High BMP4 expression in low/intermediate risk BCP-ALL identifies children with poor outcomes.

Pediatric B-cell precursor acute lymphoblastic leukemia (BCP-ALL) outcome has improved in the last decades, but leukemic relapses are still one of the main problems of this disease. Bone morphogenetic protein 4 (BMP4) was investigated as a new candidate biomarker with potential prognostic relevance, and its pathogenic role was assessed in the development of disease. A retrospective study was performed with 115 pediatric patients with BCP-ALL, and BMP4 expression was analyzed by quantitative reverse transcription polymerase chain reaction in leukemic blasts at the time of diagnosis. BMP4 mRNA expression levels in the third (upper) quartile were associated with a higher cumulative incidence of relapse as well as a worse 5-year event-free survival and central nervous system (CNS) involvement. Importantly, this association was also evident among children classified as having a nonhigh risk of relapse. A validation cohort of 236 patients with BCP-ALL supported these data. Furthermore, high BMP4 expression promoted engraftment and rapid disease progression in an NSG mouse xenograft model with CNS involvement. Pharmacological blockade of the canonical BMP signaling pathway significantly decreased CNS infiltration and consistently resulted in amelioration of clinical parameters, including neurological score. Mechanistically, BMP4 favored chemoresistance, enhanced adhesion and migration through brain vascular endothelial cells, and promoted a proinflammatory microenvironment and CNS angiogenesis. These data provide evidence that BMP4 expression levels in leukemic cells could be a useful biomarker to identify children with poor outcomes in the low-/intermediate-risk groups of BCP-ALL and that BMP4 could be a new therapeutic target to blockade leukemic CNS disease.

Dry needling of the flexor digitorum brevis muscle reduces postural control in standing: A pre-post stabilometric study.

There are studies that show the better balance after dry needling in lumbar pain. However, the postural control effects after foot dry needling are unknown. Our objective was to check if dry needling reduces postural control. Eighteen subjects with flexor digitorum brevis (FDB) muscle Myofascial trigger point were evaluated pre- and post-deep dry needling. We measured stabilometric variables in a pre-post study. We have found significant differences in three stabilometric variables: surface with eyes closed (29.36-53.21 mm2 ) (p = 0.000), medium speed of the laterolateral displacement with eyes closed (1.42-1.64 mm/s) (p = 0.004), and medium speed of the anteroposterior displacement with eyes closed (1.30-1.53 mm/s) (p = 0.025). Dry needling therapy application in FDB muscle reduces standing postural control with eyes closed.

VocabStudy: A remote collection of naturalistic topic-structured parental speech and toddlers' vocabularies using a mobile phone application.

The current work presents VocabStudy, a collection of natural language samples and children's vocabularies collected remotely by parents via a mobile phone application. The corpus contains 567,003 word tokens and represents 144 hours of speech over a period of six months from the language environment of 63 British toddlers aged 13 to 28 months. The corpus incorporates labeled speech samples of five typical routines: mealtime, bedtime, playtime, bathtime, and nappytime (i.e., diaper). To explore consistency and variability across these five linguistic contexts, topic modeling was employed. The topic most successfully detected as having a unique structure was mealtime, which was identified as such nearly 100% of the time; bathtime, nappytime, and bedtime were found to cluster together most of the time, suggesting that they have a similar language structure; playtime was correctly identified as such about 14% of the time. To validate the accuracy of parents marking the words that their child produced, the child's utterances found in the audio recordings were examined. About 18% of the vocabulary reported by parents appeared in the transcripts, and the reported vocabulary sizes were highly correlated with the number of unique words uttered by the children (ρ = .72, p < 001). The results suggest that most parents marked the words soon after their children start producing them (p < .001, d = 0.9). I discuss the advantages and disadvantages of using a mobile phone application as a method to collect children's data remotely, what worked to keep participants entering data, and what could have been done to avoid some issues encountered.

