SIGNIFICANT ELEVATION OF SERUM IL-35 CONCENTRATION CORRELATED WITH DISEASE SEVERITY IN MALARIA INFECTED MICE

Abstract

BACKGROUND:

The expression profile of Interleukin (IL) -35, a novel regulatory cytokine is yet to be clearly elucidated in malaria infection. Interleukin-35 has been reported to be diminished, and consequently contributory to the pathogenesis of autoimmune disorders, certain malignancies, and sepsis.. Hence, Interleukin-35 was investigated for its involvement in the immunopathogenesis of Plasmodium berghei rodent model of malaria infection.

METHOD:

We explored variations in IL-35 concentrations in serum samples of malaria infected male ICR mice as well as serum samples from uninfected age and sex matched controls obtained from whole blood collected on Days 1, 3 and 5 post initiation of malaria infection. Serum IL-35 quantitation was acheived by means of sandwich ELISA procedure. Furthermore, immunohistochemical analysis was performed on formalin fixed paraffin embedded tissue sections of whole brain, kidney, heart, lungs, liver and spleen of infected and control mice harvested on Day 5 post initiation of malaria infection.

RESULTS:

Significant elevation in serum expression of IL-35 was observed in infected mice throughout the infection with increasing malaria severity when compared to healthy (uninfected) control mice. Single immunohistochemical staining for the detection of IL-35p35 revealed that Liver and Splenic tissues of severely infected mice were highly positive for IL-35p35, with increasing expression evident from Day 1 through o Day 5 post malaria infection when compared to healthy controls.

CONCLUSION:

The results obtained suggest that IL-35 likely comprises a strong immune system component as an ardent member that partakes in the immune response to malaria infection thereby contributing to the robust invivo immunoregulatory response to malaria infection.

KEYWORDS: Malaria, Interleukin-35, Plasmodium berghei.