Molecular Immunology 42 (2005) 79–85

Antibodies against heat shock proteins and cholesterol in HIV infection

George Fusta,b,c,∗, Zoltan Beckd, Denes Banhegyie, Judit Kocsisa,Adrienn Bıroa, Zoltan Prohaszkaa,b,c

a Third Department of Internal Medicine, Faculty of Medicine, Semmelweis University, H-1125 Budapest, K´utvolgyi u. 4, Hungaryb Research Group on Metabolism and Atherosclerosis, Hungarian Academy of Sciences, Budapest, Hungary

c ATHERNET EC Center of Excellence, Budapest, Hungaryd Institute of Medical Microbiology, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary

e Department of Immunology, St. L´aszlo Hospital, Budapest, Hungary

Received 8 June 2004; accepted 12 July 2004Available online 20 August 2004

Abstract

ed cells. A6 lly interactw ing fromt antibodiesa results ina f anti-Hsp60a holesterola©

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This review summarizes data on the presence and function of different heat shock proteins (Hsp) in the HIV virions and the infect0 kD heat shock protein-like molecule is present in the envelope of the human immunodeficiency virus type 1 which can specificaith the transmembrane glycoprotein gp41. The role of cholesterol in the so-called cholesterol-rich lipid raft where HIV is budd

he infected cells as well as the consequential insertion of cholesterol into the envelope of HIV virion are also discussed. Naturalgainst 60 kD (Hsp60) and 70 kD (Hsp70) families of Hsp and cholesterol can be detected in most healthy individuals. HIV infectionsharp increase in the serum concentration of anti-Hsp70 and cholesterol antibodies whereas no difference in the concentration ontibodies can be detected. Highly active antiretroviral therapy leads to normalization of the levels of both anti-Hsp70 and anti-cntibodies.2004 Elsevier Ltd. All rights reserved.

eywords:HIV; AIDS; Antibodies; Heat shock protein; Cholesterol; Anti-cholesterol antibodies; Natural antibodies; HIV virion

. Introduction

Humoral immune response against HIV is most intensiverom very beginning of the infection. Different type of spe-ific antibodies can be detected, a small proportion of thems able to weakly neutralize the virus, while others (enhanc-ng antibodies) may facilitate HIV infection in the absenceTakeda et al., 1988), and presence (Robinson et al., 1988;oth et al., 1991) of human complement. Most probable,owever, vast majority of HIV-specific antibodies does notffect the natural course of HIV disease.

Besides specific antibodies, serum levels of several au-oantibodies also change in HIV infected patients. Group of

∗ Corresponding author. Tel.: +36 1 212 9351;ax: +36 1 212 9351/225 3899.

E-mail address:fustge@kut.sote.hu (G. Fust).

Susal and Daniels described two classes of autoantibodHIV infection (Susal et al., 1996). One class of these antiboies such as antibodies against the Fab and F(ab′)2 moieties ohuman IgG molecules seems to be strongly associatedthe progression of HIV disease (Susal et al., 1996). Sinceour group became interested in autoantibodies againsferent heat shock proteins (Hsps) and cholesterol andand more data (see below) have been published on poassociation of Hsps and cholesterol with HIV virions, wecided to study the titers of these autoantibodies in HIV discompared to HIV-seronegative controls.

2. Essential properties of heat shock proteins (Hsps)

Hsps are traditionally classified by their molecular weithe best understood are the so-called major Hsps w

161-5890/$ – see front matter © 2004 Elsevier Ltd. All rights reserved.oi:10.1016/j.molimm.2004.07.003

80 G. Fust et al. / Molecular Immunology 42 (2005) 79–85

molecular weight of 110, 90, 70 and 60 kDa (reviewed byMorimoto et al., 1994; Ranford et al., 2000; Prohaszka andFust, 2004). These Hsps are expressed at 37◦C in the ab-sence of heat stress. Hsps possess three intrinsic biochemi-cal activities. The first ischaperone activity, which preventsthe misaggregation of denaturated proteins and contributesto refolding of denaturated proteins into their native confor-mations. Function of Hsps to stabilize proteins in specificconformations is exploited by a variety of physiological pro-cesses regulating cell function, including the control of thecell cycle control, the processing of steroid and Vitamin Dreceptors, and antigen presentation. The second essential ac-tivity related to the protein nature of Hsps is regulation ofcellular redox state. Finally, the third principal biochemicalrole of Hsps is regulation ofprotein turnover. An exampleis ubiquitin, which is expressed in unstressed cells and isup-regulated by heat shock. It should be noted that all Hspsactivities outlined above require the cleavage of ATP, whichis catalyzed by Hsps themselves.

