 1 Andrea J. Tenner Department of Molecular Biology and Biochemistry, University of California, lrvine, California Work from the author's laboratory presented here was supported by grants from the Arthritis Foundation, American Heart Association and NIH AI#41090. In addition to contributing to the work reviewed here, the author wishes to thank Ron Nepomuceno and Sol Ruiz for helping to prepare the figures presented. Abbreviations used in this article: CCP, classical complement pathway; CR, complement receptor; FcR, Fc receptor; HSA, human serum albumin; MBL, mannose binding lectin; mAb, monoclonal antibody; SPA, pulmonary surfactant protein A. C l q is the recognition subunit of the first component (C 1) of the classical complement pathway. It is usually thought of in the context of binding to antibody-antigen complexes and activating complement (C'), a powerful effector mechanism of host defense. C' activation can lead to lysis of pathogens through the formation of the bactericidal membrane attack complex, as well as, opsonization of pathogenic substances for clearance by phagocytic cells and recruitment of these cells to the area of infection or injury. Complement activation can also occur, however, in the absence of antibody via the classical pathway, the

alternative pathway and the newly defined lectin pathway of complement activation.l The recognition molecules that interact with the foreign element and initiate this activation are Clq, C3 fragments, and mannose binding lectin (MBL) respectively. In addition, ligation of phagocyte specific surface receptors for Clq, C3, or MBL influences phagocytosis of the "targeted" microbes, 1'2 and initiates and, at times, directs the subsequent immune response to the challenge. 3'4 In early in vitro studies, C l q was shown to enhance the ingestion of particles suboptimally opsonized with the classic opsonic molecules, IgG and C3b. 5 That is, the ingestion of particles coated with limited IgG or C3b, such that they bind to phagocytic cell surfaces but are not readily ingested, could be enhanced 2- to 10-fold if the cells interacted with C l q (Figure 1). This was a very rapidly induced response requiring as little as 5 min preincubation of the cells with C l q prior to addition of the targets 6 to generate an optimal response. The region of the C lq molecule required and sufficient for this triggering of cell function was shown to reside in a portion of the collagen- like region which is normally masked by the serine proteases C l r and C l s in the macromolecular C 1 complex. However,

© Elsevier Science Inc.

upon binding to an activator (immune complexes, specific pathogens or other antibody-independent activators), the activated C l r and Cls become susceptible to regulation by C1 Inhibitor and are dissociated from the C l q molecule thereby exposing this receptor interaction site. 7 An additional requirement for functional triggering of a cell response by C l q is that it be presented in a multivalent fashion, similar to many other immunologically important receptor-ligand interactions. Since most activators of C1 contain repeating units of the activation motif7 and thereby bind multiple C lq molecules, this requirement is satisfied in physiologically appropriate situations, but prevents inappropriate activation of these processes by free C l q that may, at times, be present in tissue. To explore the molecular and biochemical basis for the C lq-mediated phagocytosis, monoclonal antibodies (mAb) have been generated and selected for their ability to inhibit the Clq-enhanced phagocytosis when preincubated with human monocytes in solution. 8 Interestingly, one of these mAb, R3, which is an IgM antibody, actually mimics the enhancement of phagocytosis when presented to the cells as crosslinked by immobilization to a surface, confirming the requirement for stable multivalent ligation of the receptor to

