Epstein-Barr virus and molecular mimicry in systemic lupus
BRIAN D. POOLE1, R. HAL SCOFIELD1,2,3, JOHN B. HARLEY1,2,3, & JUDITH A. JAMES1,2
1Oklahoma Medical Research Foundation, 825 NE 13th Street, Oklahoma, OK 73104, USA,2Oklahoma Health Sciences
Center, 825 NE 13th Street, Oklahoma, OK 73104, USA, and3Veterans Affairs Medical Center, 825 NE 13th Street,
Oklahoma, OK 73104, USA
Systemic lupus erythematosus (SLE or lupus) is a complex disease with a multifactoral etiology, with genetic, hormonal, and
environmental influences. Molecular mimicry as a result of viral infection may contribute to the development of lupus. The
pattern of autoantibody development in lupus is consistent with initiation through molecular mimicry, as the initial
autoantigenic epitopes that have been observed are limited and cross-reactive with viral proteins. Autoantibody specificity may
then later diversify to other autoantigens through B-cell epitope spreading. Epstein-Barr virus (EBV) is an excellent candidate
to be involved in molecular mimicry in lupus. EBV infection has been associated with lupus through serological and DNA
studies. Infection with EBV results in the production of the viral protein Epstein-Barr virus nuclear antigen-1 (EBNA-1),
antibodies against which cross-react withlupus-associated autoantigens, including Ro, SmB/B0,and SmD1, in lupus patients.
The immune response against EBV, and EBNA-1 in particular, differs among lupus patients and healthy controls, with
controls maintaining a limited humoral response and failing to produce long-standing cross-reactive antibodies. We
hypothesize that the humoral immune response to EBNA-1 in susceptible individuals leads to the generation of cross-reactive
antibodies. Through the process of epitope spreading, these cross-reactive antibodies target additional, non-cross reactive
autoepitopes, spread to additional autoantigens, and become pathogenic, leading eventually to clinical lupus. This paper
reviews some of the current literature supporting roles for EBVexposure and epitope spreading in SLE.
Keywords: Systemic lupus erythematosus, Epstein-Barr virus, cross-reactivity, autoimmunity, epitope spreading,
Systemic lupus erythematosus (SLE or lupus) is a
complex systemic autoimmune disease. Clinical
presentation of lupus varies among patients, including
a wide range of possible organ system damage .
Autoantibodies serve as the most common and
unifying characteristic of lupus. These antibodies are
directed against a large but limited collection of
autoantigenic targets, including DNA chromatin and
its component histones, components of the spliceo-
some, the Ro/La complex, among others [2,3]. This
complexity has made the complete understanding of
lupus etiology and pathogenesis difficult. No factor,
either genetic or environmental, appears to be solely
causal for most of the patients. Therefore, most
investigators strongly suspect that lupus has a multi-
The available immunochemical evidence is consist-
ent with a mechanism of lupus autoantibody
generation through molecular mimicry. A molecular
mimicry mechanism is possible when the antibodies
formed, either spontaneously or as a consequence of a
heteroimmune response, cross-react. That is, these
antibodies bind two different antigens. Immuno-
chemically some structural feature of each of the two
antigens is sufficiently similar to one another to
imitate or be a mimic. This antibody then plays the
ISSN 0891-6934 print/ISSN 1607-842X online q 2006 Taylor & Francis
Correspondence: J. A. James, Oklahoma Medical Research Foundation, 825 NE 13th Street Oklahoma, Oklahoma, OK 73104, USA.
Tel: 1 405 271 4987. Fax: 1 405 271 7063. E-mail: firstname.lastname@example.org
Autoimmunity, February 2006; 39(1): 63–70
initiating role in the generation of the humoral
immune response against the second antigen.
In the case of systemic lupus the data are consistent
with at least three scenarios of autoimmunity being
generated from the heteroimmune response against
EBNA-1: PPPGRRP of EBNA-1 cross-reacting
with PPPGMRPP of Sm B/B0, amino acids (aa)
35–58 of EBNA-1(GPAGPRGGGRGRGRGRGR-
GHNDGG) and aa 95–119 of Sm D1 (RRPGGR-
GRGRGRGRGRGRGRGRGA) , and aa 58–72
(GGSGSGPRHRDGVRR) of EBNA-1 cross-react-
ing with aa 169–180 (TKYKQRNSWSHK) of
60kDa Ro .
Cross-reactions may also occur without there being
any pathological significance. Of all the known and
postulated cross-reactions (Table I) in only a few is a
pathogenic role possible. The HIV infection rate is too
low to be considered seriously as a primordial immune
response from which lupus autoimmunity could
emerge. Though not directly tested, association with
anti-70K nRNP autoantibodies and cytomegalovirus
is not associated with the general lupus phenotype
Although, the initial cross-reactions are expected
and observed to be very limited, usually to a single
structure, autoantibody bindingcandiversifyover time
through the process of B cell epitope spreading.
