Effects of pitavastatin on atherosclerotic-associated inflammatory biomarkers in people living with HIV with dyslipidemia and receiving ritonavir-boosted atazanavir: a randomized, double-blind, crossover study.

BACKGROUND: Chronic inflammation has been described in people living with HIV (PLHIV) receiving antiretroviral therapy (ART) despite viral suppression. Inflammation associated non-communicable diseases, including atherosclerosis, are becoming recognized complication of HIV infection. We studied the effect of pitavastatin on atherosclerotic-associated inflammatory biomarkers in PLHIV receiving ART. METHODS: A randomized, double-blind, crossover study was conducted in HIV-infected persons with dyslipidemia and receiving atazanavir/ritonavir (ATV/r) to evaluate the effect of 2 mg/day pitavastatin treatment versus placebo. High-sensitivity CRP (hs-CRP), cytokines, and cellular markers in PLHIV receiving 12 weeks of pitavastatin or placebo were investigated. RESULTS: A total of 24 HIV-infected individuals with a median (interquartile range) age of 46 (41-54) years were recruited, and the median CD4 T cell count was 662 (559-827) cells/mm3. The median duration of ATV/r use was 36 (24-48) months. Significant change in levels of basic fibroblast growth factor (FGF) between pitavastatin treatment and placebo at week 12 from baseline was observed (27.1 vs. 20.5 pg/mL; p=0.023). However, there were no significant changes from baseline of hs-CRP and other plasma cytokine levels at week 12 of pitavastatin or placebo. Regarding cellular markers, percentages of HLA-DR+CD38-CD4+ T cells and PD1+CD4+ T cells significantly decreased from baseline in PLHIV receiving pitavastatin for 12 weeks, as compared to placebo (- 0.27 vs. 0.02%; p=0.049 and - 0.23 vs. 0.23%; p=0.022, respectively). CONCLUSIONS: Pitavastatin treatment increases basic FGF levels, and lowers HLA-DR+CD38-CD4+ T cells, and PD1+CD4+ T cells. Further study on the effects of pitavastatin on preventing cardiovascular diseases in PLHIV should be pursued.

Saliva sample pooling for the detection of SARS-CoV-2.

As the battle against coronavirus disease 2019 pandemic continues, an increase in workload and medical expenses have been a concern to the health care system worldwide. Developing a measure that helps to conserve the health care resource is, therefore, highly desirable, and the pooling of the specimens for testing is one of the attractive strategies. Recently, we showed that saliva could be a potential alternative specimen for the detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) by real-time polymerase chain reaction (RT-PCR). In the present study, we performed the pooling of saliva specimens for testing by SARS-CoV-2 RT-PCR. We showed that the saliva pool of either 5 or 10 samples, by allowing the detection of either gene in the pool at an increased cycle threshold cutoff value, further performing individual sample testing in the positive pools did not compromise the detection of SARS-CoV-2.

Expansion of Stem Cell-Like CD4+ Memory T Cells during Acute HIV-1 Infection Is Linked to Rapid Disease Progression.

Acute HIV-1 infection is characterized by high viremia and massive depletion of CD4+ T cells throughout all tissue compartments. During this time the latent viral reservoir is established but the dynamics of memory CD4+ T cell subset development, their infectability and influence on disease progression during acute HIV-1 infection has not been carefully described. We therefore investigated the dynamics of CD4+ T cell memory populations in the RV217 (ECHO) cohort during the acute phase of infection. Interestingly, while we found only small changes in central or effector memory compartments, we observed a profound expansion of stem cell-like memory CD4+ T cells (SCM) (2.7-fold; P < 0.0001). Furthermore, we demonstrated that the HIV-1 integration and replication preferentially take place in highly differentiated CD4+ T cells such as transitional memory (TM) and effector memory (EM) CD4+ T cells, while naive and less mature memory cells prove to be more resistant. Despite the relatively low frequency of productively infected SCM, we suggest that their quiescent phenotype, increased susceptibility to HIV-1 integration compared to naive cells and extensive expansion make them one of the key players in establishment and persistence of the HIV-1 reservoir. Moreover, the expansion of SCM in acute HIV-1 infection was a result of Fas upregulation on the surface of naive CD4+ T cells. Interestingly, the upregulation of Fas receptor and expansion of SCM in acute HIV-1 infection was associated with the early viral set point and disease progression (rho = 0.47, P = 0.02, and rho = 0.42, P = 0.041, respectively). Taken together, our data demonstrate an expansion of SCM during early acute HIV-1 infection which is associated with disease outcome.IMPORTANCE Understanding the immunopathology of acute HIV-1 infection will help to develop eradication strategies. We demonstrate here that a CD4+ T cell memory subset expands during acute HIV-1 infection, which is associated with disease progression.