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trigger cell function (Nepomuceno, Ruiz, Park and Tenner, Manuscript in preparation, 1998), and demonstrating that crosslinking of the surface molecule recognized by R3 alone is sufficient to induce the observed enhancement of phagocytosis. Immunoprecipitation of detergent extracts of monocytes, neutrophils, and U937 cells (a human myeloid cell line) with these mAb resulted in the identification of a 126,000 Mr surface glycoprotein, which has been designated as ClqRp, the C l q receptor that enhances phagocytosis. Using antibody affinity chromatography and further purification by SDS-PAGE, peptide sequence of the N-terminus and proteolytic fragments of this protein was obtained and used to clone the cDNA for the coding region of this receptor. 9 Homology searches of both DNA and protein data bases indicated that this protein is a novel type 1 glycoprotein, with a single transmembrane domain and a short (47 amino acid) tail. The extracellular portion of the protein consists of a region with sequence similarity to carbohydrate recognition domains (CRD) found in several other proteins involved in surface recognition and endocytosis, although as of yet it is not known if the domain functions as a CRD. In addition, there are five EGF-like domains, three containing an asparagine hydroxylation motif predictive of calcium binding EGF domains. 9 A cartoon of the domain structure of this receptor is presented in Figure 2. Transfection of CHO cells with the coding portion of this cDNA resulted in the specific expression of a polypeptide with a mobility in SDS-PAGE identical with that of the native protein isolated from human monocytes (Nepomuceno et al., manuscript in preparation). Further analysis has revealed that this molecule contains a large amount of Olinked carbohydrate and a large number of alanine, proline, and charged amino acids all of which contribute to highly aberrant migration in SDS-PAGE (Nepomuceno, et al., manuscript in preparation). Mannose binding lectin (MBL) and pulmonary surfactant protein A (SPA) have a macromolecular structure strikingly similar to that of Clq, with an N-terminal collagen-like domain contiguous with a noncollagen-like carboxyl terminal domain. The globular carboxyl terminal 0197-1859/97/$0.00 + 17.00

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200

,

Figure 1. C 1q enhances Phagocytosis of Opsonized Targets. Human monocytes isolated by countercurrent elutriation were adhered to surfaces precoated with increasing concentrations of C 1q. Sheep erythrocytes suboptimally opsonized with IgG were added and phagocytosis assessed. Phagocytic index is the number of targets ingested by 100 monocytes. Error bars indicate SD of duplicate wells.

o

0 tO

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portion of each of these proteins recognizes relatively broad categories of molecules, and the collagen-like N-terminal domain links to powerful effector mechanisms of the immune system. Evidence is accumulating that these molecules play a critical role in the defense of the host against selective pathogens and/or other deleterious substances, and are thus classified with Clq as defense collagens/°'H Both MBL and SPA have been shown to enhance the phagocytic and killing capacity of phagocytic cells, both through their opsonic properties, ie. they can enhance binding between the target and the phagocytic cell, ~2~3 as well as through their ability to enhance the ingestion of suboptimally opsonized particles 13-15similar to Clq. The anti-C 1qRp mAb inhibit the MBL- and SPA-mediated enhancement of phagocytos i s 16 (Nepomuceno, et al. In preparation), demonstrating that ClqR e is at least one common component of the receptor involved in triggering this cellular activity via these different ligands. It remains to be determined whether the 126,000 Mr

"ClqRp" is the ligand binding subunit of the "holo- receptor", and/or if it is part of a larger multicomponent receptor. Experiments are ongoing at the present time to address these critical questions, and to determine the physiologic role of this receptor. The anti-C 1qRp monoclonal antibodies were used to identify cells expressing the receptor. This receptor is selectively expressed on cells of myeloid origin, endothelial cells, and platelets, but not on cells of lymphoid lineage or fibroblasts (Figure 3). Nucleotide probes and primers derived from the cDNA sequence confirmed the selective expression of C 1qRp mRNA in these cell types. Thus, a specific role in the regulation of phagocytosis in myeloid cells can be easily postulated for this receptor. In addition, the recent report of the ingestion of apoptotic lymphocytes by endothelial cells,/v suggests that a role for the endothelial cell ClqRp may be to facilitate clearance of these cells, thereby avoiding potential inflammatory responses./s In addition to the enhancement of

N

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Figure 2. Diagrammatic representation of ClqRp domain structure. The schematic diagram illustrates the domains contained within ClqRp which include a 21 amino acid signal peptide (SP) and a C-type carbohydrate recognition domain (CRD) at the N-terminus, five Epidermal Growth Factor (EGF)-like domains, numbered, including three calcium binding (cb) EGF domains, and a single transmembrane (TM) domain. The putative N-linked glycosylation site is indicated within the second EGF domain. © Elsevier Science Inc.

