Selenium Content and/or T-2 Toxin Contamination of Cereals, Soil, and Children's Hair in Some Areas of Heilongjiang and Gansu Provinces, China

A preliminary study of T-2 toxin that cause liver injury in rats via the NF-kB and NLRP3-mediated pyroptosis pathway

T-2 toxin is recognized as the most potent and prevalent secondary metabolite among monotrichous mycotoxins produced by Fusarium species. Multiple studies have substantiated the hepatotoxic effects of T-2 toxin. This study aimed to investigate whether NF-κB and NLRP3-mediated pyroptosis is involved in the underlying mechanism of T-2 toxin hepatotoxicity. We designed three groups of rat models, blank control; solvent control and T-2 toxin (0.2 mg/kg body weight/day), which were euthanized at week 8 after gavage staining of the toxin. Through HE staining and biochemical indicators associated with liver injury, we observed that T-2 toxin induced liver damage in rats. By Western blot analysis and qRT-PCR, we found that the expression levels of pyroptosis-related genes and proteins were significantly higher in the T-2 toxin group. In addition, we also found a significant increase in the expression of p-NF-κB protein, an upstream regulator of NLRP3. In conclusion, NF-κB and NLRP3-mediated pyroptosis may be involved in the mechanism of hepatotoxic action of T-2 toxin, which provides a new perspective.

HT-2 mycotoxin and selenium deficiency: Effects on Femur development and integrity in Young mice

Kashin-Beck Disease (KBD), an osteoarticular disorder, is potentially influenced by several factors, among which selenium deficiency and HT-2 mycotoxin exposure are considered significant. However, the combined effect of these factors on femoral development remains unclear, Conducted over eight weeks on forty-eight male mice categorized into control, selenium-deficient, and HT-2 toxin-exposed groups, including dual-exposure sets, this study comprehensively monitored body weight, bone metabolism markers, and cellular health. Employing biomechanical analysis, micro-computed tomography (micro-CT), and transmission electron microscopy (TEM), we unearthed a reduction in body weight due to HT-2 toxin alone, with selenium deficiency exacerbating these effects synergistically. Our results unveil that both factors independently affect bone metabolism, yet their confluence leads to a pronounced degradation of bone health parameters, including alterations in calcium, phosphorus, and vitamin D levels, alongside marked changes in osteoblast and osteoclast activity and bone cell structures. The notable damage to femoral cortical and trabecular architectures underscores the perilous interplay between dietary selenium absence and HT-2 toxin presence, necessitating a deeper understanding of their separate and joint effects on bone integrity. These discoveries underscore the imperative for a nuanced approach to toxicology research and public health policy, highlighting the pivotal influence of environmental and nutritional factors on skeletal well-being.

Modulatory interactions of T-2 and deoxynivalenol mycotoxins on murine femoral development and osteological integrity

In this study, we conducted a systematic assessment of the effectsof deoxynivalenol (DON) and T-2 mycotoxins (T-2) on the developmental processes and structural integrity of murine femurs, considering both the isolated and synergistic effects of these toxins. To this end, we divided 72 male mice into nine groups, each subjected to varying dosages of T-2, DON, or their combinations. Over a four-week experimental period, meticulous monitoring was undertaken regarding the mice's body weight, biochemical markers of bone formation and resorption, and the activity of relevant cells. To comprehensively evaluate alterations in bone structure, we employed biomechanical analysis, micro-computed tomography (micro-CT), and transmission electron microscopy.Our findings unveiled a significant revelation: the mice exhibited a dose-dependent decrease in body weight upon exposure to individual mycotoxins, while the combined use of these toxins manifested an atypical antagonistic effect. Furthermore, we observed variations in the levels of calcium, phosphorus, and vitamin D, as well as adjustments in the activities of osteoblasts and osteoclasts, all intricately linked to the dosage and ratio of the toxins. Alterations in biomechanical properties were also noted to correlate with the dosage and combination of toxins. Analyses via micro-CT and transmission electron microscopy further corroborated the substantial impact of toxin dosage and combinations on both cortical and trabecular bone structures.In summation, our research unequivocally demonstrates the dose- and ratio-dependent detrimental effects of DON and T-2 mycotoxins on the growth and structural integrity of murine femurs. These insights accentuate the importance of a profound understanding of the potential risks these toxins pose to bone health, offering pivotal guidance for future toxicological research and public health preventative strategies.