Semantic maturation during the comprehension-expression gap in late and typical talkers.

This study investigates the influence of semantic maturation on early lexical development by examining the impact of contextual diversity-known to influence semantic development-on word promotion from receptive to productive vocabularies (i.e., comprehension-expression gap). Study 1 compares the vocabularies of 3685 American-English-speaking typical talkers (TTs) and late talkers (LTs; 16-30 months old; 1257 females, 1021 gender unknown; ethnicity unknown; data downloaded in 2018) and finds that LTs, with a longer preverbal phase, produced nouns with lower contextual diversity (R2  = .80), but verbs with higher contextual diversity (R2  = .13). Study 2 compares computational network growth models of semantic maturation and finds that verbs require more semantic maturation than nouns, and TTs produce words that are more semantically mature than LTs.

Endocytosis of the glutamate transporter 1 is regulated by laforin and malin: Implications in Lafora disease.

Lafora disease (LD) is a fatal rare type of progressive myoclonus epilepsy that appears during early adolescence. The disease is caused by mutations in EPM2A or EPM2B genes, which encode laforin, a glucan phosphatase, and malin, an E3-ubiquitin ligase, respectively. Although the exact roles of laforin and malin are still not well understood, it is known that they work as a complex in which laforin recruits targets that will be ubiquitinated by malin. Recently, we suggested that the type of epilepsy that accompanies LD could be due to deficiencies in the function of the astrocytic glutamate transporter GLT-1. We described that astrocytes from LD mouse models presented decreased levels of GLT-1 at the plasma membrane, leading to increased levels of glutamate in the brain parenchyma. In this work, we present evidence indicating that in the absence of a functional laforin/malin complex (as in LD cellular models) there is an alteration in the ubiquitination of GLT-1, which could be the cause of the reduction in the levels of GLT-1 at the plasma membrane. On the contrary, overexpression of the laforin/malin complex promotes the retention of GLT-1 at the plasma membrane. This retention may be due to the direct ubiquitination of GLT-1 and/or to an opposite effect of this complex on the dynamics of the Nedd4.2-mediated endocytosis of the transporter. This work, therefore, presents new pieces of evidence on the regulation of GLT-1 by the laforin/malin complex, highlighting its value as a therapeutic target for the amelioration of the type of epilepsy that accompanies LD.

The choroid plexus stroma constitutes a sanctuary for paediatric B-cell precursor acute lymphoblastic leukaemia in the central nervous system.

Despite current central nervous system-directed therapies for childhood B-cell precursor acute lymphoblastic leukaemia, relapse at this anatomical site still remains a challenging issue. Few reports have addressed the study of the specific cellular microenvironments which can promote the survival, quiescence, and therefore chemoresistance of B-cell precursor acute lymphoblastic leukaemia cells in the central nervous system. Herein, we showed by immunofluorescence and electron microscopy that in xenotransplanted mice, leukaemic cells infiltrate the connective tissue stroma of the choroid plexus, the brain structure responsible for the production of cerebrospinal fluid. The ultrastructural study also showed that leukaemia cells are able to migrate through blood vessels located in the choroid plexus stroma. In short-term co-cultures, leukaemic cells established strong interactions with human choroid plexus fibroblasts, mediated by an increased expression of ITGA4 (VLA-4)/ITGAL (LFA-1) and their ligands VCAM1/ICAM1. Upon contact with leukaemia cells, human choroid plexus fibroblasts acquired a cancer-associated fibroblast phenotype, with an increased expression of α-SMA and vimentin as well as pro-inflammatory factors. Human choroid plexus fibroblasts also have the capacity to reduce the proliferative index of leukaemic blasts and promote their survival and chemoresistance to methotrexate and cytarabine. The inhibition of VLA-4/VCAM-1 interactions using anti-VLA-4 antibodies, and the blockade of Notch signalling pathway by using a γ-secretase inhibitor partially restored chemotherapy sensitivity of leukaemia cells. We propose that the choroid plexus stroma constitutes a sanctuary for B-cell precursor acute lymphoblastic leukaemia cells in the central nervous system. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons, Ltd. on behalf of The Pathological Society of Great Britain and Ireland.