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phagocytosis, multiple effects of C l q on a variety of cell types have been reported (Table 1), including stimulation of superoxide production by neutrophils, eosinophils, and monocytes (Tenner, data not shown). While Clq-stimulation of superoxide production has been characterized in terms of its kinetics and some of the parameters required for activity, the receptor that binds C l q to mediate this effect has not yet been identified. However, cumulative observations suggest that the neutrophil C l q receptor that triggers superoxide production (designated as ClqRo2.) differs in some way from ClqRp (Table 2). First, none of the anti-ClqRp monoclonal antibodies either inhibited or mimicked the C 1q-induced production of O2" by neutrophils (in contrast to their inhibition of Clq-, MBL- and SPA-induced enhancement of phagocytosis). 8 Second, while mimicking C l q in the ability to enhance phagocytosis, neither M B L nor SPA induce superoxide production by neutrophils, 19 suggesting that a receptorinteraction site for C lqRo2, is unique to C 1q, whereas a different interaction site, common to MBL, SPA and C l q exists for C l q Rp. Third, more recent studies in our laboratory have determined that the region of C l q flanked by amino acids 42 to 61 on the C chain is absolutely required for activation of the neutrophil oxidative burst. 2° This region does not appear to be required for effective enhancement of phagocytosis by Clq. Several laboratories working on the identification of C l q receptors have reported the isolation of C l q b i n d i n g p r o t e i n s from cells. Ghebrehiwet and colleagues, and later others, isolated a cell-associated protein from many cell types that bound C l q through its collagen-like domain. This protein, originally designated c C l q R , migrated upon SDS-PAGE under nonreducing conditions as a 60-70,000 Mr species. 2t It was reported several years ago that the N-terminal amino acid sequence of this protein is identical to calreticulin, a Ca2÷-binding protein found in several cellular compartments, with many postulated functions, including that of a chaperone for proteins which must be retained in the endoplasmic reticulum for proper maturation of their oligosaccharide structures. These retained proteins have carbohydrate structures with high amounts of terminal

CLINICAL IMMUNOLOGY Newsletter 175

glucose which must be cleaved prior to addition of the mature terminal sugars. C l q has a large number of terminal glucoses as a result of the galactose-glucose disaccharide O-linked to most of the hydroxylysines in the collagen-like domain, perhaps explaining its interaction with cClqR/calreticulin. While a role for this protein in mediating a selective C l q induced cellular response has not been established, initial studies on this interaction in platelets and mast cells 22'23 may warrant further exploration. Ghebrehiwet and colleagues have also isolated a 33,000 M r protein which binds to the globular domain of Clq. 24 Though originally described as gC 1qR, subsequent investigators have not been able to detect the protein either on the cell surface or

secreted, but rather find it intracellularly. 25'26 More recently Muller-Esterl and colleagues have demonstrated that this protein is a mitochondrial component, suggesting that the previous extracellular localization reported may have been due to cell death and lysis. No definitive functional data indicating cellular signaling have been presented.

Significance and Clinical Relevance It has been known for some time that individuals genetically deficient in C l q are prone to bacterial infections likely due to the inability to activate the classical complement pathway leading to the bactericidal membrane attack complex. A decreased ability to rapidly phagocytose and kill microbes via C l q receptors may also play

TABLE 1. CELLULAR FUNCTIONS TRIGGERED BY C 1q Monocytes/macrophages

Neutrophils

'Eosinophils Endothelial cells

B cells Fibroblasts

Mesangial cells Vascular smooth muscle Platelet

• Enhancement of phagocytosis* • Enhanced killing of C. neoformans • Enhanced uptake of T. cruzi and L. monocytogenes4° • Influences antibody dependent and independent c~llular cytoxicity • Stimulation of oxidative metabolism • Enhancementof antibody-dependent killing of Dirofilaria immitis • Enhances uptake and processing of immune complexes4t • Enhanced killing of Schistosomula • Enhanced binding/phagocytosisof Re strain of S. minnesota • Mediates binding of immune complexes • Stimulates expression of adhesion molecules42 • Enhanced secretion of immunoglobulinby activated B cells • Stimulation of Ca÷+-activatedK÷ channels and initiation of chemotaxis • Enhanced uptake of T. cruzi • Stimulation of DNA synthesis • Enhances binding of immune complexes43 • Enhances antibody-mediatedapoptosis44 • Stimulates oxidative metabolism • Inductionof integrin and selectin expression22

•Referencesnot citedare reviewedin (5).

