Observation of host reactions to murine leprosy bacilli in spread subcutaneous tissue preparations of various strains of mice
Kawaguchi, Y.; Matsuoka, M.
Japanese Journal of Experimental Medicine 47(2): 71-79
1977
ISSN/ISBN: 0021-5031 PMID: 325252 Document Number: 123481
Male mice of 6 inbred strains (C3H, CF#1, KK, BALB/C, DDD and C57BL/6 were inoculated s.c. in the back with 0.25 ml of a 1:1000 leproma suspension (Hawaiian strain). Growth patterns of murine leprosy bacilli in s.c. tissue at the inoculation site were examined on the spread tissue preparations. No remarkable differences were observed among these mouse strains during the first 3 wk after inoculation. An acute inflammatory reaction with accumulation of many polymorphonuclear leukocytes [PMN] disappeared in 1 wk, and elongation of the bacilli was evident in mononuclear cells without increase in number. The bacilli were about 2-3 times as long as the initial length. At 2 wk the elongated bacilli were fairly abundant within the cells; some were present extracellularly. At 3 wk enlarged mononuclear cells being crowded with long bacilli, were easily demonstrable by low magnification. Four wk after inoculation, significant differences in the growth patterns were seen among these mouse strains. In C3H and CF#1 mice, an infiltrate consisting mainly of mononuclear cells was seen in the s.c. tissue at the inoculation site. Most of the mononuclear cells were heavily loaded with the long bacilli and were scattered or accumulated in the whole specimens. Lymphocytes and PM N were predominant in the other 4 strains of mice, and they surrounded a smaller number of mononuclear cells containing the long bacilli. Such difference between mouse strains became more remarkable at 5 wk because of more pronounced cellular reactions in these 4 strains. The difference between C3H and CF # 1 mice was manifested in 8-10 wk by infiltration of lymphocytes, surrounding accumulated mononuclears loaded with the bacilli, which was seen only in CF # 1 mice. The mouse strain differences in response to murine leprosy bacilli are discussed on the basis of cellular immunity in the hosts.