Ex vivo analysis of resident hepatic pro-inflammatory CD1d-reactive T cells and hepatocyte surface CD1d expression in hepatitis C.

Hepatic CD1d-restricted and natural killer T-cell populations are heterogeneous. Classical 'type 1' α-galactosylceramide-reactive CD1d-restricted T cells express 'invariant' TCRα ('iNKT'). iNKT dominating rodent liver are implicated in inflammation, including in hepatitis models. Low levels of iNKT are detected in human liver, decreased in subjects with chronic hepatitis C (CHC). However, high levels of human hepatic CD161(±) CD56(±) noninvariant pro-inflammatory CD1d-restricted 'type 2' T cells have been identified in vitro. Unlike rodents, healthy human hepatocytes only express trace and intracellular CD1d. Total hepatic CD1d appears to be increased in CHC and primary biliary cirrhosis. Direct ex vivo analysis of human intrahepatic lymphocytes (IHL), including matched ex vivo versus in vitro expanded IHL, demonstrated detectable noninvariant CD1d reactivity in substantial proportions of HCV-positive livers and significant fractions of HCV-negative livers. However, α-galactosylceramide-reactive iNKT were detected only relatively rarely. Liver CD1d-restricted IHL produced IFNγ, variable levels of IL-10 and modest levels of Th2 cytokines IL-4 and IL-13 ex vivo. In a novel FACS assay, a major fraction (10-20%) of hepatic T cells rapidly produced IFNγ and up-regulated activation marker CD69 in response to CD1d. As previously only shown with murine iNKT, noninvariant human CD1d-specific responses were also augmented by IL-12. Interestingly, CD1d was found selectively expressed on the surface of hepatocytes in CHC, but not those CHC subjects with history of alcohol usage or resolved CHC. In contrast to hepatic iNKT, noninvariant IFNγ-producing type 2 CD1d-reactive NKT cells are commonly detected in CHC, together with cognate ligand CD1d, implicating them in CHC liver damage.

Persistent low viral load on antiretroviral therapy is associated with T cell-mediated control of HIV replication.

BACKGROUND: It is unclear how stable low-level viral replication and CD4 cell numbers can be maintained under highly active antiretroviral therapy (HAART). This study was designed to analyse whether HIV-specific responses in stable partially controlled patients during antiretroviral therapy (ART) differ from those observed in complete HAART failure and whether they contribute to the control of viral load (VL). METHODS: Three groups of patients were selected according to plasma HIV RNA levels during 18 months of ART: persistently low VL (LoVL; HIV RNA <10,000 copies/ml; n = 28), undetectable VL (UnVL; HIV RNA <200 copies/ml; n = 29) and high VL (HiVL; HIV RNA >10,000 copies/ml; n = 14). T-cell responses were studied using lymphoproliferative and interferon (IFN)-gamma-ELISpot assays against HIV-p24, -gp160, recall antigens, and 15 pools of HIV-(Gag + RT) peptides. RESULTS: Frequencies of IFN-gamma-producing CD4 T cells against HIV-p24 were higher in LoVL than in UnVL or HiVL groups [median, 131, 47 and 23 spot-forming cells (SFC)/1 x 10 peripheral blood mononuclear cells (PBMC), respectively; P = 0.012 and P = 0.047]. Lymphoproliferative responses to HIV-p24 and recall antigens were similar in LoVL and UnVL groups but lower in HiVL (P = 0.004). Frequencies of HIV-specific CD8 T cells were higher in LoVL than in UnVL (1340 versus 410 SFC/1 x 10 PBMC; P = 0.001). They correlated negatively with VL in the LoVL and HiVL (r, -0.393, P = 0.039 and r, -0.643, P = 0.024, respectively) and positively correlated with anti-HIV CD4 cell frequencies in the LoVL group only (r, 0.420; P = 0.026). CONCLUSION: Persistently low viral replication (<10,000 copies/ml) during ART stimulates high frequencies of HIV-specific CD4 and CD8 T cells compared to full virus suppression or complete ART failure. The association of high anti-HIV activity with large numbers of HIV-specific CD8 T cells contribute to the control of viral replication.

Prognostic value of CA 15.3 kinetics for metastatic breast cancer.

Up to 80% of breast cancer patients developing metastases have high levels of CA 15.3. We studied the prognostic implications of CA 15.3 kinetics in 119 patients before and at first metastasis by univariate and multivariate statistics. At first metastasis, CA 15.3 was elevated in 82.4% of patients, with a lead time (median 162 days) in 42.0% of them. Kaplan-Meier analysis showed overall survival (median 1477 days) to be significantly related to estrogen receptor (ER) and progesterone receptor (PgR) status (p=0.0001) and tumor size (p=0.025). The interval between diagnosis and first abnormal CA 15.3 (p=0.0001), the CA 15.3 concentration (p=0.013), and the presence or absence of a lead time (p=0.001) also had prognostic value. ER and PgR status (p=0.0005 and p=0.0103, respectively), metastasis-free interval (p=0.0003), existence of a CA 15.3 lead time (p=0.0028), and days from diagnosis to first abnormal CA 15.3 (p=0.0055) entered in the Cox model. After first metastasis (median survival 573 days), ER and PgR status (p=0.0001 and p=0.0004, respectively), existence of a lead time for CA 15.3 (p=0.0138), and the concentration of first abnormal CA 15.3 (p=0.0145) had individual prognostic value. In the Cox model ER status (p=0.0001), nodal status (p=0.0191), existence of a lead time for CA 15.3 (p=0.0033), days from diagnosis to first abnormal CA 15.3 (p=0.0132), and concentration of first abnormal CA 15.3 (p=0.0320) were found to be independent prognostic variables. Compared to a matched historical control group that was not monitored by CA 15.3 assaying (n=140), the study group had a significantly longer survival after the first metastasis (p=0.0005). In conclusion, the kinetics of CA 15.3 before the first metastasis is of prognostic value. When associated with 18-fluorodeoxyglucose imaging, serial CA 15.3 assays may help to implement early treatment of metastases.

T-cell clonal expansion in patients with B-cell lymphoproliferative disorders.

We investigated whether T-cell clonal expansion could be found in the blood of 14 untreated patients with B-cell lymphoproliferative disorders [5 B-chronic lymphocytic leukemia (CLL), 4 myelomas, 5 non-Hodgkin lymphoma (NHL)]. The putative presence of T-cell clonotypes was analyzed with a polymerase chain reaction-based method determining V-D-J junction size patterns in 24 T-cell receptor (TCR) V beta subfamilies. This high-resolution method, analyzing CDR3 sizes of TCR transcripts, was used in conjunction with cytometric analysis of the corresponding T-cell subpopulations with 18 TCR V beta-specific monoclonal antibody. We found multiple dominant T-cell clonotypes in the blood of most patients with B-CLL or myeloma as well of a patient with stage IV NHL. In some cases, T-cell clonal expansion was so dominant that the percentage of these clonal T-cell subpopulations in blood represented more than the mean +2 SD value determined in a series of healthy controls. We conclude that a systemic antigen-specific (i.e., leading to clonotypic expansion) immune reaction involving few TCR clonotypes is a hallmark of disseminated B-cell malignancies. The nature of the putative antigens recognized is not known presently. Nonetheless, such insights into the T-cell repertoire of these patients may help to reassess the potential of immunotherapeutic strategies in B-cell malignancies.