Human B cell epitope spreading was first described in
the anti-Sm system in human SLE [15,16]. These
processes have been implicated in lupus by analysis of
pre-diagnosis serum samples in human SLE that
documents the considerable diversification of antibody
specificity over time. Furthermore, the pattern of
autoantigensrecognized inSLEis consistentwith what
has been observed in animal models of epitope
Much of our current evidence suggests that
Epstein-Barr virus (EBV) is likely to be involved in
the initiation of lupus. EBV has many characteristics
that are ideal for involvement in the development of
autoimmunity, which will be discussed below.
EBV infection has been associated with lupus
through several different lines of evidence, including
serological association of the presence of anti-EBV-
viral capsid antigen (VCA) with lupus, association of
EBV DNA, with lupus, cross-reactivity of EBV
proteins with SLE-associated autoantigens, and a
number of other lupus-specific immune differences
[12–14,18,19]. The humoral immune response
against two lupus-associated autoantigens, Sm and
60kDa Ro demonstrates both substantial epitope
spreading and cross-reactivity with EBNA-1. This
review will focus on how EBV infection may initiate
early events in autoimmunity, and propose mechan-
isms through which such early events could lead to
lupus (Figure 1).
Patterns of autoantibody appearance
Recent work from our group examined the prevalence
of autoantibody specificies in SLE before disease
occurrence. The Department of Defense Serum
Repository contains samples from more than 5 million
Active Duty Military Service men and women. We
investigated seven serum autoantibodies before SLE
diagnosis from 130 patients . A pre-diagnosis
sample was positive for a lupus autoantibody in 88%
of all patients with a mean appearance of 3.3 years
prior to diagnosis .
These samples make tracking the order and
appearance of autoantibodies possible. Antinuclear
antibodies (ANA) (by HEp-2 immunofluorescence
screening), Ro/SSA, La/SSB and antiphospholipid
antibodies appeared first, at a mean of 3.4 years prior
to diagnosis. These were followed by anti-dsDNA
antibodies with a mean of 2.2 years prior to
diagnosis, which in turn are followed by anti-Sm
and anti-nRNP antibodies with a mean time of
appearance of 1.2 years prior to diagnosis . These
are a minimum time estimate of the actual time from
the first appearance of the antibody to diagnosis,
since samples from patients with autoantibodies
already present in the first available sample were
not considered in this analysis. Therefore, the actual
length of time between the initial development of
antibodies and the observation of clinical manifes-
tations is likely much longer.
The number and type of antibody specificities in
individual patients also increased over time. At the
appearance of the first autoantibody specificity,
antibodies from individual sera recognized an
average of 1.5 out of 7 antigens evaluated. At the
time of diagnosis, the average number of autoanti-
gens recognized was 3.0, a change that occurred
progressively in time and clearly demonstrates the
broadening of autoimmunity over time . This
progressive accrual of autoantibodies is consistent
mimicry, which may begin by cross-reactivity with
a very small number of autoepitopes and subsequent
development of additional
Cross-reactivity of viral proteins with lupus-associated
VirusViral antigen Self-antigenReference
Epstein-Barr VirusEBNA-1Sm B/B0
B. D. Poole et al.
Epitope spreading in lupus
When autoimmunity first initiates with the first
cross-reactive epitope, tolerance is lost. Autoimmu-
nity may spread to other epitopes on the same
antigen, other molecules in the same complex, or
even other complexes . B cell epitope spreading
is thought to occur when T cells with specificity for
one epitope are able to provide help to B cells
specific for another. B cells recognize epitopes in the
context of intact antigens while T cells recognize
processed peptides presented in the context of
MHC. B cells capable of binding one of several
epitopes on a particular protein could bind,
internalize, and present antigen from that protein
to T cells in the context of MHC class II. Similarly,
B cells maybe capable
internalizing one component of a multimolecular
complex. Peptides derived from proteins in the
complex could then be presented to T cells [22,23].
T cells would then provide help to the B cell in the
form of cytokines and ligation of CD 40. Since
the peptide presented to the T cell is not necessarily
the antigen bound by the B cell, one antigen-specific
T cell could activate a variety of B cells with different
epitope specificities  (Figure 2).
Examination of serial serum samples from patients
with reactivity to Sm revealed that temporal epitope
spreading occurs in spliceosomal autoimmunity.
After recognition of the initial epitope, PPPGMRPP,
of binding to and
antibody recognition spreads to neighboring epitopes
on the protein. PPPGMRGP (aa 193–200) was
the next epitope bound by Sm autoantibodies, and
the autoantibody specificity spread from there to
either in soluble form or as part of the B cell antigen receptor. Antibody-bound self protein (grey) is internalized and processed by APC, and
peptides presented to T cells, allowing loss of self- tolerance. Genetic predisposition or flaws in T-cell tolerance may be necessary for this
process to occur. B cell receptor bound self protein is internalized by B cells, processed, and presented to T cells, breaking tolerance.