3. Heat shock proteins in the HIV virions andHIV-infected cells

Hsps were found to be associated with some viral parti-c vesic-ucaa 0g er-i -r thep latedpt e theo s (re-v eds withc tionsm a-p ,t ate ofH ex-p IV-p trols(

1, aH ctedp pro-g lier,h st con-t 8+it n the

response of these cells to disease specific antigens (Stebbinget al., 2003).

Several lines of evidence suggest the existence of HIVgp41 binding proteins on different cell lines (Chen et al.,1992, 1993; Ebenbichler et al., 1993, 1996). Recently we re-ported on the presence of a 60 kD heat shock protein-likemolecule in the envelope of infectious HIV strain IIIB viri-ons grown in H9, MT4 and U937 cells using a HIV-specificdouble capture method (Speth et al., 1999). In addition, by us-ing anti-Hsp60 antibodies we demonstrated that 62 kD and40 kD proteins were previously purified from H9 and Rajicell lysates by a Sepharose-gp41 column and characterizedas a possible receptor for gp41 on these cells are also humanHsp60-like proteins.

4. Role of lipid-rich rafts in the HIV infection of cells,disorders of lipid metabolism in HIV-infected patients

Recent evidences indicate that HIV-1 buds selectivelyfrom glycolipid-enriched membrane lipid rafts, and host cellcholesterol within these domains are incorporated into the vi-ral envelope (Nguyen and Hildreth, 2000). Although no dataare available on the organization of the cholesterol and otherlipids within the HIV envelope, it seems most probable thats is inh icity.

idm tal,L ,1 ea yc-e ults ini dys-t 8;M 8;P tht eent tood(

57o

con-s resenti1 n-fiea es oundt riod(

les: Hsps70, the 70 kD heat shock protein associateslar stomatitis virus (Hammond and Helenius, 1994), vac-inia virus (Jindal and Young, 1992), adenovirus (Macejaknd Luftig, 1991), Sindbis virus (Mulvey and Brown, 1995),nd rabies virus (Sagara and Kawai, 1992), as well as gp16lycoprotein of HIV during its transportation and oligom

zation (Otteken et al., 1996). Furthermore, physically puified and disrupted HIV and an other infectious agent,rion protein PrPc were shown to contain an Hsp60-rerotein (Bartz et al., 1994; Edenhofer et al., 1996). In addi-

ion, a number of viruses have been reported to inducverexpression of heat shock proteins in the infected celliewed byYoung, 1990). Several recent findings implicatome Hsps including Hsp70 in the interaction of Hspsyclosporins, FK506 and prostaglandins. These interacay block HIV-1 replication providing novel HIV-1 thereutic strategies (Brenner and Wainberg, 2001). Moreover

here are marked differences between the expression rsp70 between HIV-infected a non-infected cells. Hsp70ression is almost twice higher in the lymphocytes of Hositive individuals as compared to the HIV negative conAgnew et al., 2003).

Not only HIV replication but the expression of the CD9sp-receptor is also up-regulated in a subset of HIV infeatients, namely on the monocytes of “true long-term nonressors” (infected with HIV for more than 10 years earave a CD4+ cell count of over 400�l−1 and a viral load les

han 50 copies/ml). Increased expression of CD91 mayribute to the maintenance of the effective anti-viral CDmmune response in these patients (Stebbing et al., 2003);he same receptor on dendritic cells has a major role i

witching of cholesterol from the cell membrane where itidden state to the virus envelope alters its immunogen

In HIV infected patients significant alterations in lipetabolism (high triglyceride levels but lower levels of toDL and HDL cholesterol) were reported (Grunfeld et al.992; Feingold et al., 1993). Introduction of highly activntiretroviral therapy (HAART) may enhance hypertriglridaemia, induce increase in cholesterol levels, and res

nsulin resistance and central body fat redistribution (liporophy and lipoatrophy) (Danner et al., 1995; Lo et al., 199iller et al., 1998; Carr et al., 1998; Walli et al., 199urnell et al., 2000). In spite of intense work on this field bo

he mechanism of lipid alterations and the relation betwhese alterations and fat redistribution are poorly undersPurnell et al., 2000; Safrin and Grunfeld, 1999).

