RAGE and CCR7 mediate the transmigration of Zika-infected monocytes through the blood-brain barrier.

Details of the "Trojan Horse" mechanism by which Zika virus (ZIKV) crosses the blood-brain barrier (BBB) remain unclear. However, the migration of ZIKV-infected monocytes to the brain is thought to be dependent on both pattern-recognition and chemokine receptors. In this study, we investigated whether the migration of ZIKV-infected MonoMac-1 (MM-1) cells through the BBB is dependent on chemokine receptor 7 (CCR7) and receptor for advanced glycation end (RAGE); we also determined whether high mobility group box protein 1 (HMGB1) could facilitate the permeabilization of endothelial cells. We demonstrated that ZIKV infects MM-1 cells, leading to milieu accumulation of HMGB1. Our results suggest that HMGB1 is involved in the dysregulation of primary human brain microvascular endothelial cell junction markers. Our results also indicate that the migration of ZIKV-infected monocytes is dependent on chemokine ligand 19 (CCL19), the natural ligand of CCR7, in conditions recapitulating inflammation. RAGE-dependent migration of ZIKV-infected cells declined during transmigration assays in the presence of RAGE receptor antagonist FPS-ZM1. Understanding the molecular role of monocyte trafficking during ZIKV infections could facilitate the development of new therapeutic strategies to prevent the deleterious consequences of ZIKV neuroinfection.

Progress with Scale-Up of HIV Viral Load Monitoring - Seven Sub-Saharan African Countries, January 2015-June 2016.

The World Health Organization (WHO) recommends viral load testing as the preferred method for monitoring the clinical response of patients with human immunodeficiency virus (HIV) infection to antiretroviral therapy (ART) (1). Viral load monitoring of patients on ART helps ensure early diagnosis and confirmation of ART failure and enables clinicians to take an appropriate course of action for patient management. When viral suppression is achieved and maintained, HIV transmission is substantially decreased, as is HIV-associated morbidity and mortality (2). CDC and other U.S. government agencies and international partners are supporting multiple countries in sub-Saharan Africa to provide viral load testing of persons with HIV who are on ART. This report examines current capacity for viral load testing based on equipment provided by manufacturers and progress with viral load monitoring of patients on ART in seven sub-Saharan countries (Côte d'Ivoire, Kenya, Malawi, Namibia, South Africa, Tanzania, and Uganda) during January 2015-June 2016. By June 2016, based on the target numbers for viral load testing set by each country, adequate equipment capacity existed in all but one country. During 2015, two countries tested >85% of patients on ART (Namibia [91%] and South Africa [87%]); four countries tested <25% of patients on ART. In 2015, viral suppression was >80% among those patients who received a viral load test in all countries except Côte d'Ivoire. Sustained country commitment and a coordinated global effort is needed to reach the goal for viral load monitoring of all persons with HIV on ART.

Scale-up of HIV Viral Load Monitoring--Seven Sub-Saharan African Countries.

To achieve global targets for universal treatment set forth by the Joint United Nations Programme on human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) (UNAIDS), viral load monitoring for HIV-infected persons receiving antiretroviral therapy (ART) must become the standard of care in low- and middle-income countries (LMIC) (1). CDC and other U.S. government agencies, as part of the President's Emergency Plan for AIDS Relief, are supporting multiple countries in sub-Saharan Africa to change from the use of CD4 cell counts for monitoring of clinical response to ART to the use of viral load monitoring, which is the standard of care in developed countries. Viral load monitoring is the preferred method for immunologic monitoring because it enables earlier and more accurate detection of treatment failure before immunologic decline. This report highlights the initial successes and challenges of viral load monitoring in seven countries that have chosen to scale up viral load testing as a national monitoring strategy for patients on ART in response to World Health Organization (WHO) recommendations. Countries initiating viral load scale-up in 2014 observed increases in coverage after scale-up, and countries initiating in 2015 are anticipating similar trends. However, in six of the seven countries, viral load testing coverage in 2015 remained below target levels. Inefficient specimen transport, need for training, delays in procurement and distribution, and limited financial resources to support scale-up hindered progress. Country commitment and effective partnerships are essential to address the financial, operational, technical, and policy challenges of the rising demand for viral load monitoring.