TABLE 2. Clq RECEPTORS ClqRp* Function: Mr: Cellular Expression:

Ligands:

Enhances Phagocytosis 126.000 Mr Monocytes Neutrophils Endothelial Cells Platelets C Iq MBP SPA

ClqRo2-** Triggers superoxide production Neutrophils Eosinophils Smooth Muscle Cells Clq

*cDNAclonedand sequenced. **Functionallydefinedreceptor;see text. © 1998 Elsevier Science Inc.

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a role. In addition however, if the individual survives past the early childhood infectious diseases, almost all C 1q-deficient individuals develop autoimmune disorders, usually with lupus-like symptoms. 27 Interestingly, in addition to the high amount of anti-DNA and anticardiolipin antibodies detected in the sera o f many patients with systemic lupus erythematosus (SLE), these individuals who are not genetically deficient in C l q have antibodies to the collagen-like region of C 1q (C 1q-CLR) all of which could be relevant to a defect in the clearance of cellular debris. Antibodies to C l q - C L R are also found i n l 0 0 % of sera from h y p o c o m p l e m e n t e m i c urticarial vasculitis syndrome patients ( H U V S ) 28 and in sera of many patients with rheumatoid vasculitis. 29 Recent studies of Ahearn, et al. demonstrate that C 1q associates with the plasma membrane of apoptotic keratinocytes. 3° All of these observations would be consistent with a physiologically important role for the C l q / C l q R e system in the clearance of both pathogens and potentially pathologic material, such as apoptotic cells, cellular debris (DNA/chromatin and/ or broken mitochondria 3L32) and immune complexes. Thus, it is possible that, in vivo, a deficiency of C l q or the Clq-receptor, or an overloading of the C l q / C l q - r e c e p tor system, could lead to a less efficient clearance o f these substances, potentially leading to the detrimental deposition of immune complexes, inflammation and/or stimulation o f inappropriate antibody production. Indeed, the C l q knockout mouse generated by Walport and colleagues develops nephritis suggesting an impairment of the clearance of immune complexes and/ or cellular debris, 33 although these mice also have severely blunted secondary antibody responses to model antigens. 34 Thus, the ability to regulate these activities could be potentially therapeutic. The enhancement of phagocytic capacity o f m y e l o i d cells m a y be extremely valuable as a prophylactic treatment for individuals at risk for infection, such as individuals with genetic immunodeficiencies or infected with HIV, patients undergoing cancer chemotherapy, or patients undergoing high risk surgery. The observations that C l q , M B L and SPA do not alone trigger p r o i n f l a m m a t o r y cytokine release (Jasinskiene, et al., in preparation), 35'36 suggest that modulation of this receptor 0197-1859/97/$0.00 + 17.00

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F l u o r e s c e n c e Intensity

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Figure 3. FACS Analysis for detection of CIqR e surface expression. Cells were stained with R139 anti-C 1qRr, monoclonal antibody and with the appropriate FITC labeled secondary antibody. The horizontal axis depicts the relative fluorescence intensity for R 139 (filled) and isotype-matched control antibody (unfilled) for U937, K562 cells and primary fibroblasts as indicated. Cell types listed beneath each panel demonstrate similar profiles. would be particularly beneficial in these situations where an induction of inflammation can be extremely detrimental or fatal. Only one other molecule with similar immunoregulatory properties (no proinflammatory cytokine induction response, 37 but enhancement of microbicidal activity) that has been characterized is a glucose polymer, PGG-Glucan, which has shown significant efficacy in Phase I/II trials in reducing post surgery infections. A recent report by Ma and Kawasaki 38 suggests that M B L may be an effective agent in the treatment of certain types of tumors, supporting previous data suggesting that C lq may be involved in the enhancement of tumor cell killing. 39 It remains to be seen if C l q R p is the receptor mediating this effect, or if other M B L or C 1q receptors specific for these activities exist. The current findings of at least two distinct "C 1q" receptors should provide the opportunity for selectively enhancing protective defense mechanisms or limiting potential oxygen radical damage to the host induced via presentation of C l q in tissues.

