The effects on complement component 3 of dietary variation of protein, fat and vitamin E during growth of young mice

Abstract

Some studies have shown that nutrition lowers overall immunity to disease. To further elucidate the role of nutrition on immunity, we have investigated the effect on serum Complement C3 by three nutrients, protein, lipid and vitamin E, in BALB/c mice for up to 24 weeks. The group with high dietary vitamin E had slightly higher C3 for the first four months but by the 22nd week was lower than control. The groups receiving high or low protein had, respectively, high or low C3. Injection of thymosin fraction 5 increased the C3, suppressed by the low protein diet. The group on the high lipid diet had high C3 until the 14th week whereupon it declined to control level by the 22nd week. The low lipid diet resulted in low C3 during the early weeks but increased to control level by the 22nd week. We conclude that diet is important to complement mediated immunity of young mice. Protein calorie malnutrition (PCM) lowers overall immunity to disease (1, 2). The increased incidence of serious gram negative infections including sepsis, of defective inflammatory responses, and of decreased opsonizing activity in serum of PCM patients parallels the symptoms of people with congenital (3) or nutritionally (1) associated deficiency of complement. Complement C 3, a crucial intersection point where the paths of nonspecific immunity and antibody mediated immunity join on the way to destroying foreign organisms, is susceptible to: general nutritional status (4), deficiencies of calcium and magnesium (5), or high levels of lead (6). To further elucidate the role of nutrition on immunity, we have investigated the effect of three nutrients, protein, lipid and vitamin E, on serum C 3 levels in mice for up to 24 weeks. Because overnutrition can also affect immunity (7), we have studied both high and low nutrient levels. A part of protein deficiency is the damage to the thymus and thymus gland hormone production. Therefore the thymic factors on complement production during protein malnutrition is measured.