Engineered LINE-1 retrotransposition in nondividing human neurons.

Half the human genome is made of transposable elements (TEs), whose ongoing activity continues to impact our genome. LINE-1 (or L1) is an autonomous non-LTR retrotransposon in the human genome, comprising 17% of its genomic mass and containing an average of 80-100 active L1s per average genome that provide a source of inter-individual variation. New LINE-1 insertions are thought to accumulate mostly during human embryogenesis. Surprisingly, the activity of L1s can further impact the somatic human brain genome. However, it is currently unknown whether L1 can retrotranspose in other somatic healthy tissues or if L1 mobilization is restricted to neuronal precursor cells (NPCs) in the human brain. Here, we took advantage of an engineered L1 retrotransposition assay to analyze L1 mobilization rates in human mesenchymal (MSCs) and hematopoietic (HSCs) somatic stem cells. Notably, we have observed that L1 expression and engineered retrotransposition is much lower in both MSCs and HSCs when compared to NPCs. Remarkably, we have further demonstrated for the first time that engineered L1s can retrotranspose efficiently in mature nondividing neuronal cells. Thus, these findings suggest that the degree of somatic mosaicism and the impact of L1 retrotransposition in the human brain is likely much higher than previously thought.

Pressure and Traction Technique Improves Postural Control More Than Tactile Stimulation in Foot Plantar Fascia: A Randomized Single-Blind Trial.

OBJECTIVE: To check the acute effects of manual pressure and traction technique on balance and plantar footprint variables. DESIGN: A single-blind clinical study with 2 groups. SETTING: Private practice. PARTICIPANTS: Healthy participants (N=40; 28 female and 12 male) were recruited to carry out a single-blind study. INTERVENTIONS: Experimental group performed a bilateral plantar fascia manual pressure and traction technique. Control group performed a tactile stimulation. The position of the participant, the therapist, and the time of application of the techniques (5min) were the same for both interventions. MAIN OUTCOME MEASURES: We measured stabilometry variables and static footprint. The footprint variables were divided in rear, middle, and front foot areas. RESULTS: Significant differences were found in stabilometry variables. There was an improvement in experimental group at X displacement with eyes open (P=.014) and surface eyes closed (P=.046) variables. CONCLUSIONS: After technique the experimental group improved the stabilometry variables, specifically surface with eyes closed and X displacement with eyes open. The static footprint variables have not shown differences after the technique compared with the control group.

QardioArm Blood Pressure Monitoring in a Population With Type 2 Diabetes: Validation Study.

BACKGROUND: Home blood pressure monitoring has many benefits, even more so, in populations prone to high blood pressure, such as persons with diabetes. OBJECTIVE: The purpose of this research was to validate the QardioArm mobile device in a sample of individuals with noninsulin-dependent type 2 diabetes in accordance with the guidelines of the second International Protocol of the European Society of Hypertension. METHODS: The sample consisted of 33 patients with type 2 diabetes. To evaluate the validity of QardioArm by comparing its data with that obtained with a digital sphygmomanometer (Omron M3 Intellisense), two nurses collected diastolic blood pressure, systolic blood pressure, and heart rate with both devices. RESULTS: The analysis indicated that the test device QardioArm met all the validation requirements using a sample population with type 2 diabetes. CONCLUSIONS: This paper reports the first validation of QardioArm in a population of individuals with noninsulin-dependent type 2 diabetes. QardioArm for home monitoring of blood pressure and heart rate met the requirements of the second International Protocol of the European Society of Hypertension.