Replication and cytokine profiles of different subgenotypes of enterovirus 71 isolated from Thai patients in peripheral blood mononuclear cells.

Enterovirus 71 (EV71) and coxsackievirus A16 (CA16) are common causative agents of mild and self-limiting symptoms of childhood hand, foot, and mouth disease (HFMD). However, some EV71-infected HFMD patients can develop severe neurological and/or fatal cardiopulmonary complications. In Thailand, HFMD associated with the EV71 subgenotypes C4a and B5 were reported to be associated with diverse outcomes. However, variations in enterovirus subgenotypes and virulence factors have not been fully elucidated; this study elucidated these variations in peripheral blood mononuclear cells (PBMCs) exposed to different subgenotypes of isolated enteroviruses for 24 and 48 h. Following infection, viral titers were determined by plaque assay. Infected cells and intracellular cytokines were quantified using flow cytometry, and multiplex assay was used to examine cytokine release. All isolated subgenotypes showed replication capability in PBMCs; specifically, the replication titer of EV71 C4a tended to be higher than titers of EV71 B5 and CA16. Additionally, the infectivity of EV71 B5 was higher in monocytes than in lymphocytes. Compared with EV71 B5, EV71 C4a and CA16 had greater ability to induce intra- and extracellular cytokine responses. These findings provide new insights into variations in cellular immune responses to different EV71 subgenotypes isolated from Thai patients, which should be considered for the development of vaccines and therapeutic agents.

Allogeneic red cell transfusion and its influence on relevant humoral and cellular immunological parameters: A prospective observational trial.

BACKGROUND: It is assumed that transfusion of allogeneic red cells is associated with increased peri-operative mortality and morbidity. Also assumed is the theory of transfusion-related immunomodulation. OBJECTIVE: The aim of this study was to investigate the hypothesis that red cell transfusion specifically leads to an immunological response in surgical patients. DESIGN: Prospective observational study. SETTING: Departments of Orthopedic Surgery and Anaesthesia, University Hospital, Thailand. PATIENTS: Low-risk, noncancer patients, aged 18 to 75 years undergoing elective major spine surgery, with and without red cell transfusion therapy. INTERVENTIONS: Blood specimens were withdrawn four times (prior to surgery and on days 1, 3 and 5). MAIN OUTCOME MEASURES: Assessment of immunocompetent cells and cytokines in transfused and nontransfused patients using flow cytometry and multiplex ELISA. RESULTS: From a total of 78 patients, 61 met the requirements and were analysed in three groups: 19 with no transfusion and 26 and 16 transfused intra-operatively and on day 1 or 2, respectively. No patient experienced peri-operative haemorrhage. Postoperative infection or thrombosis occurred in 5.5% of nontransfused patients and 16.6% of transfused patients; the difference was not significant. There was no significant immunomodulatory effect of red cell transfusion: of 45 immunological parameters, only five little-relevant cytokines were significantly affected, although slightly and nonspecifically. CONCLUSION: Our data indicate that red cell transfusion alone does not create an immunological response in otherwise healthy surgical patients. Our findings do not generally contradict the transfusion-related immunomodulation phenomenon, which has, however, primarily been observed in patients with an already weakened or procedure-deteriorated immune system, such as from malignant disease, significant comorbidity, extensive abdominal/thoracic surgery and cardiopulmonary bypass. TRIAL REGISTRATION: The study was registered on 15 May 2014, before enrolment of the first patient, at www.ClinicalTrials.gov, NCT02140216.

