Anaplastic thyroid cancer (ATC) is a highly aggressive type of thyroid cancer (TC). Currently, no effective target treatments are available that can improve overall survival, with ATC representing a major clinical challenge because of its remarkable lethality. Tumor-associated macrophages (TAMs) are the most evident cells in ATCs, and their high density is correlated with a poor prognosis. However, the mechanisms of how TAMs promote ATC progression remain poorly characterized. Here, we demonstrated that the treatment of human monocytes (THP-1 cells) with ATC cell-derived conditioned media (CM) promoted macrophage polarization, showing high levels of M2 markers. Furthermore, we found that STAT3 was activated, and this was correlated with an increased expression and secretion of the inflammatory cytokine interleukin-6. Remarkably, the M2-like macrophages obtained revealed tumor-promoting activity. A cytokine array analysis demonstrated that M2-like macrophage-derived CM contained high levels of TIM3, which is an important immune regulatory molecule. Consistently, TIM3 expression was up-regulated in THP-1 cells cultured with ATC cell-derived CM. Moreover, TIM3 blockade significantly reversed the polarization of THP-1 cells induced by ATC cell-secreted soluble factors. We validated the clinical significance of the TIM3 in human TC by analyzing public datasets and found that the expression of TIM3 and its ligand galectin 9 was significantly higher in human TC tissue samples than in normal thyroid tissues. Taken together, our findings identified a new mechanism by which TIM3 induces tumor-promoting M2-like macrophage polarization in TC. Furthermore, TIM3 interference might be a potential tool for treatment of patients with ATC.

Trypanosoma cruzi infection is associated with severe T cell unresponsiveness to antigens and mitogens and is characterized by decreased IL-2 synthesis. In addition, the acquisition of the anergic phenotype is correlated with upregulation of “gene related to anergy in lymphocytes” (GRAIL) protein in CD4 T cells. We therefore sought to examine the role of GRAIL in CD4 T cell proliferation during T. cruzi infection. Balb/c mice were infected intraperitoneally with 500 blood-derived trypomastigotes of Tulahuen strain, and spleen cells from control non-infected or infected animals were obtained. CD4 T cell proliferation was assessed by CFSE staining, and the expression of GRAIL in splenic T cells was measured by real-time PCR, flow cytometry and Western blot. We found increased GRAIL expression at the early stages of infection, coinciding with the peak of parasitemia, with these findings correlating with impaired proliferation and poor IL-2 and IFN-γ secretion in response to plate-bound antibodies. In addition, we showed that the expression of GRAIL E3-ubiquitin ligase in CD4 T cells during the acute phase of infection was complemented by a high expression of inhibitory receptors such as PD-1 and CTLA-4. We demonstrated that GRAIL expression during infection was modulated by the mammalian target of the rapamycin (mTOR) pathway, since addition of IL-2 or CTLA-4 blockade in splenocytes from mice 21 days post infection led to a reduction in GRAIL expression. Furthermore, addition of IL-2 was able to activate the mTOR pathway, inducing Otubain-1 expression, which mediated GRAIL degradation and improved T cell proliferation. We hypothesize that GRAIL expression induced by the parasite may be maintained by the increased expression of inhibitory molecules, which blocked mTOR activation and IL-2 secretion. Consequently, the GRAIL regulator Otubain-1 was not expressed and GRAIL maintained the brake on T cell proliferation. Our findings reveal a novel association between increased GRAIL expression and impaired CD4 T cell proliferation during Trypanosoma cruzi infection. Chagas disease is caused by the protozoan parasite Trypanosoma cruzi and is endemic in Central and South America, where it affects about 10 million people. In addition, migration has led to the disease being established in non-endemic countries. Infection involves an acute stage that evolves to a chronic stage where infected individuals may or may not show clinical symptoms or suffer progressive heart disease. The relevance of T cells in the control of T. cruzi infection has been demonstrated in human infection and in experimental models. However, the T. cruzi parasite employs different strategies to downregulate the T cell function. These mechanisms can act at the initial time of T cell activation, leading to a state of anergy where lymphocytes do not respond. However, the molecular components that regulate this process during T. cruzi infection are not well understood. Our findings demonstrate for the first time that this T cell hyporesponsiveness could be linked to an increased expression of GRAIL. We propose that GRAIL expression induced by the parasite could be maintained by increased expression of inhibitory molecules, which blocked mTOR activation and IL-2 secretion. GRAIL could then play a key role in downregulating T cell functions by allowing the parasites to establish the chronic disease.

Vulvovaginal candidiasis (VVC) is a mucosal infection predominantly caused by Candida albicans, affecting over three-quarters of immunocompetent women worldwide. While the female genital tract mucosa is the primary defense against the fungus, the specific immune mechanisms involved in this host-pathogen interaction remain largely unknown. In this study, we explored the relevance of type-I interferons (IFNs-I) pathway using both in vitro and in vivo models of VVC. Our quantitative proteomic analysis revealed that C. albicans induces the activation of the IFNs-I pathway in human epithelial cells (ECs) of the female genital tract shortly after exposure to the fungus. Additionally, we identified β-glucans as a crucial fungal component involved in triggering this pathway. Using a VVC model in IFN-α/β receptor-deficient (Ifnar1-/-) mice, we demonstrated that IFNs-I regulate the fungal burden, C. albicans epithelial invasion, polymorphonuclear neutrophils (PMNs) recruitment, inflammatory tissue response, local cytokine balance, and the composition of T cell subsets in the draining lymph nodes. These findings underscore the pivotal role of the IFNs-I pathway in ECs-mediated responses against C. albicans, especially in the early stages of VVC development, offering insights into potential therapeutic targets for this condition.