Surface Molecules Released by Trypanosoma cruzi Metacyclic Forms Downregulate Host Cell Invasion

Area of Science:

• Parasitology
• Cell Biology
• Infectious Diseases

Background:

• Trypanosoma cruzi metacyclic trypomastigote (MT) surface molecule release and its impact on host cell invasion are not fully understood.
• T. cruzi strains exhibit varying abilities to invade host cells, necessitating investigation into underlying mechanisms.

Purpose of the Study:

• To investigate differential release of MT surface molecules by T. cruzi strains.
• To determine the effect of released surface molecules on host cell invasion.

Main Methods:

• Incubation of MT forms in different media (D10, PBS++) to collect conditioned media (CM).
• Western blot analysis of CM using antibodies against gp82 and gp90.
• Host cell invasion assays using HeLa cells incubated with CM from different T. cruzi strains.

Main Results:

• Conditioned medium from poorly invasive G strain (G-CM) contained high levels of gp82 and gp90, inhibiting host cell invasion.
• Conditioned medium from highly invasive CL strain (CL-CM) had low levels of these molecules and did not inhibit invasion.
• G-CM's inhibitory effect was neutralized by antibodies against gp82 and gp90.

Conclusions:

• Spontaneously released MT surface molecules, gp82 and gp90, impair parasite-host cell interaction and invasion.
• gp82 may compete for host cell receptors, while gp90 further downregulates invasion.
• Differential release of these molecules by T. cruzi strains influences their invasive potential.