Loeb M R
Department of Pediatrics, University of Rochester Medical Center, NY 14642.
Microb Pathog. 1988 Jan;4(1):9-13. doi: 10.1016/0882-4010(88)90042-3.
In the course of using the infant rat model to determine the ability of various rabbit antisera to protect against challenge by Haemophilus influenzae type b we made two unexpected observations. In these experiments 4-day-old rats were inoculated s.c. on the dorsum with either rabbit serum or physiological buffers (sham serum) and then were challenged the next day with H. influenzae type b injected i.p. Bacteremia, as a marker for disease, was measured 24 h later on day 6. We observed the following. (i) Pre-immune, i.e., normal rabbit serum, containing minimal levels of antibodies to outer membrane proteins and depleted of antibodies to capsule and lipopolysaccharide, nevertheless significantly (P less than 0.01) protected the rats from challenge with H. influenzae type b when compared to a sham inoculation of buffer; (ii) In the absence of a serum inoculation on day 4 (a buffer was used as a sham serum inoculation), the levels of bacteremia obtained after inoculation with bacteria on day 5 depended upon the composition of the buffer in which the H. influenzae inoculum was suspended. Use of phosphate buffered saline (PBS) resulted in higher levels of bacteremia than PBS containing 0.5% bovine serum albumin (PBS-BSA) (P less than 0.001), i.e. the BSA apparently acted to protect the rats from H. influenzae infection. In fact the use of PBS-BSA as an inoculum buffer masked the protective effect noted above of the absorbed normal rabbit serum.
在使用幼鼠模型来确定各种兔抗血清抵御b型流感嗜血杆菌攻击的能力的过程中，我们有两项意外发现。在这些实验中，给4日龄的大鼠背部皮下接种兔血清或生理缓冲液（假血清），然后在第二天经腹腔注射b型流感嗜血杆菌进行攻击。在第6天24小时后测量作为疾病标志物的菌血症。我们观察到以下情况：(i) 免疫前的，即正常兔血清，含有极低水平的外膜蛋白抗体，且去除了针对荚膜和脂多糖的抗体，但与假接种缓冲液相比，仍能显著（P<0.01）保护大鼠免受b型流感嗜血杆菌的攻击；(ii) 在第4天未接种血清（用缓冲液作为假血清接种）的情况下，第5天接种细菌后获得的菌血症水平取决于悬浮b型流感嗜血杆菌接种物的缓冲液组成。使用磷酸盐缓冲盐水（PBS）导致的菌血症水平高于含有0.5%牛血清白蛋白的PBS（PBS-BSA）（P<0.001），即BSA显然起到了保护大鼠免受b型流感嗜血杆菌感染的作用。事实上，使用PBS-BSA作为接种物缓冲液掩盖了上述吸收的正常兔血清的保护作用。
