Immune responses against measles virus in cynomolgus monkeys

Measles virus (MV) induces profound suppression of the immune response during and for weeks after acute infection. On the other hand, virus-specific immune responses that mediate viral clearance and confer long-lasting immunity are efficiently generated. To investigate this paradox, we studied the immune responses to MV using a monkey model of acute measles. Cynomolgus monkeys were experimentally infected with wild-type MV (MV-HL) and showed marked leukopenia associated with a steady reduction in CD4+ T cell numbers for 18 days post-inoculation. Transient expression of interferon and IL-6 were observed in the serum between 4 and 6 days post-inoculation, and IL-10 levels increased after 11 days post-inoculation. Interestingly, IL-8 showed a three-peak increase that correlated with an increase in neutrophils. A non-human primate model of measles allows the early immune response against MV to be studied in more detail.     

Concentrations of C-reactive Protein in Normal Monkeys (Macaca irus) and in Monkeys Inoculated with Bordetella bronchiseptica R-5 and Measles Virus

The concentrations of C-reactive protein (CRP) in serum from normal crab-eating monkeys (Macaca irus) were measured by means of a monkey-specific turbidimetric immunoassay (TIA), and the changes in the serum CRP concentrations in crab-eating monkeys inoculated with Bordetella bronchiseptica R-5 and measles virus (Ichinose or NK 3 strain) were also examined. The CRP concentrations in sera from 54 normal crab-eating monkeys ranged from 0 to 8.3 g/ml (mean 2.2±1.9). No significant difference was found in the CRP concentrations between males and females (p>0.05). The concentrations of CRP in the sera from four crab-eating monkeys inoculated intrabronchially with 10⁹ live B. bronchiseptica increased gradually to a peak at 2 days after inoculation. The peak concentrations of CRP were from 102.4 to 313.2 g/ml, 54–96 times the preinoculative values of 1.9–5.6 g/ml. When the same four crab-eating monkeys were inoculated intrabronchially with measles virus 34 days after inoculation of B. bronchiseptica, the serum CRP concentrations did not increase. Monitoring of CRP is useful for assessing monkeys with acute B. bronchiseptica infection and will probably be of value in the diagnosis of other bacterial infections.