Mechanobiology of immune cells: Messengers, receivers and followers in leishmaniasis aiding synthetic devices

Biomarker Insights: Evaluation of Presepsin, Apelin, and Irisin Levels in Cutaneous Leishmaniasis

Background/Objectives: Cutaneous leishmaniasis (CL) is a skin disease caused by Leishmania parasites. Presepsin, irisin, and apelin are biomarkers that are involved in the inflammatory response. The aim of this study was to investigate the association between serum levels of specific biomarkers, such as presepsin, apelin, and irisin, and the clinical features, location, number, and size of lesions in patients with CL. Methods: This study is a single-centre, prospective cohort study involving a total of 30 patients with skin lesions compatible with CL and 30 healthy matched controls. Age, sex, type of skin lesion, location of skin lesion, number of skin lesions, and diameter of skin lesions were recorded. The levels of presepsin, irisin, and apelin measured in the blood samples of the patient group were analysed in comparison to those in the healthy control group. Results: The findings revealed that presepsin levels were significantly elevated in the patient group compared to the controls (p = 0.000). However, no statistically significant differences were observed between the groups for irisin and apelin levels (p-values 0.096 and 0.836, respectively). A negative correlation was identified between presepsin levels and the number of skin lesions, the diameter of the largest lesion, and the total diameter of the lesions (p = 0.000). Conclusions: It appears that measuring presepsin levels in patients with CL may be beneficial. Presepsin has the potential to serve as a prognostic marker in CL, offering significant benefits in guiding clinicians in assessing disease progression and response to treatment.

Single-cell ATAC sequencing identifies sleepy macrophages during reciprocity of cytokines in L. major infection

The hallmark characteristic of macrophages lies in their inherent plasticity, allowing them to adapt to dynamic microenvironments. Leishmania strategically modulates the phenotypic plasticity of macrophages, creating a favorable environment for intracellular survival and persistent infection through regulatory cytokine such as interleukin (IL)-10. Nevertheless, these effector cells can counteract infection by modulating crucial cytokines like IL-12 and key components involved in its production. Using sophisticated tool of single-cell assay for transposase accessible chromatin (ATAC) sequencing, we systematically examined the regulatory axis of IL-10 and IL-12 in a time-dependent manner during Leishmania major infection in macrophages Our analysis revealed the cellular heterogeneity post-infection with the regulators of IL-10 and IL-12, unveiling a reciprocal relationship between these cytokines. Notably, our significant findings highlighted the presence of sleepy macrophages and their pivotal role in mediating reciprocity between IL-10 and IL-12. To summarize, the roles of cytokine expression, transcription factors, cell cycle, and epigenetics of host cell machinery were vital in identification of sleepy macrophages, which is a transient state where transcription factors controlled the epigenetic remodeling and expression of genes involved in pro-inflammatory cytokine expression and recruitment of immune cells.IMPORTANCELeishmaniasis is an endemic affecting 99 countries and territories globally, as outlined in the 2022 World Health Organization report. The disease's severity is compounded by compromised host immune systems, emphasizing the pivotal role of the interplay between parasite and host immune factors in disease regulation. In instances of cutaneous leishmaniasis induced by L. major, macrophages function as sentinel cells. Our findings indicate that the plasticity and phenotype of macrophages can be modulated to express a cytokine profile involving IL-10 and IL-12, mediated by the regulation of transcription factors and their target genes post-L. major infection in macrophages. Employing sophisticated methodologies such as single-cell ATAC sequencing and computational genomics, we have identified a distinctive subset of macrophages termed "sleepy macrophages." These macrophages exhibit downregulated housekeeping genes while expressing a unique set of variable features. This data set constitutes a valuable resource for comprehending the intricate host-parasite interplay during L. major infection.

Synthetic biology for combating leishmaniasis

Leishmaniasis is a neglected tropical disease caused by protozoan parasites of the Leishmania genus. Despite the efforts to control and treat the disease, it still remains a major public health problem in many countries. Synthetic biology is a rapidly evolving interdisciplinary field that combines biology, engineering, and computer science to design and construct novel biological systems. In recent years, synthetic biology approaches have shown great promise for developing new and effective strategies to combat leishmaniasis. In this perspective, we summarize the recent advances in the use of synthetic biology for the development of vaccines, diagnostic tools, and novel therapeutics for leishmaniasis.

Leishmaniasis: Immune Cells Crosstalk in Macrophage Polarization

Leishmaniasis is a complex infectious parasitic disease caused by protozoa of the genus Leishmania, belonging to a group of neglected tropical diseases. It establishes significant global health challenges, particularly in socio-economically disadvantaged regions. Macrophages, as innate immune cells, play a crucial role in initiating the inflammatory response against the pathogens responsible for this disease. Macrophage polarization, the process of differentiating macrophages into pro-inflammatory (M1) or anti-inflammatory (M2) phenotypes, is essential for the immune response in leishmaniasis. The M1 phenotype is associated with resistance to Leishmania infection, while the M2 phenotype is predominant in susceptible environments. Notably, various immune cells, including T cells, play a significant role in modulating macrophage polarization by releasing cytokines that influence macrophage maturation and function. Furthermore, other immune cells can also impact macrophage polarization in a T-cell-independent manner. Therefore, this review comprehensively examines macrophage polarization's role in leishmaniasis and other immune cells' potential involvement in this intricate process.