. Presence of antibodies against 60 kD (Hsp60) and0 kD (Hsp70) Hsps as well as cholesterol in the seraf healthy subjects

Antibodies against human Hsp60 and Hsp70 can beidered as true natural autoantibodies since they are p

n the blood of almost every healthy individuals (Xu et al.,993; Pockley et al., 1998). In recent studies we could corm this assumption for the IgG type anti-Hsp60 (Prohaszkat al., 1999, 2001; Burian et al., 2001; Bene et al., 2002) andnti-Hsp70 (Kocsis et al., 2002) antibodies. Moreover, therum concentration of the anti-Hsp60 antibodies was fo be fairly constant in middle aged men for a 5-year peBıro et al., submitted for publication).

G. Fust et al. / Molecular Immunology 42 (2005) 79–85 81

According to the studies of Alving’s group, naturally oc-curring autoantibodies against cholesterol reacting with the3�-OH group of the compound are present in the sera of al-most all healthy individuals (Alving et al., 1989; Alving andSwartz, 1991). We could confirm this findings in our recentstudy (Horvath et al., 2001a; Bıro et al., 2003).

6. Relationship between the antibodies to Hsp60,anti-C1q antibodies as well as antibodies mediatingcomplement-dependent replication enhancement(C-ADE) present in the sera of HIV-infectedindividuals

In serum samples from 120 HIV patients we measured(Prohaszka et al., 1999) in parallel serum concentrations ofanti-human Hsp60 antibodies, those of the IgG antibodiesagainst the C1q complement proteins as well as a specialtype of anti-HIV antibodies (C-ADE) which mediated in vitroenhancement of HIV infection (Fust et al., 1994; Szabo et al.,1999; Banhegyi et al., 2003).

We found a strong positive correlation between levels ofanti-Hsp60 and anti-C1q-antibodies (Fig. 1). Later we ob-served similar correlation in the sera of patients with mixedconnective tissue disease (MCTD), while autoantibody levelsa theh uned i-b dictede ob

form ffecto tingC tlywl IDSp g-

F manc heats rmanc

Fig. 2. Relationship between the serum levels of anti-Hsp60 antibodies andthe ability of the same sera to enhance/neutralize HIV infection in vitro.Odds ratio and its significance is indicated.

nosis (Fust et al., 1994), there is a strong positive correlationbetween C-ADE and viral load (Szabo et al., 1999), and fi-nally HAART results in their disappearance form the circu-lation of HIV patients (Banhegyi et al., 2003). We studied therelationship between C-ADE and anti-Hsp60 antibody lev-els. The two types of antibodies negatively correlated to eachother (R= 0.309,P= 0.0076). When the distribution of serumsamples which neutralized or enhanced HIV-growth in vitroin the presence of complement was studied, it turned out thatenhancement occurs mainly in samples which contained arelatively low level of anti-Hsp60 antibodies (Fig. 2).

7. Levels of anti-Hsp60 antibodies are not differentbetween HIV-infected and not infected individualswhereas serum concentration of anti-Hsp70antibodies is markedly elevated in HIV patients

Our studies revealed marked differences in the behav-ior of the IgG antibodies to Hsp60 and Hsp70 in HIV-infection: while no differences between HIV-infected andHIV-seronegative subjects in the anti-Hsp60 levels werefound, HIV patients had significantly higher serum con-centration of anti-Hsp70 antibodies compared to the HIV-seronegative controls.

74H on-t e in-v ts ofI erea ISA).Ti IV-s lev-e

p70w nd in6

gainst Hsp60 and C1q did not significantly correlate inealthy persons or patients with several other autoimmiseases (Horvath et al., 2001b). Moreover, anti-C1q antodies recognized the solid phase Hsp60 and three prepitope regions ofM. paratuberculosisHsp65 were able tind efficiently anti-C1q antibodies.

According to our studies, which has been performedore than a decade, C-ADE has a significant harmful en the clinical course of HIV disease. Antibodies media-ADE appear very early after HIV infection (concomitanith the seroconversion) (Szabo et al., 1999), their level is

ower in the asymptomatic stage as compared to the Aatients (Toth et al., 1991), their high titer herald a bad pro

ig. 1. Positive correlation between the levels of IgG antibodies to huomplement protein C1q (anti-C1q) and IgG antibodies to 60 kD humanhock proteins (Hsp60) in the sera of 72 HIV infected patients. Speaorrelation coefficient and its significance are indicated.

