TRIM8 as a predictor for prognosis in childhood acute lymphoblastic leukemia based on a signature of neutrophil extracellular traps.

Background: Neutrophil extracellular traps (NETs) can be attributed to the metastasis, occurrence, and immune evasion of cancer cells. We investigated the prognostic value of NET-related genes in childhood acute lymphoblastic leukemia (cALL) patients. Methods: Differential gene expression analysis was conducted on samples collected from public databases. Grouping them based on the expression level of NET-related genes, we assessed the correlation between immune cell types and the risk score for having a poor prognosis of cALL, with an evaluation of the sensitivity of drugs used in cALL. We further divided the groups, integrating survival data. Subsequently, methods including multivariable Cox algorithms, least absolute shrinkage and selection operator (LASSO), and univariable were utilized to create a risk model predicting prognosis. Experiments in cell lines and animals were performed to explore the functions of TRIM8, a gene selected by the model. To validate the role of TRIM8 in leukemia development, lentivirus-mediated overexpression or knockdown of TRIM8 was employed in mice with T-ALL and B-ALL. Results: Kaplan-Meier (KM) analysis underscored the importance of differentially expressed genes identified in the groups divided by genes participated in NETs, with enrichment analysis showing the mechanism. Correlation analysis revealed significant associations with B cells, NK cells, mast cells, T cells, plasma cells, dendritic cells, and monocytes. The IC50 values of drugs such as all-trans-retinoic acid (ATRA), axitinib, doxorubicin, methotrexate, sorafenib, and vinblastine were increased, while dasatinib exhibited a lower IC50. A total of 13 NET-related genes were selected in constructing the risk model. In the training, testing, and merged cohorts, KM analysis demonstrated significantly improved survival for low-risk cALL patients compared to high-risk cALL patients (p < 0.001). The area under the curve (AUC) indicated strong predictive performance. Experiments in Jurkat and SUP-B15 revealed that TRIM8 knockdown decreased the proliferation of leukemia cell lines. Further experiments demonstrated a more favorable prognosis in mice with TRIM8-knockdown leukemia cells. Results of cell lines and animals showed better outcomes in prognosis when TRIM8 was knocked down. Conclusion: We identified a novelty in a prognostic model that could aid in the development of personalized treatments for cALL patients. Furthermore, it revealed that the expression of TRIM8 is a contributing factor to the proliferation of leukemia cells and worsens the prognosis of cALL.

Genome-wide methylation and gene-expression analyses in thalassemia.

Thalassemia is the most common autosomal genetic disorder in humans. The pathogenesis of thalassemia is principally due to the deletion or mutation of globin genes that then leads to disorders in globin-chain synthesis, and its predominant clinical manifestations include chronic forms of hemolytic anemia. However, research on the epigenetics and underlying pathogenesis of thalassemia is in its nascency and not yet been systematically realized. In this study, we compared the results of RNA-seq and the whole-genome bisulfite sequencing (WGBS) on 22 peripheral blood samples from 14 thalassemic patients and eight healthy individuals revealed a genome-wide methylation landscape of differentially methylated regions (DMRs). And functional-enrichment analysis revealed the enriched biological pathways with respect to the differentially expressed genes (DEGs) and differentially methylated genes (DMGs) to include hematopoietic lineage, glucose metabolism, and ribosome. To further analyze the interaction between the transcriptome and methylome, we implemented a comprehensive analysis of overlaps between DEGs and DMGs, and observed that biological processes significantly enriched the immune-related genes (i.e., our hypermethylated and down-regulated gene group). Hypermethylated and hypomethylated regions of thalassemia-related genes exhibited different distribution patterns. We thus, further identified and validated thalassemia-associated DMGs and DEGs by multi-omics integrative analyses of DNA methylation and transcriptomics data, and provided a comprehensive genomic map of thalassemia that will facilitate the exploration of the epigenetics mechanisms and pathogenesis underlying thalassemia.

Surveillance and Outcomes of Pediatric Hematopoietic Stem Cell Transplantation Recipients During the Recent COVID-19 Outbreak in China.

