Controlling IL-7 Injections in HIV-Infected Patients

Polymorphisms in the genes encoding RLR and TLR3 and CMV DNAemia in subjects coinfected with human immunodeficiency virus and cytomegalovirus

Cytomegalovirus (CMV) is a pathogen that is common worldwide and is often present in individuals infected with human immunodeficiency virus (HIV). Pattern recognition receptors (PRRs) are host sensors that activate the immune response against infectious agents. However, it is unclear whether PRR single-nucleotide polymorphisms (SNPs) are associated with the occurrence of CMV DNAemia in subjects coinfected with HIV and CMV. HIV/CMV-coinfected patients with and without CMV DNAemia were recruited for this study. The DDX58 rs10813831 and IFIH1 (rs3747517 and rs1990760) polymorphisms were genotyped using the TaqMan Allelic Discrimination Assay, whereas the DDX58 rs12006123 and TLR3 (rs3775291 and rs3775296) SNPs were analyzed using a polymerase chain reaction restriction fragment length polymorphism (PCR-RFLP) assay. A mutation present in at least one allele of the DDX58 rs12006123 SNP occurred at least two times more frequently in HIV/CMV-coinfected patients with CMV DNAemia than in coinfected subjects without CMV DNAemia (OR, 2.50; 95% CI, 1.33-4.68; p = 0.004, in the dominant model). A higher level of CMV DNAemia was observed in subjects who had the heterozygous (GA) or homozygous recessive (AA) genotype for the DDX58 rs12006123 SNP compared with those who had the wild-type (GG) genotype (p = 0.0003). Moreover, in subjects with a mutation detected in at least one allele of the DDX58 rs12006123 SNP, a lower serum IFN-β concentration was found compared with those who had a wild-type (GG) genotype for this polymorphism (p = 0.024). The DDX58 rs12006123 SNP is associated with CMV DNAemia in HIV/CMV-coinfected patients.

On "Reflections on the concept of optimality of single decision point treatment regimes"

This is a discussion of "Reflections on the concept of optimality of single decision point treatment regimes" by Trung Dung Tran, Ariel Alonso Abad, Geert Verbeke, Geert Molenberghs, and Iven Van Mechelen. The authors propose a thoughtful consideration of optimization targets and the implications of such targets for the resulting optimal treatment rule. However, we contest the assertation that targets of optimization have been overlooked and suggest additional considerations that researchers must contemplate as part of a complete framework for learning about optimal treatment regimes.

Modeling antibody dynamics following herpes zoster indicates that higher varicella-zoster virus viremia generates more VZV-specific antibodies

Introduction

Studying antibody dynamics following re-exposure to infection and/or vaccination is crucial for a better understanding of fundamental immunological processes, vaccine development, and health policy research.

Methods

We adopted a nonlinear mixed modeling approach based on ordinary differential equations (ODE) to characterize varicella-zoster virus specific antibody dynamics during and after clinical herpes zoster. Our ODEs models convert underlying immunological processes into mathematical formulations, allowing for testable data analysis. In order to cope with inter- and intra-individual variability, mixed models include population-averaged parameters (fixed effects) and individual-specific parameters (random effects). We explored the use of various ODE-based nonlinear mixed models to describe longitudinally collected markers of immunological response in 61 herpes zoster patients.

Results

Starting from a general formulation of such models, we study different plausible processes underlying observed antibody titer concentrations over time, including various individual-specific parameters. Among the converged models, the best fitting and most parsimonious model implies that once Varicella-zoster virus (VZV) reactivation is clinically apparent (i.e., Herpes-zoster (HZ) can be diagnosed), short-living and long-living antibody secreting cells (SASC and LASC, respectively) will not expand anymore. Additionally, we investigated the relationship between age and viral load on SASC using a covariate model to gain a deeper understanding of the population's characteristics.

Conclusion

The results of this study provide crucial and unique insights that can aid in improving our understanding of VZV antibody dynamics and in making more accurate projections regarding the potential impact of vaccines.

Modeling the immune response to HIV infection

The interplay between immune response and HIV is intensely studied via mathematical modeling, with significant insights but few direct answers. In this short review, we highlight advances and knowledge gaps across different aspects of immunity. In particular, we identify the innate immune response and its role in priming the adaptive response as ripe for modeling. The latter have been the focus of most modeling studies, but we also synthesize key outstanding questions regarding effector mechanisms of cellular immunity and development of broadly neutralizing antibodies. Thus far, most modeling studies aimed to infer general immune mechanisms; we foresee that significant progress will be made next by detailed quantitative fitting of models to data, and prediction of immune responses.