Seroprevalence of antibodies to enterovirus 71 and coxsackievirus A16 among people of various age groups in a northeast province of Thailand.

BACKGROUND: Hand, foot and mouth disease (HFMD) is endemic among population of young children in Thailand. The disease is mostly caused by enterovirus 71 (EV71) and coxsackievirus A16 (CA16). METHODS: This study conducted serosurveillance for neutralizing (NT) antibodies to EV71 subgenotypes B5 and C4a, and to CA16 subgenotypes B1a and B1b, in 579 subjects of various ages using a microneutralization assay in human rhabdomyosarcoma (RD) cells. These test viruses were the major circulating subgenotypes associated with HFMD in Thailand during the study period. RESULTS: We found that the levels of seropositivity against all 4 study viruses were lowest in the age group of 6-11 months, i.e., 5.5% had antibody to both EV71 subgenotypes, while 14.5% and 16.4% had antibody to CA16 subgenotypes B1a and B1b, respectively. The percentages of subjects with antibodies to these 4 viruses gradually increased with age, but were still less than 50% in children younger than 3 years. These laboratory data were consistent with the epidemiological data collected by the Ministry of Public Health which showed repeatedly that the highest number of HFMD cases was in children aged 1 year. Analyses of amino acid sequences of the test viruses showed 97% identity between the two subgenotypes of EV71, and 99% between the two subgenotypes of CA16. Nevertheless, the levels of seropositivity and antibody titer against the two subgenotypes of EV71 and of CA16 were not significantly different. CONCLUSIONS: This study clearly demonstrated NT antibody activity across EV71-B5 and EV71-C4a subgenotypes, and also across CA16-B1a and CA16-B1b subgenotypes. Moreover, there were no significant differences by gender in the seropositive rates and antibody levels to any of the 4 virus subgenotypes.

Expansion of Inefficient HIV-Specific CD8 T Cells during Acute Infection.

UNLABELLED: Attrition within the CD4(+)T cell compartment, high viremia, and a cytokine storm characterize the early days after HIV infection. When the first emerging HIV-specific CD8(+)T cell responses gain control over viral replication it is incomplete, and clearance of HIV infection is not achieved even in the rare cases of individuals who spontaneously control viral replication to nearly immeasurably low levels. Thus, despite their partial ability to control viremia, HIV-specific CD8(+)T cell responses are insufficient to clear HIV infection. Studying individuals in the first few days of acute HIV infection, we detected the emergence of a unique population of CD38(+)CD27(-)CD8(+)T cells characterized by the low expression of the CD8 receptor (CD8(dim)). Interestingly, while high frequencies of HIV-specific CD8(+)T cell responses occur within the CD38(+)CD27(-)CD8(dim)T cell population, the minority populations of CD8(bright)T cells are significantly more effective in inhibiting HIV replication. Furthermore, the frequency of CD8(dim)T cells directly correlates with viral load and clinical predictors of more rapid disease progression. We found that a canonical burst of proliferative cytokines coincides with the emergence of CD8(dim)T cells, and the size of this population inversely correlates with the acute loss of CD4(+)T cells. These data indicate, for the first time, that early CD4(+)T cell loss coincides with the expansion of a functionally impaired HIV-specific CD8(dim)T cell population less efficient in controlling HIV viremia. IMPORTANCE: A distinct population of activated CD8(+)T cells appears during acute HIV infection with diminished capacity to inhibit HIV replication and is predictive of viral set point, offering the first immunologic evidence of CD8(+)T cell dysfunction during acute infection.

Disseminated cryptococcosis in an HIV-seronegative pregnant woman with transient T-lymphocytopenia: a case report and review of the literature.

We report a case of an HIV-seronegative pregnant woman with disseminated cryptococcosis, poorly controlled during gestation. Immunological studies showed T-lymphocytopenia during gestation, but rapid recovery postpartum. T-lymphocytopenia may play a role in increased susceptibility to and severity of cryptococcal infection during pregnancy.

