c-fos and c-jun mRNA expression in activated cord and adult lymphocytes: an analysis by Northern hybridization.

BACKGROUND AND OBJECTIVES

To further analyze the neonatal immune response to an antigenic challenge such as blood transfusion, c-fos and c-jun mRNA expression were analyzed in twelve in-vitro-stimulated normal cord blood and ten in-vitro-stimulated normal adult peripheral blood lymphocyte samples.

MATERIALS AND METHODS

Lymphocyte samples were stimulated by either the mitogen phytohemagglutinin (PHA) or the monoclonal antibody alphaCD3. Proliferation rate and Northern blot hybridization were employed.

RESULTS

Cord lymphocytes revealed a greater proliferation rate with PHA and alphaCD3 than adult lymphocytes (p = 0.0081 and 0.0023, respectively). In addition, Northern blot analysis of cord and adult samples revealed similar maximal increases in c-fos (99+/-15 and 126+/-11%, p = 0.0126) and c-jun (123+/-9 and 185+/-38%, p = 0.0291) mRNA expression, respectively, as early as 15 min post-alphaCD3 stimulation. Adult lymphocytes showed an equivalent increase in mRNA expression of c-fos and c-jun (140+/-25 and 155+/-31%) at 30 min post-PHA stimulation, while cord lymphocyte maximum c-fos and c-jun expression (82+/-6 and 142+/-12%) occurred at 15 min post-PHA stimulation (c-fos, p = 0.0354; c-jun, p = 0.0112).

CONCLUSION

Although cord lymphocyte proliferation rates were significantly greater than those of adult lymphocytes following stimulation, lymphocyte activation, as analyzed by c-fos and c-jun mRNA expression, appears similar in both cord and adult samples. We conclude that cord lymphocyte activation exhibits an adult-type profile.