Analysis of the antigen specific T cell repertoires in HIV infection

In addition to HIV infection, several acquired immunodeficiencies lead to d epletion of CD4 lymphocytes. These include immunosuppression resulting from high dose cancer chemotherapy or induced to control graft rejection, as we ll as in autoimmune diseases. The consequence of this depletion is an incre ased susceptibility to opportunistic infections or the inability to control primary infection in the case of HIV infection. In all instances a full or partial immunoreconstitution is desirable. In order to monitor the cellula r immune state of a patient, rational information cannot be simply derived from phenotypic quantification of T lymphocytes. Instead loss or recovery o f CD4 cells should be monitored by defining the specificity, the function a nd the clonality of the relevant cell population. Several methods are now a vailable for this type of investigation. Here we describe an approach for t he definition of clonal heterogeneity of antigen specific CD4 lymphocytes, a parameter that may help monitor loss or reconstitution in acquired immuno deficiencies. As examples of antigen specific CD4 T cell responses we focu sed on Pneumocystis carinii and on cytomegalovirus, as prototypic opportuni stic pathogens which are responsible for severe infections in AIDS and in o ther immunosuppressive conditions which arise for instance following transp lantation. Specific CD4 T cell lines were generated from normal controls an d from seropositives in order to select antigen specific lymphocytes. The c ells were subsequently analyzed for clonal diversity according to TCR BV ge ne family usage and according to TCR CDR3 size heterogeneity (spectratyping ). (C) 2001 Published by Elsevier Science BN.