CRISPR/Cas9 genome editing of CCR5 combined with C46 HIV-1 fusion inhibitor for cellular resistant to R5 and X4 tropic HIV-1.

Hematopoietic stem-cell (HSC) transplantation using a donor with a homozygous mutation in the HIV co-receptor CCR5 (CCR5Δ32/Δ32) holds great promise as a cure for HIV-1. Previously, there were three patients that had been reported to be completely cured from HIV infection by this approach. However, finding a naturally suitable Human Leukocyte Antigen (HLA)-matched homozygous CCR5Δ32 donor is very difficult. The prevalence of this allele is only 1% in the Caucasian population. Therefore, additional sources of CCR5Δ32/Δ32 HSCs are required. The Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR)/CRISPR-associated (Cas) system is one method to mediate CCR5 knockout in HSCs that has been successfully employed as a gene editing tool in clinical trials. Additional anti-HIV-1 strategies are still required for broad-spectrum inhibition of HIV-1 replication. Here in this study, we combined an additional anti-HIV-1 therapy, which is C46, a cell membrane-anchored HIV-1 fusion inhibitor with the CRISPR/Cas9 mediated knockout CCR5. The combined HIV-1 therapeutic genes were investigated for the potential prevention of both CCR5 (R5)- and CXCR4 (X4)-tropic HIV-1 infections in the MT4CCR5 cell line. The combinatorial CRISPR/Cas9 therapies were superior compared to single method therapy for achieving the HIV-1 cure strategy and shows potential for future applications.

HIV-1 proviral DNA in purified peripheral blood CD34+ stem and progenitor cells in individuals with long-term HAART; paving the way to HIV gene therapy.

Human immunodeficiency virus (HIV)-1 infection is an important public health problem worldwide. After primary HIV-1 infection, transcribed HIV-1 DNA is integrated into the host genome, serving as a reservoir of the virus and hindering a definite cure. Although highly active antiretroviral therapy suppresses active viral replication, resulting in undetectable levels of HIV RNA in the blood, a viral rebound can be detected after a few weeks of treatment interruption. This supports the concept that there is a stable HIV-1 reservoir in people living with HIV-1. Recently, a few individuals with HIV infection were reported to be probably cured by hematopoietic stem transplantation (HSCT). The underlying mechanism for this success involved transfusion of uninfected hematopoietic stem and progenitor cells (HSPCs) from CCR5-mutated donors who were naturally resistant to HIV infection. Thus, gene editing technology to provide HIV-resistant HSPC has promise in the treatment of HIV infections by HSCT. In this study, we aimed to find HIV-infected individuals likely to achieve a definite cure via gene editing HSCT. We screened for total HIV proviral DNA by Alu PCR in peripheral blood mononuclear cells (PBMCs) of 20 HIV-infected individuals with prolonged viral suppression. We assessed the amount of intact proviral DNA via a modified intact proviral DNA assay (IPDA) in purified peripheral CD34+ HSPCs. PBMCs from all 20 individuals were positive for the gag gene in Alu PCR, and peripheral CD34+ HSPCs were IPDA-negative for six individuals. Our results suggested that these six HIV-infected individuals could be candidates for further studies into the ability of gene editing HSCT to lead to a definite HIV cure.

Development of a high-throughput flow cytometric neutralization assay to screen for human enterovirus A71 (EVA71) neutralizing antibodies.

The conventional method for screening neutralizing antibodies to human enterovirus A71 (EVA71) (microneutralization assay) is time consuming and requires an expert to perform manual evaluation. An automated neutralization assay could shorten the testing time, improve reproducibility, and provide automatic analysis. This study aimed to develop a high-throughput flow cytometric neutralization assay to screen for EVA71 neutralizing antibodies, and to develop quality control materials to ensure accurate testing. The results of this study demonstrate the high potential viability of the proposed flow cytometric method. Compared to the standard method, the flow cytometric method was shown to require a smaller sample volume, provide a much faster turnaround time, provide a rapid result for interpreting the neutralizing antibody level, and allow for possible quantification of results. The observed drawbacks of the proposed method include higher cost per test, longer hands-on time, and lower sensitivity in low titer conditions, which could lead to false negative results. The developed quality control materials were demonstrated to be effective and storable for 1 month. These results pave the way for the optimization and implementation of an automated neutralization assay to screen for neutralizing antibodies not only against EVA71, but also against other viruses in the enterovirus genus.

