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Perfil imunol?gico associado ? susceptibilidade, resist?ncia e cura na infec??o por Leishmania ( Leishmania ) infantum

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Previous issue date: 2014-10-10 / A leishmaniose visceral (LV) ? end?mica no Brasil, sendo a regi?o nordeste a que apresenta maior incid?ncia, apesar de nos ?ltimos 30 anos ter aumentado o n?mero de casos em outras regi?es do pa?s. A LV na Am?rica Latina ? resultante da infec??o por Leishmania infantum. No entanto, nem todas as pessoas infectadas desenvolvem doen?a; na verdade, a maioria apresenta resolu??o espont?nea da infec??o sem sintomas caracter?sticos de LV. Tradicionalmente a avalia??o do perfil imunol?gico tem sido realizada utilizando a reestimula??o de c?lulas mononucleares de sangue perif?rico em cultura. Esses estudos revelaram que pacientes com LV apresentavam inibi??o tanto da prolifera??o linfocit?ria quanto da resposta pr?-inflamat?ria anti-Leishmania. O presente trabalho teve por objetivo avaliar a resposta imune na LV sintom?tica, na cura p?s-tratamento e assintom?tica. Para isso, analisamos caracter?sticas imunofenot?picas relacionadas ? ativa??o, Treg e mem?ria de linf?citos, por citometria de fluxo, assim como a produ??o de citocinas ex vivo ou em cultura de sangue total. Para os volunt?rios com LV, foi realizado um estudo longitudinal com reavalia??o imunol?gicas aos 4 e 14 meses ap?s a cura cl?nica. O grupo controle incluiu pessoas provenientes de regi?o end?mica, sendo dividido em 2 grupos: Controle Positivo, formado por pessoas que apresentaram sorologia e?ou PCR anti-Leishmania positivos e Controle Negativo formado por pessoas com sorologia e PCR anti-Leishmania negativos. Durante a LV os linf?citos CD4 apresentam um maior perfil de ativa??o e mem?ria, al?m de serem maiores produtores de citocinas em cultura, quando comparado aos linf?citos CD8, contudo essa ativa??o n?o ? Leishmania espec?fica, visto que ocorreu tanto em aus?ncia (CD4+CD25+:10,60%, CD8+CD25+:5,36%; p<0,0001) quanto em presen?a de ant?genos sol?veis de Leishmania (SLA), (CD4+CD25+: 10,20%, CD8+CD25+:3,28%; p=0,0003). H? ativa??o de linf?citos durante a LV (CD4+CD69+: 4,9%), quando comparado aos grupos Controle Positivo (CD4+CD69+: 1,96% p=0,0045) e Negativo (CD4+CD69+: 1,35% p=0,0062), mas esta ativa??o tamb?m n?o ? Leishmania espec?fica. O perfil de ativa??o linfocit?ria permanece elevado mesmo 14 meses ap?s o fim do tratamento, por?m ap?s a cura a ativa??o ? Leishmania espec?fica (CD4+CD25+ em aus?ncia de SLA: 8,44%, presen?a de SLA: 10,70% p=0,0279). Linf?citos CD8+CD25+ foram capazes de produzir IFN-? em presen?a de ant?geno tanto em Controles Positivos (aus?ncia de SLA: 5,17%, presen?a de SLA: 9,52% p=0,0391) como em LV curados (Curado 4 meses: aus?ncia de SLA: 3,90%, presen?a SLA: 10,70% p=0,0098). C?lulas presentes no sangue total de pessoas com LV ativa s?o capazes de produzir IFN-? em resposta ao SLA (IFN-? em aus?ncia de SLA: 3,61 pg?mL e em presen?a de SLA: 44,26 pg?mL; p=0,0020), assim como LV recuperado (IFN-? em aus?ncia de SLA: 2,29 pg?mL e presen?a de SLA: 139,80 pg?mL; p=0,0005). Contudo o elevado n?vel de IL-10 parece estar inibindo a atividade pro-inflamat?ria de IFN-? e TNF-? em pacientes na fase sintom?tica. Contrariamente as demais citocinas pro-inflamat?rias, a cultura de sangue total do grupo LV ativa n?o apresentou produ??o de IL-2 Leishmania espec?fica (em aus?ncia de SLA: 2,42 pg?mL e em presen?a de SLA: 2,56 pg?mL). Com base nesses dados n?s conclu?mos que a restaura??o da ativa??o de linf?citos e a diminui??o da produ??o de IL-10, Leishmania espec?fica, est?o relacionados ? um perfil imunol?gico protetor. / Visceral Leishmaniasis (VL) is endemic in Brazil and the northeast region had the
highest incidence
of the disease
, despite, in the last 30 years,
it
has spread
to all
geographic regions of the
country.
Leishmania infantum