References 1. TurnerMW: Mannose-binding lectin: the pluripotent molecule of the innate immune system. Immunol Today, 1997. 2. Bobak DA, Washburn RG, Frank MM: Clq enhances the phagocytosis of cryptococcus neoformans blastospores by human monocytes. J Immunol 141:592-597, 1988. 3. BendelacA, Fearon DT: Innate immunity:

© 1998 Elsevier Science Inc.

Innate pathways that control acquired immunity. Current Opin in Immunol 9:1-3, 1998. 4. Fearon DT, Locksley RM: The instructive role of innate immunity in the acquired immune response. Science 272:50-54, 1996. 5. TennerAJ: Functional Aspects of the Clq receptors. Behring lnst Mitt 93:241-253, 1993. 6. Ruiz S, Tenner AJ: Clq, pulmonary surfactant protein A (SPA) trigger enhanced phagocytic capacity with identical kinetics and via the same 126,000 Mr cell surface "C lq receptor." Mol Immunol 33:651996 (Abstract). 7. Cooper NR: The classical complement pathway: activation and regulation of the first complement component. Adv lmmunol 37:151-216, 1985. 8. GuanE, Robinson SL, Goodman EB et al.: Cell surface protein identified on phagocytic cells modulates the C Iq-mediated enhancement of phagocytosis. J hnmunol 152:4005-4016, 1994. 9. Nepomuceno RR, Henschen-EdmanAH, Burgess WHet al.: cDNA cloning and primary structure analysis of C lqRe, the human C 1q/MBL/SPA receptor that mediates enhanced phagocytosis in vitro, hnmunity 6:119-129, 1997. 10. Krieger M, Acton S, Ashkenas Jet al.: Molecular flypaper, host defense, and atherosclerosis. J Biol Chem 7:4569-4572, 1993. 11. Epstein J, Eichbaum Q, Sheriff S, Ezekowitz RAB: The collections in innate immunity. Current Opin. in lmmunol 8:29-35, 1996. 12. Manz-Keinke H, Plattner H, Schlepper-Schafer J: Lung surfactant protein A (SP-A) enhances serum-independent phagocytosis of bacteria by alveolar macrophages. Eur J Cell Biol 57:95100. 1992. 13. van lwaarden F, Welmers B, VerhoefJet al.: Pulmonary surfactant protein A enhances the host-defense mechanism of rat alveolar macrophages. Am J Respir Cell Mol Biol 2:9198, 1990.

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14. Tenner AJ, Robinson SL, Ezekowitz RAB: Mannose binding protein (MBP) enhances mononuclear phagocyte function via a receptor that contains the 126,000 M, component of the C l q receptor. Immunity 3:485-493, 1995. 15. Tenner AJ, Robinson SL, Borchelt Jet al.: Human pulmonary surfactant protein (SP-A), a protein structurally homologous to Clq, can enhance FcR- and CR 1-mediated phagocytosis. J Biol Chem 264:13923-13928, 1989. 16. Varner JA, Emerson DA, Juliano RL: Integrin 51 expression negatively regulates cell growth: Reversal by attachment to fibronectin. Mol Biol Cell 6:725-740, 1995. 17. Hess KL, Tudor KSRS, Johnson JD et al.: Human and murine high endothelial venule cells phagocytose apoptotic leukocytes. Exp Cell Res 236:404-411, 1997. 18. Jasinskiene N, Rochford R, Ruiz S, Tenner AJ: Complement component C 1q selectively enchances phagocytosis but not the production of proinflammatory cytokines. 1996. 19. Goodman EB, Tenner AJ: Signal transduction mechanisms of C lq-mediated superoxide production: Evidence for the involvement of temporally distinct stauosporine insensitive and sensitive pathways. J Immunol 148:3920-3928, 1992, 20. Ruiz S, Henschen-Edman AH, Tenner AJ: Localization of the site on the complement component C 1q required for the stimulation of neutropbil superoxide production. J Biol Chem 270:30627-30634, 1995. 21. Ghebrehiwet B, Bossone S, Erdei A e t al.: Reversible biotinylation of C I q with a cleavable biotinyl derivative: Application in C lq receptor (C lqR) purification. J Immunol Meth 110:251260, 1988. 22. Peerschke EIB, Reid KBM, Ghebrehiwet B: Platelet activation by C 1q results in the induction of CqrJB3 integrins (GPIIb-Illa) and the expression of P-selectin and procoagulant activity. J Exp Med 178:579-587, 1993. 23. Ghebrehiwet B, Kew RR, Gruber BL et al.: Murine mast cells express two types of C I q receptors that are involved in the induction of chemotaxis and chemokinesis. J Immunol 155:2614-2619, 1995. 24. Ghebrehiwet B, Lim B, Peerschke EIB et al.:

