O-ACETYL GROUP IN BINDING OF MBA AND RABBIT ANTISERUM TO TYPE 9V POLYSACCHARIDE

O-乙酰基在肺炎球菌结合特性中的作用 用9V型多糖（PS）单克隆抗体， 抗体（MAb）和兔抗血清。 O-乙酰基的碱水解 9V PS组显著降低兔9V抗血清的结合 9V PS。 然而，与9V MAb的结合受 O-乙酰基含量的损失表明MAb表位在9V 骨干 正如从9A PS的结构所预期的， 与兔9A抗血清的反应与O-乙酰基含量无关。 碱性水解的9V PS与9V抗血清的抗体结合为 类似于9A抗血清。 丹麦人报道的因子g表位 血清研究所包含的第9组PS被认为是 O-乙酰基决定簇。 因此，g因子特异性兔9V抗血清 识别涉及O-乙酰基的表位，9V MAb 识别骨架结构中的表位，较少受 O-乙酰基。 9V型肺炎球菌被更有效地杀死， 人PMN在9V PS MAb和补体存在下与 兔9V抗血清。 被动免疫可提供有效保护 早期肺炎球菌感染

The role of O-acetyl group on binding characterization to pneumococcal type 9V polysaccharide (PS) was studied by using 9V PS monoclonal antibody (MAb) and rabbit antiserum. Alkali hydrolysis of O-acetyl groups from the 9V PS markedly decreased binding of rabbit 9V antiserum to the 9V PS. However, the binding with 9V MAb was less affected by the loss of O-acetyl content indicating that the MAb epitope is in the 9V backbone. As expected from the structure of the 9A PS the binding reaction with rabbit 9A antisera was independent of the O-acetyl content. The antibody binding of alkali-hydrolyzed 9V PS with 9V antisera was similar to the 9A antisera. The Factor g epitope reported by the Danish Serum Institute contained in the group 9 PS is considered to be the O-acetyl determinant. Thus, factor g-specific rabbit 9V antisera recognized an epitope that involves O-acetyl groups, and 9V MAb recognizes an epitope in the backbone structure, less affected by the O-acetyl group. Type 9V pneumococci were killed more effectively by human PMNs in the presence of the 9V PS MAb and complement compared to rabbit 9V antiserum. Passive immunity could provide effective protection for pneumococcal infection in early life.