Overview of T-2 Toxin Enterotoxicity: From Toxic Mechanisms and Detoxification to Future Perspectives

Fusarium species produce a secondary metabolite known as T-2 toxin, which is the primary and most harmful toxin found in type A trichothecenes. T-2 toxin is widely found in food and grain-based animal feed and endangers the health of both humans and animals. T-2 toxin exposure in humans and animals occurs primarily through food administration; therefore, the first organ that T-2 toxin targets is the gut. In this overview, the research progress, toxicity mechanism, and detoxification of the toxin T-2 were reviewed, and future research directions were proposed. T-2 toxin damages the intestinal mucosa and destroys intestinal structure and intestinal barrier function; furthermore, T-2 toxin disrupts the intestinal microbiota, causes intestinal flora disorders, affects normal intestinal metabolic function, and kills intestinal epidermal cells by inducing oxidative stress, inflammatory responses, and apoptosis. The primary harmful mechanism of T-2 toxin in the intestine is oxidative stress. Currently, selenium and plant extracts are mainly used to exert antioxidant effects to alleviate the enterotoxicity of T-2 toxin. In future studies, the use of genomic techniques to find upstream signaling molecules associated with T-2 enterotoxin toxicity will provide new ideas for the prevention of this toxicity. The purpose of this paper is to review the progress of research on the intestinal toxicity of T-2 toxin and propose new research directions for the prevention and treatment of T-2 toxin toxicity.

Daucosterol confers protection against T-2 toxin induced blood-brain barrier toxicity through the PGC-1α-mediated defensive response in vitro and in vivo

T-2 toxin is a common environmental pollutant and contaminant in food and animal feed that represents a great challenge to human and animal' health throughout the world. Using natural compounds to prevent the detrimental effects of T-2 toxin represents an attractive strategy. Peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α) is a critical regulator in various cellular processes. Recently, PGC-1α activation has been reported to confer protection against neurological injuries. We aimed to identify a potent PGC-1α activator from plants as a chemopreventive compound and to demonstrate the efficacy of the compound in attenuating T-2 toxin-induced blood-brain barrier (BBB) toxicity. We identified daucosterol, which binds directly to the 71-74 (-1100 to -1000 bp) position of the second promoter of human PGC-1α by hydrogen bonding. An in vitro and in vivo T-2 toxin induced BBB injury model revealed that this compound can protect against this injury by increasing transepithelial/transendothelial electrical resistance, reducing sodium fluorescein (NaF) infiltration and increasing the expression of tight junction-related proteins (zonula occludens-1 (ZO-1), occludin (OCLN), claudin-5 (CLDN5)) expression. In conclusion, we identified daucosterol as representing a novel of PGC-1α activators and illustrated the mechanism of specific binding site. Furthermore, we have demonstrated the feasibility of using natural compounds targeting PGC-1α as a therapeutic approach to protect humans from environmental insults that may occur daily such as lipopolysaccharide.

A review of anorexia induced by T-2 toxin

The presence of anorexia in animals is the most well-known clinical symptom of T-2 toxin poisoning. T-2 toxin is the most characteristic type A toxin in the trichothecene mycotoxins. The consumption of T-2 toxin can cause anorexic response in mice, rats, rabbits, and other animals. In this review, the basic information of T-2 toxin, appetite regulation mechanism and the molecular mechanism of T-2 toxin-induced anorectic response in animals are presented and discussed. The objective of this overview is to describe the research progress of anorexia in animals produced by T-2 toxin. T-2 toxin mainly causes antifeedant reaction through four pathways: vagus nerve, gastrointestinal hormone, neurotransmitter and cytokine. This review aims to give an academic basis and useable reference for the prevention and treatment of clinical symptoms of anorexia in animals resulting from T-2 toxin.

