Borrelia turicatae from Ticks in Peridomestic Setting, Camayeca, Mexico.

We conducted surveillance studies in Sinaloa, Mexico, to determine the circulation of tick-borne relapsing fever spirochetes. We collected argasid ticks from a home in the village of Camayeca and isolated spirochetes. Genomic analysis indicated that Borrelia turicatae infection is a threat to those living in resource-limited settings.

Pentoxifylline and Norcantharidin Modify p62 Expression in 2D and 3D Cultures of B16F1 Cells.

Three-dimensional cell cultures have improved the evaluation of drugs for cancer therapy, due to their high similarity to solid tumors. In melanoma, autophagy appears to show a dual role depending on the progression of the disease. p62 protein has been proposed for the evaluation of autophagic flux since its expression is an indicator of the state of autophagy. Pentoxifylline (PTX) and Norcantharidin (NCTD) are drugs that have been shown to possess anticancer effects. In this work, we used B16F1 mouse melanoma cells in two-dimensional (2D) monolayer cultures and three-dimensional (3D) spheroids to test the effect of PTX and NCTD over the p62 expression. We analyzed the effect on p62 expression through Western blot and immunofluorescence assays. Our results indicate that PTX decreases p62 expression in both cell culture models, while Norcantharidin increases its expression in 3D cultures at 24 h. Therefore, these drugs could have a potential therapeutic use for the regulation of autophagy in melanoma, depending on the state of evolution of the disease.

New records of Ornithodoros turicata (Ixodida: Argasidae) in rural and urban sites in the Mexican states of Aguascalientes and Zacatecas indicate the potential for tick-borne relapsing fever.

Soft ticks from the Ornithodoros genus are vectors of relapsing fever (RF) spirochetes around the world. In Mexico, they were originally described in the 19th century. However, few recent surveillance studies have been conducted in Mexico, and regions where RF spirochetes circulate remain vague. Here, the presence of soft ticks in populated areas was assessed in two sites from the Mexican states of Aguascalientes and Zacatecas. Argasidae ticks were collected, identified by morphology and mitochondrial 16S rDNA gene sequencing, and tested for RF borreliae. The specimens in both sites were identified as Ornithodoros turicata but no RF spirochetes were detected. These findings emphasize the need to update the distribution of these ticks in multiple regions of Mexico and to determine the circulation of RF borreliosis in humans and domestic animals.

A bioinformatic prediction of antigen presentation from SARS-CoV-2 spike protein revealed a theoretical correlation of HLA-DRB1*01 with COVID-19 fatality in Mexican population: An ecological approach.

SARS-CoV-2 infection is causing a pandemic disease that is reflected in challenging public health problems worldwide. Human leukocyte antigen (HLA)-based epitope prediction and its association with disease outcomes provide an important base for treatment design. A bioinformatic prediction of T cell epitopes and their restricted HLA Class I and II alleles was performed to obtain immunogenic epitopes and HLA alleles from the spike protein of the severe acute respiratory syndrome coronavirus 2 virus. Also, a correlation with the predicted fatality rate of hospitalized patients in 28 states of Mexico was done. Here, we describe a set of 10 highly immunogenic epitopes, together with different HLA alleles that can efficiently present these epitopes to T cells. Most of these epitopes are located within the S1 subunit of the spike protein, suggesting that this area is highly immunogenic. A statistical negative correlation was found between the frequency of HLA-DRB1*01 and the fatality rate in hospitalized patients in Mexico.

Conformational changes in myeloperoxidase induced by ubiquitin and NETs containing free ISG15 from systemic lupus erythematosus patients promote a pro-inflammatory cytokine response in CD4+ T cells.