Autoreactive T cells provide help for autoreactive B cells, leading to maturation and diversification of the autoantibody response.
Molecular mimicry resulting in autoimmunity. Cross-reactive anti-pathogen antibodies bind self proteins. The antibodies could be
initial antigen (designated by the black rectangle) can present
peptides derived from that antigen to T-cells. B: B cells specific for a
different epitope or antigen (open circle) that forms a complex with
the initial antigen is able to internalize the entire complex, and
present peptides from the original antigen to the T-cell, which then
provides help for a mature antibody response.
Process of epitope spreading. A: B cells specific for an
Molecular mimicry in SLE
include multiple epitopes . Epitope spreading
in the case of Sm autoimmunity is not limited to
the Sm B/B0protein. Patients who develop Sm
autoimmunity will almost invariably develop anti-
RNP , demonstrating the ability of lupus
autoimmunity to spread between proteins. The
human anti-Ro response develops in a similar
fashion as the anti-Sm response, with initial
recognition of one epitope, followed by spreading
to multiple sites .
Epitope spreading also occurs in models of
spontaneous SLE. In a non-immunized mouse
model of lupus, longitudinal analysis of MRL-lpr/lpr
mice showed thatthe
hnRNP A2/B1 diversified from peptides aa 35–55
to aa 50–70 [26,27]. Anti-chromatin antibodies are
also generated spontaneously in these mice. On
average, the first antibodies specific for chromatin to
arise in this model recognize discontinuous, native
epitopes, followed by antibodies to dsDNA or
histone proteins . These findings demonstrate
epitope spreading in a model that was not driven
The available evidence strongly suggests that EBV
infection is involved in the development of SLE.
Two studies examining the prevalence of EBV
antibodies in pediatric lupus patients detected a
significant increase in EBV infection in lupus
patients(OR . 49,OR . 14)
matched controls [12,13]. EBV DNA was also
found significantly more frequently in these patients
compared to controls [12,13]. Indeed, EBV DNA
was recovered from all of the patients studied.
Significant increases in EBV seroconversion were
also found in adult lupus patients (OR ¼ 9.4, CI
95% [1.5-infinity] corrected for familial control
EBV proteins are cross-reactive with a number of
SLE autoantigens. The lifelong, periodically reacti-
vating nature of EBV infection insures that there
will be multiple opportunities for these cross-reactive
In addition, the natural host cells of EBV are B cells,
which are responsible for the production of the
autoantibodies that are central to SLE. Infection with
EBV activates and/or immortalizes B-cells, and
interferes with the normal regulatory mechanisms
that control antibody
expressed during viral latency, LMP-1, mimics the
EBV produces a Bcl-2 homolog that inhibits
apoptosis in infected cells , and a viral IL-10
homologue which also can likely modify the host
immune system .
the immune system.
from CD40 .
EBV and molecular mimicry in lupus
60kDa Ro system
Additional supportive evidence for a role for EBV in
SLE comes from the human 60kDa Ro system. Anti-
Ro is among the first autoantibody specificities
developed in patientswhowill eventually be diagnosed
with lupus . In our recent published work, serial
serum samples were analyzed in which Ro autoanti-
bodies developed after the first sample was collected
. By solid-phase peptide epitope mapping, nine of
29 patients had monospecific antibodies to the same
single epitope, TKYKQRNGWSHK, amino acids
169–180. Seventeen of the remaining twenty patients
also recognized this peptide in addition to other
specificities. Sera from later time points were available
for the nine patients who had originally generated
antibodies only against aa 169–180, and the
antibodies present in these samples demonstrated
spreading over time to multiple Ro epitopes . Other
work has shown this Ro169 peptide to be a key 60kDa
Ro humoral SLE epitope [32–34]
When these anti-Ro antibodies from patients in the
earliest stages of Ro autoimmunity were purified, they
were found to cross-react with EBNA-1 at amino acids
58–72 . Immunity to EBNA-1 was always present
in these patients before Ro autoimmunity could be
detected, indicating that EBV infection came before
the development of autoimmunity. In several cases,
the progression of antibody reactivity from EBV-VCA,
to EBNA-1, to Ro could be observed in serial serum
Similarly, immunization of rabbits or mice with
peptides derived from the Ro autoantigen led to
generation of antibodies against not only the
immunizing peptide, but also multiple epitopes of
Ro, and against several other autoantigens. Immuniz-
ation of mice with 52kDa Ro lead to antibodies
against 48kDa Ro and 60kDa Ro, and immunization
with 60kDa Ro similarly resulted in anti-48 and 52kD
Ro immunity . Several studies investigating the
immunization of rabbits or mice with peptides derived
from the 60kDa Ro protein found that immunity
developed against many different proteins, including
anti-La, Sm B0SmD1, nRNP A and nRNP C
antibodies. Time course analysis revealed that
autoantibodies appeared first against Ro, then
SmB/B0, followed by nRNP A and C. Antibodies to
La were among the last to appear [36–41].