is the
m
ain
etiological agent
of VL in Latin America, Europe and North Africa.
However,
not all infected individuals
develop the disease; in fact, the majority present spontaneous re
solution of infection
without
symptoms. The evaluation of the immunological profil
e has been mostly
conducted
stimulating, with
Leishmania
spp. antigen, peripheral blood mononuclear
cells
isolated from subjects with VL. These studies showed that VL patients had an
inhibition of both, lymphocyte proliferation and proinflammatory response
to
Leishmania
spp. antigen. Our study aimed to evaluate the immune response in active
LV, cured post treatment and asymptomatic infection. To reach this aim, we analyzed
immunophenotypic features related to activation, Treg and memory lymphocytes, by
flow
cytometry, as well as, evaluation of cytokine production, in
ex vivo
or in whole
blood culture. In
active
VL volunteers, a longitu
dinal study was
conducted with
reassessment at 4 and 14 months after clinical cure.
The control group included
individuals th
at live
d
in endemic region and were
either
Positive Control, consisting
of individuals with
positive anti
-
L
eishmania
spp.
serology and/or
positive
PCR
for
Leishmania
?
spp.
and Negative Control composed by individuals with
negative anti
-
Leishmania antibodie
s
serology and
negative
PCR
for Leishmania
. During VL, CD4
lymphocytes showed greater activation and memory profile
s
and
were
the
major
source of cytokines in culture when compared to CD8 lymphocytes
, and these were
not
Leishmania
specific. There
were
act
ivated lymphocytes during VL (CD4
+
CD69
+
:4.9%) when compared to control groups, Positive (CD4
+
CD69
+
:1.96%,
p=0.0045) and Negative (CD4
+
CD69
+
:1.35%, p=0.006), on the other hand, this was
non
-
specific activation. The lymphocyte activation profile remain
ed
el
evated even 14
months post treatmen
t. A
fter
clinical
cure
,
the activation
was
Leishmania
specific
(CD4
+
CD25
+
absence of SLA:
8.4%, and presence of SLA:
10.7% p=0.0279).
CD8
+
CD25
+
lymphocytes
were
able to produce
Leishmania
specific IFN
-
? in both,
Positive
Controls (absence of SLA 5.2% and presence of SLA: 9.5%, p=0.0391) and
Cured 4 month (absence of SLA: 3.9%; presence of SLA: 10.7% p=0.0098). Whole
blood culture cells, of VL patients,
were
able to produce IFN
-
?, by SLA stimulation
(absence of SLA: 28.0 pg
?mL, and presence: 44.3 pg?mL p=0.0020) as well as
recovered groups (absence of SLA 2.3 pg?mL and presence of SLA 139.8 pg?mL,
p=0.0005). However, the high level of IL
-
10 seem
ed
to inhibit pro
-
inflammatory
activity of IFN
-
? and TNF
-
?
during symptomatic dis
ease
.
Unlike other pro
-
inflammatory cytokines, active VL group d
id
not produce
Leishmania
specific IL
-
2
(absence of SLA 2.4 pg?mL and presence of SLA: 2.6 pg?mL). Based on these data
we conclude that the restoration of lymphocyte activation and decreased i
n IL
-
10
Leishmania
specific production
were
related to a protective immune profile.

Identiferoai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/19591
Date10 October 2014
CreatorsGalv?o, Joanna Gardel Valverde
Contributors15603016434, http://lattes.cnpq.br/7120263570947836, Nascimento, Eliana Lucia Tomaz do, 20167415468, http://lattes.cnpq.br/3995803872021711, Sales, Val?ria Soraya de Farias, 25069144472, http://lattes.cnpq.br/8525532896559374, Cruz, Alda Maria da, 80612920763, http://lattes.cnpq.br/2028714603825846, Bacellar, Maria Olivia Amado Ramos, 12436496587, http://lattes.cnpq.br/0199786420638506, Jer?nimo, Selma Maria Bezerra
PublisherUniversidade Federal do Rio Grande do Norte, PROGRAMA DE P?S-GRADUA??O EM BIOQU?MICA, UFRN, Brasil
Source SetsIBICT Brazilian ETDs
LanguagePortuguese
Detected LanguageEnglish
Typeinfo:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis
Sourcereponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN
Rightsinfo:eu-repo/semantics/openAccess

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