IgY antibodies for the immunoprophylaxis and therapy of respiratory infections

Abbas, Aymn Talat; El-Kafrawy, Sherif Aly; Sohrab, Sayed Sartaj; Azhar, Esam Ibraheem Ahmed

PMN phagocytosis is a fundamental determinant of an appropriate innate immune response against bacterial infections. Dysfunction in this pathway cause excessive bacterial colonization, leading to parenchymal infection that might develop into sepsis. 105 IgY was observed to be more hydrophobic than mammalian IgG. 75 This hydrophobicity helps the Fc portion to be oriented opposite the antigen, exposing it to Fc-receptor interaction. This feature of increased surface hydrophobicity of the IgY suggests increased phagocytic killing of P. aeruginosa through opsonization ( Figure 1B ) ( Table 1) . 66 A recent clinical study investigating the use of polyclonal anti-Pseudomonas IgY antibodies to prevent P. aeruginosa recurrence in CF patients is underway (ClinicalTrials.gov identifier NCT01455675). 110 Severe acute respiratory syndrome Coronaviruses (CoVs) were only known to cause the common cold in vertebrates until 2002, when severe acute respiratory syndrome (SARS)-CoV emerged in China. 111 The disease rapidly spread worldwide, causing approximately 8000 infections with a 10% mortality rate. 112, 113 During the SARS outbreak in China, passive immunization using sera from recovered SARS patients showed positive results. 80 Anti-SARS coronavirus IgYs were evaluated after isolation from egg yolk of pathogen-free chickens immunized with SARS coronavirus antigen. 80 The generated IgY had a high purity and good biological activity, and IgY antibody was able to neutralize the SARS coronavirus at a dilution of up to 1:640. The results of the neutralization experiments showed high concordance with ELISA results. The efficiency of IgY was not altered after lyophilization, potentially making transport and handling easy for passive immunization and shortterm protection. 80 After evaluation using experimentally infected animal models, anti-SARS IgY produced in this study might be a good candidate for mass production as a SARS-CoV immunotherapeutic (Table 1) .