HIV type 1 drug resistance in adults receiving highly active antiretroviral therapy in Abidjan, Côte d'Ivoire.

As antiretroviral therapy continues to scale-up in developing countries, there is concern that high levels of HIV drug resistance to antiretroviral drugs will occur. Here we describe rates of emergence of HIV-1 drug resistance and factors associated with their occurrence among adults who received antiretroviral therapy (ART) for >1 year through the Côte d'Ivoire national drug access program from 1998 to 2003. To detect genotypic drug resistance, we sequenced all 1- and 2-year specimens with detectable HIV RNA viral load. To assess factors associated with emerging drug resistance, we used log normal regression with interval censoring, including covariates in the model for self-reported drug adherence, CD4 cell count, and HIV viral load at therapy initiation, and observed changes in these measures, type of prescribed ART drugs, diagnoses of opportunistic illness, and demographic characteristics. An estimated 14.2% [95% confidence limits (CL) 11.7, 16.9] and 26.6% (95% CL 22.7, 30.8) of patients developed primary drug-resistant mutations within 1 year and 2 years after initiation of therapy, respectively. Factors associated with drug resistance included drug nonadherence, partial or lack of viral suppression, higher viral load or lower CD4 at initiation of therapy, and initiation of ART with what is now considered substandard dual combination therapy. Our results demonstrate the need to strengthen adherence and continuity in treatment programs in order to avoid interruption of ART drugs. Treatment programs should pay attention to indicators of emerging drug resistance: incomplete or lesser decreases in viral load or increases in CD4 cell counts following initiation of therapy, and the occurrence of AIDS opportunistic illnesses.

Virologic and immunologic responses to antiretroviral therapy among HIV-1 and HIV-2 dually infected patients: case reports from Abidjan, Côte d'Ivoire.

In four of five HIV-1 and HIV-2 dually infected patients treated with efavirenz-based therapy, viral load was undetectable for HIV-1 only, with limited increase in CD4+ counts. Both viral loads were undetectable and CD4+ counts increased in one patient treated with protease inhibitor regimen. Specific guidelines for treating HIV-dually infected patients are needed that should avoid the use of non-nucleoside reverse transcriptase inhibitors.

Virologic and immunologic response to antiretroviral therapy and predictors of HIV type 1 drug resistance in children receiving treatment in Abidjan, Côte d'Ivoire.

We describe changes in HIV-1 viral load, CD4+ T cell percentage, and incidence of drug resistance and factors associated with drug resistance for 134 children receiving antiretroviral therapy (ART) for approximately 1 year in Abidjan. Between August 1998 and September 2003, ART was initiated for 395 HIV-infected children ages 0-15 years in the Côte d'Ivoire national drug access initiative. All 1-year samples with detectable HIV RNA >1000 copies/ml were tested for HIV-1 drug resistance and changes in viral load and CD4+ T cell counts were also determined. At treatment initiation, 80% of children had CD4+ T cell percentages <15% and a median viral RNA load of 5.6 log copies/ml. The median age at treatment initiation was 7 years with only 25% of patients less than 4 years of age. Of the 134 children receiving therapy, 72 (54%) had undetectable viral load. The estimated 1-year viral load decline was 1.9 log10 copies/ml and the CD4+ T cell percentage increase was 10.9%. The estimated 1-year cumulative probability for developing any class of drug resistance was 0.44 (95% CI, 0.35, 0.53). In a multivariate analysis, the magnitude of virologic response to therapy was inversely associated with development of drug resistance. Children with less CD4+ T cell rise from baseline values and the use of dual therapy were also associated with the development of drug resistance. Guidelines are needed for the treatment of pediatric HIV infection in Africa in order to minimize the occurrence of drug resistance and enhance better virologic, immunologic, and clinical outcomes.

Performance of drug-resistance genotypic assays among HIV-1 infected patients with predominantly CRF02_AG strains of HIV-1 in Abidjan, Cote d'Ivoire.

