Impact of Thiamine Deficiency on T‐cell Dependent and T‐cell Independent Antibody Production in Lake Trout

Lake trout Salvelinus namaycush on thiamine‐replete and thiamine‐depleted diets were evaluated for the effects of thiamine status on in vivo responses to the T‐dependent antigen trinitophenol (TNP)‐keyhole limpet hemocyanin (TNP‐KLH), the T‐independent antigen trinitrophenol‐lipolysaccaharide (TNP‐LPS), or Dulbecco's phosphate‐buffered saline (DPBS; negative control fish). Plasma antibody concentrations were evaluated for possible differences in total anti‐TNP activity as well as differences in response kinetics. Associations between anti‐TNP activity and muscle and liver thiamine concentrations as well as ratios of muscle‐to‐liver thiamine to anti‐TNP activity were also examined. Thiamine‐depleted lake trout that were injected with TNP‐LPS exhibited significantly more anti‐TNP activity than thiamine‐replete fish. The depleted fish injected with TNP‐LPS also exhibited significantly different response kinetics relative to thiamine‐replete lake trout. No differences in activity or kinetics were observed between the thiamine‐replete and ‐depleted fish injected with TNP‐KLH or in the DPBS negative controls. Anti‐TNP activity in thiamine‐depleted lake trout injected with TNP‐KLH was positively associated with muscle thiamine pyrophosphate (thiamine diphosphate; TPP) concentration. A negative association was observed between the ratio of muscle‐to‐liver TPP and T‐independent responses. No significant associations between anti‐TNP activity and tissue thiamine concentration were observed in the thiamine‐replete fish. We demonstrated that thiamine deficiency leads to alterations in both T‐dependent and T‐independent immune responses in lake trout. Received July 25, 2011; accepted July 12, 2012