In the first series of experiments, serum samples fromIV infected patients were enrolled in the study. As c

rol, serum samples from 217 healthy blood donors werolved in the study after informed consent. The amoungG-type antibodies reacting with the two type of Hsps wssessed by enzyme-linked immunosorbent assay (ELhe results of comparison are depicted inTable 1. No signif-

cant difference between the HIV-infected patients and Heronegative controls was found for anti-Hsp60 antibodyls.

In a further experiment, IgG antibody levels against Hsere measured in the sera of 47 HIV-infected patients a3 healthy HIV-seronegative subjects (Table 1). Their lev-

82 G. Fust et al. / Molecular Immunology 42 (2005) 79–85

Table 1Comparison of the serum concentrations of IgG anti-human Hsp60 and anti-human Hsp70 antibodies in HIV patients and HIV seronegative controls

HIV patients (median 25–75%) HIV seronegative controls (median 25–75%) P-value (Mann–Whitney test)

Anti-Hsp60 (AU/ml) 35.8 (23.8–49.8),n = 74 36.0 (24.4–50.6),n = 214 0.1429Anti-Hsp70 (AU/ml) 1409 (1031–2214),n = 47 626 (429–970),n = 63 <0.0001

els were found to be significantly (P < 0.0001), more thantwice higher in the HIV patients than in the control sub-jects. When high anti-Hsp70 antibody levels were definedas values exceeding 1500 AU/ml, a limit near to the 90% ofconcentrations measured in the healthy controls, high anti-Hsp70 concentration occurred in 20/47 and 7/63 HIV pa-tients and healthy controls, respectively (P= 0.0002, Fisher’sexact test). Anti-Hsp70 antibody levels in HIV-seropositivepatients did not correlate to the CD4+ cell count (r = 0.294,P = 0.121) or viral load (r = −0.1164,P = 0.718) (Kocsis etal., 2003).

8. Highly active antiretroviral therapy (HAART)results in normalization of anti-Hsp70 antibodyconcentration

We compared anti-Hsp70 antibody levels in serum sam-ples taken from 19 HIV patients before the initiation ofHAART and after administration of HAART for 11–41 (me-dian = 24) months (Table 2). Serum concentrations of anti-Hsp70 antibodies significantly decreased upon HAART. Dur-ing this period viral load significantly dropped to almost zero,while CD4+ cell counts significantly raised (Kocsis et al.,2003).

The reasons for different behavior for the autoantibodiest er-s eartd ation;w sig-n odyl actorof weenCw Bc lev-e l Bc imi-l didn withp

TC unt du

AVC

Therefore, it is tempting to speculate that changes in theanti-Hsps levels are due to the inductive effect of the Hsps as-sociated to the virus. According toGurer et al. (2002)Hsp70and certain other heat shock proteins (Hsp27, Hsp40, Hsp60,and Hsp70) incorporate into the membrane of HIV virions.According to their observations Hsp70 was the most abundantHsp associated with HIV virions, therefore it can be assumedthat its increased expression on the surface of HIV-infectedcells and its incorporation into the membrane of HIV virionsmay lead to increased immune response against this protein.The drop of anti-Hsp70 antibody levels during administrationof HAART (which blocks HIV replication, consequently in-hibits enhanced Hsp70 expression and markedly decreasesviral load) indirectly supports this explanation.

9. ACHA levels are substantially higher in the sera ofHIV patients than in the HIV-seronegative controls,high ACHA levels are associated withhypocholesterolemia

ACHA concentration was measured in the sera of 46 HIVinfected patients and 110 HIV seronegative healthy controls.In the case of HIV patients not treated yet with HAART thelevels of these autoantibodies were almost four times highert luesw ec-t hlys

ing6 up,o refT ighA 50(

V-s ount(Pc

o human 60 kD and 70 kD in HIV infection is poorly undtood. Interestingly enough in patients with coronary hisease (CHD) we have observed a quite opposite situhile serum concentration of anti-Hsp60 antibodies wasificantly elevated in CHD, and high anti-Hsp60 antib

evels were found to be a strong and independent risk ff CHD (Prohaszka et al., 2001; Burian et al., 2001), no dif-

erence in the anti-Hsp70 levels could be detected betHD patients and healthy controls (Kocsis et al., 2002). Aell-known phenomenon in HIV infection is polyclonalell activation which results in increased IgG and IgAls in HIV patients. Our findings indicate that polyclonaell activation does not concern antibodies to Hsp60. Sarly, serum concentration of the anti-Hsp60 antibodiesot differ from the controls in SLE, a disease associatedolyclonal B cell activation (Horvath et al., 2001b).