Cell type specificity and host genetic polymorphisms influence antibody-dependent enhancement of dengue virus infection.

Antibody-dependent enhancement (ADE) is implicated in severe, usually secondary, dengue virus (DV) infections. Preexisting heterotypic antibodies, via their Fc-gamma receptor (FcγR) interactions, may increase disease severity through enhanced target cell infection. Greater numbers of infected target cells may contribute to higher viremia and excess cytokine levels often observed in severe disease. Monocytes, macrophages, and immature and mature dendritic cells (DC) are considered major cellular targets of DV. Apheresis of multiple donors allowed isolation of autologous primary myeloid target cell types for head-to-head comparison of infection rates, viral output, and cytokine production under direct infection (without antibody) or ADE conditions (with antibody). All studied cell types except immature DC supported ADE. All cells undergoing ADE secreted proinflammatory cytokines (interleukin-6 [IL-6] and tumor necrosis factor alpha [TNF-α]) at enhancement titers, but distinct cell-type-specific patterns were observed for other relevant proteins (alpha/beta interferon [IFN-α/ß] and IL-10). Macrophages produced type I interferons (IFN-α/ß) that were modulated by ADE. Mature DC mainly secreted IFN-ß. Interestingly, only monocytes secreted IL-10, and only upon antibody-enhanced infection. While ADE infection rates were remarkably consistent in monocytes (10 to 15%) across donors, IL-10 protein levels varied according to previously described regulatory single nucleotide polymorphisms (SNPs) in the IL-10 promoter region. The homozygous GCC haplotype was associated with high-level IL-10 secretion, while the ACC and ATA haplotypes produced intermediate and low levels of IL-10, respectively. Our data suggest that ADE effects are cell type specific, are influenced by host genetics, and, depending on relative infection rates, may further contribute to the complexity of DV pathogenesis.

Enterovirus 71-Induced Autoimmune Hemolytic Anemia in a Boy.

Autoimmune hemolytic anemia (AIHA) can be induced by recent or concomitant infections. Many infectious agents are postulated to be associated with this condition. Treatment of infection induced AIHA still varies. This report describes a previously healthy Thai boy who developed AIHA associated with enterovirus-71 infection. He was successfully treated with oral prednisone.

Detectable Duration of Viable SARS-CoV-2, Total and Subgenomic SARS-CoV-2 RNA in Noncritically Ill COVID-19 Patients: a Prospective Cohort Study.

Determination of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infectivity is important in guiding the infection control and differentiating between reinfection and persistent viral RNA. Although viral culture is the gold standard to determine viral infectivity, the method is not practical. We studied the kinetics of SARS-CoV-2 total RNAs and subgenomic RNAs (sgRNAs) and their potential role as surrogate markers of viral infectivity. The kinetics of SARS-CoV-2 sgRNAs compared to those of the culture and total RNA shedding in a prospective cohort of patients diagnosed with coronavirus disease 2019 (COVID-19) were investigated. A total of 260 nasopharyngeal swabs from 36 patients were collected every other day after entering the study until the day of viral total RNA clearance, as measured by reverse transcription PCR (RT-PCR). Time to cessation of viral shedding was in order from shortest to longest: by viral culture, sgRNA RT-PCR, and total RNA RT-PCR. The median time (interquartile range) to negativity of viral culture, subgenomic N transcript, and N gene were 7 (5 to 9), 11 (9 to 16), and 18 (13 to 21) days, respectively (P < 0.001). Further analysis identified the receipt of steroid as the factors associated with longer duration of viral infectivity (hazard ratio, 3.28; 95% confidence interval, 1.02 to 10.61; P = 0.047). We propose the potential role of the detection of SARS-CoV-2 subgenomic RNA as the surrogate marker of viral infectivity. Patients with negative subgenomic N RNA RT-PCR could be considered for ending isolation. IMPORTANCE Our study, combined with existing evidence, suggests the feasibility of the use of subgenomic RNA RT-PCR as a surrogate marker for SARS-CoV-2 infectivity. The kinetics of SARS-CoV-2 subgenomic RNA should be further investigated in immunocompromised patients.

