The characterization of CD4+ T-cell subsets reflects the immune status and is important in the maintenance of tumorigenesis and homeostasis. To identify changes in the balance of T helper (Th)1, Th2, Th17 and regulatory T cells (Treg) in individuals with renal cell carcinoma (RCC), the present study investigated a total of 131 patients with RCC and 36 healthy volunteers. The number of CD4+ T‑be...

Naïve FoxP3-expressing regulatory T-cells (Tregs) are essential to control immune responses via continuous replenishment of the activated-Treg pool with thymus-committed suppressor cells. The mechanisms underlying naïve-Treg maintenance throughout life in face of the age-associated thymic involution remain unclear. We found that in adults thymectomized early in infancy the naïve-Treg pool is re...

There is now compelling evidence that TNFR2 is constitutively expressed on CD4(+) Foxp3(+) regulatory T cells (Tregs) and TNF-TNFR2 interaction is critical for the activation, expansion and functional stability of Tregs. However, we showed that the expression of TNFR2 was also up-regulated on CD4(+) Foxp3(-) effector T cells (Teffs) upon TCR stimulation. In order to define the role of TNFR2 in ...

Rabbit antithymocyte globulin therapy (rATG) is a potent lymphocyte-depleting agent commonly used following renal transplantation to reduce the risk of acute rejection. Standard doses (7-10 mg/kg) of rATG result in profound lymphopenia and predispose patients to infection and malignancy. The effects of lower doses of rATG (LoD-rATG, 3-5 mg/kg) on peripheral blood lymphocytes (PBL) are as yet un...

BACKGROUND To describe T-cell and natural killer (NK) cell phenotypes within nursing home elderly. METHODS Nursing home elderly were recruited from four nursing homes in Hamilton, Ontario between September 2010 and December 2011. Healthy adults were recruited from McMaster University between September 2011 and December 2011. Nursing home elderly ≥65 years were eligible; those on immunosuppres...

BACKGROUND Mice exposed to sand fly saliva are protected against vector-transmitted Leishmania major. Although protection has been related to IFN-γ producing T cells, the early inflammatory response orchestrating this outcome has not been defined. METHODOLOGY/PRINCIPAL FINDINGS Mice exposed to uninfected P. duboscqi bites and naïve mice were challenged with L. major-infected flies to characte...

The immunomodulatory properties of CD8 T cells with regulatory phenotype have become evident. It remains unclear whether the immunomodulatory function of CD8(+)CD28(-) T cells requires antigen-specific TCR interaction with major histocompatibility complex class I (MHC I). We have isolated naïve CD8(+)CD28(-) T suppressor cells (Tsup) from H2-Kk Des-TCR mice that express a transgenic, MHC class ...

BACKGROUND Successful combination antiretroviral therapy (cART) increases levels of CD4+ T-cells, however this increase may not accurately reflect long-term immune recovery since T-cell dysregulation and loss of T-cell homeostasis often persist. We therefore assessed the impact of a decade of effective cART on immune regulation, T-cell homeostasis, and overall T-cell phenotype. METHODS We con...

Higher morbidity and mortality following infections, particularly influenza, is observed in the elderly population. Because of this, people over 65 years old are often targeted for preventive immunization. Many vaccines, however, are not as effective in generating protective antibodies in older individuals. CD4+ T cells, through their B cell helper functions, play a central role in the humoral ...

CD4+ T cells with cytotoxic activity (CD4 CTL) have been observed in various immune responses. These cells are characterized by their ability to secrete granzyme B and perforin and to kill the target cells in an MHC class II-restricted fashion. Although CD4 CTLs were once thought to be an in vitro artifact associated with long-term culturing, they have since been identified in vivo and shown to...