able 2hanges in the anti-Hsp70 levels, viral load as well as CD4+ T cell co

Before initiation of HAART(median 25–75%)

nti-Hsp70 (AU/ml) 1309 (887–2213)iral load (copies/ml) 12000 (3082–59850)D4+ T cells (ml−1) 180 (151–434)

ring 24 (11–41) months HAART in 19 HIV patients

After 24 months (median)HAART (median 25–75%)

P-value (Wilcoxonmatched pair test)

640 (386–959) <0.0010 (0–1205) 0.003

404 (278–690) <0.01

han in the controls, the median (interquartile range) vaere 121 (65–216) AU/ml and 32 (18–48) AU/ml, resp

ively. The difference between the two groups was higignificant (P < 0.0001).

High ACHA levels as defined as those exceed0 AU/ml, a value near to 90% of the HIV-seronegative groccurred significantly (P < 0.0001), about eight times mo

requently in the control than in the patient group (Fig. 3).he odds ratio (95% confidence interval) of those with hCHA level to belong to the HIV infected group was

18–139,P < 0.0001).ACHA levels in the first serum samples of HI

eropositive patients did not correlate to the CD4+ cell cR= −0.061,P= 0.684), CD4+ cell percentage (R= −0.204,= 0.169), CD8+ cell count (R= 0.220,P= 0.138) or CD8+

ell percentage (R= 0.202,P = 0.174).

G. Fust et al. / Molecular Immunology 42 (2005) 79–85 83

Fig. 3. Frequency of subjects with high (>60 AU/ml) serum levels of ACHAamong 46 HIV patients and 110 HIV-seronegative controls.P-value forMann–Whitney test is indicated.

There was no correlation either between ACHA and totalserum IgG (R= 0.343,P= 0.182) or anti-Hsp60 autoantibody(R= 0.119,P = 0.627) levels (Horvath et al., 2001a).

Interestingly enough, we found significant negative cor-relation between ACHA and serum cholesterol levels. Bothserum ACHA and cholesterol levels were available for 39patients. There was a significant (R= −0.35,P= 0.026) neg-ative correlation between the two variables. ACHA levelswere significantly (P = 0.004), more than twice higher inthe 10 patients with low (<3.8 nmol/l) than in the 29 patientswith normal (>3.8 nmol/l) serum cholesterol concentrations145 (79–269) AU/ml, and 62 (44–105) AU/ml, respectively.High (>60 AU/ml) ACHA levels were found in all (10/10)and 15/29 patients with low and normal serum cholesterolconcentration, respectively (P = 0.0066).

HAART results in sharp decrease in ACHA concentra-tion, binding of ACHA to cholesterol-coated plates can beinhibited by preincubation with HIV virions (Horvath et al.,2001a).

At least two serum samples taken 3–71 months (median= 19 months) apart were available from 41 HIV patients onHAART. As shown inFig. 4, ACHA levels significantly (P<0.0001) decreased during the follow-up period. There was asignificant positive correlation (R= 0.692,P= 0.004) betweenthe extent of ACHA decrease and the length of follow up. Byc ringt nlys

ibito V-1p ives dif-fo atedw toc oundIp IgGa HIV-1 0( ein-

Fig. 4. Changes in serum concentration of IgG ACHA (A), total IgG con-centration (B), and antibodies to Hsp60 (C) in 41 HIV patients during a 19months (median) HAART treatment.P-values for Mann–Whitney test areindicated.

cubated with the same amounts of viral preparations at roomtemperature for 60 min, washed out, and the plates were incu-bated with 1:80 dilution of the same HIV-seropositive serum.No inhibition was observed even after preincubation with thehighest doses of HIV-1 preparations.