Background: The COVID-19 pandemic presents challenges for healthcare systems globally, especially in vulnerable populations such as pediatric hematopoietic stem cell transplant (HSCT) recipients. This study examines the clinical characteristics and outcomes of COVID-19 infection in pediatric HSCT recipients within one year post-HSCT. Methods: Retrospective analysis was conducted on data from 247 pediatric patients. None of them had received SARS-CoV-2 vaccination or had prior infection. SARS-CoV-2 infection was confirmed using RT-PCR testing. COVID-19 disease severity was categorized according to established guidelines. Demographic, clinical, laboratory, imaging and treatment data were collected. Results: The median age of the cohort was 7±3.7 years, with thalassemia major as the predominant underlying disease. Allogeneic HSCT was performed in the majority of cases, with haploidentical donors being the most common source of grafts. Nearly half of the patients developed COVID-19, with significantly higher infection rates observed in recipients over 100 days compared to recipients within 100 days post-HSCT (40.1% vs 21.7%, p<0.05, Fisher's Exact test). Fever (n=107, 43.2%) and cough (n=88, 35.6%) were the most common symptoms. While most patients had mild disease and did not require specific anti-viral treatment, a significant proportion required hospitalization (n=34, 13.8%). Various treatments were employed hospitalized patients, including Paxlovid (n=19, 55.9%), methylprednisolone (n=7, 20.6%), IL-6 antibody (n=2, 5.9%), mesenchymal stem cells (n=3, 8.8%), and exosomes nebulization therapy (n=2, 5.9%). Despite multidisciplinary approaches, one patient died from severe respiratory failure. However, overall survival of all patients remained high (99.53%; CI 96.72-99.93%), indicating favorable outcomes in pediatric HSCT recipients with COVID-19. Conclusion: This study provides insights into clinical features, therapeutic measures, and outcomes of pediatric HSCT recipients following COVID-19 infection in a large HSCT center in China. These findings contribute to our understanding of COVID-19 in this population and inform strategies to mitigate the impact the pandemic's impact on their care.

A Retrospective Analysis of the Therapeutic Outcomes of 117 Neuroblastoma Patients Treated at a Single Pediatric Oncology Center in China.

OBJECTIVE: Recent therapeutic advances have greatly enhanced the survival rates of patients with neuroblastoma (NB). However, the outcomes of neuroblastoma patients in China, particularly those with high-risk (HR) NB, remain limited. METHOD: We retrospectively analyzed the clinical data and outcomes of NB patients who were treated at a tertiary pediatric cancer facility in China between January 2013 and October 2021. RESULTS: A total of 117 NB patients were recruited. Patients with very low-risk (VLR), low-risk (LR), intermediate-risk (IR), and HR-NB patients made up 4%, 27%, 15%, and 54% of total patient population, respectively. Patients diagnosed between 2013 and 2018 were treated according to the protocol of Sun Yat-Sen University Cancer Center and those diagnosed between 2019 and 2021 were treated according to the COG ANBL0531 or ANBL0532 protocol with or without autologous stem cell transplantation (ASCT). The 5-year EFS and OS of all risk groups of patients were 67.29% and 77.90%, respectively. EFS and OS were significantly decreased in patients with higher risk classifications (EFS: VLR/LR vs IR vs HR: 97.22% vs 67.28% vs 51.83%; ***P = .001; OS: VLR/LR vs IR vs HR: 97.06% vs 94.12% vs 64.38%; *P = .046). In HR-NB patients treated according to the COG protocol between 2019 and 2021, the 3-year OS of patients who received tandem ASCT was significantly greater than those who did not receive ASCT (93.33% % vs 47.41%; *P = .046; log-rank test). EFS was not significantly different between patients with and without ASCT (72.16% vs 60.32%). CONCLUSION: Our findings show that patients with lower risk classification have a positive prognosis for survival. The prognosis of patients with HR-NB remains in need of improvement. ASCT may enhance OS in HR-NB patients; however, protocol adjustment may be necessary to increase EFS in these patients.

Outcomes and Risk Factor Analysis of Plastic Bronchitis Among 321 Children with Influenza Pneumonia After Bronchoscopy Examination.

