Evidence for Genetic Basis of Seasonal Differences in Antibody Formation Between Two Mouse Strains

Abstract

In order to confirm the presence of an acrophase difference based upon genotype in the seasonal expression of an immune competence end point, splenic plaque-forming cell (PFC) response to sheep red blood cells (SRBC), female B6C3F1 and CD1 mice were concurrently studied for PFC response during two studies performed in each season for 1 year. Mice were multiply housed, fed ad libitum, and standardized to light (06:00-18:00); dark (18:00-06:00). For each strain and study, subgroups were either naive (n = 10), received a vehicle (n = 10) or Cytoxan (n = 5). Challenge with SRBC occurred in early afternoon 4 days before harvesting of spleens and PFC assay. All other procedures were performed early in the daily light span. Analysis of variance and single cosinor analysis revealed a significant seasonal time effect for PFC in naive mice of both strains. Antibody formation was greatest in spring for CD1 mice and in summer for the B6C3F1 mice. These acrophases were consistent with earlier results for both strains and show the phenomena to be reproducible and genetically based.

The Influence of Vehicle Gavage on Seasonality of Immune System Parameters in the B6C3F1 Mouse

“…Despite any potential dietary confounders, seasonal patterns of IgMantibody production were found in data obtained over the 4-year period studied. Also, the comparison of immunotoxicity endpoints in concurrent studies in B6C3F1 and CD1 mouse strains given the same diet (identical lot numbers of rodent chow) revealed consistent, although different, seasons of peak response, implicating genetic control of rhythm (Ratajczak et al, 1993). This observation minimizes diet as a confounding influence on rhythm changes in our studies.…”

“…We have also documented seasonal differences in antibody formation and host resistance in mice of different strains (Ratajczak et al, 1993). This current investigation is a retrospective analysis of 49 separate immunotoxicity studies conducted over a 4-year period to determine the effects of oral dosing vehicles on the seasonality of various routinely measured immunotoxicity endpoints.…”

Seasonal variation in blood concentrations of interleukin-6, adrenocorticotrophic hormone, metabolites of catecholamine and cortisol in healthy volunteers

“…atmospheric temperature, light-dark cycle) as well as by the fairly homogeneous genetic constitution of the Japanese population. This view is supported by findings in experimental animals; seasonal rhythms in the immune system are genetically determined (Ratajczak et al 1993) and/or are entrained by the photoperiod or by changes in temperature (Vetvicka et al 1993). Nagoya is characterised by rather higher mean atmospheric temperatures and a longer photoperiod than that experienced in the Crawford study (Crawford et al 2000).…”

Ethics of pesticide testing in humans.

“…There are many cues available for animals to detect season, even in our light-tight animal-care facilities. For example, immune responses determined in laboratory conditions are affected by seasonal influences, with a lower response usually occurring during winter months, although this sensitivity to winter depends on the strain (Dozier et al 1997;Ratajczak et al 1993). Lamb et al (2003) criticized our discussion that our data may follow an inverted dose-response curve.…”