Secretory-IgA Antibodies Play an Important Role in the Immunity to Streptococcus pneumoniae

Abstract

This study was designed to investigate whether secretory-IgA (S-IgA) Abs induced by a pneumococcal surface protein A (PspA)-based nasal vaccine are necessary for prevention of streptococcal colonization. Mice nasally immunized with PspA plus a plasmid expressing Flt3 ligand (pFL) cDNA as a mucosal adjuvant showed significantly higher levels of PspA-specific S-IgA and IgG Ab responses in both plasma and nasal washes when compared with naive mice. Although IgA−/− mice given nasal PspA plus pFL had significantly high levels of PspA-specific IgG Abs, high numbers of CFUs were detected in nasal washes and nasal passages. In contrast, vaccinated wild-type mice showed essentially no bacteria in the nasal cavity. Further, a nasal vaccine consisting of PspA plus pFL effectively reduced pre-existing Streptococcus pneumoniae in the nasal cavity. These results show that PspA-based vaccine-induced specific S-IgA Abs play a necessary role in the regulation of S. pneumoniae colonization in the nasal cavity.

Novel Monoclonal Antibodies for Studies of Human and Rhesus Macaque Secretory Component and Human J-Chain

“…We found that IgA forms of HIV Env antibodies had similar or lower affinity, or weaker activity, than IgG antibodies of the same specificity. (24) However, multivalency of dimeric and larger polymeric Ig forms of IgA and SIgA will enhance their efficacy over monomeric Ig by at least an order of magnitude. (24,54) Finally, we found that MAb 9H7 could identify SIgA versus dIgA and mIgA molecules.…”

“…(24) However, multivalency of dimeric and larger polymeric Ig forms of IgA and SIgA will enhance their efficacy over monomeric Ig by at least an order of magnitude. (24,54) Finally, we found that MAb 9H7 could identify SIgA versus dIgA and mIgA molecules. Thus, these new reagents should be of use in the study of the biology of dIgA and SIgA in humans and SIgA in macaques and, as well, in monitoring the production and/or isolation of these forms of IgA.…”

“…(1,21,22) SIgA plays a critical role in protection against mucosal pathogens. (23)(24)(25) For example, SIgA antibodies in nasal secretions are correlates of protection in children against influenza. (26,27) Recombinant IgAs have been produced for human trials as therapeutics for infections.…”

Desenvolvimento e avaliação da resposta imune humoral de uma vacina anti-pneumocócica conjugada: polissacarídeo capsular sorotipo 14 - proteína de superfície pneumocócica A.

“…Sendo assim, a prevalência de sorotipos específicos deve-se, em parte, ao grau de expressão e conformação de adesinas pneumocócicas de superfície que permitem o reconhecimento e a adesão à célula hospedeira. Estas proteínas de superfície contribuem para as características hidrofóbica e eletrostática da superfície do pneumococo e, por isso, facilitam, em parte, a sua aderência por interações físico-químicas inespecíficas (BOGAERT; GROOT;HERMANS, 2004;GARCÍA-RODRIGUEZ;MARTINEZ, 2002;NOVAK;TUOMANEN, 1999;TUOMANEN, 1997).…”

“…Essas citocinas alteram o número e o tipo de receptores nas células epiteliais e endoteliais alterando, também, a afinidade de colinas presentes na parede celular do pneumococo por esses receptores promovendo, então, a migração transcelular através do epitélio respiratório e endotélio vascular, resultando no acesso da bactéria à circulação (BOGAERT; GROOT;HERMANS, 2004;GARCÍA-RODRIGUEZ;MARTINEZ, 2002;TUOMANEN, 1997).…”