T-2 toxin-induced chondrocyte apoptosis contributes to growth plate damage through Smad2 and Smad3 signaling

The growth plate cartilage is one of the most common areas that Kashin-Beck Disease attacks. However, the exact mechanism of growth plate damage remains unclear. Here, we demonstrated that Smad2 and Smad3 were closely associated with the differentiation of chondrocytes. Reduction of Smad2 and Smad3 were found both in T-2 toxin-induced human chondrocytes in vitro and in T-2 toxin-induced rat growth plate in vivo. Blunting Smad2 or Smad3 both strikingly induced human chondrocytes apoptosis, implying a plausible signaling pathway to clarify the mechanism of T-2 toxin-induced oxidative damage. Furthermore, decreased Smad2 and Smad3 were also observed in the growth plates of KBD children. Collectively, our findings clearly illustrated that T-2 toxin-induced chondrocyte apoptosis contributes to growth plate damage through Smad2 and Smad3 signaling, which refines the pathogenesis of endemic osteoarthritis and provides two potential targets for the prevention and repairment of endemic osteoarthritis.

Selenium Improves Bone Microenvironment-Related Hematopoiesis and Immunity in T-2 Toxin-Exposed Mice

The T-2 toxin is one of the most frequent contaminants in the environment and agricultural production globally. It exerts a wide range of toxic effects. Selenium (Se), as an antioxidant, has the potential to be widely used to antagonize mycotoxin toxicity. To investigate the protective effects of Se on bone microenvironment (BM)-related hematopoiesis and immunity after T-2 toxin exposure, 36 male mice were treated with the T-2 toxin (1 mg/kg) and/or Se (0.2 mg/kg) by intragastric administration for 28 days. The results showed that Se alleviated T-2 toxin-induced cytopenia and splenic extramedullary hematopoiesis. Se also significantly relieved T-2 toxin-induced immunosuppression, as assessed by immune factors and lymphocytes. Furthermore, Se also attenuated oxidative stress and apoptosis and improved the BM in T-2 toxin-exposed mice. Therefore, Se improves BM-related hematopoiesis and immunity after T-2 toxin exposure. This study provides references for identifying the toxic mechanism and screening potential therapeutic drugs of the T-2 toxin.

Increased FGFR3 is involved in T-2 toxin-induced lesions of hypertrophic cartilage associated with endemic osteoarthritis

This study evaluated the effect of fibroblast growth factor receptor 3 (FGFR3) on damaged hypertrophic chondrocytes of Kashin-Beck disease (KBD). Immunohistochemical staining was used to evaluate FGFR3 expression in growth plates from KBD rat models and engineered cartilage. In vitro study, hypertrophic chondrocytes were pretreated by FGFR3 binding inhibitor (BGJ398) for 24 h before incubation at different T-2 toxin concentrations. Differentiation -related genes (Runx2, Sox9, and Col Ⅹ) and ECM degradation -related genes (MMP-13, Col Ⅱ) in the hypertrophic chondrocytes were analyzed using RT-PCR, and the corresponding proteins were analyzed using western blotting. Hypertrophic chondrocytes death was detected by the Annexin V/PI double staining assay. The integrated optical density of FGFR3 staining was increased in knee cartilage of rats and engineered cartilage treated with T-2 toxin. Both protein and mRNA levels of Runx2, Sox9, Col Ⅱ, and Col Ⅹ were decreased in a dose-dependent manner when exposed to the T-2 toxin and significantly upregulated by 1 μM BGJ398. The expression of MMP-1, MMP-9, and MMP-13 increased in a dose-dependent manner when exposed to T-2 toxin and significantly reduced by 1 μM BGJ398. 1 μM BGJ398 could prevent early apoptosis and necrosis induced by the T-2 toxin. Inhibiting the FGFR3 signal could alleviate extracellular matrix degradation, abnormal chondrocytes differentiation, and excessive cell death in T-2 toxin-induced hypertrophic chondrocytes.