Background: Plastic bronchitis (PB) is a rare and severe lung disease. It can be triggered by influenza virus infection, which is a common respiratory infection in children. Bronchoscopy can aid in the early detection and treatment of PB. However, the outcomes and risk for PB development in pediatric patients with influenza virus infection are not fully understood. Methods: Data from 321 children diagnosed with influenza virus pneumonia who underwent bronchoscopy examinations between 1st January, 2009 and 31st December, 2020 were retrospectively analyzed to assess the outcomes and risk factors associated with PB development. Results: This study included 97 girls and 224 boys with influenza virus pneumonia with a median age of 42 months. Among them, 36 patients (11.2%) were categorized as having PB based on bronchoscopy findings. PB patients had significantly longer fever durations (p=0.010) and higher risks of developing severe conditions including respiratory failure (p<0.001), acute respiratory distress syndrome (p<0.001), and air-leak syndrome (p<0.001) compared to non-PB patients. Conventional treatment including the use of neuraminidase inhibitors and antibiotics did not differ between the PB and non-PB patients, but PB patients required more anti-inflammatory treatment (p=0.019) and ventilator support (p<0.001). Combined univariate and multivariate analyses suggested that radiographic findings, including mediastinal emphysema (p=0.012) and lung consolidation (p=0.012), as well as increased levels of neutrophils (p=0.026), aspartate aminotransferase (p=0.004), and lactate dehydrogenase (p<0.001), were identified as risk factors for PB development in patients with influenza virus pneumonia. Although PB patients required more intensive care and had longer hospital stays, they all recovered well after treatment. Conclusion: Influenza virus infection is linked to PB development in children. Identifying risk factors and early intervention such as bronchoscopy can improve the prognosis of children with PB.

Successful Treatment of Rare Pulmonary Coprinopsis cinerea Infection in a 17-Year-Old Female After Hematopoietic Stem Cell Transplantation: A Case Report.

Invasive fungal infections (IFIs) are among the most severe complications in recipients of hematopoietic stem cell transplantation (HSCT) recipients and in patients with hematological malignancies. An increasing number of uncommon fungal infections have been reported in this era of antifungal prophylaxis. Coprinopsis cinerea is a rare pathogen that causes opportunistic infections in the immunocompromised patients, including HSCT recipients and is associated with very high mortality rates. Herein, we present a successfully treated pediatric HSCT patient with breakthrough pulmonary IFI caused by Coprinopsis cinerea despite posaconazole, prophylaxis using multidisciplinary approaches.

Multi-omics association analysis reveals interactions between the oropharyngeal microbiome and the metabolome in pediatric patients with influenza A virus pneumonia.

Children are at high risk for influenza A virus (IAV) infections, which can develop into severe illnesses. However, little is known about interactions between the microbiome and respiratory tract metabolites and their impact on the development of IAV pneumonia in children. Using a combination of liquid chromatography tandem mass spectrometry (LC-MS/MS) and 16S rRNA gene sequencing, we analyzed the composition and metabolic profile of the oropharyngeal microbiota in 49 pediatric patients with IAV pneumonia and 42 age-matched healthy children. The results indicate that compared to healthy children, children with IAV pneumonia exhibited significant changes in the oropharyngeal macrobiotic structure (p = 0.001), and significantly lower microbial abundance and diversity (p < 0.05). These changes came with significant disturbances in the levels of oropharyngeal metabolites. Intergroup differences were observed in 204 metabolites mapped to 36 metabolic pathways. Significantly higher levels of sphingolipid (sphinganine and phytosphingosine) and propanoate (propionic acid and succinic acid) metabolism were observed in patients with IAV pneumonia than in healthy controls. Using Spearman's rank-correlation analysis, correlations between IAV pneumonia-associated discriminatory microbial genera and metabolites were evaluated. The results indicate significant correlations and consistency in variation trends between Streptococcus and three sphingolipid metabolites (phytosphingosine, sphinganine, and sphingosine). Besides these three sphingolipid metabolites, the sphinganine-to-sphingosine ratio and the joint analysis of the three metabolites indicated remarkable diagnostic efficacy in children with IAV pneumonia. This study confirmed significant changes in the characteristics and metabolic profile of the oropharyngeal microbiome in pediatric patients with IAV pneumonia, with high synergy between the two factors. Oropharyngeal sphingolipid metabolites may serve as potential diagnostic biomarkers of IAV pneumonia in children.

circKL inhibits the growth and metastasis of kidney cancer by sponging miR­182­5p and upregulating FBXW7.

