Primary Structure of the Human Vk2 Regions Elicited by Haemophilus influenzae Type b Polysaccharide Vaccines ; The J Gene Usage Is Restricted in Child Antibodies Using the A2 Gene = Primary Structure of the Human Vk2 Regions Elicited by Haemophilus influenzae Type b Polysaccharide Vaccines ; The J Gene Usage Is Restricted in Child Antibodies Using the A2 Gene

다국어 초록 (Multilingual Abstract)

The Haemophilus influenzae type b (Hib) has been a major cause of bacterial meningitis in children who are less than two years old. The variable (V) region repertoire of adult Caucasian antibodies (Abs) to Hib polysaccharide (PS) has been characterized well. The majority of adult antibodies against Hb uses VL that is derived from the Vk gene A2 and have arginine at the N region. In order to explore the possibility those antibody responses to Hib-PS is variable in various age groups, we examined the VL regions of the antibodies to Hib-PS in Korean adults and children. We immunized Korean adults (n = 8) and children (n = 39) with Hib tetanus conjugated vaccines, isolated RNAs from the peripheral lymphocytes, and amplified the A2-derived VL regions by RT PCR. The PCR products were subcloned and sequenced. Forty-seven out of 54 independent clones from children used the Jk2, or Jk3 gene in preference. The adults, however, used all of the Jk genes evenly With respect to the amino acid sequences of variable regions, adult A2-Jk recombinants have a germline sequence. But, the 76th codon (AGC) of child A2-Jk2 recombinants was substituted with CGC (arginine) in most cases (88%) and 77 percent of child clones using the A2-Jk3 genes have isoleucine-109 at the junction of Jk-Ck instead of threonine that is found in a germline sequence. These results suggest that the mechanism of antibody production in young children is different from that of adults.