Product Citations: 5

Plasmodium falciparum Malaria Susceptibility and Severity: Influence of MyD88-Adaptor-Like Gene (rs8177374) Polymorphism.

In Infection and Drug Resistance on 6 December 2022 by Ammar, A. I., El-Hefnawy, S. M., et al.

MyD88-adapter-like (MAL), as an essential adapter protein for a variety of TLRs (Toll-like receptors), modulates the inflammatory response. Many infectious illnesses are influenced by single nucleotide polymorphisms (SNPs) that modify MAL function. We aimed to examine the influence of the MAL rs8177374 polymorphism on Plasmodium falciparum malaria susceptibility and severity.
Samples from 141 Plasmodium falciparum malaria patients and 147 healthy controls were used in the study. Patients were subdivided into mild and severe groups based on their clinical results, as defined by the World Health Organization (WHO). Genotypes for MAL rs8177374 were identified by allele-specific PCR technique, and TNF-alpha and IL-12 levels were measured using ELISA.
The MAL rs8177374 (CT) genotype is associated with an increased risk of malaria (OR: 2.52; 95% CI: 1.44-4.41). Furthermore, the CT and TT genotypes gave considerable protection against severe malaria (OR: 0.07; 95% CI: 0.03-0.19 and OR: 0.03; 95% CI: 0.007-0.1 respectively). And the T allele was linked to a higher risk of malaria (OR: 1.7; 95% CI: 1.18-2.5), while protecting patients from severe malaria (OR: 0.135; 95% CI: 0.07-0.3). Mutants (CT and TT) have greater TNF-alpha and IL-12 levels compared to wild-type (CC).
Malaria risk is linked to single nucleotide polymorphism in the MyD88-adaptor-like gene. People with the MAL rs8177374 mutant variant may be less likely to get severe malaria.
© 2022 Ammar et al.

Colorectal cancer-derived microvesicles modulate differentiation of human monocytes to macrophages.

In Journal of Translational Medicine on 2 February 2016 by Baj-Krzyworzeka, M., Mytar, B., et al.

Tumour-derived microvesicles (TMVs) are important players in tumour progression, modulating biological activity of immune cells e.g. lymphocytes, monocytes and macrophages. This phenomenon is particularly interesting in the progression of colon cancer, as macrophages in this type of tumour are relevant for the recovery processes. In the present study, the role of colon cancer cell-derived microvesicles in monocyte differentiation and activity profile (polarization) was investigated.
Monocyte-derived macrophages (MDM) were differentiated in vitro in the presence of TMVs obtained from colon cancer: Caco-2, SW620, LoVo or SW480 cell lines and analysed according to their morphology and biological functions, as defined by cytokine secretion, reactive oxygen intermediate (ROI) production and cytotoxic activity against respective colon cancer cells.
Monocytes differentiated with TMVs exhibited morphological and phenotypical characteristics of macrophages. An early contact (beginning with the first day of the in vitro culture) of monocytes with TMVs resulted in increased IL-10 secretion and only slightly elevated TNF release. Early, or prolonged contact resulted in low ROI production and low cytotoxicity against tumour cells. On the other hand, late contact of MDM with TMVs, stimulated MDM to significant TNF and IL-12 secretion, ROI production and enhanced cytotoxicity against tumour cells in vitro. In addition, differences in MDM response to TMVs from different cell lines were observed (according to cytokine secretion, ROI production and cytotoxicity against tumour cells in vitro). Biological activity, STATs phosphorylation and microRNA profiling of MDMs indicated differences in their polarization/activation status which may suggest mixed polarization type M1/M2 with the predominance of proinflammatory cells after late contact with TMVs.
Macrophage activity (polarization status) may be regulated by contact with not only tumour cells but also with TMVs. Their final polarization status depends on the contact time, and probably on the vesicle "cargo", as signified by the distinct impact of TMVs which enabled the switching of MDM maturation to regulatory macrophages.

  • Cancer Research

Histopathological and immunohistochemical aspects of American cutaneous leishmaniasis before and after different treatments.