Spliceosomal Sm system
Early epitopes of Sm autoantibodies cross-react with
EBNA-1, the major latent protein of EBV infection.
In four patients who developed anti-Sm reactivity
while under observation, the first anti-Sm B/B0
response was mapped to few epitopes, with the
repeated peptide sequence PPPGMRPP always being
B. D. Poole et al.
recognized by the first Sm-positive sample. Not only is
PPPGMRPP the first antigen bound by the anti-Sm B
response, antibodies targeted against this sequence
account for an overwhelming proportion of the anti-
Sm antibody population, highlighting its critical role
in anti-Sm autoimmunity . In one experiment,
98% of Sm-binding sera recognized PPPGMRPP
. Purified rabbit antibodies against the EBNA-1-
derived peptide PPPGRRP from strongly cross-react
with the Sm epitope PPPGMRPP , and purified
anti-PPPGMRPP from human lupus patient sera
cross-react with PPPGRRP.
Immunization of rabbits with the SmB/B0-derived
peptides PPPGMRPP or PPPGIRGP on a branched
lysine support lead to the production of antibodies
against up to 96 distinct sites dispersed throughout the
spliceosome, demonstrating that antibody recognition
had spread from the immunizing peptide to novel
epitopes. Immunized rabbits also developed antibody
reactivity against Sm D (12 of 13 rabbits), nRNP 70K
(12/13 rabbits), Sm C (13/13), RNP A (11/13),
double stranded DNA (dsDNA), and ANA, as well as
features of lupus such as thrombocytopenia, seizures
and proteinuria [4,44].
Immunization of mice with the peptide PPPG-
MRPP led to strain-specific epitope spreading. Some
strains (129/J, A/J, AKR/J, Balb/c, PL/J and SJL/J)
produced antibodies that bound multiple epitopes of
SmB/B0and nRNP upon immunization, while other
strains (C3H/HeJ, C57Bl/6J, C57Bl/10J, C57BL/J,
DBA/2J and NZB/Binj) produced antibodies only
against the immunizing peptide . These immu-
nization experiments confirmed the data obtained
using the rabbit model, and also indicated that genetic
background is an important component of epitope
spreading. Repetition of this experiment by an
independent group confirmed the development of
ANA and epitope spreading to additional determi-
nants of Sm B/B0and the development of autoanti-
bodies against RNPA and Ro . A third attempt to
demonstrate epitope spreading to the native forms of
Sm and U1RNP in response to PPPGMRPP
immunization using a different immunogenic back-
bone showed lupus-like autoimmune-mediated dis-
ease, including kidney damage, but no evidence of
epitope spreading in the three rabbits tested .
EBNA-1 antibodies from lupus patients also cross-
react with Sm D1. EBNA-1 contains a large glycine–
arginine (GR) repeat that is homologous with a region
on the C-terminal end of Sm D1, a lupus-associated
autoantigen and component of the spliceosome [5,6].
Approximately 30% of tested sera from lupus patients
bound to Sm-derived peptides containing the GR
region, while sera from patients with rheumatoid
arthritis, systemic sclerosis, or Sjo ¨gren’s syndrome did
not. Interestingly, the only non-lupus sera that bound
were from patients with infectious mononucleosis .
it was found that they also bound to EBNA-1 .
Intriguingly, although some normal EBV-infected
individuals as well as lupus patients make antibodies
against the EBNA-1 GR repeat, only antibodies from
sequence derived from Sm D1 . Furthermore,
epitope analysis revealed that 8/9 sera from Sm D-
reactive lupus patients bound to the GR repeat region
of Sm D1, as did sera from lupus patients without Sm
specific antibodies by precipitin. Normal controls did
dimethylation of Sm D1 and Sm D3 peptides may
render them more antigenic .
Animal models confirmed the importance of the
GR-repeat in Sm autoimmunity. Immunization of
rabbits with a peptide containing the Sm D1 GR
repeat region led to anti-Sm D1 immunity, as well as
some epitope spreading to Sm D3 . Immunization
of mice with the cross-reactive EBNA-1 peptide is
sufficient to cause Sm D1 autoimmunity, illustrating
the potential for cross-reactive antibodies to EBNA-1
to participate in molecular mimicry . Antibodies
from MRL lpr/lpr mice, which spontaneously develop
a lupus-like syndrome, also bind to the GR-repeat
region of Sm D1 .
Animal models demonstrate that a cross-reactive
anti-EBNA-1 immune response can lead to lupus-like
disease. Immunization of rabbits with the cross-
reactive epitopes derived from either Ro or EBNA-1
led to antibody recognition of EBNA-1 and of other
lupus autoantigens, including Sm B0, nRNP, and
dsDNA. These rabbits also developed clinical
features, such as leukopenia, thrombocytopenia, and
increases in serum creatinine . Peptide immuniz-
ation, however, is not the natural route through which
an organism would encounter EBNA-1. We expect
that the human cases of lupus developed anti-EBNA-1
first and then, with maturity, the cross-reactive
specificities. To see if a more physiologic method
of introducing EBNA-1 would still produce auto-
immunity, Sundar injected mice with EBNA-1
DNA expression vectors and found that expression
of EBNA-1 led to the production of anti-Sm and
anti-DNA antibodies . These experiments
show that full-length, endogenous expression or
peptide immunization EBNA-1 can lead to broad
SLE unique EBV responses
The ubiquitous nature of EBV infection naturally
raises the question of why these cross-reactive epitopes
do not lead to autoimmunity in all infected people.
