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Published on: February 23, 2018
Atypical Antibody Dynamics During Human Coronavirus HKU1 Infections
Ferdyansyah Sechan1,2, Marloes Grobben1,2, Arthur W D Edridge1,2
1Laboratory of Experimental Virology, Department of Medical Microbiology and Infection Prevention, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands.
Insights
Human coronavirus HKU1 (HCoV-HKU1) infections show unusual antibody responses and milder symptoms compared to other endemic coronaviruses. Most infected individuals did not exhibit a significant antibody rise, challenging typical immune response patterns.
Area of Science:
- Virology
- Immunology
- Infectious Diseases
Background:
- Human coronaviruses (HCoVs) are common respiratory pathogens.
- HCoV-HKU1 is one of four endemic HCoVs, often considered less prevalent.
- Previous studies suggest lower incidence and serological detection rates for HCoV-HKU1.
Purpose of the Study:
- To investigate antibody dynamics following PCR-confirmed HCoV-HKU1 infections.
- To compare HCoV-HKU1 infection symptoms with those of other endemic HCoVs.
- To develop and utilize novel assays for HCoV-HKU1 antibody detection.
Main Methods:
- Expressed a new HCoV-HKU1 nucleocapsid protein antigen for ELISA.
- Utilized a spike-based Luminex assay for antibody detection.
- Collected and analyzed serum samples during infection and one month post-infection.
Main Results:
- Over half of HCoV-HKU1-infected subjects showed no antibody rise via ELISA or Luminex assay.
- Some subjects displayed a notable decline in antibody levels.
- HCoV-HKU1-infected individuals reported milder symptoms compared to those infected with other endemic HCoVs.
Conclusions:
- HCoV-HKU1 infections exhibit atypical antibody dynamics, including a lack of serological response in many cases.
- The observed antibody patterns differ significantly from those seen with other endemic HCoVs.
- Milder symptom presentation is characteristic of HCoV-HKU1 infections.
Abstract:
Human coronavirus HKU1 (HCoV-HKU1) is one of the four endemic coronaviruses. It has been suggested that there is a difference in incidence, with PCR-confirmed HCoV-NL63 and HCoV-OC43 infections occurring more commonly, whereas HCoV-HKU1 is the least seen. Lower incidence of HCoV-HKU1 infection has also been observed in serological studies. The current study aimed to investigate antibody dynamics during PCR-confirmed HCoV-HKU1 infections using serum collected during infection and 1 month later. We expressed a new HCoV-HKU1 antigen consisting of both the linker and carboxy-terminal domain of the viral nucleocapsid protein and implemented it in ELISA. We also applied a spike-based Luminex assay on serum samples from PCR-confirmed infections by the four endemic HCoVs. At least half of HCoV-HKU1-infected subjects consistently showed no antibody rise via either assay, and some subjects even exhibited substantial antibody decline. Investigation of self-reported symptoms revealed that HCoV-HKU1-infected subjects rated their illness milder than subjects infected by other HCoVs. In conclusion, HCoV-HKU1 infections reported in this study displayed atypical antibody dynamics and milder symptoms when compared to the other endemic HCoVs.