BACKGROUND: Neutrophil extracellular traps (NETs) from patients with systemic lupus erythematosus (SLE) are characterized by lower ubiquitylation and myeloperoxidase (MPO) as a substrate. The structural and functional effect of such modification and if there are additional post-translational modifications (PTMs) are unknown. METHODS: To assess the expression and functional role of PTMs in NETs of patients with SLE; reactivation, proliferation and cytokine production was evaluated by flow cytometry using co-cultures with dendritic cells (DC) and CD4+ from SLE patients and healthy controls. The impact of ubiquitylation on MPO was assessed by molecular dynamics. The expression of ISG15 in NETs was evaluated by immunofluorescence and Western Blot. RESULTS: Fifteen patients with SLE and ten healthy controls were included. In the co-cultures of CD4+ lymphocytes with DC stimulated with ubiquitylated MPO or recombinant MPO, a higher expression of IFNγ and IL-17A was found in CD4+ from SLE patients (p < 0.05). Furthermore, with DC stimulated with ubiquitylated MPO a trend towards increased expression of CD25 and Ki67 was found in lupus CD4+ lymphocytes, while the opposite was documented in controls (p < 0.05). Through molecular dynamics we found the K129-K488-K505 residues of MPO as susceptible to ubiquitylation. Ubiquitylation affects the hydration status of the HEME group depending on the residue to which it is conjugated. R239 was found near by the HEME group when the ubiquitin was in K488-K505. In addition, we found greater expression of ISG15 in the SLE NETs vs controls (p < 0.05), colocalization with H2B (r = 0.81) only in SLE samples and increased production of IFNγ in PBMCs stimulated with lupus NETs compared to healthy controls NETs. CONCLUSION: The ubiquitylated MPO has a differential effect on the induction of reactivation of CD4+ lymphocytes in patients with SLE, which may be related to structural changes by ubiquitylation at the catalytic site of MPO. Besides a lower ubiquitylation pattern, NETs of patients with SLE are characterized by the expression of ISG15, and the induction of IFNγ by Th1 cells.

Differential expression of TLR2 and TLR4 in α4ß7-positive leukocytes of patients with axial spondyloarthritis.

OBJECTIVES: Expression of α4ß7 integrin can identify gut-homing immune cells. This study aimed to determine the expression of Toll-like receptor 2 (TLR2) and TLR4 in α4ß7-positive leukocytes of patients with axial SpA (axSpA). METHODS: We analysed the frequencies of α4ß7-positive T cells, Tγδ cells and monocytes in 14 patients with axSpA and 14 healthy controls, together with the expression of TLR2 and TLR4 by flow cytometry. Also, the concentration of faecal calprotectin was measured in all patients and controls. RESULTS: We found significantly higher percentages of α4ß7-positive T (P = 0.026) and Tγδ cells (P = 0.0118) in the patients with axSpA than in controls; these cells showed differential expression of TLR2 and TLR4 when compared with α4ß7-negative cells. Such differences were not correlated with disease activity or faecal calprotectin concentration. CONCLUSION: There is an increase in circulating α4ß7-positive T and Tγδ cells in patients with axSpA. These cells differentially express TLR2 and TLR4.

Fatty acid metabolism and brain mitochondrial performance of juvenile Nile tilapia (Oreochromis niloticus) exposed to the water-accommodated fraction of Maya crude oil.

Crude oil and its derivatives are still the primary source of energy for humankind. However, during its transportation and treatment, spills of this resource can occur in aquatic environments. Nile tilapia is one of the most globally widespread fish species. This species is even found in brackish water due to its tolerance to salinity and pollution. In this study, the performance of brain cells (mitochondrial membrane potential [ΔΨm], calcium [Ca2+] and O2 and H2O2 levels) exposed to crude oil was assessed. In addition, fatty acid metabolism (cholesterol concentration and fatty acid synthase [FAS], acyl CoA-oxidase [AOX] and catalase [CAT] activities) in the brain, heart, liver and intestine of Nile tilapia exposed to the water-accommodated fraction (WAF) of 0.01, 0.1 or 1 g/L Maya crude oil (MCO) for 96 h were evaluated. After exposure, in brain cells, there were only increases in ROS and slight reductions in ΔΨm. Exposure to WAF of MCO induced and increased the levels of cholesterol and altered FAS and AOX activities in all examined tissues. The brain is the most susceptible organ to alterations in the activity of fatty acid metabolic enzymes and cholesterol levels relative to the heart, liver and intestine. The correlation between inhibition of the activity of CAT and AOX suggests a possible reduction in the proliferation and size of peroxisomes. Most biomarkers were significantly altered in the brains of Nile tilapia exposed to the WAF containing 1 g/L MCO in comparison to the control.

Stress proteins in the pathogenesis of spondyloarthritis.

Spondyloarthritis is an autoinflammatory rheumatic disease in which arthritis and osteoproliferation lead the patients who suffer from it to chronic disability. This disease is associated with the expression of class I MHC molecule HLA-B27, which tends to be misfolded in the endoplasmic reticulum and, therefore, expressed in aberrant forms. This phenomena lead to endoplasmic reticulum stress, which in time, evokes a whole response to cellular injury. Under these conditions, the molecules involved in restoring cell homeostasis play a key role. Such is the case of the "heat-shock proteins", which usually regulate protein folding, but also have important immunomodulatory functions, as well as some roles in tissue modeling. In this review, we attempt to summarize the involvement of cell stress and heat-shock proteins in the homeostatic disturbances and pathological conditions associated with this disease.

