Selected artcles February 2016
The perks of papain-based vaccination
Papain-Based Vaccination Modulates Schistosoma mansoni Infection-Induced Cytokine Signals
N. Abdel Aziz, H. Tallima, E. A. Hafez and R. El Ridi
Here, Egyptian researchers show that injection of mice with papain one day before exposure to S. mansoni appeared to diminish or shut off all infection-induced epidermal and lymph node cytokine signals, which were relegated to levels similar to or lower than those released by naive mice.
Schistosoma mansoni and Schistosoma haematobium infect more that 200 million people, causing severe disease characterized by intense inflammatory responses to the parasite eggs that fail to exit the mammalian host to continue the life cycle in the intermediate snail stage.
Nada Abdel Aziz was doing her masters under supervision of Associate Prof. Hatem Tallima, Prof. Ebtisam Hafez and Prof. Rashika El Ridi
– My responsibilities were doing the practical work and analyzing the data under my supervisors’ supervision and monitoring the mice.
In the present study, the researchers started to elucidate the molecular basis of C57BL/6 mouse resistance to S. mansoni following treatment with the cysteine peptidase papain. They attempted to detect the early immunological signals in the epidermal, dermal and draining lymph nodes following S. mansoni infection in untreated and papain-pretreated mice.
– The main findings here are that Schistosoma mansoni infection in C57BL/6 mice induces immunological chaos and that a papain pretreatment or papain-based vaccination diminishes or shuts off S. mansoni infection early induction of type 1, type 17, and type 2 cytokines except for thymic stromal lymphopoietin, and respectively, re-programs or conditions the immune system towards a polarized type 2 immune milieu, Nada Abdel Aziz says.
Similarly to other helminthic parasites, significant resistance to S.mansoni infection is dependent on type 2 immune responses.
The researchers believe that the establishment of infection can be prevented if a proper composition of a cysteine peptidase-based vaccine can be selected, that is capable of entirely overcoming the infection-induced immunological chaos and generating a powerful, schistosome ESP-specific type 2 polarized memory immune response.
– The most fun during this study was that we strongly believe and are sure that our work will have a great impact on people’s life, particularly those 800 million who are at risk of infection which is the main reason actually, that creates high inspiration and motivation to do such work, Nada Abdel Aziz concludes.
Molecular mechanisms of macrophage M1/M2 polarization
The Phenotypic and Functional Features of Human M2 Macrophages Generated Under Low Serum Conditions
L. V. Sakhno, E. Ya. Shevela, M. A. Tikhonova, A. A. Ostanin and E. R. Chernykh
In this study performed by Russian researchers it is demonstrated that GM-CSF-induced macrophages are not stringently predetermined to M1 polarization.
Macrophages are highly plastic cells which can differentiate into either a classical, pro-inflammatory M1 type or an alternatively activated, anti-inflammatory M2 type. Activation conditions determine which type they differentiate into. The present study was aimed at the investigation of cytokine production and pro-apoptogenic/inhibitory molecule expression in macrophages generated with GM-CSF using either different conditions (with or without serum and different growth factors).
The researchers find that deprivation of serum factors in the cultures of GM-CSF-differentiated macrophages skew their phenotype towards M2-like cells and that macrophages generated in growth factor deficient conditions differ from conventional M1 cells by the decreased expression of HLA-DR molecules, higher expression of M2-marker CD206 and pro-apoptogenic/co-inhibitory molecules TRAIL, FasL, B7-H1 and also possessed a decreased ability to stimulate the proliferation of allogenic PBMCs.
In summary, the study expands the knowledge of the molecular mechanisms of M1/M2 polarization.