Only three likely possibilities exist. The difference is
between those who develop lupus because of the host
response to EBV, because of differences in the EBV
random. This last possibility seems to be eliminated
Molecular mimicry in SLE
by the strong genetic component in SLE [53,54],
which is also consistent with the host response being
the important variable. To this point there is no
evidence that lupus risk varies with viral strain.
The answer may be found in the lupus-specific
differences in the humoral immune response to
EBNA-1. In a study of EBV-positive pediatric lupus
patients and controls, patientsweremore likely to have
anti-EBNA-1 than controls, with 36/36 patients
compared to 25/36 controls having antibody recogniz-
ing EBNA-1 (p , 0.005) . Lupus through anti-
Sm B/B0or anti-Ro may be impossible in normal
individuals who do not develop anti-EBNA-1
Epitope mapping of the EBNA-1 antibody speci-
ficity in these pediatric SLE patients revealed that
lupus patients recognize a much broader range of
epitopes than controls. Control sera primarily recog-
nized two epitopes, both of which are part of a large
glycine–alanine repeat. Sera from lupus patients,
however, bound to multiple epitopes found through-
out the protein . Increased diversity of EBNA-1
epitope recognition by lupus patients may result in
production of cross-reactive antibodies, which par-
The reasons for these lupus-specific alterations in
EBNA-1 immunity are not completely known.
However, cross-reactive antibodies, including those
against PPPGMRPP, are produced during infectious
mononucleosis. In people who do not develop lupus,
these antibodies are generally cleared by 4 months
after the resolution of mononucleosis .
SLE patients carry increased EBV viral loads, and
cellular immunity against EBV is altered in SLE
patients [17,56,57]. EBV viral load was found to be
40-fold higher in lupus patients than controls,
resulting from increased numbers of latently infected
cells in the periphery [56,57]. Such an increase in
viral load may provide a large increase in cross-
reactive antigen. The cellular immune response to
EBV differs in lupus, with a decreased cytotoxic
T-cell response and heightened CD 4 þ T cell
reactivity . Such differences in infection or
T-cell immunity as well as genetic or other factors
may prevent lupus patients from eliminating these
cross-reactive antibody specificities or, alternatively,
allow them to return, allowing molecular mimicry to
From EBV infection to lupus
Cross-reactivity of anti-pathogen antibodies with self-
proteins is a compelling hypothesis to explain the
initial loss of tolerance seen in SLE. Under this
hypothesis, cross-reactive anti-pathogen antibodies
are formed in response to viral infection, and bind
self-proteins. For example, as a result of EBV
infections, anti-EBNA-1 antibodies that also bind to
60kD. Ro are formed and EBNA-specific B cells that
can bind Ro with their antigen receptor are activated.
These antibodies could be either immunoglobulins in
soluble form, or as B cell antigen receptors, since
either dendritic cells or B cells are capable of
presenting antigen to T-cells. Dendritic cells are
efficient at initiating T-cell immunity, whereas B cells
present peptides from their specific antigen with
extremely high efficiency [22,58]. Antibody-bound
self-protein would be internalized and processed by
these antigen-presenting cells, and self-peptides
presented to T cells, potentially resulting in the loss
of tolerance to these self-antigens . Autoreactive
T cells could then provide help for autoreactive B
cells, leading to maturation and diversification of the
autoantibody response (Figure 2). Recognition of self
antigens in an inflammatory milieu of cytokines, such
as would result from viral infection, could also
predispose antigen presenting cells (APCs) to present
self-antigen in a stimulatory, as opposed to tolero-
Development of lupus autoimmunity may begin
with molecular mimicry involving EBV infection and
generated as a result of infection. These antibodies allow the targeting by the immune system of proteins containing the cross-reactive epitope
or epitopes. Epitope spreading then generates a range of autoantibodies. When these autoantibodies attain the required specificity or
concentration, they become pathogenic, and SLE ensues.
Development of SLE. SLE is initiated when a genetically susceptible individual is infected with EBV. Cross-reactive antibodies are
B. D. Poole et al.
cross-reactivity to cellular autoantigens. Cross-reac-
tivity between EBNA-1 and multiple lupus antigens
has been observed in lupus patients, and the ability
of EBNA-1 to induce lupus-like autoimmunity
has been demonstrated in multiple animal models.