Flow cytometric CD4 enumeration of four different HIV-infected blood samples at the cost of one monoclonal antibody reagent.

BACKGROUND: The frequency and absolute number of CD4+ T-lymphocytes continue to be one of the major clinical markers for management of HIV/AIDS. The present standard dual-platform (DP) three-color and two-color PanLeucogating flow cytometric (FCM) methods for most developing countries are either expensive if manufacturers' monoclonal antibody reagents are used or limited due to an insufficient supply of generic reagents. Clearly, more affordable FCM methods are needed. OBJECTIVE: To develop a novel DP FCM method using biotin-streptavidin-fluorochrome labeling in combination with the two standard DP methods for 4 different white blood cells (WBC) using only one monoclonal antibody reagent. METHODS: The percentage of CD4+ T-lymphocytes in 116 HIV-infected blood samples was determined using our new method. Results were compared with the two standard methods. Correlation and agreement of the pair method were determined using linear regression, Bland-Altman and percent similarity analysis. RESULTS: Our study showed that percentage of CD4+ T-lymphocyte values obtained from the new method correlated highly with the standard three-color and the two-color methods (r2 = 0.95 {n=52} and 0.97 {n=64}). The mean bias and percent similarity for the new method compared with the two standard methods were -0.53% (limit of agreement {LOA}:-5.22% to +4.16% with percent similarity of 99.28; and -0.22% with LOA of -3.42% to +2.98%, the percent similarity of 98.15, respectively. CONCLUSIONS: Our FCM method using biotin to label 4 different WBC samples followed by streptavidin staining is reliable for determination of CD4+ T-lymphocytes. Such an approach will significantly reduce the cost for monitoring HIV-infected patients in resource-limited settings.

Correction: Seroprevalence of Zika virus in pregnant women from central Thailand.

[This corrects the article DOI: 10.1371/journal.pone.0257205.].

Seroprevalence of Zika virus in pregnant women from central Thailand.

Zika virus (ZKV) infection in a pregnant woman, especially during the first trimester, often results in congenital anomalies. However, the pathogenic mechanism is unknown and one-third of ZKV infected pregnancies are asymptomatic. Neutralizing antibodies against ZKV has been reported in 70% of Thai adults, but the prevalence among pregnant women is unknown. Currently, vaccines and specific treatments for ZKV are under development. A better understanding of the immune status of pregnant women will increase the success of effective prevention guidelines. The prevalence of ZKV infection in pregnant women in antenatal care clinics was investigated during the rainy season from May to October 2019 at Siriraj Hospital, Bangkok, Thailand. We recruited 650 pregnant women (39.42% first, 52.26% second and 7.36% third trimester) and found that 30.77% had ZKV-specific IgG, and 39.81% had neutralizing antibodies (nAb) against ZKV (titer ≥10). Specific and neutralizing antibody levels varied by maternal age, trimester, and month. We further characterized the cross-reaction between ZKV and the four Dengue virus (DENV) serotypes by focused reduction neutralization test (FRNT) and found that cross-reactions were common. In conclusion, about 60% of pregnant women who living in central Thailand may be at risk of ZKV infection due to the absence of neutralizing antibodies against ZKV. The functions of cross-reactive antibodies between related viral genotypes require further study. These findings have implications for health care monitoring in pregnant women including determining the risk of ZKV infection, assisting the development of a flavivirus vaccine, and informing the development of preventative health policies.

Response of Severe EV71-Infected Patients to Hyperimmune Plasma Treatment: A Pilot Study.

