Longitudinal Assessment of Virological Failure and Antiretroviral Drug Resistance among Treatment-naive Subjects Living with HIV

INTRODUCTION

Human immunodeficiency virus (HIV) infection, the etiological agent of acquired immunodeficiency syndrome (AIDS), is a serious public health issue. Therapeutic measures have been successful in increasing the survival and improving the quality of life. However, some treatment-naive subjects living with HIV present resistance-associated mutations as a result of late diagnosis and/or mutant strain infections. The objective of this study was to identify the virus genotype and assess the antiretroviral resistance profile based on the results of HIV genotyping in treatment-naive subjects living with HIV, after six months of taking antiretroviral therapy.

METHODS

This was a prospective cohort study on treatment-naive adults living with HIV attending a specialized outpatient clinic in southern Santa Catarina State, Brazil. The participants were interviewed and had blood samples drawn. The genotypic antiretroviral drug resistance profile was examined in patients with detectable viral loads.

RESULTS

65 treatment-naive subjects living with HIV were recruited for this study. After six months of taking antiretroviral therapy, resistance-associated mutations were observed in 3 (4.6%) subjects living with HIV.

CONCLUSION

Subtype C was identified as the circulating subtype in southern Santa Catarina State, and L10V, K103N, A98G, and Y179D were the most common mutations found in treatment-naive subjects.

[Analysis and Control of Viral Infection Mechanisms by Glycobiology]

Glycans are present in all living organisms, including viruses, bacteria, and animals, and perform various biological functions. The author has been studying influenza viruses' glycan usage mechanisms, particularly the functional analysis of neuraminidase (NA), a viral sialidase. The authors recently focused on influenza virus NAs' high sialidase activity with the aim of using sialidase activity detection as a virus detection technology. Using the probe BTP3-Neu5Ac, allows fluorescent imaging of sialidase activity, we created a new technique for easy, rapid, and high sensitivity fluorescent imaging of virus-infected cells. The detection of viruses using BTP3-Neu5Ac does not require specific antibodies and can be performed by simply adding reagents. Furthermore, fluorescence imaging of sialidase as a virus detection technology has many advantages, including isolating viruses from fluorescently imaged infected cells. This detection technique is easy to use in basic research and hygiene testing, where viral culture is conducted and is expected to be widely used.

A Single Point Mutation in the Rhinovirus 2B Protein Reduces the Requirement for Phosphatidylinositol 4-Kinase Class III Beta in Viral Replication

Rhinoviruses (RVs) replicate on cytoplasmic membranes derived from the Golgi apparatus. They encode membrane-targeted proteins 2B, 2C, and 3A, which control trafficking and lipid composition of the replication membrane. The virus recruits host factors for replication, such as phosphatidylinositol 4 (PI4)-kinase 3beta (PI4K3b), which boosts PI4-phosphate (PI4P) levels and drives lipid countercurrent exchange of PI4P against cholesterol at endoplasmic reticulum-Golgi membrane contact sites through the lipid shuttling protein oxysterol binding protein 1 (OSBP1). We identified a PI4K3b inhibitor-resistant RV-A16 variant with a single point mutation in the conserved 2B protein near the cytosolic carboxy terminus, isoleucine 92 to threonine (termed 2B[I92T]). The mutation did not confer resistance to cholesterol-sequestering compounds or OSBP1 inhibition, suggesting invariant dependency on the PI4P/cholesterol lipid countercurrents. In the presence of PI4K3b inhibitor, Golgi reorganization and PI4P lipid induction occurred in RV-A16 2B[I92] but not in wild-type infection. The knockout of PI4K3b abolished the replication of both the 2B[I92T] mutant and the wild type. Doxycycline-inducible expression of PI4K3b in PI4K3b knockout cells efficiently rescued the 2B[I92T] mutant and, less effectively, wild-type virus infection. Ectopic expression of 2B[I92T] or 2B was less efficient than that of 3A in recruiting PI4K3b to perinuclear membranes, suggesting a supportive rather than decisive role of 2B in recruiting PI4K3b. The data suggest that 2B tunes the recruitment of PI4K3b to the replication membrane and allows the virus to adapt to cells with low levels of PI4K3b while still maintaining the PI4P/cholesterol countercurrent for establishing Golgi-derived RV replication membranes.IMPORTANCE Human rhinoviruses (RVs) are the major cause of the common cold worldwide. They cause asthmatic exacerbations and chronic obstructive pulmonary disease. Despite recent advances, the development of antivirals and vaccines has proven difficult due to the high number and variability of RV types. The identification of critical host factors and their interactions with viral proteins and membrane lipids for the establishment of viral replication is a basis for drug development strategies. Our findings here shed new light on the interactions between nonstructural viral membrane proteins and class III phosphatidylinositol 4 kinases from the host and highlight the importance of phosphatidylinositol 4 phosphate for RV replication.

