Antibodies advance the search for a cure

α-Helical coiled-coil peptide materials for biomedical applications

Self-assembling coiled coils, which occur commonly in native proteins, have received significant interest for the design of new biomaterials-based medical therapies. Considerable effort over recent years has led to a detailed understanding of the self-assembly process of coiled coils, and a diverse collection of strategies have been developed for designing functional materials using this motif. The ability to engineer the interface between coiled coils allows one to achieve variously connected components, leading to precisely defined structures such as nanofibers, nanotubes, nanoparticles, networks, gels, and combinations of these. Currently these materials are being developed for a range of biotechnological and medical applications, including drug delivery systems for controlled release, targeted nanomaterials, 'drug-free' therapeutics, vaccine delivery systems, and others. WIREs Nanomed Nanobiotechnol 2017, 9:e1424. doi: 10.1002/wnan.1424 For further resources related to this article, please visit the WIREs website.

A Case of Long-Term Seronegative Human Immunodeficiency Virus (HIV) Infection: The Importance of the Humoral Response to HIV

Background. Seronegative human immunodeficiency virus (HIV) infections are exceedingly rare but might inform HIV-host physiology.

Methods. We investigate the cause and consequences of a patient infected with HIV who did not mount a humoral response to HIV for 4 years.

Results. The patient was confirmed HIV-uninfected by nucleic acid testing 4 months before rapidly progressing to acquired immune deficiency syndrome. The patient's humoral deficit was specific to HIV: he mounted robust humoral responses to all challenge vaccines including influenza A(H1N1)pdm09 and all T cell-dependent and -independent serotypes in the 23-valent pneumococcal polysaccharide vaccine. The virus had similar gp120 antigenicity to HIV-positive control serum as NL4-3 and YU2 prototype strains. Two human leukocyte antigen alleles associated with rapid progression were identified (B*08 and B*35), and a cytotoxic T-lymphocyte epitope site variant was noted: E277K. Viral decay (t_1/2 ≈ 39 weeks) suggested that relatively long-lived cells were the source of ongoing viremia. Human immunodeficiency virus viremia was not suppressed until after the patient developed a humoral immune response, despite therapeutic antiretroviral levels. No resistance was detected by virtual phenotyping of virus obtained from serum or from gastrointestinal biopsies despite considerable antiretroviral selection pressure.

Conclusions. Ineffective antibody production may be associated with a subgroup of extremely rapid HIV progressors. Although antiretroviral therapy may be sufficient to slow propagation of infection, it appears to be ineffective for HIV viral clearance in the absence of a humoral response.

A new hypothesis on HIV cure

In this opinion article, I provide the rationale for my hypothesis that nucleoside reverse transcriptase inhibitors (NRTIs) may prevent human immunodeficiency virus (HIV) cure by promoting the survival of cells with integrated provirus. If correct, we may be closer to a cure than we realize.

Passive transfer of neutralizing mAb KD-247 reduces plasma viral load in patients chronically infected with HIV-1

OBJECTIVE

Neutralizing antibodies against HIV-1 such as a humanized mAb KD-247 can mediate effector functions that attack infected cells in vitro. However, the clinical efficacy of neutralizing antibodies in infected individuals remains to be determined. We evaluated the safety, tolerability and pharmacokinetics of KD-247 infusion and its effect on plasma HIV-1 RNA load and CD4 T-cell count.

DESIGN AND METHODS

KD-1002 is a phase Ib, double-blind, placebo-controlled, dose-escalation study of KD-247 in asymptomatic HIV-1 seropositive individuals who did not need antiretroviral therapy. Individuals were randomized to 4, 8 or 16 mg/kg KD-247 or placebo, and received three infusions over a 2-week period.

RESULTS

Patients were randomized to receive one of the three doses of KD-247 and the treatment was well tolerated. We observed a significant decrease in HIV RNA in the 8 and 16 mg/kg KD-247 cohorts, with two individuals who achieved more than 1 log reduction of HIV RNA. Two patients in the 16 mg/kg cohort had selections and/or mutations in the V3-tip region that suggested evasion of neutralization. Long-term suppression of viral load was observed in one patient despite a significant decrease in plasma concentration of KD-247, suggesting effects of the antibody other than neutralization or loss of fitness of the evading virus.

CONCLUSION

The results indicate that KD-247 reduces viral load in patients with chronic HIV-1 infection and further clinical trials are warranted.