The progression from EBV infection to the diverse
autoimmune response seen in SLE may be easily
imagined (Figure 3). EBV infects a lupus-susceptible
person, resulting in molecular mimicry due to the
production of cross-reactive anti-EBNA-1 antibodies.
These autoantibodies react with self-proteins such
as Ro, Sm B/B0, or Sm D1. Epitope spreading
increases the autoimmune response to novel epitopes
on the protein. Cross-reactivity and physical associa-
tion allow the immune response to spread beyond the
initial protein, and develop sufficiently to cause
 Benseler SM, Silverman ED. Systemic lupus erythematosus.
Pediatr Clin North Am 2005;52:443–467, vi.
 Sawalha AH, Harley JB. Antinuclear autoantibodies in
systemic lupus erythematosus. Curr Opin Rheumatol 2004;
 Hardin JA. The lupus autoantigens and the pathogenesis of
systemic lupus erythematosus. Arthritis Rheum 1986;29:
 James JA, Scofield RH, Harley JB. Lupus humoral auto-
immunity after short peptide immunization. Ann N YAcad Sci
 Sabbatini A, Bombardieri S, Migliorini P. Autoantibodies from
patients with systemic lupus erythematosus bind a shared
sequence of SmD and Epstein-Barr virus-encoded nuclear
antigen EBNA I. Eur J Immunol 1993;23:1146–1152.
 Petersen J, Rhodes G, Roudier J, Vaughan JH. Altered immune
response to glycine-rich sequences of Epstein-Barr nuclear
antigen-1 in patients with rheumatoid arthritis and systemic
lupus erythematosus. Arthritis Rheum 1990;33:993–1000.
 McClain MT, Heinlen LD, Dennis GJ, Roebuck J, Harley JB,
James JA. Early events in lupus humoral autoimmunity
suggest initiation through molecular mimicry. Nat Med.
 Incaprera M, Rindi L, Bazzichi A, Garzelli C. Potential role of
the Epstein-Barr virus in systemic lupus erythematosus
autoimmunity. Clin Exp Rheumatol 1998;16:289–294.
 Newkirk MM, van Venrooij WJ, Marshall GS. Autoimmune
response to U1 small nuclear ribonucleoprotein (U1 snRNP)
associated with cytomegalovirus infection. Arthritis Res
 Deas JE, Liu LG, Thompson JJ, Sander DM, Soble SS, Garry
RF, Gallaher WR. Reactivity of sera from systemic lupus
erythematosus and Sjogren’s syndrome patients with peptides
derived from human immunodeficiency virus p24 capsid
antigen. Clin Diagn Lab Immunol 1998;5:181–185.
 Perl A, Colombo E, Dai H, Agarwal R, Mark KA, Banki K,
Poiesz BJ, Phillips PE, Hoch SO, Reveille JD, et al. Antibody
reactivity to the HRES-1 endogenous retroviral element
identifies a subset of patients with systemic lupus erythema-
tosus and overlap syndromes. Correlation with antinuclear
antibodies and HLA class II alleles. Arthritis Rheum
 James JA, Kaufman KM, Farris AD, Taylor-Albert E, Lehman
TJ, Harley JB. An increased prevalence of Epstein-Barr virus
infection in young patients suggests a possible etiology for
systemic lupus erythematosus. J Clin Invest 1997;100:
 Harley JB, James JA. Epstein-Barr virus infection may be
an environmental risk factor for systemic lupus erythematosus
in children and teenagers. Arthritis Rheum 1999;42:
 James JA, NeasBR, MoserKL, HallT,Bruner GR,Sestak AL,
Harley JB. Systemic lupus erythematosus in adults is
associated with previous Epstein-Barr virus exposure. Arthritis
 James JA, Gross T, Scofield RH, Harley JB. Immunoglobulin
epitope spreading and autoimmune disease after peptide
immunization: Sm B/B0-derived PPPGMRPP and PPP-
GIRGP induce spliceosome autoimmunity. J Exp Med
 Arbuckle MR, Reichlin M, Harley JB, James JA. Shared early
autoantibody recognition events in the development of anti-
Sm B/B0in human lupus. ScandJ Immunol 1999;50:447–455.
 McClain M,Poole B, Bruner B, Kaufman K, Harley J, JamesJ.
An altered immune response to Epstein-Barr virus nuclear
antigen-1 (EBNA-1) in pediatric systemic lupus erythemato-
sus. Arthritis Rheum, In Press.
 Parks CG, Cooper GS, Hudson LL, Dooley MA, Treadwell
EL, Clair St, EW, Gilkeson GS, Pandey JP. Association of
Epstein-Barr virus with systemic lupus erythematosus: effect
modification by race, age, and cytotoxic T lymphocyte-
associated antigen 4 genotype. Arthritis Rheum 2005;52:
 Chen CJ, Lin KH, Lin SC, Tsai WC, Yen JH, Chang SJ, Lu
SN, Liu HW. High prevalence of immunoglobulin A antibody
against Epstein-Barr virus capsid antigen in adult patients with
lupus with disease flare: Case control studies. J Rheumatol
 Arbuckle MR, McClain MT, Rubertone MV, Scofield RH,
Dennis GJ, James JA, Harley JB. Development of autoanti-
bodies before the clinical onset of systemic lupus erythema-
tosus. N Engl J Med 2003;349:1526–1533.