The second generation of HIV-1 vertically exposed infants: a case series from the Italian Register for paediatric HIV infection

BACKGROUND

In the Highly Active Antiretroviral Therapy (HAART) era, the prognosis of children perinatally infected with HIV-1 has significantly improved, so the number of perinatally-infected females entering child-bearing age and experiencing motherhood is increasing.

METHODS

A description of the medical history and pregnancy outcomes of women with perinatal acquired HIV-1 infection enrolled in the Italian Register for HIV infection in Children.

RESULTS

Twenty-three women had 29 pregnancies. They had started an antiretroviral therapy at a median of 7.7 years (interquartile range, IQR 2.3 - 11.4), and had experienced a median of 4 therapeutic regimens (IQR 2-6). Twenty women (87%) had taken zidovudine (AZT) before pregnancy, in 14 cases as a starting monotherapy. In 21 pregnancies a protease inhibitor-based regimen was used. At delivery, the median of CD4+ T lymphocytes was 450/μL (IQR 275-522), and no viral load was detectable in 15 cases (reported in 21 pregnancies). Twenty-eight children were delivered through caesarean section (median gestational age: 38 weeks, IQR 36-38, median birth weight: 2550 grams, IQR 2270 - 3000). Intravenous AZT was administered during delivery in 26 cases. All children received oral AZT (median: 42 days, IQR 31 - 42), with no adverse events reported. No child acquired HIV-1 infection.

CONCLUSIONS

Despite a long history of maternal infection, multiple antiretroviral regimens and, perhaps, the development of drug-resistant viruses, the risk of mother-to-child transmission does not seem to have increased among the second-generation of HIV-1 exposed infants.

Update on successes and challenges regarding mother-to-child transmission of HIV

PURPOSE OF REVIEW

There is an unprecedented global commitment to reverse the pediatric HIV epidemic by making prevention of mother-to-child transmission (PMTCT) services accessible in all countries. This review outlines the successes made and the challenges that remain.

RECENT FINDINGS

In resource-rich countries, mother-to-child transmission rates of HIV as low as 1% have been achieved. The efficacy of short-course antiretrovirals for PMTCT in Africa is estimated at 50%. Coinfections with herpes simplex virus type 2, other sexually transmitted infections resulting in genital ulcers, and endemic infectious diseases (e.g., malaria) may increase the risk of mother-to-child transmission of HIV. Vertical transmission of drug-resistant viruses has been reported; the prevalence and effect of transmitted resistant virus on treatment outcomes are under investigation. Obstacles facing PMTCT in resource-limited countries include the lack of healthcare infrastructure, limited manpower, and competing public health priorities with the limited healthcare budget.

SUMMARY

Although the birth of an HIV-infected child in a resource-rich country is now a sentinel health event, in most resource-limited countries the birth of an HIV-infected child continues to be the status quo. Comprehensive PMTCT, including antiretroviral treatment for HIV-infected women and children, should be paramount in resource-limited countries.