Fat-associated lymphoid cluster in Cyprinus carpio: Characterisation and its relation with peritoneal haemangiosarcoma.

FALC cells are natural helper cells producing Th2-type cytokines, which express c-kit, Sca-1, IL7R and CD45 in mouse and human. These cells are involved in allergic responses and contribute to the inflammatory reactions of adipose tissue; however, a lack of information prevails about the presence of these cells in other species. The aim of the study was to identify and characterise FALC cells in the common carp (Cyprinus carpio) using immunohistochemistry and molecular biology techniques as well as to explore their relationships with their microenvironment. Histological description of the FALC was performed using H&E and polyclonal antibodies were used against cell-surface markers such as c-kit, Sca-1 and CD45. Furthermore, gene expression of c-kit, Sca-1 and IL7R was assessed. C. carpio FALC cells express the same surface markers reported in FALC of the mouse at both the pre- and post-transcriptional level. By exposure to the soluble fraction of helminths, FALC cells produce abundant Th2 cytokines (IL-5, IL-6 and IL-13) but do not synthesise IL-1α. Additionally, FALC cells probably participate in vascular remodelling of the intestine vessels, inducing tumours because a malignant haemangiosarcoma in the peritoneal cavity was found. In this tumour, abundant FALC with their characteristic cell-surface markers were detected. The findings of this study suggest the involvement of some proto-oncogenes such as c-kit and Sca-1, and the deregulation of Src kinases modulated by CD45 present in C. carpio FALC with the ontogeny of peritoneal haemangiosarcoma in this fish species.

Relationship between biomarkers and endocrine-disrupting compounds in wild Girardnichthys viviparus from two lakes with different degrees of pollution.

Despite great efforts worldwide to evaluate the effects of endocrine-disrupting compounds (EDCs) in fish, there is little information available about the interactions of EDCs with the disruption of the sexual endocrine axis in fish species with matrotrophic viviparity and intraluminal gestation. To understand these interactions, six sampling campaigns were performed within a period of 1 year in two lakes with different degrees of pollution. A battery of biomarkers of the oestrogenic response was assessed in the liver [vitellogenin, CYP 1A1, epoxide hydrolase activity, and metallothioneins (MT)] and MT in the head of Girardinichthys viviparus. Linear correlation analysis and canonical correspondence analysis were performed to explore the relationship between the oestrogenic response with EDCs and with metals. The biomarker responses were assessed using the water content of EDCs (oestrone, 17-ß-oestradiol, oestriol, 17-α-ethinyl oestradiol, total phenols, bisphenol A, nonyl phenol, octyl phenol), as well as the PAHs indene[1,2,3-c,d]pyrene, naphthalene, pyrene, benzo[a]anthracene, benzo[k]fluoranthene and benzo[a]pyrene) and metals (Cu, Fe, Mn, Pb and Zn). Greater disruption of the sexual endocrine axis occurred in fish of both sexes inhabiting the polluted lake whose effects were apparently influenced by CYP 1A1 activity and by 17-α-ethinyl oestradiol. In addition, non-estrogenic mechanisms in the hypothalamus and pituitary glands in male fish were observed, elicited by endogenous levels and the water concentration of Pb. In contrast, in females from the less polluted lake, VTG induction was related to exogenous oestrogens. The disruption of the hypothalamic-pituitary-gonadal axis is a complex process influenced by both endogenous and exogenous factors and contributes to male feminisation by exposure to EDCs.

Biomarkers involved in energy metabolism and oxidative stress response in the liver of Goodea gracilis Hubbs and Turner, 1939 exposed to the microcystin-producing Microcystis aeruginosa LB85 strain.