The most probable explanation for this observation is asfollows. The immunogeneicity of cholesterol increases be-cause of its presence in the envelope of HIV virions and con-sequential enhanced exposure to the immune system. In ac-cordance with this assumption, recent evidences indicate thatHIV-1 buds selectively from glycolipid-enriched membranelipid rafts, and host cell cholesterol within these domains areincorporated into the viral envelope (Nguyen and Hildreth,2000). Our present finding on the ability of HIV-1BA-L and toa lesser extent HIV-1IIIB to inhibit IgG binding to cholesterol-coated plate from a HIV-seropositive serum sample as well asthe sharp decrease in ACHA levels – in parallel with the dropin viral load – during HAART also supports this explanation.

ontrast anti-Hsp60 levels did not change significantly duhe same period of HAART and total IgG concentration olightly decreased (Fig. 4).

In an other experiment we studied the possibility to inhf the ACHA binding to cholesterol-coated plates by HIreparations. Aliquots of 1:80 dilution of a HIV-seropositerum was incubated at room temperature for 60 min witherent amounts (104, 105 and 106 RT cpm/ml) of HIV-1BA-L-r HIV-1IIIB preparations. Control samples were incubith buffer instead of virus. The mixtures were addedholesterol-coated ELISA plates and the amounts of bgG were determined as described above. The HIV-1BA-Lreparation dose-dependently inhibited the binding ofntibodies to cholesterol-coated plates. In the case ofIIIB detectable (10%) inhibition was found only with 16

RT) cpm/ml preparation. As control, the plates were pr

84 G. Fust et al. / Molecular Immunology 42 (2005) 79–85

10. Conclusions

HIV infection results in alteration of formation of sev-eral autoantibodies (Susal et al., 1996). Our recent findingsindicate that serum concentration two additional types of au-toantibodies – anti-Hsp70 and anti-cholesterol antibodies –is also significantly elevated in untreated HIV patients andHAART results in an almost complete normalization of theirtiters. The most probable explanation for this finding lay inthe nature of association of these compound with the HIV en-velope. Since the virus buds through the cholesterol-rich lipidrafts, cholesterol is present in high concentration in the viralenvelope. Similarly Hsp70 was found to be the most abun-dant Hsp associated with HIV virions. Presence of Hsp70and cholesterol in the viral envelop probably substantiallyincreases its immunogeneicity. When, however, along withthe sharp decrease of the number of HIV particles the anti-gen load also significantly drops, levels of antibodies againstHsp70 and cholesterol also markedly decrease towards nor-mal values. Although Hsp60-like molecules can be depictedby a capture assay in the HIV virions, it seems that the Hsp60concentration in the HIV particles is much lower that that ofthe Hsp70 (Gurer et al., 2002). Probably due to this fact thereis no increase in the anti-Hsp60 antibody levels in HIV in-fection.

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Bıro, A., et al., 2003. Serum anti-cholesterol antibodies in chronichepatitis-C patients during IFN-�-2b treatment. Immunobiology 207,161–168.

Brenner, B.G., Wainberg, Z., 2001. Heat shock proteins: novel therapeutictools for HIV infection? Expert Opin. Biol. Therapy 1, 67–77.

Burian, K., et al., 2001. Independent and joint effects of antibodies to hu-man heat-shock protein 60 and Chlamydia pneumoniae infection in thedevelopment of coronary atherosclerosis. Circulation 103, 1503–1508.

Carr, A., et al., 1998. A syndrome of peripheral lipodystrophy, hyper-lipidemia and insulin resistance in patients receiving HIV proteaseinhibitors. AIDS 12, 51–58.

Chen, Y.C., et al., 1992. HIV-1 gp41 contains two sites for interactionwith several proteins on the helper T-lymphoid cell line, H9. AIDS6, 533–539.

Chen, Y.C., et al., 1993. HIV-1 gp41 binds to several proteins on thehuman B-cell line, Raji. Mol. Immunol. 30, 1159–1163.

Danner, S.A., et al., 1995. A short-term study of the safety, pharma-cokinetics, and efficacy of ritonavir, an inhibitor of HIV-1 protease.European–Australian Collaborative Ritonavir Study Group. N. Engl.J. Med. 333, 1528–1533.

Ebenbichler, C., et al., 1993. Cell surface proteins binding to recombi-nant soluble HIV-1 and HIV-2 transmembrane proteins. AIDS 7, 489–495.