OBJECTIVE: We evaluated the performance of three genotypic assays to detect resistant mutations among HIV-1 infected patients with known antiretroviral drug resistance profile in Abidjan, Cote d'Ivoire, most of whom had the circulating recombinant form (CRF02_A/G) of HIV-1. METHODS: The 56 patients analyzed in this study were enrolled in a pilot program to make available antiretroviral therapy (ART) to HIV-infected patients in Abidjan through the UNAIDS Drug Access Initiative (DAI). These patients had failed ART, as demonstrated by rebound in RNA viral load. Their plasma samples had been previously analyzed for ART genotypic drug-resistance by VircoGEN (Mechelen, Belgium) and were known to have primary and secondary resistance mutations, and also had phenotypic drug-resistance by a recombinant virus assay technology (Mechelen, Belgium). The two assays we evaluated were: VircoGEN, TruGene HIV-1, and ViroSEQ HIV-1 assays. RESULTS: For the reverse transcriptase gene, all 27 samples that had the T215Y/F mutation were detected by VircoGEN , ViroSEQ, and TrueGene. All 19 (100%) samples that had the K70R/E mutation detected by VircoGEN were detected by ViroSEQ, and 18 (94.7%) by TrueGene. All ten samples with the M184V mutation, three with the K65R, two with the G190A mutation, one with the K103N mutation, and one with the V75T mutation were detected similarly by all three assays. For the protease gene, all three assays detected the I84V (n = 1), M46I (n = 1), and L90M (n = 1) mutations. CONCLUSION: These results suggest that any of these assays should be considered for monitoring the occurrence of drug resistance among HIV-infected patients receiving antiretroviral therapy in West Africa.

Differences in HIV-2 plasma viral load and immune activation in HIV-1 and HIV-2 dually infected persons and those infected with HIV-2 only in Abidjan, Côte D'Ivoire.

OBJECTIVE: To determine whether blood plasma levels of HIV-2 RNA viral loads and immune activation markers differ between persons infected with HIV-2 only and those dually infected with HIV-1 and HIV-2. METHODS: Between September 1996 and February 2000, we collected, analyzed and compared levels of HIV-2 RNA in plasma and immune activation markers among 52 persons infected with HIV-2 alone and 75 with confirmed dual infection. We also compared viral load and immune activation in patients who were infected with HIV-1 only and those who were dually infected. RESULTS: When we conducted a CD4 T-cell count-stratified multivariate analysis of HIV-2 viral load, controlling for difference in CD4 T-cell counts, age and sex: at < 200 x 10 CD4 T cells/l, HIV-2 viral load was 2.0 log10 copies/ml lower in dually infected patients than in HIV-2 only patients (P < 0.0001). At CD4 T-cell counts between 200 x 10 and 500 x 10/l, HIV-2 viral load was 0.3 log10 copies/ml lower in dually infected patients (P = 0.45). However, at CD4 T-cells counts > 500 x 10/l, HIV-2 viral load was 0.9 log10 copies/ml higher in dually infected patients (P < 0.0001). Dually infected persons with undetectable HIV-2 viral loads had significantly higher median levels of CD8 T cells expressing CD38 (P < 0.001) and HLA-DR (P = 0.01) than HIV-2 only infected patients. CONCLUSION: These results suggest that in dual infection, the level of HIV-2 replication depends on the immune status of the patients, with HIV-1 out-replicating HIV-2 as disease progress.

HIV-specific T helper responses and frequency of exposure among HIV-exposed seronegative female sex workers in Abidjan, Cote d'Ivoire.

BACKGROUND: The characteristics of human immunodeficiency virus (HIV) exposure that determine the induction of HIV-specific T cells and, in particular, T helper cells are not well understood. METHODS: HIV-1 Gag- and Env-specific T helper cells were analyzed by use of an interferon (IFN)- gamma enzyme-linked immunosorbent spot (ELISPOT) assay and by use of IFN- gamma secretion flow cytometry. Responses among HIV-exposed seronegative (ESN) female sex workers (FSWs) were compared with responses among HIV-seropositive FSWs and HIV-seronegative female blood donors from Abidjan, Cote d'Ivoire. RESULTS: Low-level ELISPOT responses were detected in 8 (20%) of 40 ESN FSWs. All of 25 HIV-seropositive FSWs had high-level ELISPOT responses. HIV-specific CD4+ T cells and, occasionally, CD8+ T cells were detected by secretion flow cytometry in 3 (38%) of 8 ESN FSWs and in 4 (80%) of 5 HIV-seropositive FSWs. ESN FSWs with detectable HIV-specific T helper responses had more clients on the previous working day (P=.02) and more exposures to HIV per month (P=.02) and tended to have a lower total duration of commercial sex work. CONCLUSIONS: These findings demonstrate that the presence of HIV-specific T helper cells in ESN FSWs is associated with the frequency, rather than the duration, of exposure to HIV. The data may have important implications for the evaluation of HIV vaccine efficacy.