Abnormal expression of TSG-6 disturbs extracellular matrix homeostasis in chondrocytes from endemic osteoarthritis

Background and aims: Kashin-Beck disease (KBD) is a unique endemic osteochondropathy with unclear pathogenesis in China. T-2 toxin exposure has been identified as a significant risk factor of KBD. However, the mechanism of articular cartilage damage induced by T-2 toxin is a conundrum. We explored the role of the extracellular matrix-related gene TSG-6 in the articular chondrocyte damage process under the exposure of HT-2 toxin.

Methods: TSG-6 was identified as a candidate gene by mining our previous gene expression profiling of KBD and verified by qRT-PCR and immunohistochemistry. Then, TSG-6 was silenced by RNA interference technology and overexpressed induction by TNF-α. Gradient concentrations of HT-2 toxin were added to intervene with C28/I2 chondrocytes. MTT was used to observe the proliferation and cell viability of chondrocytes, and qRT-PCR was utilized to detect the expression changes of MMP1, MMP3, MMP13, COL2A1, and proteoglycan before and after treatments for verification.

Results: TSG-6 was upregulated in KBD chondrocytes at the mRNA level and upregulated in the superficial, middle, and deep zones of KBD cartilage. After TSG-6 silencing, the expression of MMP1, MMP3, MMP13, and proteoglycan was significantly decreased while COL2A1 expression was significantly increased, which was reversed after the overexpression of TSG-6 induced by TNF-α (p < 0.05). The survival rate of chondrocytes was correspondingly reduced with an increase in the HT-2 toxin concentration. Compared with the blank control group, the expression of MMPs was increased in the intervention group of HT-2 toxin, while the expression of proteoglycan and COL2A1 decreased (p < 0.05).

Conclusion: The upregulation of the TSG-6 gene may play a role in promoting the damage and degradation of the extracellular matrix in KBD chondrocytes under the exposure of HT-2 toxin.

Genetic Variants and Protein Alterations of Selenium- and T-2 Toxin-Responsive Genes Are Associated With Chondrocytic Damage in Endemic Osteoarthropathy

The mechanism of environmental factors in Kashin–Beck disease (KBD) remains unknown. We aimed to identify single nucleotide polymorphisms (SNPs) and protein alterations of selenium- and T-2 toxin–responsive genes to provide new evidence of chondrocytic damage in KBD. This study sampled the cubital venous blood of 258 subjects including 129 sex-matched KBD patients and 129 healthy controls for SNP detection. We applied an additive model, a dominant model, and a recessive model to identify significant SNPs. We then used the Comparative Toxicogenomics Database (CTD) to select selenium- and T-2 toxin–responsive genes with the candidate SNP loci. Finally, immunohistochemistry was applied to verify the protein expression of candidate genes in knee cartilage obtained from 15 subjects including 5 KBD, 5 osteoarthritis (OA), and 5 healthy controls. Forty-nine SNPs were genotyped in the current study. The C allele of rs6494629 was less frequent in KBD than in the controls (OR = 0.63, p = 0.011). Based on the CTD database, PPARG, ADAM12, IL6, SMAD3, and TIMP2 were identified to interact with selenium, sodium selenite, and T-2 toxin. KBD was found to be significantly associated with rs12629751 of PPARG (additive model: OR = 0.46, p = 0.012; dominant model: OR = 0.45, p = 0.049; recessive model: OR = 0.18, p = 0.018), rs1871054 of ADAM12 (dominant model: OR = 2.19, p = 0.022), rs1800796 of IL6 (dominant model: OR = 0.30, p = 0.003), rs6494629 of SMAD3 (additive model: OR = 0.65, p = 0.019; dominant model: OR = 0.52, p = 0.012), and rs4789936 of TIMP2 (recessive model: OR = 5.90, p = 0.024). Immunohistochemistry verified significantly upregulated PPARG, ADAM12, SMAD3, and TIMP2 in KBD compared with OA and normal controls (p < 0.05). Genetic polymorphisms of PPARG, ADAM12, SMAD3, and TIMP2 may contribute to the risk of KBD. These genes could promote the pathogenesis of KBD by disturbing ECM homeostasis.

