The cellular immune response to cell-associated and cell-free cytomegalovirus (CMV) antigens after primary CMV-infection in non-immunocompromised hosts: development and maintenance of CMV-latency and its influence on immunocompetence.

Development and maintenance of cellular immunity to cell-associated CMV-antigens (CMVFF) was investigated in non-immunocompromised hosts during the first year (group I, n = 11) and 1 to 5 years (group II, n = 9) after a symptomatic primary CMV infection, as well as in healthy CMV-seropositive controls without a history of CMV disease (group III, n = 28). During the acute phase (0-2 months) of a primary CMV-infection CMVFF-induced lymphocyte proliferation was severely decreased compared to that in the post-illness phase (5-12 months), and to that in groups II and III. After the reconvalescent period (3-4 months) it gradually increased to levels seen in group III. In group II higher responses to CMVFF were found than in group III or during the post-illness phase of a primary infection. In general CMV-virion induced lymphocyte proliferation showed the same pattern of development as the CMVFF-induced lymphocyte response, but during the acute phase (0-2 months) a lack of correlation was observed between lymphocyte proliferation to CMVFF and CMV-virions. Lymphocyte proliferation to PHA, Con A, allogeneic lymphocytes and recall antigens were severely depressed in the acute phase of a primary CMV-infection and restored gradually to levels seen in groups II and III, with the exception of Con A-reactivity. The latter response remained depressed when compared to healthy seropositive controls, not only during the post-illness period, but also later on (group II).