Antibodies to coronaviruses are higher in older compared with younger adults and binding antibodies are more sensitive than neutralizing antibodies in identifying coronavirus-associated illnesses.

Human coronaviruses (HCoV) are common causes of respiratory illnesses (RI) despite preexisting humoral immunity. Sera were obtained near the onset of RI and 3 to 4 weeks later as part of a prospective study of 200 subjects evaluated for RI from 2009 to 2013. Antibodies against common HCoV strains were measured by enzyme-linked immunosorbent assay and neutralization assay comparing older adults with cardiopulmonary diseases (99 subjects) to younger, healthy adults (101 subjects). Virus shedding was detected in respiratory secretions by polymerase chain reaction. Of 43 HCoV-associated illnesses, 15 (35%) occurred in 14 older adults (aged ≥60 years) and 28 (65%) in 28 younger adults (aged 21-40 years). Binding and neutralizing antibodies were higher in older adults. Only 16 (35.7%) of RI with increases in binding antibodies also had increases in neutralizing antibodies to HCoV. Increases in binding antibodies with RI were more frequent than increased neutralizing antibodies and virus shedding, and more frequent in younger compared to older adults. Functional neutralizing antibodies were not stimulated as often as binding antibodies, explaining in part a susceptibility to reinfection with HCoV. Monitoring binding antibodies may be more sensitive for the serologic detection of HCoV infections.

Interpatient mutational spectrum of human coronavirus-OC43 revealed by illumina sequencing.

Human coronaviruses (HCoV) are RNA viruses that cause respiratory tract infections with viral replication of limited duration. The host and viral population heterogeneity could influence clinical phenotypes. Employing long RT-PCR with Illumina sequencing, we quantified the gene mutation load at 0.5% mutation frequency for the 4529 bp-domain spanning the Spike gene (4086 bp) of HCoV-OC43 in four upper respiratory clinical specimens obtained during acute illness. There were a total of 121 mutations for all four HCoV samples with the average number of mutations at 30.3 ± 10.2, which is significantly higher than that expected from the Illumina sequencing error rate. There were two mutation peaks, one at the 5' end and the other near position 1 550 in the S1 subunit. Two coronavirus samples were genotype B and two were genotype D, clustering with HCoV-OC43 strain AY391777 in neighbor-joining tree phylogenetic analysis. Nonsynonymous mutations were 76.1 ± 14% of mutation load. Although lower than other RNA viruses such as hepatitis C virus, HCoV-OC43 did exhibit quasi-species. The rate of nonsynonymous mutations was higher in the HCoV-OC43 isolates than in hepatitis C (HCV) virus genotype 1a isolates analyzed for comparison in this study. These characteristics of HCoV-OC43 may affect viral replication dynamics, receptor binding, antigenicity, evolution, transmission, and clinical illness.

Coronavirus and Other Respiratory Illnesses Comparing Older with Young Adults.

BACKGROUND: Study of human coronavirus and other virus-associated respiratory illnesses is needed to describe their clinical effects on chronically ill, older adults. METHODS: A prospective study during 2009 to 2013 clinically assessed acute respiratory illnesses soon after onset and 3 to 4 weeks later in patients aged ≥60 years with chronic lung and heart diseases (group 1, 100 subjects) and healthy adults aged 18 to 40 years (group 2, 101 subjects). Respiratory secretions were tested for nucleic acids of a panel of respiratory viruses. An increase in antibody titer was assessed for 4 coronavirus strains. RESULTS: Virus-associated illnesses (29 [39.1%] of 74 illnesses in group 1 and 59 [48.7%] of 121 illnesses in group 2) occurred in all calendar quarters, most commonly in the first and fourth quarters. Coronaviruses (group 1: 14 [18.9%] illnesses; group 2: 26 [21.5%] illnesses) and enteroviruses/rhinoviruses (group 1: 14 [18.9%] illnesses; group 2: 37 [30.6%] illnesses) were most common. Virus co-infections occurred in 10 illnesses. Illnesses with 9 to 11 symptoms were more common in group 1 (17 [23.0%]) than in group 2 (15 [12.4%]) (P < .05). Compared with group 2, more group 1 subjects reported dyspnea, more severe disease of longer duration, and treatment for acute illness with prednisone and antibiotics. Coronavirus-associated illnesses (percent of illnesses, group 1 vs group 2) were characterized by myalgias (21% vs 68%, P < .01), chills (50% vs 52%), dyspnea (71% vs 24%, P < .01), headache (64% vs 72%), malaise (64% vs 84%), cough (86% vs 68%), sputum production (86% vs 60%), sore throat (64% vs 80%), and nasal congestion (93% vs 96%). CONCLUSIONS: Respiratory illnesses were commonly associated with coronaviruses and enteroviruses/rhinoviruses affecting chronically ill, older patients more than healthy, young adults.

Prevalence of antibodies to four human coronaviruses is lower in nasal secretions than in serum.