Goodea gracilis is an endemic fish that only habitats in some water bodies of Central Mexico that are contaminated with cyanobacteria-producing microcystins (MC); however, a lack of information on this topic prevails. With the aim to generate the first approximation about the physiological changes elicited by cyanobacterium that produce MC congeners in this fish species, specimens born in the laboratory was exposed for 96 h to cell densities of 572.5, 1145, 2290, 4580, and 9160 × 10(6) cells of Microcystis aeruginosa strain LB85/L, and a set of novel endpoint related to hepatic gluconeogenesis (ADH/LDH) and pro-oxidant forces O2., H2 O2 ) in addition to biomarkers of oxidative damage and antioxidant response was evaluated in the liver. Results suggest that high inhibition of protein serine/threonine phosphatase (PP) may trigger many metabolic processes, such as those related to hepatic gluconeogenesis (ADH/LDH) and pro-oxidant O2⋅, H2 O2 , TBARS, ROOH, RC=O) as well as antioxidant (SOD, CAT, GPx) response to oxidative stress. Particularly, we observed that inhibition of LDH and PP, and H2 O2 increase and TBARS production were the key damages induced by high densities of M. aeruginosa. However, changes between aerobic and anaerobic metabolism related with ROS metabolism and ADH/LDH balance are apparently an acclimation of this fish species to exposure to cyanobacteria or their MCs. Fish species living in environments potentially contaminated with cyanobacteria or their MCs possess mechanisms of acclimation that allow them to offset the damage induced, even in the case of fish that have never been exposed to MCs.

Protective role of DDAH2 (rs805304) gene polymorphism in patients with myocardial infarction.

The purpose of the present study was to establish the role of DDAH gene polymorphisms in the risk of developing myocardial infarction (MI) in a clinical cohort of Mexican patients. One polymorphism (rs1498373) in the DDAH1 and three in the DDAH2 (rs805304, rs3131383, and rs805305) genes were performed by TaqMan genotyping assays in 473 patients with MI and 447 healthy unrelated controls. Similar distribution of DDAH1 and DDAH2 polymorphisms was observed in MI patients and healthy controls. Under a recessive model adjusted for age, gender, and obesity, the rs805304 C allele was associated with decreased risk of MI (OR = 0.70, 95% CI = 0.51-0.96, P = 0.030). The effect of the polymorphisms on various cardiovascular risk factors was analyzed. Under a recessive model adjusted for age and gender, the DDAH2 rs805304 C allele was associated with decreased risk of obesity (OR = 0.35, 95% CI = 0.22-0.57, P = 0.001). The three DDAH2 polymorphisms were in strong linkage disequilibrium. Our results suggest that the rs805304 C allele was associated with decreased risk of MI and decreased risk of obesity.

Dysregulation of long non-coding RNAs in Takayasu arteritis: A proof-of-concept study.

Takayasu arteritis (TAK) is a rare systemic vasculitis primarily affecting the aorta and its major branches. Early diagnosis is critical to prevent severe vascular complications, yet current biomarkers are insufficient. This proof-of-concept study explores the potential of long non-coding RNAs (lncRNAs) in TAK, an area largely unexplored. In this cross-sectional study, 53 TAK patients, 53 healthy controls, and 10 rheumatoid arthritis (RA) patients were enrolled. Clinical evaluations, disease activity assessments, and lncRNA expression levels were analyzed. TAK patients exhibited significant dysregulation in several lncRNAs, including THRIL (19.4, 11.1-48.8 vs. 62.5, 48.6-91.4 arbitrary units [a.u.]; p < 0.0001), HIF1A-AS1 (4.5, 1.8-16.6 vs. 26.5, 19.8-33.7 a.u.; p < 0.0001), MALAT-1 (26.9, 13.8-52.5 vs. 92.1, 58.5-92.1 a.u.; p < 0.0001), and HOTAIR (8.0, 2.5-24.5 vs. 36.0, 30.0-43.8 a.u.; p < 0.0001), compared to healthy controls. Notably, HOTAIR (area under the ROC curve [AUC] = 0.825), HIF1A-AS1 (AUC = 0.820), and THRIL (AUC = 0.781) demonstrated high diagnostic potential with superior specificity (approximately 95%). While lncRNAs showed diagnostic promise, no significant correlations with TAK activity were observed. Comparative analysis with RA patients revealed distinct lncRNA expression patterns. This study unveils significant dysregulation of lncRNAs THRIL, HIF1A-AS1, and HOTAIR in TAK patients, underscoring their potential as biomarkers and opening avenues for further research into the mechanistic roles of these lncRNAs in TAK pathogenesis.

Measurement of suppressor activity of T CD4⁺CD25⁺ T reg cells using bromodeoxyuridine incorporation assay.