Hand, foot, and mouth disease (HFMD) is highly prevalent in East and Southeast Asia. It particularly affects children under five years of age. The most common causative agents are coxsackieviruses A6 and A16, and enterovirus A71 (EV71). The clinical presentation is usually mild and self-limited, but, in some cases, severe and fatal complications develop. To date, no specific therapy or worldwide vaccine is available. In general, viral infection invokes both antibody and cell-mediated immune responses. Passive immunity transfer can ameliorate the severe symptoms of diseases such as COVID-19, influenza, MERS, and SARS. Hyperimmune plasma (HIP) from healthy donors with high anti-EV71 neutralizing titer were used to transfuse confirmed EV71-infected children with neurological involvement (n = 6). It resulted in recovery within three days, with no neurological sequelae apparent upon examination 14 days later. Following HIP treatment, plasma chemokines were decreased, whereas anti-inflammatory and pro-inflammatory cytokines gradually increased. Interestingly, IL-6 and G-CSF levels in cerebrospinal fluid declined sharply within three days. These findings indicate that HIP has therapeutic potential for HFMD with neurological complications. However, given the small number of patients who have been treated, a larger cohort study should be undertaken. Successful outcomes would stimulate the development of anti-EV71 monoclonal antibody therapy.

DC-SIGN (CD209) mediates dengue virus infection of human dendritic cells.

Dengue virus is a single-stranded, enveloped RNA virus that productively infects human dendritic cells (DCs) primarily at the immature stage of their differentiation. We now find that all four serotypes of dengue use DC-SIGN (CD209), a C-type lectin, to infect dendritic cells. THP-1 cells become susceptible to dengue infection after transfection of DC-specific ICAM-3 grabbing nonintegrin (DC-SIGN), or its homologue L-SIGN, whereas the infection of dendritic cells is blocked by anti-DC-SIGN antibodies and not by antibodies to other molecules on these cells. Viruses produced by dendritic cells are infectious for DC-SIGN- and L-SIGN-bearing THP-1 cells and other permissive cell lines. Therefore, DC-SIGN may be considered as a new target for designing therapies that block dengue infection.

Immune response to influenza vaccination in ESRD patients undergoing hemodialysis vs. hemodiafiltration.

BACKGROUND: On-line hemodiafiltration (HDF) clears more azotemic toxins compared to high-flux hemodialysis (HD). The response to vaccination is impaired in dialysis patients. We wished to determine whether the immune responses to influenza vaccine in dialysis patients treated by HDF were stronger than those treated by HD. MATERIALS AND METHODS: We conducted a prospective cohort study in chronic dialysis patients during the 2016 and 2017 influenza seasons. All participants received a single standard dose of trivalent influenza vaccine, and we studied the elicited humoral immune response by hemagglutination inhibition test, and cell-mediated immune response by enumeration of lymphocyte cellular markers and proliferation assays. RESULTS: We immunized 60 end-stage renal disease (ESRD) patients: 42 (70%) treated with HD and 18 patients (30%) with HDF. The median (interquartile range) age was 65.0 (55.0-74.5) years. All patients developed seroprotection to at least one influenza vaccine strain at one month post-vaccination, and did not differ between groups. By logistic regression, age was the only factor independently associated with seroconversion to all vaccine strains (odds ratio 0.89, 95% confidence interval 0.80-0.98; p = 0.022). Seroprotection to all vaccine strains was sustained for longer in patients treated with HDF, and the results remained the same after age adjustment. For cellular immune response, patients who seroconverted to all vaccine strains had higher CD38+ T cell subpopulations pre-vaccination. Patients treated by HDF had higher lymphocyte proliferation to circulating influenza A strains. CONCLUSIONS: Seroconversion to all influenza vaccine strains was associated with age. Patients treated with HDF demonstrated seroprotection was sustained for longer compared to those treated by HD and greater lymphocyte proliferation to circulating influenza A strains. These encouraging results for HDF require confirmation in a larger dialysis population. TRIAL REGISTRATION: ClinicalTrial.gov, NCT04122222.