Changes in levels of immune activation and reconstitution markers among HIV-1-infected Africans receiving antiretroviral therapy.

OBJECTIVE: To describe changes in immune activation and reconstitution markers among HIV-1-infected patients receiving antiretroviral therapy (ART) in Abidjan, Côte d'Ivoire. METHODS: Between November 1998 and February 2001, we analyzed changes in immune activation and reconstitution markers among 52 patients. Good virologic responders (n = 26) were defined as those who had suppressed and maintained plasma viral load (VL) below the detection limit of the assay for at least 12 months. Poor virologic responders (n = 26) were defined as those with a detectable VL at 6 and 12 months after beginning ART. RESULTS: Of the 26 good virologic responders, 20 (77%) were on highly active antiretroviral therapy (HAART) compared with one (4%) of the poor responders. Among the 26 good responders, baseline median levels of CD38+CD8+ T cells were elevated, but had decreased significantly at 6 months (P < 0.001) and at 12 months of therapy (P < 0.001). Median levels of HLA-DR+CD8+ T cells also decreased from baseline at 6 months (P < 0.001) and at 12 months of therapy (P < 0.001). Levels of CD62L+CD4+ T cells increased steadily during the 6 and 12 months of therapy and reached levels observed among HIV-negative blood donors (P = 0.07). Among the 26 poor responders, median levels of CD38+CD8+ T cells decreased significantly at 12 months of therapy (P = 0.006), but were higher than levels in blood donors (P = 0.005). Levels of HLA-DR+CD8+ T cells decreased significantly at 12 months of therapy (P < 0.001). Levels of CD62L+CD4+ decreased over time. CONCLUSION: Our results suggest that HAART can be successfully used in African populations with elevated baseline immune activation markers.

Antiretroviral therapy in HIV-2-infected patients: changes in plasma viral load, CD4+ cell counts, and drug resistance profiles of patients treated in Abidjan, Côte d'Ivoire.

OBJECTIVE: To describe changes in plasma viral load, CD4+ cell counts, and drug resistance profiles of HIV-2-infected patients receiving antiretroviral (ARV) therapy in Abidjan, Côte d'Ivoire. METHODS: Consecutive blood samples were collected from 18 HIV-2-infected ARV-naive patients who had received ARV therapy in the UNAIDS drug access initiative (UNAIDS-DAI) in Abidjan between August 1998 and July 2000. Changes in HIV-2 plasma viral load, CD4+ cell counts, and genotypic and phenotypic drug resistance testing were determined. RESULTS: At baseline, 11 (61%) of the 18 patients initiated highly active antiretroviral therapy (HAART) and seven (39%) received dual therapy. No significant change in median viral load was observed at 2 months (P = 0.09), at 6 months (P = 0.06), and at 12 months of therapy (P = 0.26). No significant increase in CD4+ cell counts was observed at 12 months (P = 0.10). All four patients on indinavir-containing HAART had undetectable viral loads at 2-4 months of therapy. However, none of seven patients on nelfinavir-containing HAART had a substantial decrease in viral load. Viruses from 14 patients were analyzed, 12 of which (86%) had at least one primary resistance mutation that is known to confer resistance to HIV-1 virus. Three patients had the multi-drug-resistant mutation, Q151M, two of whom showed reduced susceptibility to zidovudine, didanosine, stavudine and zalcitabine. CONCLUSION: Our limited findings show that nelfinavir-containing regimens may have limited virologic benefit to HIV-2-infected patients.