The suppressor effect of T regulatory lymphocytes in co-cultures with T effector cells obtained by magnetic columns from healthy donors and activated by CD3/CD28 was measured by a proliferation assay using BrdU incorporation and an ELISA test. Tritiated thymidine incorporation was used as a reference since it is the gold standard for proliferation assays. Both methods were used simultaneously in the same samples in order to compare them. Correlation between them was statistically significant (p < 0.001). The purification using magnetic columns was very efficient since CD4⁺CD25⁺ cells were also FOXP3⁺ therefore; they were identified as suppressor T cells. The use of BrdU incorporation in suppression assays is an excellent method that avoids the use of radioactive contaminating materials.

Pro-oxidant and antioxidant responses in the liver and kidney of wild Goodea gracilis and their relation with halomethanes bioactivation.

In mammals, it has been shown that halomethanes (HM) are bioactivated by enzymes such as CYP 2E1 and the theta isoform of GST to produce reactive metabolites. However, in fish, little information is available, although HM can form autochthonously in aquatic environments. This study assessed the effect of HM in dusky splitfin (Goodea gracilis) from three lakes of the Valley of Mexico by analysing specific HM biomarkers as well as a broad range of biomarkers. The concentration of HM was a function of its half-life (higher in deep waters), while its precursors and solar radiation are secondary factors that determine its concentration. The kidney showed higher basal metabolism than the liver, probably because of its function as a haematopoietic and filtration organ. Using integrated biological response version 2 (IBRv2), it was found that the hepatic and renal O2· content is a pro-oxidant force capable of inducing oxidative stress (ROOH, TBARS and RC=O). Early damage was found to be dependent on low concentrations of HM in Major Lake, whereas late damage was observed in fish exposed to higher concentrations of HM in Zumpango Lake and Ancient Lake. The activities of enzymes involved in antioxidant defence seemed to be inefficient. The quantitative assessment of biomarkers (ANOVA) and the estimate of parameter A obtained from IBRv2 provided different information. However, the data support the greater predictive power of IBRv2, but it requires a series of interrelated biomarkers to infer these possibilities. G. gracilis presents marked patterns of adaptation, which are dependant on the HM concentrations in environmental mixtures, although the response is complex and many toxicants could induce similar responses.

The role of γδ T cells in the immunopathogenesis of inflammatory diseases: from basic biology to therapeutic targeting.

The γδ T cells are lymphocytes with an innate-like phenotype that can distribute to different tissues to reside and participate in homeostatic functions such as pathogen defense, tissue modeling, and response to stress. These cells originate during fetal development and migrate to the tissues in a TCR chain-dependent manner. Their unique manner to respond to danger signals facilitates the initiation of cytokine-mediated diseases such as spondyloarthritis and psoriasis, which are immune-mediated diseases with a very strong link with mucosal disturbances, either in the skin or the gut. In spondyloarthritis, γδ T cells are one of the main sources of IL-17 and, therefore, the main drivers of inflammation and probably new bone formation. Remarkably, this population can be the bridge between gut and joint inflammation.

Norcantharidin Nanoemulsion Development, Characterization, and In Vitro Antiproliferation Effect on B16F1 Melanoma Cells.

Melanoma is a highly lethal type of cancer that has had an increase in incidence in the last decades. Nevertheless, current therapies lack effectiveness and have highly disabling side effects, which calls for new therapeutic strategies. Norcantharidin (NCTD) is an acid derivative with potential antitumor activity isolated from natural blister beetles. However, its solubility limitations restrict its use. To address this issue, we developed an oil-in-water nanoemulsion using commonly available cosmetic ingredients, which increased NCTD solubility 10-fold compared to water. The developed nanoemulsion showed a good droplet size and homogeneity, with adequate pH and viscosity for skin application. In vitro drug release studies showed a sustained release profile, ideal for prolonged therapeutic effects. Accelerated stability studies proved that the formulation was reasonably stable under stress conditions, with particle separation fingerprints, instability index, particle size, and sedimentation velocity analyses being conducted. To assess the therapeutic potential of the developed formulation, in vitro studies were conducted on melanoma B16F1 cells; results showed an IC50 of 1.026 +/- 0.370 mg/kg, and the cells' metabolic activity decreased after exposure to the NCTD nanoemulsion. Hence, a new "easy-to-make" nanoformulation with therapeutic potential on melanoma cells was developed, as a possible adjuvant for future melanoma treatment.

Tumor-Infiltrating iNKT Cells Activated through c-Kit/Sca-1 Are Induced by Pentoxifylline, Norcantharidin, and Their Mixtures for Killing Murine Melanoma Cells.