Transforming growth factor-β receptors mediates matrix degradation and abnormal hypertrophy in T-2 toxin-induced hypertrophic chondrocytes

This study investigated whether transforming growth factor-β receptor I (TGF-βRI) and TGF-βRII mediate matrix degradation and abnormal hypertrophy in T-2 toxin-induced hypertrophic chondrocytes. Hypertrophic chondrocytes were exposed to TGF-βRI and TGF-βRII binding inhibitor (GW788388) for 24 h prior to exposure to different concentrations of T-2 toxin (0, 10, 25, and 50 ng/mL for 48 h). Hypertrophic chondrocytes were assessed based on the expression of matrix-degrading and terminal differentiation-related genes and cell viability. Matrix metalloproteinases (MMPs, MMP-13, MMP-1, and MMP-9) were reduced in the GW788388+T-2 toxin group compared to the T-2 toxin group. The expression of terminal differentiation-related genes (MMP-2, MMP-10, and collagen X) was increased in hypertrophic chondrocytes in the inhibited groups compared to that in the T-2 toxin group. The survival rate of chondrocytes decreased significantly in a dose-dependent manner. GW788388 did not significantly block the reduced cell viability in hypertrophic chondrocytes exposed to T-2 toxin. The upregulated expression of TGF-βRI and TGF-βRII mediates the abnormal chondrocyte hypertrophy and extracellular matrix degeneration observed in T-2 toxin-induced hypertrophic chondrocytes.

T-2 toxin induces articular cartilage damage by increasing the expression of MMP-13 via the TGF-β receptor pathway

T-2 toxin pre-disposes individuals to osteoarthritis, Kashin-Beck disease (KBD). The major pathological change associated with KBD is the degradation of the articular cartilage matrix. Herein, we investigated the key molecules that regulate T-2 toxin-mediated cartilage degradation. Potential KBD treatments were also investigated. Sprague Dawley rats were divided into the T-2 toxin group and the control group. The T-2 toxin group received 100 ng/g BW/day, whereas the control group received a similar dose of PBS. The expression of matrix metalloproteinase-13 (MMP-13) and TGF-β receptor I/II (TGF-βRI/II) was analyzed using immunohistochemical staining. C28/I2 chondrocytes were exposed to TGF-βRI/II binding inhibitor (GW788388) for 24 h before incubation in different T-2 toxin concentrations (0, 6, 12, and 24 ng/mL for 72 h). The expression of mRNA for TGF-βRI/II, MMP-13 and proteins for MMP-13, and Smad-2 in chondrocytes were analyzed using RT-PCR and western blot, respectively. Safranin O staining revealed that T-2 toxin treatment modulated the expression of articular cartilage matrix. On the other hand, T-2 toxin treatment sharply increased the expression of MMP-13, TGF-βRI, and TGF-βRII in the rat cartilages. Interestingly, blocking the TGF-βRs-smad 2 signaling pathway using GW788388 abrogated the effect of T-2 toxin on upregulating MMP-13 expression. The expression of MMP-13 in chondrocytes induced with T-2 toxin is regulated via the TGF-βRs signaling pathway. As such, inhibiting the expression of TGF-βRs is a potential KBD treatment.

Upregulated expression of transforming growth factor-β receptor I/II in an endemic Osteoarthropathy in China

Background

Kashin–Beck disease (KBD) is a chronic, deforming, endemic osteochondropathy that begins in patients as young as 2–3 years of age. The pathogenesis of KBD remains unclear, although selenium (Se) deficiency and T-2 toxin food contamination are both linked to the disease. In the present study, we evaluated transforming growth factor-β receptor (TGF-βR I and II) levels in clinical samples of KBD and in pre-clinical disease models.