Circular RNAs (circRNAs) are a type of non­coding RNA with important roles in the regulation of various biological processes involved in malignant progression. However, the potential molecular mechanisms and roles of circRNAs in kidney cancer have remained to be fully elucidated. In a previous study by our group, high­throughput microarray sequencing data were analyzed to determine the differentially expressed circRNAs in kidney cancer. In this analysis, a novel circRNA (hsa_circ_0100312, named circKL) was identified as a frequently downregulated circRNA in kidney cancer cells and tissues by reverse transcription­quantitative PCR. In the present study, Cell Counting Kit­8, colony formation, Transwell, wound­healing and mouse xenograft assays as well as a lung metastasis experiment were performed to confirm the functions of circKL. The experiments confirmed that circKL overexpression significantly inhibited the proliferation, migration, tumor growth and metastasis of kidney cancer both in vitro and in vivo. The potential molecular mechanisms of circKL were investigated by performing dual­luciferase and RNA immunoprecipitation assays. Western blot assays confirmed that overexpression of circKL significantly increased the protein level of F­box and WD repeat domain containing 7 (FBXW7). All results suggested that circKL suppressed the growth and migration of kidney cancer by sponging microRNA (miR)­182­5p and upregulating FBXW7 expression. Overall, the circKL/miR­182­5p/FBXW7 axis was indicated to have a key role in the growth and metastasis of kidney cancer and may be targeted as a novel therapeutic strategy.

Cytomegalovirus Infection and the Implications of Drug-Resistant Mutations in Pediatric Allogeneic Hematopoietic Stem Cell Transplant Recipients: A Retrospective Study from a Tertiary Hospital in China.

INTRODUCTION: Drug-resistant cytomegalovirus (CMV) infection remains a challenge in the management of pediatric recipients of hematopoietic stem cell transplantation (HSCT). In this study, we retrospectively reviewed the clinical data on pediatric recipients of HSCT and identified known and unknown drug-resistant CMV variants. METHODS: A total of 221 children underwent allogeneic HSCT between October 2017 and November 2019 at Shenzhen Children's Hospital; of these, 35 patients were suspected of having drug-resistant CMV infections and were tested for drug-resistant mutations in the UL97 and UL54 genes by Sanger sequencing. RESULTS: Mutations in UL97 or UL54, or in both, were detected in 11 patients. Most of these mutations have not been previously reported. The UL97 mutation (A582V) was detected in only one patient who also harbored two UL54 mutations (T760X and R876W). One patient with both the G604S and T691A mutations in the UL54 gene died of CMV pneumonia. We investigated the risk factors associated with the development of drug-resistant CMV infection. Patients in whom both the donor and recipient had positive CMV serostatuses were less likely to have drug-resistant mutations (Fisher's exact test, p < 0.05). CONCLUSION: Newly and previously detected CMV mutations in UL97 and UL54 may be associated with the development of drug-resistant CMV infection. The detection of these mutations may provide guidance for the management of post-transplant CMV infections.

c.3G>A mutation in the CRYAB gene that causes fatal infantile hypertonic myofibrillar myopathy in the Chinese population.

Infantile hypertonic myofibrillar myopathy is characterized by the rapid development of rigid muscles and respiratory insufficiency soon after birth, with very high mortality. It is extremely rare, and only a few cases having been reported until now. Here we report four Chinese infants with fatal neuromuscular disorders characterized by abdominal and trunk skeletal muscle stiffness and rapid respiratory insufficiency progression. Electromyograms showed increased insertion activities and profuse fibrillation potentials with complex repetitive discharges. Immunohistochemistry staining of muscle biopsies showed accumulations of desmin in the myocytes. Powdery Z-bands with dense granules across sarcomeres were observed in muscle fibers using electron microscopy. All patients carry a homozygous c.3G>A mutation in the CRYAB gene, which resulted in the loss of the initiating methionine and the absence of protein. This study's findings help further understand the disease and highlight a founder mutation in the Chinese population.

Co-Transplantation of Haploidentical Stem Cells and a Dose of Unrelated Cord Blood in Pediatric Patients with Thalassemia Major.

Allogeneic stem cell transplantation is a cure for patients suffering from thalassemia major (TM). Historically, patients were limited by the selection of donors, while the advancement of haploidentical stem cell transplantation (haplo-SCT) has greatly expanded the donor pool. However, the outcomes of haplo-SCT in TM recipients vary between different programs. In this study, we retrospectively studied 73 pediatric TM patients (median age, 7 years; range, 3 to 14 years) who underwent haplo-cord transplantation. Both the estimated overall survival and transfusion-free survival were 95.26% (CI 95.77% to 96.23%). Neither primary nor secondary graft failures were observed. The median follow-up period was 811 days (range, 370 to 1433 days). Median neutrophil and platelet engraftment times were 22 days (range, 8 to 48 days) and 20 days (range, 8 to 99 days), respectively. Acute graft-versus-host disease (aGVHD) was observed in 52% of patients and of these, 25% developed grade III to IV aGVHD. Cord blood engraftment was associated with delayed immune recovery and increased aGVHD severity. Viral DNAemia occurred in a relatively high proportion of patients but only 7% of patients developed CMV disease, while another 7% of patients had post-transplantation lymphoproliferative disorder. Long-term complication outcomes were good. Only one patient developed extensive chronic GVHD. No surviving patients were reliant on blood transfusion by the time this manuscript was submitted. This is one of the largest studies on the outcomes of pediatric TM patients who received stem cell transplantations from alternative donors. The haplo-cord program is safe and practical for TM patients that do not have matched donors.