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25.

26.

27.

28.

29.

30.

31.

32.

33.

34.

35.

Isolation, cDNA cloning, and overexpression of a 33-kD cell surface glycoprotein that binds to the globular "heads'of Clq. J Exp Med 179:1809-1821, 1994. Van den Berg RH, Prins F, Faber-Krol MC et al.: Intracellular localization of the human receptor for the globular domains of C lq. J lmmunol 158:3909-3916, 1997. Dedio J, Muller-Esterl W: Kininogen binding protein p33/gClqR is localized in the vesicular fraction of endothelial cells. FEBS Lett 399:255258, 1996. Bowness P, Davies KA, Norsworthy PJ et al.: Hereditary C l q deficiency and systemic lupus erythematosus. Q J Med 87:455-464, 1994. Wisnieski JJ, NaffGB: Serum IgG Antibodies to C lq in hypocomplementemic urticarial vasculitis syndrome. Arthritis Rheum 32:1119-1127, 1989. Siegert CEH, Daha MR, van der Voort EAM et al.: IgG and lgA antibodies to the collagen-like region of C l q in rheumatoid vasculitis. Arthritis and Rheumatism 33:1646-1654, 1990. Korb LC, Ahearn JM: C l q binding directly and specifically to surface blebs of apoptotic human keratinocytes. J Immunol 158:4525-4528, 1997. Jiang H, Cooper B, Robey FAet al.: DNA binds and activates complement via a specific sequence on the human C l q A chain. J Biol Chem 267:25597-25601, 1992. Kagiyama A, Savage HE, Michael LH et al.: Molecular basis of complement activation in ischemic myocardium: Identification of specific molecules of mitochondrial origin that bind human C l q and fix complement. Circ Res 64:607-615, 1988. Botto M, Nash J, Taylor P, Bygrave A, Pandolfi P, Loos M, Davies A, Walport M J: Immune complex processing in a marine model of C l q deficiency. Mol Immunol 33:71S, 1996.(Abstract). Cutler A J, Botto M, Davis KA, Gray D, Walport M J: C l q knockout m i c e - abnormal humoral immune responses to both T-dependent and T-independent antigens. Behring Inst Mitt 1998(Abstract), in Press. Soell M, Lett E, Holveck F et al.: Activation of human monocytes by streptococcal rhamnose glucose polymers is mediated by CD 14 antigen,

36.

37.

38.

39.

40.

41.

42.

43.

44.