Ebenbichler, C.F., et al., 1996. The human immunodeficiency virus type 1transmembrane gp41 protein is a calcium-binding protein and interactswith the putative second-receptor molecules in a calcium-dependentmanner. J. Virol. 70, 1723–1728.

Edenhofer, F., et al., 1996. Prion protein PrPc interacts with molecularchaperones of the Hsp60 family. J. Virol. 70, 4724–4728.

Fust, G., et al., 1994. Neutralizing and enhancing antibodies measured inuals

09.F im-

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J tresss. J.

K pro-unol.

K heated.

L cet

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M iated

Little is known about the in vitro and in vivo effecthe anti-Hsps and ACHA antibodies on the HIV virions aIV-infected cells. Very recently we prepared IgG type mclonal ACHA and started to study their effect on in vitro Hroduction.

cknowledgements

This work was supported by theATHERNET(QLG1-T-2002-90397) grant of the Fifth FP of EC (http://www.thernet.hu/), Ministry of Education (FKFP 0138/01), ainistry of Welfare (ETT 248/2001) of Hungary.

eferences

gnew, L.L., et al., 2003. Altered lymphocyte heat shock proteinexpression in patients with HIV disease. AIDS 17, 1985–1988.

lving, C.R., Swartz Jr., G.M., Wassef, M., 1989. Naturally occurautoantibodies to cholesterol in humans. Biochem. Soc. Trans637–639.

lving, C.R., Swartz Jr., G.M., 1991. Antibodies to cholesterol, choterol conjugates and liposomes: implications for atherosclerosisautoimmunity. Crit. Rev. Immunol. 10, 441–453.

anhegyi, D., et al., 2003. Significant decrease of the enhment/neutralization index in HIV patients during highly activetiretroviral therapy (HAART). Immunol. Lett. 89, 25–30.

artz, S.R., et al., 1994. An Hsp60 related protein is associatedpurified HIV and SIV. J. Med. Primatol. 23, 151–154.

ene, L., et al., 2002. Impaired humoral immune response againscobacterial 65-kDa heat shock protein (HSP65) in patients witflammatory bowel disease. Dig. Dis. Sci. 47, 1432–1437.

complement-restored serum samples from HIV-1-infected individcorrelate with immunosuppression and disease. AIDS 8, 603–6

eingold, K.R., et al., 1993. The hypertrigliceridemia of acquiredmunodeficiency syndrome is associated with an increased prevof low density lipoprotein subclass pattern B. J. Clin. EndocrMetabol. 76, 1423–1427.

runfeld, C., et al., 1992. Lipids, lipoproteins, triglyceride clearancecytokines in human immunodeficiency syndrome. J. Clin. EndocrMetabol. 74, 1045–1052.

urer, C., Cimarelli, A., Luban, J., 2002. Specific incorporation ofshock protein 70 family members into primate lentiviral virionsVirol. 76, 4666–4670.

ammond, C., Helenius, A., 1994. Folding of VSV G protein: sequeinteraction with BiP and calnexin. Science 266, 456–458.

orvath, A., et al., 2001a. High level of anticholesterol antibo(ACHA) in HIV patients. Normalization of serum ACHA concetration after introduction of HAART. Immunobiology 203, 75768.

orvath, L., et al., 2001b. Levels of antibodies against C1q and 60family of heat shock proteins in the sera of patients with varautoimmune diseases. Immunol. Lett. 5, 103–109.

indal, S., Young, R.A., 1992. Vaccinia virus infection induces a sresponse that leads to association of Hsp70 with viral proteinVirol. 66, 5357–5362.

ocsis, J., et al., 2002. Antibodies against the human heat shocktein Hsp70 in patients with severe coronary artery disease. ImmInvest. 31, 219–231.

ocsis, J., et al., 2003. Elevated levels of antibodies against 70 kDshock proteins (Hsp70) in sera of patients with HIV infection. J. MVirol. 71, 480–482.

o, J.C., et al., 1998. ‘Buffalo hump’ in men with HIV-1 infection. Lan351, 867–870.

acejak, D.V., Luftig, R.B., 1991. Association of Hsp70 with the anovirus type 5 fiber protein in infected Hep-2 cells. Virology 1120–125.

iller, K.D., et al., 1998. Visceral abdominal-fat accumulation assocwith use of indinavir. Lancet 351, 871–875.