Case Report: Myeloid Sarcoma Development During Treatment for B Cell Lymphoblastic Lymphoma in a Boy with KRAS/NRAS Gene Mutations.

Here, we report a rare case of a 12-year-old boy who was initially diagnosed with B cell lymphoblastic lymphoma (BLBL) and developed myeloid sarcoma (MS) eight months after chemotherapy. Next-generation sequencing (NGS) showed mutations of KRAS and NRAS genes in both the bone marrow and lymph node. He presented an abnormal karyotype of 46, XY, -9, der (16) t (9; 16) (q13; q12), +mar. He received chemotherapy according to the South China Children's Leukemia Group 2016 protocol. Complete remission was achieved by the 15th day post-treatment. Eight months later and immediately prior to the start of maintenance therapy, the patient developed fever, skin nodules in both upper arms, and enlargement of bilateral testes. Pathological analysis of skin and testicular biopsies suggested the diagnosis of myeloid sarcoma (MS). Again, NGS examination showed mutations of KRAS and NRAS genes. The patient underwent haploidentical hematopoietic stem cell transplantation but unfortunately did not survive. The interval of eight-month interval between the initial disease onset and MS brings into question whether MS developed as part of the initial onset of disease or as a secondary tumor in association with chemotherapy. Thus, understanding the pathogenesis of MS involving abnormalities of lymphoid progenitors may assist in the prediction of prognosis and development of novel target therapies.

Identification and Treatment of Tuberculosis in Pediatric Recipients of Allogeneic Hematopoietic Stem Cell Transplantation: Case Series and Review of the Literature.

BACKGROUND: Tuberculosis is a rare but life-threatening complication in patients who received hematopoietic stem cell transplantation. Early identification and intervention are essential to prevent severe complications. CASE PRESENTATION: We report two pediatric patients who developed tuberculosis after receiving hematopoietic stem cell transplantation for thalassemia major among 330 recipients between January 2012 and August 2019. Patient A presented with pulmonary tuberculosis and patient B presented with lymph node tuberculosis mimicking post-transplantation lymphoproliferative disorder associated with Epstein-Barr virus reactivation. Patient B's condition was deteriorated, and shortly after the initiation of anti-tuberculosis therapy, the patient was found to have disseminated pulmonary tuberculosis. Patient B was also found to have tuberculous granulomas, an uncommon manifestation of tuberculosis causing severe airway obstruction. Both patients developed critical respiratory failure and required mechanical ventilation; however, they recovered with almost full resolution of pulmonary lesions after multiple treatment adjustments. CONCLUSION: Tuberculosis must be carefully evaluated in all pediatric patients that receive hematopoietic stem cell transplantation, regardless of the identification of other pathogens. Prophylactic tuberculosis therapy should be considered for high-risk pediatric hematopoietic stem cell transplantation recipients from tuberculosis-endemic regions.

Massive hydatid cysts in the lung and liver of a 4-year-old boy.

Hydatids may persist for years if left undiagnosed. Early identification is challenging, especially in patients from nonendemic regions. It is crucial for clinicians to be aware of the presence of the disease to avoid devastating outcomes.

Murine Skin-resident γδT Cells Impair the Immune Response to HSV in Skin.