and mannan binding protein inhibits TNFrelease. J Immunol 154:851-860, 1995. Mclntosh JC, Mervin-Blake S, Conner E et al.: Surfactant Protein-A protects growing cells and reduces tumor necrosis factor-activity from lipopolysaccharide-stimulated macrophages. Am J Physiol Lung Cell Mol Physiol 271:L310L319, 1996. Poutslaka D, Mengozzi M, Vannier E et al.: Cross-linking of the beta-glucan receptor on human monocytes results in Interleukin-I receptor antagonist but not Interleukin-1 production. Blood 12:3695-3700, 1993. Ma Y and Kawasaki T: In vivo gene therapy of a human colorectal tumor with recombinant vaccina virus encoding human mannan-binding protein (MBP). Behring Inst Mitt 1998(Abstract), in Press. Leu RW, Zhou A, Shannon BJ et al.: Inhibitors of C lq biosynthesis suppress activation of routine macrophages for both antibody-independent and antibody-dependent tumor cytotoxicity. J Immunol 144:2281-2286, 1990. Alvarez-Dominguez C, Carrasco-Marin E, Leyva-Cobian F: Role of complement component C 1q in phagocytosis of Listeria monocytogenes by murine macrophage-like cell lines. Infect Immun 61:3664-3672, 1993, Ohkuro M., Kobayashi K, Takahashi K et al.: Effect of C lq on the processing of immune complexes by human neutrophils. Immunol 83:507-511, 1994. Lozada C, Levin RI, Huie M e t al.: Identification of Clq as the heat-labile serum cofactor required for immune complexes to stimulate endothelial expression of the adhesion molecules E-selectin and intercellular and vascular cell adhesion molecules 1. Proc Natl Acad Sci USA 92:83788382, 1995. Van den Dobbelsteen MEA, Van der Woude F J, Schroeijers WEM et al.: C1Q, a subunit of the first component of complement, enhances the binding of aggregated IgG to rat renal mesangial cells. J Immunol 151:4315-4324, 1993. Sato T, Van Dixhoorn MGA, Heemskerk E et al.: C lq, a subunit of the first component of complement, enhances antibody-mediated apoptosis of cultured rat glomerular mesangial cells. Clin Exp Immunol 109:510-517, 1997.

I n d e x t o V o l u m e 17 abstracts from 10th annual AMLI Meeting, 6:87-92 acetic acid, 9:136 activins, 8:109 acute respiratory distress syndrome (ARDS), complement system and, 12:169, 170 AIDS dementia complex, see Dementia, HlV-associated alkaline phosphatase, 4:55 allergy testing, by flow cytometry-based multiplex system, 10/11:157 alpha fetoprotein (AFP), 10/11:157 Alzheimer's disease, IL-1 in, 5:63 AML models, bone marrow transplantation in, effect of IL-2 on, 5:68 AML1 meeting, abstracts from, 6:87-92 Anderson, Loft, 2/3:21, 22-29 anemia, reticulocyte count in, 1:1 antibiotics, see also specific agent for human granulocytic ehrlicbiosis, 10/11:143

anti-D anti gamma chain flow cytometric test, 2/3:33 antigen presenting cells (APC), 10/11:141 antimicrobial effects of nitric oxide, 8:119 antisense probes, in in situ hybridization,4:55 apoptosis, 5:62, 9:125, 63, 126 in B-CLL, dysreglation of, 9:128-129 archiving, 1:9-10 arthritis, see also Rheumatoid arthritis collagen-induced,chemokines in, 7:96 Aspergillus,5:71 assays, in flow cytometry-basedmultiplexsystem, IlYl1:156157 Asthana, Deshratn, 5:61, 62-65 asthma, 8:120 chemokines in, 7:97 exhaled nitric oxide in, 8:120 astrocytes, 5:64 cytokine production from, 5:62

© 1998 Elsevier Science Inc.

Atkinson, John B., 12:168-173 atopic diseases, chemokines in, 7:97 ATP,9:133 Anlt, Kenneth A., 1:1, 2-7 autoimmune disease, effect of chemokines on, 7:96 autoimmune manifestations, in TGF13l-knockout mice, 8:112 automation, in in situ hybridization, 4:55, 57 B-cell lymphoma, application of in situ hybridization to, 4:58 B lymphocytes, 7:99 Babesia microti. 10/11: 142 bacteriology environments, application of multiparametric flow cytometry to, 2/3:39-44 bare lymphocyte syndrome, 10/11:149 Baunoch, Savid A., 4:54-60 BCL-1, in chronic lymphocytic leukemia, 9:127-128 BCL-2, 9:128-129 "Benefit services," 4:51 13chemokines, 5:62

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