Influence of Different Hardness Custom Foot Insoles in the Electromyography Activity Patterns of the Thigh and Hip Muscles during Motorcycling Sport: A Crossover Study.

: Nowadays, the use of insoles in sport practice have been recognized to decrease the foot and lower limb injury patterns. The aim of this study was to analyse the effect of four types of hardness insoles (HI) in the activity patterns of the hip and thigh muscles (HTM) in motoriders during motorcycling sport. The study was a crossover trial. Subjects were elite motoriders. The mean age was 33 ± 5.14 years. Electromyography (EMG) of hip and thigh muscles (HTM) data was registered via surface while subjects were riding on an elite motorcycle simulator. Subjects had to complete different tests with randomly hardest insoles (HI): 1: only polypropylene (58° D Shore); 2: Polypropylene (58° D Shore) with selective aluminium in hallux and metatarsal heads (60 HB Brinell hardness); 3: Ethylene vinyl acetate (EVA) (52° A Shore); and finally, 4: Ordinary EVA (25° A Shore) as the control. EMG patterns of the HTM, riding on an elite motorcycle simulator, showed the lowest peak amplitude with the insoles with polypropylene and selective aluminium. Using the hardest insoles in our study (selective aluminium) the EMG amplitude peaks decreased in all HTM.

Neuroticism Traits and Anxiety Symptoms are Exhibited in Athletes With Chronic Gastrocnemius Myofascial Pain Syndrome.

San-Antolín, M, Rodríguez-Sanz, D, Becerro-de-Bengoa-Vallejo, R, Losa-Iglesias, ME, Martínez-Jiménez, EM, López-López, D, and Calvo-Lobo, C. Neuroticism traits and anxiety symptoms are exhibited in athletes with chronic gastrocnemius myofascial pain syndrome. J Strength Cond Res 34(12): 3377-3385, 2020-Common psychological factors, such as anxiety or neurotic personality traits, seem to be associated with pain suffered by athletes. Gastrocnemius muscles present a high prevalence for injury in athletes. These muscles are a region in which myofascial pain syndrome (MPS) frequently develops. Myofascial pain syndrome is characterized by the presence of active myofascial trigger points (MTrPs). This study compared different personality and anxiety symptoms between athletes with and without active MTrPs in the gastrocnemius. A case-control study was conducted in an outpatient clinic. Athletes who performed moderate or vigorous physical activity according to the International Physical Activity Questionnaire were included. Fifty paired-matched athletes with and without active MTrPs in their gastrocnemius muscles (n = 25 in each group) were recruited. Different personality traits (neuroticism, extraversion, psychoticism, and sincerity) and anxiety (state and trait) were evaluated by the Eysenck Personality Questionnaire and State-Trait Anxiety Inventory, respectively. Statistically significant differences (p < 0.01) with an effect size from moderate to large (d = 0.75-1.29) were found for greater neuroticism and sincerity traits in addition to state and trait anxiety in athletes with gastrocnemius MPS compared with healthy controls. In conclusion, athletes with gastrocnemius active MTrPs exhibited higher neuroticism and anxiety symptoms compared with healthy athletes. Mental health may play a key role in athletes with myofascial pain, and future studies should be performed to determine whether neuroticism-related and anxiety-related psychological care could be a key intervention in athletes with gastrocnemius active MTrPs to improve athletic performance and rehabilitation or prevent injuries.

Immediate Effects of Intermittent Bilateral Ankle Plantar Flexors Static Stretching on Balance and Plantar Pressures.

