Immune response to a laminin-binding protein (Lmb) in group A streptococcal infection.
BACKGROUND
A laminin-binding protein (Lmb) similar to that of group B streptococcus is conserved in group A streptococcus (GAS) and has a role in adhesion of GAS to epithelial cells. The role of this protein is yet to be clarified in disease process and thus, it is important to know its role in binding of GAS to laminin and the immunogenic response against it in patients related with GAS infection.


METHODS
A recombinant protein (rGAS-Lmb) was purified using the lmb gene from M1 GAS and tested for its role in binding of GAS with laminin. The antibody response against rGAS-Lmb in patient sera related with GAS infection was measured by ELISA.


RESULTS
The rGAS-Lmb bound with laminin directly and inhibited the binding of GAS to laminin. The antibody response against rGAS-Lmb in patients with uncomplicated streptococcal infection (U. Strep) and those with rheumatic fever (RF) were significantly higher than those in the control group (P < 0.0001 and P < 0.001, respectively). No difference of anti-rGAS-Lmb antibody titer could be found between these two disease groups.


CONCLUSIONS
The higher antibody response in patients with GAS infection implies that the protein is well expressed during the period of infection and may be related with the colonization and infection of GAS in pharyngeal mucosa.
Wahid
Rezwanul M
RM
Department of Pediatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima 890-8520, Japan.
Yoshinaga
Masao
M
Nishi
Junichiro
J
Maeno
Nobuaki
N
Sarantuya
Jav
J
Ohkawa
Toshiya
T
Jalil
Abdul M
AM
Kobayashi
Keiko
K
Miyata
Koichiro
K
D018829:Adhesins, Bacterial / Q000276:immunology* / Q000302:isolation & purification; D000293:Adolescent; D000907:Antibodies, Bacterial; D002648:Child; D006801:Humans; D011994:Recombinant Proteins; D013290:Streptococcal Infections / Q000276:immunology*; D013297:Streptococcus pyogenes
D018829:Adhesins, Bacterial; D000907:Antibodies, Bacterial; D011994:Recombinant Proteins