Effect of specific bacteria on lymphocyte proliferation in diseased and nondiseased tonsils

Tonsillar tissue lymphocyte (TTL) function as measured by lymphocyte proliferation was assessed in vitro in 38 tonsils--30 diseased and 8 normal controls. TTLs from diseased and control tonsils were challenged with intact, heat-inactivated bacteria which may be found in the core of diseased tonsils; these bacteria were Streptococcus pyogenes and Hemophilus influenzae type B (HIB), as well as the dominant bacterium (DB) grown from that particular tonsillar core. The phytomitogen leukoagglutinin (LA) was used as a nonspecific activator. Lymphocyte proliferation was quantified and reported using a stimulation index (SI) which was based upon viable cell counts at 2, 4, and 6 days following inoculation. Overall, the greatest degree of lymphocyte proliferation in diseased TTLs (SI = .91) was produced by HIB. However, both SP and HIB produced more lymphocyte proliferation in the nondiseased TTLs than in the diseased TTLs (P < .01). H influenzae (non-B) and group A beta-hemolytic streptococci were the pathogens most frequently cultured as the dominant bacteria from the core of diseased tonsils; Streptococcus viridans was most frequently cultured in nondiseased tonsils. The DB caused greater TTL proliferation in diseased (SI = .89) versus control (SI = .63) TTLs (P < .001). These findings suggest a differential proliferative response in vitro for diseased and nondiseased TTLs in response to specific bacteria. The role of possibly pathogenic bacteria and commensals, as well as the implications for clinical disease, are discussed.