OBJECTIVE: The purpose of this study was to analyze the immediate effects of an intermittent plantar flexion static-stretching protocol on balance and plantar pressures. METHODS: The study included a sample size of 24 healthy participants (21 female and 3 male). Participants were 32.20 ± 8.08 years, 166.20 ± 8.43 cm, and 62.77 ± 9.52 kg. All participants performed an intermittent plantar flexion static-stretching protocol. Five sets (60 seconds intermittent stretch; 15 seconds for the rest time) of a passive plantar flexor stretching (70% to 90% of the point of discomfort) were performed. Static footprint analysis and a stabilometry analysis were performed before and after stretching. A P value < .05 with a CI of 95% was considered statistically significant for all tests. RESULTS: Intermittent ankle plantar static stretching resulted in a significantly greater forefoot surface contact area and lower rear foot medium and maximum plantar pressures. In addition, static stretching caused a lower displacement of the center of pressure for both eyes open and eyes closed conditions. CONCLUSION: An intermittent plantar flexor static-stretching protocol improved balance and reduced rear foot plantar pressures (maximum and medium pressures).

Heel Height as an Etiology of Hallux Abductus Valgus Development: An electromagnetic Static and Dynamic First Metatarsophalangeal Joint Study.

Background: Hallux abductus valgus (HAV) is a forefoot condition produced by extrinsic and intrinsic factors. Shoes with a high heel height and a typical narrow tip toe box can induce deviations in both the proximal phalanx of the hallux (PPH) and the first metatarsal (IMTT) bones. Nevertheless, the isolated role of heel height remains unclear in the development of HAV pathology. Objectives: The goal was to determine if the heel height increase of shoes without a narrow box toe could augment the PPH and IMTT deviation in frontal, sagittal, and transverse planes toward the first metatarsophalangeal joint (MPJ) and the first metatarsocuneiform joint (MCJ), respectively, during static and dynamic conditions in relation to precursor movements of HAV. Methods: Women with an average age of 25.10 ± 4.67 years were recruited in this cross-sectional study to assess the three planes of motion of PPH and IMTT while wearing high heels with heights at 3, 6, 9 cm and unshod conditions via sandals. The measurements used an electromagnetic goniometer device with sensors placed on medial aspects of the PPH and IMTT bones under static and dynamic conditions. Results: Wearing shoes with a 6 cm heel in dynamic condition may increase the PPH valgus and abduction deviation from 3.15 ± 0.10° to 3.46 ± 0.05° (p < 0.05) and from 1.35 ± 0.28° to 1.69 ± 0.30° (p < 0.001), respectively. In addition, a PPH abduction increase from 1.01 ± 0.36° to 1.31 ± 0.46° (p < 0.05) after wearing shoes with a 6 cm heel height was observed under static conditions. Conclusions: Wearing shoes with a heel height of 6 cm without a narrow box toe interference may produce PPH abduction and valgus deviations related to HAV formation.

Electromyographic Evaluation of the Impacts of Different Insoles in the Activity Patterns of the Lower Limb Muscles during Sport Motorcycling: A Cross-Over Trial.

Customized foot insoles (CFI) have been recognized to reduce the prevalence of foot disorders in sport. The aim of this study was to evaluate the effect of four types of CFI on the activity patterns of the lower limb muscles (LLM) in healthy people during sport motorcycling. METHODS: This was a cross-over trial (NCT03734133. Participants were recruited from an outpatient foot specialist clinic. Their mean age was 33 ± 5.14 years. While participants were sport motorcycling in a simulator, the electromyography (EMG) function was registered for LLM via surface electrodes. Participants completed separate tests while wearing one of four types of CFI: (1) only polypropylene (58° Shore D), (2) selective aluminum (60 HB Brinell hardness) in metatarsal and first hallux areas and polypropylene elsewhere (58° Shore D), (3) ethylene vinyl acetate (EVA) (52° Shore A), and (4) standard EVA (25° Shore A) as the control. RESULTS: The activity patterns of the LLM while sport motorcycling showed significantly lower peak amplitude for the selective aluminum CFI than the other types of CFI. CONCLUSION: EMG amplitude peaks for several LLM were smaller for the hardest CFI (selective aluminum 60 HB Brinell hardness) than the other CFIs (polypropylene 58° Shore D, EVA 52° Shore A, and standard EVA 25° Shore A), except for the fibularis longus in right curves that is increased when the knee touches the road increasing the stability.

