The immune checkpoint CD96 defines a distinct lymphocyte phenotype and is highly expressed on tumor-infiltrating T cells

CD96 has recently been shown to be a potent immune checkpoint molecule in mice, but a similar role in humans is not known. In this study, we provide a detailed map of CD96 expression across human lymphocyte lineages, the kinetics of CD96 regulation on T-cell activation and co-expression with other conventional and emerging immune checkpoint molecules. We show that CD96 is predominantly expressed by T cells and has a unique lymphocyte expression profile. CD96 high T cells exhibited distinct effector functions on activation. Of note, CD96 expression was highly correlated with T-cell markers in primary and metastatic human tumors and was elevated on antigen- experienced T cells and tumor-infiltrating lymphocytes. Collectively, these data demonstrate that CD96 may be a promising immune checkpoint to enhance T-cell function against human cancer and infectious diseas

T cell subpopulations in lymph nodes may not be predictive of patient outcome in colorectal cancer

<p>Abstract</p> <p>Background</p> <p>The immune response has been proposed to be an important factor in determining patient outcome in colorectal cancer (CRC). Previous studies have concentrated on characterizing T cell populations in the primary tumour where T cells with regulatory effect (Foxp3+ Tregs) have been identified as both enhancing and diminishing anti-tumour immune responses. No previous studies have characterized the T cell response in the regional lymph nodes in CRC.</p> <p>Methods</p> <p>Immunohistochemistry was used to analyse CD4, CD8 or Foxp3+ T cell populations in the regional lymph nodes of patients with stage II CRC (n = 31), with (n = 13) or without (n = 18) cancer recurrence after 5 years of follow up, to determine if the priming environment for anti-tumour immunity was associated with clinical outcome.</p> <p>Results</p> <p>The proportions of CD4, CD8 or Foxp3+ cells in the lymph nodes varied widely between and within patients, and there was no association between T cell populations and cancer recurrence or other clinicopathological characteristics.</p> <p>Conclusions</p> <p>These data indicate that frequency of these T cell subsets in lymph nodes may not be a useful tool for predicting patient outcome.</p

CD8\u3csup\u3e+\u3c/sup\u3e T Cells Responding to Influenza Infection Reach and Persist at Higher Numbers Than CD4\u3csup\u3e+\u3c/sup\u3e T Cells Independently of Precursor Frequency

The activation, localization, phenotypic changes, and function of CFSE-labeled naive influenza-specific CD8+ and CD4+ T cells following influenza infection were examined. Response of adoptively transferred CD8+ T cells was seen earliest in draining lymph node. Highly activated cells were found later in the lung, airways, and spleen, were cytolytic, and expressed IFN-γ upon restimulation. Similar amounts of division at early time points, but higher numbers of CD8+ T cells, were detected at 9 and 30 days postinfection after cotransfer of CD4+ and CD8+ T cells followed by infection. Transfer of much smaller numbers of CD4+ and CD8+ T cells led to more extensive expansion but the same difference in final number between the two cell types. These studies demonstrate how CD8+ and CD4+ T cells respond to influenza at early time points postinfection and the differential kinetics of antigenspecific CD4+ and CD8+ T cells

Improved anti-tumor activity of a therapeutic melanoma vaccine through the use of the dual COX-2/5-LO inhibitor licofelone

Immune-suppressive cell populations impair anti-tumor immunity and can contribute to the failure of immune therapeutic approaches. We hypothesized that the non-steroidal anti-inflammatory drug (NSAID) licofelone, a dual COX-2/5-LO inhibitor, would improve therapeutic melanoma vaccination by reducing immune-suppressive cell populations. Therefore, licofelone was administered after tumor implantation, either alone or in combination with a peptide vaccine containing a long tyrosinase-related protein (TRP)2-peptide and the adjuvant α-galactosylceramide, all formulated into cationic liposomes. Mice immunized with the long-peptide vaccine and licofelone showed delayed tumor growth compared to mice given the vaccine alone. This protection was associated with a lower frequency of immature myeloid cells (IMCs) in the bone marrow (BM) and spleen of tumor-inoculated mice. When investigating the effect of licofelone on IMCs in vitro, we found that the prostaglandin E2-induced generation of IMCs was decreased in the presence of licofelone. Furthermore, pre-incubation of BM cells differentiated under IMC-inducing conditions with licofelone reduced the secretion of cytokines interleukin (IL)-10 and -6 upon LPS stimulation as compared to untreated cells. Interestingly, licofelone increased IL-6 and IL-10 secretion when administered after the LPS stimulus, demonstrating an environment-dependent effect of licofelone. Our findings support the use of licofelone to reduce tumor-promoting cell populations