Methods

Human specimens were obtained from the hand phalanges of eight donors with KBD and eight control donors. Animal models of the disease were established using Sprague–Dawley rats, which were fed an Se-deficient diet for 4 weeks and later administered the T-2 toxin. Cartilage cellularity and morphology were examined by hematoxylin and eosin staining. Expression and localization of TGF-βRI and II were evaluated using immunohistochemical staining and western blotting.

Results

In the KBD samples, chondral necrosis was detected based on cartilage cell disappearance and alkalinity loss in the matrix ground substance. In the necrotic areas, TGF-βRI and II staining were strong. Positive percentages of TGF-βRI and II staining were higher in the cartilage samples of KBD donors than in those of control donors. TGF-βRI and II staining was also increased in cartilage samples from rats administered T-2 toxin or fed on Se-deficient plus T-2 toxin diets.

Conclusion

TGF-βRI and II may be involved in the pathophysiology of KBD. This study provides new insights into the pathways that contribute to KBD development.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12891-021-04939-6.

Mechanism of DNA methylation-mediated downregulation of O6-Methylguanine-DNA methyltransferase in cartilage injury of Kashin-Beck Disease

OBJECTIVE

Kashin-Beck Disease (KBD) is an endemic osteoarthropathy, in which excessive apoptosis of chondrocytes occurs. O6-methylguanine-DNA methyltransferase (MGMT), a DNA damage repair gene, plays an important role in apoptosis but the mechanism is unclear in KBD cartilage injury. This study was to investigate the expression and promoter methylation of MGMT in KBD patients and its role in DNA damage and apoptosis of chondrocytes.

METHODS

MGMT mRNA and protein level were detected by quantitative real-time PCR and immunohistochemistry. Demethylation of MGMT was carried out using 5-Aza-2'-deoxycytidine, and the methylation level of MGMT promoter was measured by quantitative methylation specific PCR. Next, shRNA was used to knockdown the expression of MGMT. Cell viability, apoptosis and DNA damage were determined by MTT assay, flow cytometry, Hoechst 33342 staining and alkaline comet assay following T-2 toxin and selenium treatment.

RESULTS

MGMT protein expression and mRNA levels were decreased (p = 0.02, p = 0.007) and promoter methylation was increased (p = 0.008) in KBD patients. Meanwhile, MGMT level was upregulated by 5-Aza-2'-deoxycytidine in chondrocytes (p = 0.0002). DNA damage and apoptosis rates were increased in MGMT-silenced chondrocytes (all p < 0.0001). Furthermore, DNA damage and apoptosis were increseaed in chondrocytes treated with T-2 toxin (all p < 0.0001), but were decreased after selenium treatment (p < 0.0001, p = 0.01). Decreased mRNA level and increased methylation of MGMT were found in T-2 toxin group (p = 0.005, p = 0.002), while selenium reversed it (p = 0.02, p = 0.004).

CONCLUSIONS

MGMT might play a crucial part in the pathogenesis of KBD cartilage injury, which providing a therapeutic target for KBD.

A Spatial Ecological Study on Hair Selenium Level of Residents in Keshan Disease Endemic and Non-endemic Areas in Heilongjiang Province, China

