Photo Credit: Kitsawet Saethao
The following is a summary of “Aberrant expression of SOCS impairs the anti-leishmanial immune response,” published in the December 2023 issue of Allergy & Immunology by Jafarzadeh et al.
Achieving a delicate balance between specific immune cell subsets is pivotal in managing Leishmania infection. This balance involves orchestrating the activities of T-helper (Th) cell subsets (Th1 and Th2) and macrophage types (M1 and M2) within the immune system. Essential in this equilibrium are the suppressors of cytokine secretion (SOCS) proteins, particularly SOCS1 and SOCS3. These regulatory proteins wield significant control over signaling pathways activated by cytokines, essential for driving the immune response against Leishmania.
During Leishmania infection, the immune system encounters pathogen-associated molecular patterns (PAMPs) derived from the parasite, such as lipophosphoglycan (LPG) and CpG-DNA. These elements interact with toll-like receptors (TLRs), specifically TLR2 and TLR9, prompting the activation of SOCS expression. However, the levels of SOCS1 and SOCS3 within infected macrophages can become aberrant, disrupting the interactions between macrophages and T-cells. Consequently, this disruption impairs the balanced polarization of macrophage subsets and impedes the vital functions of macrophages, such as apoptosis and leishmanicidal activity. This scenario promotes the establishment of infection and allows the parasite to replicate more effectively within the host.
Moreover, imbalances in SOCS3 levels within T-cells negatively impact the differentiation process of Th1 cells. This aberration further exacerbates the situation by creating an environment conducive to increased parasite replication, the formation of lesions, and the initiation of pathological immune responses. Therefore, modulating the expression and function of SOCS in immune effector cells presents a strategic approach to counteract the survival of the parasite, potentially curtailing disease progression in Leishmania infection.
Source: sciencedirect.com/science/article/abs/pii/S1043466623003393