 LakeP, Mitchison NA.Regulatory mechanisms in the immune
response to cell-surface antigens. Cold Spring Harb Symp
Quant Biol 1977;41(Pt 2):589–595.
 Mamula MJ, Janeway Jr, CA. Do B cells drive the
diversification of immune responses? Immunol Today
 Roth R, Nakamura T, Mamula MJ. B7 costimulation and
autoantigen specificity enable B cells to activate autoreactive T
cells. J Immunol 1996;157:2924–2931.
 Craft J, Fatenejad S. Self antigens and epitope spreading
in systemic autoimmunity. Arthritis Rheum 1997;40:
 Fisher DE, Reeves WH, Wisniewolski R, Lahita RG,Chiorazzi
N. Temporal shifts from Sm to ribonucleoprotein reactivity in
systemic lupus erythematosus. Arthritis Rheum 1985;28:
 Topfer F, Gordon T, McCluskey J. Intra- and intermolecular
spreading of autoimmunity involving the nuclear self-antigens
La (SS-B) and Ro (SS-A). Proc Natl Acad Sci USA
 Dumortier H, Monneaux F, Jahn-Schmid B, Briand JP,
Skriner K, Cohen PL, Smolen JS, Steiner G, Muller S. B and
T cell responses to the spliceosomal heterogeneous nuclear
ribonucleoproteins A2 and B1 in normal and lupus mice.
J Immunol 2000;165:2297–2305.
 Burlingame RW, Rubin RL, Balderas RS, Theofilopoulos AN.
Genesis and evolution of antichromatin autoantibodies in
murine lupus implicates T-dependent immunization with self
antigen. J Clin Invest 1993;91:1687–1696.
 Stunz LL, Busch LK, Munroe ME, Sigmund CD, Tygrett LT,
Waldschmidt TJ, Bishop GA. Expression of the cytoplasmic
tail of LMP1 in mice induces hyperactivation of B lymphocytes
Molecular mimicry in SLE
and disordered lymphoid architecture. Immunity 2004;21:
 Henderson S, Huen D, Rowe M, Dawson C, Johnson G,
Rickinson A. Epstein-Barr virus-coded BHRF1 protein, a viral
homologueof Bcl-2,protects human B cells from programmed
cell death. Proc Natl Acad Sci USA 1993;90:8479–8483.
 Suzuki T, Tahara H, Narula S, Moore KW, RobbinsPD, Lotze
MT. Viral interleukin 10 (IL-10), the human herpes virus 4
cellular IL-10 homologue, induces local anergy to allogeneic
and syngeneic tumors. J Exp Med 1995;182:477–486.
 Scofield JI. 1996, AR 1992 Epitope mapping of the
Ro/SSA60KD autoantigen reveals disease-specific antibody-
binding profiles. Eur J Clin Invest 1996;26:514–521.
 Routsias JG, Tzioufas AG, Sakarellos-Daitsiotis M, Sakarellos
C, Moutsopoulos HM. Epitope mapping of the Ro/SSA60KD
autoantigen reveals disease-specific antibody-binding profiles.
Eur J Clin Invest 1996;26:514–521.
 Scofield AN, Kurien BT, Gordon TP, Scofield RH. Can B cell
epitopes of 60kDa Ro distinguish systemic lupus erythema-
tosus from Sjogren’s syndrome? Lupus 2001;10:547–553.
 Tseng CE, Chan EK, Miranda E, Gross M, Di Donato F,
Buyon JP. The 52kd protein as a target of intermolecular
spreading of the immune response to components of the SS-
A/Ro-SS-B/La complex. Arthritis Rheum 1997;40:936–944.
 McClain MT, Scofield RH, Kurien BT, Gross TF, James JA.
Selective small antigenic structures are capable of inducing
widespread autoimmunity which closely mimics the humoral
fine specificity of human SLE. Scand J Immunol 2002;56:
 Scofield RH, Henry WE, Kurien BT, James JA, Harley JB.
Immunization with short peptides from the sequence of the
systemic lupus erythematosus-associated 60kDa Ro autoanti-
gen results in anti-Ro ribonucleoprotein autoimmunity.
J Immunol 1996;156:4059–4066.
 Scofield RH, Kurien BT, Ganick S, McClain MT, Pye Q,
James JA, Schneider RI, Broyles RH, Bachmann M, Hensley
K. Modification of lupus-associated 60kDa Ro protein with
the lipid oxidation product 4-hydroxy-2-nonenal increases
antigenicity and facilitates epitope spreading. Free Radic Biol
 Deshmukh US, Lewis JE, Gaskin F, Kannapell CC, Waters
ST, Lou YH, Tung KS, Fu SM. Immune responses to Ro60
and its peptides in mice. I. The nature of the immunogen and
endogenous autoantigen determine the specificities of the
induced autoantibodies. J Exp Med 1999;189:531–540.