This study was aimed to provide, by mapping the spatial distribution of hair selenium levels of residents, visualized evidence for assessment of KD elimination from a perspective of selenium nutrition of the residents living in the KD-endemic and non-endemic areas. Using a spatial ecological research design, 401 male permanent residents in KD-endemic and non-endemic areas participated in this study. Demographic information and hair samples were obtained through a questionnaire survey and sample collection, respectively. Hair selenium was measured using hydride generation atomic fluorescence spectrometry. Thematic maps were created, and spatial analysis was conducted using ArcGIS 9.0. The median of hair selenium of the participants was 0.30 (IQR, 0.23-0.34) mg/kg. The median hair selenium of the residents in the KD-endemic areas was significantly lower than that of the residents of the non-endemic areas. The hair selenium levels of residents were spatially clustered, with cold spots and hot spots located in northwest and southwest regions respectively. Residents living in KD-endemic areas may still have selenium deficiency. Measuring hair selenium levels of residents in KD-endemic areas as a molecular marker of selenium nutritional status as part of KD surveillance could provide visualized evidence for the evaluation of KD elimination from a perspective of selenium nutrition of the residents living in the KD endemic areas.

The WNT/β-catenin signalling pathway induces chondrocyte apoptosis in the cartilage injury caused by T-2 toxin in rats

We investigated whether the WNT/β-catenin signalling pathway is involved in paediatric Kashin-Beck disease (KBD) and T-2-toxin-induced cartilage injury in rats to better understand the mechanism of KBD. One hundred twenty-two children were selected and assigned to the case (31), internal control (41), and external control (50) groups. The serum β-catenin and bone morphogenetic protein 2（BMP2）levels in each group were measured and compared. Thirty-six rats were randomly assigned to three groups, which received no intervention, T-2 toxin, or solvent. After 18 weeks, the expression of LDL receptor related proteins 5 (LRP5), β-catenin, BMP2, BAX, BCL2, APAF1, and caspase 9 was measured and compared. The serum BMP2 levels were significantly elevated in the children with KBD and in the rats treated with T-2 toxin. In the T-2 toxin group, LRP5 and β-catenin expression was reduced, whereas BAX, APAF1, and caspase 9 expression was increased. In conclusion, the WNT/β-catenin signalling pathway is suppressed in KBD, which induces chondrocyte apoptosis, leading to cartilage injury. Therefore, BMP2 may play a role in the pathogenesis of KBD.

An update on T-2 toxin and its modified forms: metabolism, immunotoxicity mechanism, and human exposure assessment

T-2 toxin is the most toxic trichothecene mycotoxin, and it exerts potent toxic effects, including immunotoxicity, neurotoxicity, and reproductive toxicity. Recently, several novel metabolites, including 3',4'-dihydroxy-T-2 toxin and 4',4'-dihydroxy-T-2 toxin, have been uncovered. The enzymes CYP3A4 and carboxylesterase contribute to T-2 toxin metabolism, with 3'-hydroxy-T-2 toxin and HT-2 toxin as the corresponding primary products. Modified forms of T-2 toxin, including T-2-3-glucoside, exert their immunotoxic effects by signaling through JAK/STAT but not MAPK. T-2-3-glucoside results from hydrolyzation of the corresponding parent mycotoxin and other metabolites by the intestinal microbiota, which leads to enhanced toxicity. Increasing evidence has shown that autophagy, hypoxia-inducible factors, and exosomes are involved in T-2 toxin-induced immunotoxicity. Autophagy promotes the immunosuppression induced by T-2 toxin, and a complex crosstalk between apoptosis and autophagy exists. Very recently, "immune evasion" activity was reported to be associated with this toxin; this activity is initiated inside cells and allows pathogens to escape the host immune response. Moreover, T-2 toxin has the potential to trigger hypoxia in cells, which is related to activation of hypoxia-inducible factor and the release of exosomes, leading to immunotoxicity. Based on the data from a series of human exposure studies, free T-2 toxin, HT-2 toxin, and HT-2-4-glucuronide should be considered human T-2 toxin biomarkers in the urine. The present review focuses on novel findings related to the metabolism, immunotoxicity, and human exposure assessment of T-2 toxin and its modified forms. In particular, the immunotoxicity mechanisms of T-2 toxin and the toxicity mechanism of its modified form, as well as human T-2 toxin biomarkers, are discussed. This work will contribute to an improved understanding of the immunotoxicity mechanism of T-2 toxin and its modified forms.