Slow velocity of the center of pressure and high heel pressures may increase the risk of Sever's disease: a case-control study.

BACKGROUND: This study determined if the body mass index, dynamic plantar-pressures, plantar surface contact-area, velocity of the centre of pressure (COP), gastrocnemius equinus, and gastrocnemius soleus equines are related to calcaneal apophysitis (Sever's disease) in athletic children. METHODS: This case-control study examined 106 boys enrolled in a soccer academy, including 53 with Sever's disease and 53 age-matched healthy controls. The dynamic average and maximum peak plantar-pressures, plantar surface contact-area, and velocity of the COP were evaluated with a digital pressure sensor platform. Goniometry was used to measure the ankle dorsiflexion range of motion and thereby identify gastrocnemius equinus and gastrocnemius soleus equinus. RESULTS: Participants with Sever's condition had significantly higher BMI and peak plantar-pressures (maximum and average) at the heel (Cohen's d > 3 for pressures) than the controls. Those with Sever's disease also had significantly slower velocity of the COP (Cohen's d > 3). Boys with Sever's disease were also 8 times more likely to have bilateral gastrocnemius equinus than disease controls. CONCLUSIONS: High heel plantar pressure and low velocity of COP are related to Sever's condition in boys, although it is not clear whether these factors predispose individuals to the disease or are consequences of the disease. Gastrocnemius ankle equinus could be a predisposing factor for Sever's condition.

Characterization of human fibroblastic reticular cells as potential immunotherapeutic tools.

Fibroblastic reticular cells (FRCs) are essential players during adaptive immune responses not only as a structural support for the encounter of antigen-presenting cells and naive T lymphocytes but also as a source of modulatory signals. However, little is known about this cell population in humans. To address the phenotypical and functional analysis of human FRCs here we established splenic (SP) and mesenteric lymph node (LN) CD45-CD31-CD90+podoplanin+ myofibroblastic cell cultures. They shared the phenotypical characteristics distinctive of FRCs, including the expression of immunomodulatory factors and peripheral tissue antigens. Nevertheless, human FRCs also showed particular features, some differing from mouse FRCs, like the lack of nitric oxide synthase (NOS2) expression after interferon (IFN)γstimulation. Interestingly, SP-FRCs expressed higher levels of interleukin (IL)-6, BMP4, CCL2, CXCL12 and Notch molecules, and strongly adapted their functional profile to lipopolysaccharide (LPS), polyinosinic:polycytidylic acid (Poly I:C) and IFNγ stimulation. In contrast, we found higher expression of transforming growth factor (TGF)ß and Activin A in LN-FRCs that barely responded via Toll-Like Receptor (TLR)3 and constitutively expressed retinaldehyde dehydrogenase 1 enzyme, absent in SP-FRCs. This study reveals human FRCs can be valuable models to increase our knowledge about the physiology of human secondary lymphoid organs in health and disease and to explore the therapeutic options of FRCs.

Retrotransposons in pluripotent cells: Impact and new roles in cellular plasticity.

Transposable Elements are pieces of DNA able to mobilize from one location to another within genomes. Although they constitute more than 50% of the human genome, they have been classified as selfish DNA, with the only mission to spread within genomes and generate more copies of themselves that will ensure their presence over generations. Despite their remarkable prevalence, only a minor group of transposable elements remain active in the human genome and can sporadically be associated with the generation of a genetic disorder due to their ongoing mobility. Most of the transposable elements identified in the human genome corresponded to fixed insertions that no longer move in genomes. As selfish DNA, transposable element insertions accumulate in cell types where genetic information can be passed to the next generation. Indeed, work from different laboratories has demonstrated that the main heritable load of TE accumulation in humans occurs during early embryogenesis. Thus, active transposable elements have a clear impact on our pluripotent genome. However, recent findings suggest that the main proportion of fixed non-mobile transposable elements might also have emerging roles in cellular plasticity. In this concise review, we provide an overview of the impact of currently active transposable elements in our pluripotent genome and further discuss new roles of transposable elements (active or not) in regulating pluripotency. This article is part of a Special Issue entitled: Stress as a fundamental theme in cell plasticity.