Little is known about the prevalence of mucosal antibodies induced by infection with human coronaviruses (HCoV), including HCoV-229E and -OC43 and recently described strains (HCoV-NL63 and -HKU1). By enzyme-linked immunosorbent assay, we measured anti-HCoV IgG antibodies in serum and IgA antibodies in nasal wash specimens collected at seven U.S. sites from 105 adults aged 50 years and older (mean age, 67 ± 9 years) with chronic obstructive pulmonary disease. Most patients (95 [90%]) had at least one more chronic disease. More patients had serum antibody to each HCoV strain (104 [99%] had antibody to HCoV-229E, 105 [100%] had antibody to HCoV-OC43, 103 [98%] had antibody to HCoV-NL63, and 96 [91%] had antibody to HCoV-HKU1) than had antibody to each HCoV strain in nasal wash specimens (12 [11%] had antibody to HCoV-229E, 22 [22%] had antibody to HCoV-OC43, 8 [8%] had antibody to HCoV-NL63, and 31 [31%] had antibody to HCoV-HKU1), respectively (P < 0.0001). The proportions of subjects with IgA antibodies in nasal wash specimens and the geometric mean IgA antibody titers were statistically higher for HCoV-OC43 and -HKU1 than for HCoV-229E and -NL63. A higher proportion of patients with heart disease than not had IgA antibodies to HCoV-NL63 (6 [16%] versus 2 [3%]; P = 0.014). Correlations were highest for serum antibody titers between group I strains (HCoV-229E and -NL63 [r = 0.443; P < 0.0001]) and between group II strains (HCoV-OC43 and -HKU1 [r = 0.603; P < 0.0001]) and not statistically significant between HCoV-NL63 and -OC43 and between HCoV-NL63 and -HKU1. Patients likely had experienced infections with more than one HCoV strain, and IgG antibodies to these HCoV strains in serum were more likely to be detected than IgA antibodies to these HCoV strains in nasal wash specimens.

Cellular immune responses in asymptomatic human immunodeficiency virus type 1 (HIV-1) infection and effects of vaccination with recombinant envelope glycoprotein of HIV-1.

Effects of human immunodeficiency virus type 1 (HIV-1) recombinant envelope glycoprotein vaccines on cell-mediated immune (CMI) responses were assessed in HIV-1-infected patients. Asymptomatic, antiretroviral-treatment-naïve, HIV-1-infected patients with CD4(+) T-cell counts greater than 400/microl received multiple intramuscular injections of HIV-1 IIIB recombinant envelope glycoprotein (rgp160) vaccine or HIV-1 MN recombinant envelope glycoprotein (rgp120) vaccine (eight patients, referred to as the HIV-1 vaccinees) or placebo or hepatitis B vaccine (three patients, referred to as the controls). Lymphocyte proliferation in response to HIV-1 envelope glycoproteins, both homologous and heterologous to the HIV-1 immunogens, was absent prior to study treatment in all patients but increased significantly during the vaccination series and after the final vaccination in HIV-1 vaccinees (P < 0.05) and remained absent in control patients. In flow cytometric analyses of intracellular cytokines, T-cell receptor stimulation with an anti-CD3 antibody induced gamma interferon (IFN-gamma) expression by activated CD4(+) and CD8(+) lymphocytes at greater frequencies than did stimulation with recombinant envelope glycoprotein and p24 of HIV-1 (P < 0.05). Mean frequencies of HIV-1 envelope glycoprotein-stimulated, activated intra-cellular IFN-gamma-producing CD4(+) and CD8(+) lymphocytes and of interleukin-2-producing CD4(+) lymphocytes did not increase after vaccination, but cytokine-producing cells were detectable in some patients. Comparing pre- to post-HIV-1 vaccination time points, changes in frequencies of activated, IFN-gamma-producing CD4(+) cells correlated inversely with changes in lymphocyte proliferation in response to recombinant envelope glycoprotein in HIV-1 vaccinees (P < 0.05). Increased CMI responses to HIV-1 envelope glycoprotein measured by lymphocyte proliferation were associated with HIV-1 recombinant envelope glycoprotein vaccines.

Binding of antibodies to human immunodeficiency virus type 1 (HIV-1)-infected lymphocytes elicited by vaccines and by natural infection.

Binding of antibodies to oligomeric envelope glycoprotein of R5-tropic primary isolates of human immunodeficiency virus type 1 (HIV-1) was studied by flow cytometry using sera from HIV-1 vaccine recipients and clade B and C HIV-1-infected patients, and monoclonal and polyclonal antibodies to neutralizing epitopes of HIV-1. Vaccine recipients received recombinant canarypox virus vaccine expressing HIV-1 gene products, and SF-2 recombinant gp120 subunit vaccine. Anti-gp120 neutralizing antibodies including human monoclonal antibody 2G12 and goat polyclonal anti-serum to V3 loop peptide [peptide T1-SP10MN(A)] bound to HIV-1-infected cells. Sera from vaccine recipients bound to HIV-1-infected cells, but at levels lower than did infected patient sera.