 Deshmukh US, Lewis JE, Gaskin F, Dhakephalkar PK,
Kannapell CC, Waters ST, Fu SM. Ro60 peptides induce
antibodies to similar epitopes shared among lupus-related
autoantigens. J Immunol 2000;164:6655–6661.
 McCluskey J, Farris AD, Keech CL, Purcell AW, Rischmueller
M, Kinoshita G, Reynolds P, Gordon TP. Determinant
spreading: Lessons from animal models and human disease.
Immunol Rev 1998;164:209–229.
 Petrovas CJ, Vlachoyiannopoulos PG, Tzioufas AG, Alex-
opoulos C, Tsikaris V, Sakarellos-Daitsiotis M, Sakarellos C,
Moutsopoulos HM. A major Sm epitope anchored to
sequential oligopeptide carriers is a suitable antigenic substrate
to detect anti-Sm antibodies.
 James JA, Harley JB. Linear epitope mapping of an Sm B/B0
polypeptide. J Immunol 1992;148:2074–2079.
 James JA, Harley JB. B-cell epitope spreading in autoimmu-
nity. Immunol Rev 1998;164:185–200.
 James JA, Harley JB. A model of peptide-induced lupus
autoimmune B cell epitope spreading is strain specific and is
not H-2 restricted in mice. J Immunol 1998;160:502–508.
 Mason LJ, Timothy LM, Isenberg DA, Kalsi JK. Immuniz-
ation with a peptide of Sm B/B0results in limited epitope
spreading but not autoimmune disease. J Immunol
 Vlachoyiannopoulos PG, Petrovas C, Tzioufas AG, Alex-
opoulos C, Tsikaris V, Guialis A, Nakopoulou L, Sakarellos-
Daitsiotis M, Sakarellos C, Davaris P, Moutsopoulos HM.
No evidence of epitope spreading after immunization with
the major Sm epitope P-P-G-M-R-P-P anchored to
sequential oligopeptide carriers (SOCs). J Autoimmun
 Marchini B, Dolcher MP, Sabbatini A, Klein G, Migliorini P.
Immune response to different sequences of the EBNA I
molecule in Epstein-Barr virus-related disorders and in
autoimmune diseases. J Autoimmun 1994;7:179–191.
 Brahms H, Raymackers J, Union A, de Keyser F, Meheus L,
Luhrmann R. The C-terminal RG dipeptide repeats of the
spliceosomal Sm proteins D1 and D3 contain symmetrical
dimethylarginines, which form a major B-cell epitope for anti-
Sm autoantibodies. J Biol Chem 2000;275:17122–17129.
 James JA, Mamula MJ, Harley JB. Sequential autoantigenic
determinants of the small nuclear ribonucleoprotein Sm D
shared by human lupus autoantibodies and MRL lpr/lpr
antibodies. Clin Exp Immunol 1994;98:419–426.
 Riemekasten G, Marell J, Trebeljahr G, Klein R, Hausdorf G,
Haupl T, Schneider-Mergener J, Burmester GR, Hiepe F.
A novel epitope on the C-terminus of SmD1 is recognized by
the majority of sera from patients with systemic lupus
erythematosus. J Clin Invest 1998;102:754–763.
 Sundar K, Jacques S, Gottlieb P, Villars R, Benito ME, Taylor
DK, Spatz LA. Expression of the Epstein-Barr virus nuclear
antigen-1 (EBNA-1) in the mouse can elicit the production of
 Tsao BP. Update on human systemic lupus erythematosus
genetics. Curr Opin Rheumatol 2004;16:513–521.
 Nath S, Kilpatrick J, Harley JB. Genetics of human systemic
lupus erythematosus: the emerging picture. Curr Opin
 McClain MT, Rapp EC, Harley JB, James JA. Infectious
mononucleosis patients temporarily recognize a unique, cross-
reactive epitope of Epstein-Barr virus nuclear antigen-1. J Med
 Moon UY, Park SJ, Oh ST, Kim WU, Park SH, Lee SH, Cho
CS, Kim HY, Lee WK, Lee SK. Patients with systemic lupus
erythematosus have abnormally elevated Epstein-Barr virus
load in blood. Arthritis Res Ther 2004;6:R295–R302.
 Kang I, Quan T, Nolasco H, Park SH, Hong MS, Crouch J,
Pamer EG, Howe JG, Craft J. Defective control of latent
Epstein-Barr virus infection in systemic lupus erythematosus.
J Immunol 2004;172:1287–1294.
 Lanzavecchia A. Antigen-specific interaction between Tand B
cells. Nature 1985;314:537–539.
 Doyle HA, Yan J, Liang B, Mamula MJ. Lupus autoantigens:
Their origins, forms, and presentation. Immunol Res
B. D. Poole et al.