In Anais Brasileiros De Dermatologia on 30 March 2013 by Viana, A. G., Mayrink, W., et al.

The histopathology and immune responses of the healing process of leishmaniasis are still poorly studied.
This study aimed to examine the histopathological and immunological aspects of lesions of patients with cutaneous leishmaniasis before and after different therapeutic methods.
We studied 23 individuals grouped according to the treatments: Glucantime, Glucantime + Leishvacin and Glucantime + Leishvacin associated with Bacillus Calmette-Guerin. For analysis of the histopathological changes present in the dermis and epidermis, histological sections were stained with hematoxylin and eosin. The samples were immunostained before and after treatment to analyze the expression of interferon (IFN)-γ, interleukin (IL) 12, IL-10 and IL-4.
Before treatment the presence of intense infiltrates of mononuclear cells was noticed and after treatment, even with a diagnosis of clinical cure, the subjects still showed a moderate inflammatory process. In the immunohistochemical analyses, we noticed a difference between the cytokines, with increased expression of cytokines IFN-γ and IL-12 compared to IL 10 and IL-4, both before and after treatment and, comparatively, the difference in this expression was more intense before treatment. However, the cytokine expression analyzed by treatment group showed no statistically significant difference.
We conclude that a clinical cure does not always coincide with the histopathological one, and that before treatment there is a predominance of Th1 cytokines. In terms of treatment type, there was no difference in the progression of healing for all the three types of treatment, indicating their clinical equivalence.

Subepithelial and intraepithelial lymphocytes of human adenoids and tonsils were characterized and directly compared to determine the potential contribution of these tissues to mucosal and systemic immune responses. The distribution of T and B cell subsets, cytokine patterns, and antibody (Ab) isotype profiles were similar for adenoids and tonsils. Both tissues contained predominantly B cells ( approximately 65%), approximately 5% macrophages, and 30% CD3(+) T cells. The T cells were primarily of the CD4(+) subset ( approximately 80%). Tonsillar intraepithelial lymphocytes were also enriched in B cells. The analysis of dispersed cells revealed a higher frequency of cells secreting IgG than IgA and the predominant Ig subclass profiles were IgG1 > IgG3 and IgA1 > IgA2, respectively. In situ analysis also revealed higher numbers of IgG- than IgA-positive cells. These IgG-positive cells were present in the epithelium and in the subepithelial zones of both tonsils and adenoids. Mitogen-triggered T cells from tonsils and adenoids produced both Th1- and Th2-type cytokines, clearly exhibiting their pluripotentiality for support of cell-mediated and Ab responses. Interestingly, antigen-specific T cells produced interferon-gamma and lower levels of interleukin-5. These results suggest that adenoids and tonsils of the nasopharyngeal-associated lymphoreticular tissues represent a distinct component of the mucosal-associated lymphoreticular tissues with features of both systemic and mucosal compartments.

  • Immunology and Microbiology
  • Pathology

Interleukin (IL)-4 is a major regulatory cytokine governing bioactive IL-12 production by mouse and human dendritic cells.

In The Journal of Experimental Medicine on 18 September 2000 by Hochrein, H., O'Keeffe, M., et al.

Interleukin (IL)-12 may be secreted as a bioactive T helper type 1 (Th1) cell-inducing heterodimer, as a monomer, or as an antagonistic homodimer. We analyzed the IL-12 produced by mouse splenic dendritic cells (DCs), human thymic DCs, and cultured human monocyte-derived DCs. IL-12 production required both a microbial or T cell-derived stimulus and an appropriate cytokine milieu. The different IL-12 forms were differentially regulated by the cytokines present rather than the stimulus used. IL-4 alone or together with granulocyte/macrophage colony-stimulating factor or interferon gamma effectively enhanced the production of the bioactive heterodimer and selectively reduced the antagonistic homodimer of IL-12. Therefore, IL-4, the major Th2-driving cytokine, provides a negative feedback causing DCs to produce the major Th1-inducing cytokine, bioactive IL-12.

  • Immunology and Microbiology
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