Devi S J, Schneerson R, Egan W, Ulrich T J, Bryla D, Robbins J B, Bennett J E
Laboratory of Developmental and Molecular Immunity, National Institute of Child Health and Human Development, Bethesda, Maryland 20892.
Infect Immun. 1991 Oct;59(10):3700-7. doi: 10.1128/iai.59.10.3700-3707.1991.
We synthesized Cryptococcus neoformans serotype A glucuronoxylomannan (GXM) conjugate vaccines under conditions suitable for human use to prevent disseminated cryptococcosis. The purified, sonicated GXM was derivatized with adipic acid dihydrazide through either hydroxyl or carboxyl groups and then covalently bound to tetanus toxoid (TT) or Pseudomonas aeruginosa exoprotein A (rEPA). The immunogenicity of these conjugates was evaluated in BALB/c and general purpose mice by subcutaneous injection in saline. The conjugates elicited higher GXM antibody responses than GXM alone. Booster immunoglobulin G (IgG) and IgM responses were elicited by all conjugates in BALB/c mice. The conjugates prepared through hydroxyl activation (GXM-TT2 and GXM-rEPA) were more immunogenic than the one prepared through carboxyl activation (GXM-TT1). GXM antibody response was enhanced by the administration of monophosphoryl lipid A 2 days following the injection of GXM-TT2 (P less than 0.03). The conjugates also elicited IgG antibodies to the carrier proteins. Gel diffusion tests using conjugate-induced hyperimmune sera and chemically modified GXMs suggested that the specificity of GXM-TT1-induced antibodies was conferred by the O-acetyl groups. Hyperimmune sera generated by GXM-TT2 precipitated with the chemically unmodified and the de-O-acetylated GXMs but not with the carboxyl-reduced and de-O-acetylated GXM. GXM-TT2-induced hyperimmune serum also precipitated with the capsular polysaccharides of C. neoformans serotypes D, B, and C. The conjugate vaccines prepared through hydroxyl activation of the GXM are sufficiently immunogenic and appear to be suitable for clinical evaluation.
我们在适合人类使用的条件下合成了新型隐球菌A血清型葡糖醛酸木聚糖甘露聚糖（GXM）结合疫苗，以预防播散性隐球菌病。将纯化并经超声处理的GXM通过羟基或羧基与己二酸二酰肼衍生化，然后与破伤风类毒素（TT）或铜绿假单胞菌外毒素A（rEPA）共价结合。通过在盐水中皮下注射，在BALB/c小鼠和普通小鼠中评估了这些结合物的免疫原性。与单独的GXM相比，结合物引发了更高的GXM抗体反应。所有结合物在BALB/c小鼠中均引发了加强免疫的免疫球蛋白G（IgG）和IgM反应。通过羟基活化制备的结合物（GXM-TT2和GXM-rEPA）比通过羧基活化制备的结合物（GXM-TT1）具有更强的免疫原性。在注射GXM-TT2后2天给予单磷酰脂质A可增强GXM抗体反应（P小于0.03）。结合物还引发了针对载体蛋白的IgG抗体。使用结合物诱导的超免疫血清和化学修饰的GXM进行的凝胶扩散试验表明，GXM-TT1诱导的抗体的特异性由O-乙酰基赋予。GXM-TT2产生的超免疫血清与化学未修饰和去O-乙酰化的GXM沉淀，但不与羧基还原和去O-乙酰化的GXM沉淀。GXM-TT2诱导的超免疫血清也与新型隐球菌D、B和C血清型的荚膜多糖沉淀。通过GXM的羟基活化制备的结合疫苗具有足够的免疫原性，似乎适合进行临床评估。