G. Fust et al. / Molecular Immunology 42 (2005) 79–85 85

Morimoto, R.I., Tissieres, A., Georgopoulos, G., 1994. The Biology ofHeat-Shock Proteins and Molecular Chaperons. Cold Spring HarborLaboratory Press.

Mulvey, M., Brown, D.T., 1995. Involvement of the molecular chaperoneBiP in maturation of Sindbis virus envelope glycoproteins. J. Virol.69, 1621–1627.

Nguyen, D.H., Hildreth, J.E.K., 2000. Evidence for budding of humanimmunodeficiency virus type 1 selectively from glycolipid-enrichedmembrane lipid rafts. J. Virol. 74, 3264–3269.

Otteken, A., Patricia, L.E., Moss, B., 1996. Folding, assembly,and intracellular trafficking of the human immunodeficiency virustype 1 envelope glycoprotein analyzed with monoclonal antibod-ies recognizing maturational intermediates. J. Virol. 70, 3407–3415.

Pockley, A.G., Shepherd, J., Corton, J.M., 1998. Detection of heat shockprotein 70 (Hsp70) and anti-Hsp70 antibodies in the serum of normalindividuals. Immunol. Invest. 27, 367–377.

Prohaszka, Z., et al., 1999. C1q autoantibodies in HIV infection: corre-lation to elevated levels of autoantibodies against 60 kD heat-shockproteins. Clin. Immunol. Immunpathol. 90, 247–255.

Prohaszka, Z., et al., 2001. Comparative study on antibodies to humanand bacterial 60 kD heat shock proteins in a large cohort of patientswith coronary heart disease and healthy subjects. Eur. J. Clin. Invest.31, 285–292.

Prohaszka, Z., Fust, G., 2004. Immunological aspects of heat shockproteins—the optimum stress of life. Mol Immunol. 41, 29–44.

Purnell, J.Q., et al., 2000. Effect of ritonavir on lipids and post-heparinlipase activities in normal subjects. AIDS 14, 51–57.

Ranford, J.C., et al., 2000. Chaperonins are cell-signalling proteins: theed.

Robinson, W.E., Montefiori, D.C., Mitchell, W.M., 1988. Antibody-dependent enhancement of human immunodeficiency virus type 1 in-fection. Lancet i, 790–794.

Safrin, S., Grunfeld, C., 1999. Fat distribution and metabolic changes inpatients with HIV infection. AIDS 13, 2493–2505.

Sagara, J., Kawai, A., 1992. Identification of heat-shock protein 70 in therabies virion. Virology 190, 845–848.

Speth, C., et al., 1999. A 60 kD heat-shock protein-like molecule interactswith the HIV transmembrane glycoprotein gp41. Mol. Immunol. 36,619–628.

Stebbing, J., et al., 2003. The heat-shock protein receptor CD91 is up-regulated on monocytes of HIV-1-infected “true” long-term nonpro-gressors. Blood 101, 4000–4004.

Susal, C., Daniel, V., Opelz, G., 1996. Does AIDS emerge from a disequi-librium between two complementary groups of molecules that mimicthe MHC? Immunol. Today 17, 114–119.

Szabo, J., et al., 1999. Strong correlation between the complement-mediated antibody-dependent enehancement of HIV-1 infection andplasma viral load. AIDS 13, 1841–1849.

Takeda, A., Tuazon, C.H., Ennis, F.A., 1988. Antibody-enhanced infectionby HIV-1 via Fc receptor-mediated entry. Science 242, 580–583.

Toth, D.F., et al., 1991. Neutralizing and complement-dependent enhanc-ing antibodies in different stages of HIV infection. AIDS 5, 263–268.

Walli, R., et al., 1998. Treatment with protease inhibitors associated withperipheral insulin resistance and impaired oral glucose tolerance inHIV-1-infected patients. AIDS 12, F167–F173.

Xu, Q., Willeit, J., Marosi, M., Kleindienst, R., Oberhollenzer, F., Kiechl,S., Stulnig, T., Luef, G., Wick, G., 1993. Association of serum anti-bodies to heat-shock protein 65 with carotid atherosclerosis. Lancet341, 255–259.

Y Im-

unfolding biology of molecular chaperones. Exp. Rev. Mol. MAvailable at http://www-ermm.cbcu.cam.ac.uk.

oung, R.A., 1990. Stress proteins and immunology. Annu. Rev.munol. 8, 401–420.