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

TISSUE FACTOR PROMOTER POLYMORPHISM AND CD142 EXPRESSION
IN CD 14+ CELLS FROM DENGUE VIRUS-INFECTED PATIENTS
ANA PAULA SARRETA TERRA (PG) (1) ; TAYSSIA BEATRIZ DOS SANTOS
(IC) (1) ; JULIANA ALINE DE SOUZA COSTA (IC) (1) ANA CAROLINA SANTANA
DE OLIVEIRA (PG) (1) ; ANA CRISTINA LOPES TOSTA (PG) (1) ; DENISE
MACIAL CARVALHO (PG) (1) ; DAVID NASCIMENTO SILVA TEIXEIRA (1 );
1.Laboratory of Immunobiology and Cellular Activation (LIPAC), Department of
Medical Clinic - Federal University of Triangulo Mineiro, Uberaba-MG
Introduction: Dengue fever is an infection caused by a flavivirus that remains
as an important epidemiological problem in tropical countries as Brazil. It can
cause a wild variety of symptoms since a self-limiting febrile disease to a
significant plasma leakage leading to severe hemorrhagic symptoms. Several
immunological and hematological factors are different expressed in those
patients. Tissue Factor (TF) is a component of coagulation cascade that
converts prothrombin to thrombin. The present work aims to analyze TF
expression (CD142) in monocytes correlating to TF polymorphism in dengue
infection patients compared to non-infected ones.
Methods and Results: Blood samples were collected from volunteers in EDTA
tubes. Clinical exams, Cell Blood Counts and IgM serology were done to
confirm Dengue virus infection. TF expression was analyzed by flow cytometry
(CD142 expression on CD14+ cells) and a polymorphism on tissue factor gene
at promoter region was investigated by polymerase chain reaction (PCR). PCR
products were visualized on 1% agarose gel, showing the following bands:
Homozygotes for the insert with a 205bp band (II); homozygous for deletion
showing an 187bp band (DD) and heterozygous presenting 187bp and 205bp
bands (ID). Our results showed an increased CD142 expression on CD14+ cells
from dengue patients (mean fluorescence intensity, MFI = 76,99) compared to
individuals without dengue (MFI = 39,85). PCR data showed no correlation
between clinical forms and TF genotypes. Discussion: Increased expression of
CD142 suggests an important role for tissue factor during the acute phase of
dengue virus infection. However, more studies are needed and a greater
number of patients should be investigated to rule out an association between
TF gene polymorphisms and development of DHF. Our work may contribute to
understand mechanisms involved in immune response and DHF development.
Financial support: CAPES, FAPEMIG, UFTM and FUNEPU