The involvement of NK and other cytotoxic cells is considered the first defense line against cancer. However, a significant lack of information prevails on the possible roles played by factors considered characteristic of primitive cells, such as c-kit and Sca-1, in activating these cells, particularly in melanoma models subjected to treatments with substances under investigation, such as the case of norcantharidin. In this study, B16F1 murine melanoma cells were used to induce tumors in DBA/2 mice, estimating the proportions of NK and iNKT cells; the presence of activation (CD107a+) and primitive/activation (c-kit+/Lya6A+) markers and some tumor parameters, such as the presence of mitotic bodies, nuclear factor area, NK and iNKT cell infiltration in the tumor, infiltrated tumor area, and infiltrating lymphocyte count at 10x and 40x in specimens treated with pentoxifylline, norcantharidin, and the combination of both drugs. Possible correlations were estimated with Pearson's correlation analysis. It should be noted that, despite having demonstrated multiple correlations, immaturity/activation markers were related to these cells' activation. At the tumor site, iNKT cells are the ones that exert the cytotoxic potential on tumor cells, but they are confined to specific sites in the tumor. Due to the higher number of interactions of natural killer cells with tumor cells, it is concluded that the most effective treatment was PTX at 60 mg/kg + NCTD at 0.75 mg/kg.

Norcantharidin toxicity profile: an in vivo murine study.

Norcantharidin (NCTD) is the demethylated analog of cantharidin, with allegedly reduced toxicity. However, there is still limited information regarding its posology and potential risk in its use in cancer treatment. Healthy BDF1 mice were intraperitoneally administered with norcantharidin (0, 3, 6, 12, and 25 mg/kg) every 24 h for 6 days. Survivor mice were euthanized, and the brain, lungs, kidneys, spleen, and liver were procured for enzymatic and histopathological analysis in the liver and kidney. DL50 were 8.86 mg/kg for females and 11.77 mg/kg for males. The treatments with 3.0 mg/kg and 6.0 mg/kg significantly modified the phosphorylase, alanine transaminase, and γ-glutamyl transferase activities; however, an organ-specific response was detected. A significant dose-dependent decrease was observed in the kidney for ROS, while the liver had the opposite effect. Histopathological analysis revealed a significant elevation in hepatocytes' nuclei average size and total area (3 mg/kg), as well as centrilobular vein and adjacent sinusoidal capillaries showed a significant difference. The portal triad presented a significant difference in veins and capillarity count in 6 mg/kg. Renal samples showed cortex convoluted tubules' average size significantly augmented in both doses' groups, and tubule count was found augmented in 6 mg/kg. These physiological effects of NCTD can be exploited as treatment strategies if able to operate in an established posology and proper testing.

Heat shock protein 60 from Klebsiella pneumoniae protects mononuclear cells from apoptotic cell death induced by dexamethasone.

AIMS: Bacterial heat shock proteins can have anti-apoptotic effects on human cells. We investigated whether enterobacterial HSP60 can protect peripheral blood mononuclear cells (PBMC) from DXM-induced apoptosis and if this effect requires cytoskeleton participation. MAIN METHODS: Anti-apoptotic effect from enterobacterial HSP60 was analyzed by adding these proteins to peripheral mononuclear cells cultures before DXM induction. Percentage of apoptotic cells was determined by SubG0 peak and TUNEL techniques in a flow cytometer. KEY FINDINGS: Our results showed significant protective effect of HSP60 Klebsiella pneumoniae and E. coli, in the DXM-induced apoptosis in PBMC. Similar results were obtained with recombinant human HSP60. The same protective effect of proteins was observed in CD4+ and CD8 + T cell subpopulations. To analyze if enterobacterial HSP60 need internalization to have the anti-apoptotic effect, we used cytoskeleton inhibitors such as: nocodazole, cytochalasin D and amiloride, the three inhibitors significantly affected the protective role of HSP60 in apoptosis induced with DXM. Results suggest that the protective effect of HSP60 K. pneumoniae and E. coli requires the participation of contractile structures for the internalization of this protein by the cells, we suggest that the internalization of enterobacterial HSP60 could be carry out by macropinocytosis. SIGNIFICANCE: We report for the first time that K. pneumoniae and E. coli HSP60 have protective effect in the apoptosis induced with DXM in PBMC from healthy subjects and that this effect requires the internalization of the protein with active participation of the cytoskeleton.