Biomechanical analysis of acromioclavicular joint dislocation repair using coracoclavicular suspension devices in two different configurations.

BACKGROUND: The best treatment option for some acromioclavicular (AC) joint dislocations is controversial. For this reason, the aim of this study was to evaluate the vertical biomechanical behavior of two techniques for the anatomic repair of coracoclavicular (CC) ligaments after an AC injury. MATERIALS AND METHODS: Eighteen human cadaveric shoulders in which repair using a coracoclavicular suspension device was initiated after injury to the acromioclavicular joint were included in the study. Three groups were formed; group I (n = 6): control; group II (n = 6): repair with a double tunnel in the clavicle and in the coracoid (with two CC suspension devices); group III (n = 6): repair in a "V" configuration with two tunnels in the clavicle and one in the coracoid (with one CC suspension device). The biomechanical study was performed with a universal testing machine (Electro Puls 3000, Instron, Boulder, MA, USA), with the clamping jaws set in a vertical position. The force required for acromioclavicular reconstruction system failure was analyzed for each cadaveric piece. RESULTS: Group I reached a maximum force to failure of 635.59 N (mean 444.0 N). The corresponding force was 939.37 N (mean 495.6 N) for group II and 533.11 N (mean 343.9 N) for group III. A comparison of the three groups did not find any significant difference despite the loss of resistance presented by group III. CONCLUSION: Anatomic repair of coracoclavicular ligaments with a double system (double tunnel in the clavicle and in the coracoid) permits vertical translation that is more like that of the acromioclavicular joint. Acromioclavicular repair in a "V" configuration does not seem to be biomechanically sufficient.

Attenuated and replication-competent vaccinia virus strains M65 and M101 with distinct biology and immunogenicity as potential vaccine candidates against pathogens.

Replication-competent poxvirus vectors with an attenuation phenotype and with a high immunogenic capacity of the foreign expressed antigen are being pursued as novel vaccine vectors against different pathogens. In this investigation, we have examined the replication and immunogenic characteristics of two vaccinia virus (VACV) mutants, M65 and M101. These mutants were generated after 65 and 101 serial passages of persistently infected Friend erythroleukemia (FEL) cells. In cultured cells of different origins, the mutants are replication competent and have growth kinetics similar to or slightly reduced in comparison with those of the parental Western Reserve (WR) virus strain. In normal and immune-suppressed infected mice, the mutants showed different levels of attenuation and pathogenicity in comparison with WR and modified vaccinia Ankara (MVA) strains. Wide genome analysis after deep sequencing revealed selected genomic deletions and mutations in a number of viral open reading frames (ORFs). Mice immunized in a DNA prime/mutant boost regimen with viral vectors expressing the LACK (Leishmania homologue for receptors of activated C kinase) antigen of Leishmania infantum showed protection or a delay in the onset of cutaneous leishmaniasis. Protection was similar to that triggered by MVA-LACK. In immunized mice, both polyfunctional CD4(+) and CD8(+) T cells with an effector memory phenotype were activated by the two mutants, but the DNA-LACK/M65-LACK protocol preferentially induced CD4(+) whereas DNA-LACK/M101-LACK preferentially induced CD8(+) T cell responses. Altogether, our findings showed the adaptive changes of the WR genome during long-term virus-host cell interaction and how the replication competency of M65 and M101 mutants confers distinct biological properties and immunogenicity in mice compared to those of the MVA strain. These mutants could have applicability for understanding VACV biology and as potential vaccine vectors against pathogens and tumors.