IgG2 represent 22% of serum proteins and bind to FC receptor with very low affinity. Therefore this is a good choice if you need a stable and soluble antibody.
IgG2 is the most efficient subclass for providing protection against pneumococcal pathogens. We hypothesised that some individuals may be unable to mount an effective pneumococcal capsular polysaccharide (PCP) IgG2 response despite having a normal PCP IgG concentration (PCP IgG2 deficient). The median pre-vaccination PCP IgG2 concentration was significantly lower in individuals referred for immunological investigation compared to healthy controls (2.8 mg/L range, 95% CI 1.1-88 vs 29.5mg/L, 95% CI 13.5-90, p=0.0002). PCP IgG:IgG2 ratios were significantly higher for the referral population than for healthy controls suggesting the increased production of PCP specific subclasses other than IgG2. The percentage of individuals with PCP IgG2 deficiency was significantly higher in referral groups compared to controls (31% vs 5%; p=0.0009) and in an individual with PCP IgG2 deficiency, the balance of PCP specific IgG subclass antibodies post vaccination changed from IgG2>IgG1>IgG3>IgG4 to IgG1>IgG3>IgG2>IgG4. The median PCP IgG2 concentration in those with PCP IgG2 deficiency was significantly lower in the referral groups compared to controls (7.8 mg/L, 95% CI 1.1-12 vs 12.7 mg/L, 95% CI 11.8-13.1; p=0.006). The data suggests a defect in the production PCP IgG2 may be present in individuals with normal PCP IgG referred for immunological investigation. - Source :PubMed
The mechanisms involved in sequential immunoglobulin G (IgG) class switching are still largely unknown. Sequential IG class switching is linked to higher levels of somatic hypermutation (SHM) in vivo, but it remains unclear if these are generated temporally during an immune response or upon activation in a secondary response. We here aimed to uncouple these processes and to distinguish memory B cells from primary and secondary immune responses. SHM levels and IgG subclasses were studied with 454 pyrosequencing on blood mononuclear cells from young children and adults as models for primary and secondary immunological memory. Additional sequencing and detailed immunophenotyping with IgG subclass-specific antibodies was performed on purified IgG(+) memory B-cell subsets. In both children and adults, SHM levels were higher in transcripts involving more downstream-located IGHG genes (esp. IGHG2 and IGHG4). In adults, SHM levels were significantly higher than in children, and downstream IGHG genes were more frequently utilized. This was associated with increased frequencies of CD27(+)IgG(+) memory B cells, which contained higher levels of SHM, more IGHG2 usage, and higher expression levels of activation markers than CD27(-)IgG(+) memory B cells. We conclude that secondary immunological memory accumulates with age and these memory B cells express CD27, high levels of activation markers, and carry high SHM levels and frequent usage of IGHG2. These new insights contribute to our understanding of sequential IgG subclass switching and show a potential relevance of using serum IgG2 levels or numbers of IgG2-expressing B cells as markers for efficient generation of memory responses.Immunology and Cell Biology advance online publication, 13 June 2017; doi:10.1038/icb.2017.43. - Source :PubMed
Patients with IgG-deficiency often suffer from repeated bacterial infections with S. pneumoniae. Since there is a lack of knowledge regarding whether IgG-deficient patients would benefit from conjugate pneumococcal vaccination, we set out to evaluate the effect of Prevnar13 vaccination in IgG1- and/or IgG2-deficient patients. - Source :PubMed
To determine the role of serum and tissue IgG2 in orbital biopsies with the histological features of IgG4-related disease (IgG4-RD) in comparison with non-IgG4-related orbital inflammatory disorders (OID), including autoimmune disorders. - Source :PubMed
The effects of intradermal application of antigen with or without different adjuvants and activation of immune response are presented in this study. Six groups of six piglets each were immunized with keyhole limpet haemocyanin (KLH) antigen in combination with aluminium hydroxide or oil-based adjuvants (complete and incomplete Freund's adjuvants, Montanide ISA 206 and Emulsigen). IgG1 and IgG2 levels in sera were measured by KLH-specific ELISA. Interestingly, oil-based adjuvants induced high primary IgG2 response, suggesting the Th1 lymphocyte polarization. Also, considering the similarities between human and porcine organism, we suggest that intradermal application could be considered as an effective vaccine delivery route in both veterinary and human medicine. - Source :PubMed