immunology of infectious and parasitic diseases - XXXVII Congress ...

LYMPHOCYTIC APOPTOSIS IN HUMAN P. FALCIPARUM AND P. VIVAX MALÁRIA:
RELATIONSHIP WITH IMUNE RESPONSE TO THE PARASITES
EVELYN KETY PRATT RICCIO 1 ; PAULO RENATO RIVAS TOTINO 1 ; VÍTOR ENNES
VIDAL 2 ; IRENE DA SILVA SOARES 3 ; MAURÍCIO MARTINS RODRIGUES 4 ; JOSÉ
MARIA DE SOUZA 5 ; LILIAN ROSE PRATT-RICCIO 1 ; RENATO PORROZZI DE
ALMEIDA 6 ; MARIA DA GLÓRIA BONECINI DE ALMEIDA 7 ; GRAZIELA MARIA
ZANINI 8 ; CLÁUDIO TADEU DANIEL RIBEIRO 1 ; MARIA DE FÁTIMA FERREIRA DA
CRUZ 1 .
1 Laboratory of Malaria Research, Fiocruz, 2 Laboratory of Molecular Biology and
Endemic Disease, Fiocruz, 3 Department of Clinical Analyses and Toxicology, University
of São Paulo, 4 Department of Microbiology, Immunology and Parasitology, Federal
University of São Paulo, 5 Ambulatory and Laboratory of Malaria Clinical Assays,
Instituto Evandro Chagas,
6
Laboratory of Leishmaniasis Research,
Fiocruz, 7 Immunology Service of Evandro Chagas Clinical Research Institute, Fiocruz
and 8 Parasitology Service, Evandro Chagas Clinical Research Institute, Fiocruz.
INTRODUCTION: Infection with Plasmodium is characterized by both activation and
suppression of the immune system during the course of the disease. As apoptosis is an
important mechanism regulating the activation of lymphocytes, we decided to study the
role of lymphocytic apoptosis during a non complicated malaria attack.
METHODOLOGY: Blood samples were collected from 35 individuals living in malaria
endemic area with positive blood smears, as well as from 17 individuals without
previous reported malaria episodes. Apoptosis in T and B cells were analyzed ex–vivo
and after 96 hour-culture. Cellular and humoral immune responses after antigenic
stimulation, absolute numbers of T and B cells, B cells polyclonal activation and the
auto-immune response against components of erythrocytes membrane, cardiolipin,
actin and DNA were also investigated. RESULTS: In ex-vivo analyses low levels of
apoptosis and high levels of cellular activation in CD4 + cells were observed in malaria
patients, although increased levels of early apoptosis in CD4 + and CD8 + cells had been
detected. High levels of IFN- and IL-10 and low levels of TNF were also verified in
malaria patients. No difference was observed between TNF and IL-10 plasmatic levels
between P. vivax and P. falciparum infections, although high levels of IFN- was
registered in P. vivax malaria patients. No relationship was observed between cytokines
levels and activation, viability or PBMC apoptosis. After 96 hour-culture, apoptosis
levels in malaria patients were increased in CD4 + , CD8 + and B cells, and even in the
presence of stimuli the cellular proliferation was lower than in healthy individuals.
Antibodies against membrane erythrocyte components, cardiolipin and DNA were
similarly detected in malaria patients and healthy individuals, while antibodies against