Total IgA and IgA reactivity to antigen I/II epitopes in HLA-DRB1*04 positive subjects

Abstract

Bacterial adherence to the acquired dental pellicle, important in dental caries (caries), is mediated by receptor-adhesins such as salivary agglutinin binding to Streptococcus mutans antigen I/II (I/II). Ten selected I/II epitopes were chosen to determine their reactivity to human salivary IgA. Previous studies suggested that a specific HLA biomarker group (HLA-DRB1*04) may have differential influence of immune responses to I/II. However, it was not known whether secretory IgA (SIgA) responses to the selected epitopes from HLA-DRB1*04 positive subjects were different compared to controls, or across other caries-related factors such as total IgA (TIgA). Thirty-two total subjects were matched according to HLA type, gender, ethnicity and age. HLA genotyping, oral bacterial, immunoglobulin and antibody analyses were performed. A large observed difference emerged with regard to the natural immune reservoir of TIgA in HLA-DRB1*04 positive subjects, specifically, a 27.6% reduction compared to controls. In contrast to all other epitopes studied, HLA-DRB1*04 positive subjects also exhibited reduced reactivity to I/II epitope 834–853. HLA-DRB1*04 positive subjects exhibited lower specific SIgA activity/TIgA to 834–853 and also a lower specific reactivity to 834–853/whole cell S. mutans UA159. Furthermore, HLA-DRB1*04 positive subjects exhibited lower responses to I/II in its entirety. The large observed difference in TIgA and the 834–853 reactivity pattern across multiple measures suggest potentially important connections pertaining to the link between HLA-DRB1*04 and caries.

Association between HLA-DRB1* allele polymorphism and caries susceptibility in Han Chinese children and adolescents in the Xinjiang Uygur Autonomous Region

“…Moreover, Bagherian et al 21 found that the allele frequency of HLA-DRB1*04 was 10-fold greater in children with caries than in caries-free children, which suggested that the HLA-DRB1*04 allele might confer susceptibility to caries. Valarini et al 22 performed a comparative analysis of 15-to 19-year-old students with or without caries; their findings confirmed a close relationship between HLA genes and caries. In particular, the HLA-DQ gene was more frequently found in students with caries.…”

“…Valarini et al. 22 performed a comparative analysis of 15- to 19-year-old students with or without caries; their findings confirmed a close relationship between HLA genes and caries. In particular, the HLA-DQ gene was more frequently found in students with caries.…”

PERAN IMUNOGLOBULIN A (SIgA) DALAM MENGHAMBAT PEMBENTUKAN BIOFILM STREPTOKOKUS MUTANS PADA PERMUKAAN GIGI

“…Sekretori IgA (SIgA) saliva dapat berikatan secara spesifik dengan epitop dari bagian antigen I/II S. mutans, sehingga bakteri tidak dapat berikatan dengan pelikel saliva dan S. mutans tidak akan berkolonisasi pada permukaan gigi. 3,4,6,[7][8][9] Penulisan artikel ini bertujuan untuk mengetahui peran SIgA dalam meningkatkan pertahanan mukosa mulut terhadap bakteri patogen Streptococcus mutans.…”

“…Famili protein ini direpresentasikan oleh SpaP, SspA atau SspB yang terdapat pada permukaan S. mutans (Gambar 2). [3][4][5]9 Selain itu, Streptococcus mutans dapat memproduksi asam dari substrat karbohidrat (glukosa dan fruktosa) yang dikenal dengan sifat asidogenik. Di samping itu sifat asidurik, memungkinkan bakteri ini dapat bertahan dalam kondisi pH rendah (pH 3,0) yang menyebabkan demineralisasi pada email, sehingga meningkatkan potensi kariogenik.…”

Genetic factors affecting dental caries risk

“…In a Caucasian population, a higher dose of streptococcal antigen was required to release T‐helper activity in DR4 positive individuals compared to cells carrying the HLA DR1,2,3,6 cross reactive groups . McCarlie et al . reported HLA‐DR4 positive subjects exhibited reduced reactivity to S. mutans antigen I/II, lower specific secretory immunoglobulin A activity/total Immunoglobulin A and a lower specific reactivity to whole cell S. mutans UA159, suggesting a potential link between HLA‐DR04 and caries.…”