BACKGROUND: HSV is an important cause of brain infection. Virus entry is often through breeches in the skin. γδT cells play an immunoprotective role in mice after corneal, genital or footpad (subcutaneous) HSV infection. METHODS: Here we report that the presence of γδT cells in murine skin is associated with increased severity of herpetic disease, reduced protective cytokine responses and increased viral spread from the skin to the sensory ganglia in the zosteriform model. γδT cell-deficient (TCR δ -/-) mice displayed significantly decreased herpetic lesion severity after flank HSV infection compared to WT C57BL/6 controls at both primary and secondary skin infection sites. RESULTS: Viral titer at the primary skin site was similar to WT mice in γδT cell-deficient mice, but was significantly decreased in the ganglia and secondary skin site. γδT cell-deficient mice showed increased Th1 responses by both T cells and non-T cells at the primary site, and decreased T-cell Th17 responses and immune infiltration at the secondary site. CONCLUSION: Cytokine responses of epidermal and dermal γδT cells to HSV also differed in WT mice (Th1 in epidermis, and Th17 in the dermis), suggesting a functional dichotomy between these two subsets. Our data suggest that in contrast to other mouse models of HSV infection, skinresident γδT cells promote the pathogenesis of HSV in skin.

Evaluation of the vitamin D and biomedical statuses of young children with ß-thalassemia major at a single center in southern China.

BACKGROUND: In young children, ß-thalassemia major (ß-TM) is associated with potentially severe clinical characteristics, including poor growth, feeding difficulties, hepatosplenomegaly, bone metabolic disorders, and skeletal abnormalities. METHODS: In this study, we reviewed the demographic and clinical characteristics (e.g., age, sex, duration of blood transfusion and chelating therapy, and vitamin supplementation) and serum biomarker levels (e.g., iron accumulation, bone metabolism, liver, kidney, and thyroid function markers) of 32 patients that received regular blood transfusion at a single center in southern China with the aim of stratifying the risk of severe complications such as osteopenia, endocrinopathies, and multi-organ failures. RESULTS: Although all patients exhibited moderately to strongly elevated serum ferritin levels, this biomarker was significantly higher in children older than ≥5 years, compared to younger children (*p < 0.05, 1512 ± 192.6 vs. 2337 ± 299.8 ng/ml, Mann-Whitney U test). Older children had a significantly lower 25-hydroxy vitamin D3 (25(OH)D3) level, compared to younger children (**p < 0.01, 34.25 ± 11.06 vs. 23.05 ± 9.95 ng/ml, Mann-Whitney U test). No age-related differences were observed in serum calcium, phosphorus, and PTH levels. Regarding liver function, the serum alanine aminotransferase (ALT) level was significantly increased in children older than ≥5 years, compared to younger children (*p < 0.05, 19.17 ± 2.44 vs. 43.45 ± 9.82I U/ml, Mann-Whitney U test). However, no age-related differences were observed in the serum levels of other liver or kidney and thyroid biomarkers. CONCLUSIONS: Our results suggest that in older children, hepatic iron overload may be associated with a low serum concentration of 25(OH)D3, an indicator of vitamin D deficiency and altered bone metabolism. Iron accumulation may also be associated with a higher concentration of ALT, a sensitive marker of liver malfunction. These findings may provide important clinical indications of the need for intervention to prevent severe complications in children with ß thalassemia.

Asymptomatic actinomycosis in a girl with thalassemia major.

We present a rare case of lung actinomycosis in a girl with thalassemia major with a competent immunological status. Chest computed tomography scans showed high intensity nodules in the right lower lung. Diagnosis was confirmed by revealing of actonomycetes from the staining of bronchoalveolar fluid. The patient was given intravenous penicillin then oral amoxicillin and clavulanate potassium. This patient responded well after antibiotic treatment for four months. Our report suggests that clinicians should evaluate the immune response underlying asymptomatic infections before conducting hematopoietic stem cell transplantations.

Treg depletion attenuates the severity of skin disease from ganglionic spread after HSV-2 flank infection.

Regulatory T cells (Tregs) attenuate lesion severity and disease after HSV ocular or genital infection, but their role in cutaneous infection remains unclear. Treg depletion (anti-CD25 mAb in C57BL/6 mice or diphtheria toxin (DT) in DEREG mice) prior to tk-deficient HSV-2 flank infection significantly decreased skin lesion severity, granulocyte receptor-1(Gr-1(+)) cell number, and chemokine (KC) expression in the secondary skin, but significantly increased immune effectors and chemokine expression (MCP-1, KC, VEGF-A) in the draining LN, and activated, interferon-γ producing CD8(+)T cells in the ganglia. Treg depletion also significantly reduced HSV-2 DNA in the ganglia. Thus, Tregs increase the severity of recurrent skin lesions, and differentially alter chemokine expression and immune effector homing in the skin and LN after cutaneous infection, and limit CD8(+) T cell responses in the ganglia. Our data suggests that effects of Treg manipulation on recurrent herpes lesions should be considered when developing Treg mediated therapeutics.