Although a fraction of human blood memory CD4+ T cells expresses chemokine (C-X-C motif) receptor 5 (CXCR5), their relationship to T follicular helper (Tfh) cells is not well-established. Here we show that human blood CXCR5+ CD4+ T cells share functional properties with Tfh cells, and appear to represent their circulating memory compartment. Blood CXCR5+ CD4+ T cells comprised three subsets; T helper 1 (Th1), Th2 and Th17 cells. Th2 and Th17 cells within CXCR5+, but not within CXCR5−, compartment efficiently induced naïve B cells to produce immunoglobulins via interleukin-21 (IL-21). In contrast, Th1 cells from both CXCR5+ and CXCR5− compartments lacked the capacity to help B cells. Patients with juvenile dermatomyositis, a systemic autoimmune disease, displayed a profound skewing of blood CXCR5+ Th subsets towards Th2 and Th17 cells. Importantly, the skewing of subsets correlated with disease activity and frequency of blood plasmablasts. Collectively, our study suggests that an altered balance of Tfh subsets contributes to human autoimmunity.

Summary Little is known on the functional differences of the human skin myeloid DC subsets, epidermal CD207+ Langerhans cells (LCs) and dermal CD14+ DCs. We show that CD14+ DCs prime CD4+ T cells into cells that induce naïve B cells to switch isotype and become plasma cells. LCs preferentially induce the differentiation of CD4+ T cells secreting Th2 cytokines and are remarkably efficient at priming and crosspriming naïve CD8+ T cells. A third DC population, CD14-CD207-CD1a+ DC population, which resides in the dermis can activate CD8+ T cells better than CD14+ DCs but less efficiently than LCs. Thus, human skin display three DC subsets, two of them i.e. CD14+ DCs and LCs, display functional specializations; the preferential activation of humoral or cellular immunity respectively.

Tumor budding is a well-established independent prognostic factor in colorectal cancer but a standardized method for its assessment has been lacking. The primary aim of the International Tumor Budding Consensus Conference (ITBCC) was to reach agreement on an international, evidence-based standardized scoring system for tumor budding in colorectal cancer.The ITBCC included 9 sessions with presentations, a pre-meeting survey, and an e-book covering the key publications on tumor budding in colorectal cancer. The "Grading of Recommendation Assessment, Development and Evaluation" method was used to determine the strength of recommendations and quality of evidence.

Because of its value as a prognostic indicator and its reproducibility, tumour 'budding' would be a good index to estimate the aggressiveness of rectal cancer.

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Seasonal influenza vaccine protects 60 to 90% of healthy young adults from influenza infection. The immunological events that lead to the induction of protective antibody responses remain poorly understood in humans. We identified the type of CD4+ T cells associated with protective antibody responses after seasonal influenza vaccinations. The administration of trivalent split-virus influenza vaccines induced a temporary increase of CD4+ T cells expressing ICOS, which peaked at day 7, as did plasmablasts. The induction of ICOS was largely restricted to CD4+ T cells co-expressing the chemokine receptors CXCR3 and CXCR5, a subpopulation of circulating memory T follicular helper cells. Up to 60% of these ICOS+CXCR3+CXCR5+CD4+ T cells were specific for influenza antigens and expressed interleukin-2 (IL-2), IL-10, IL-21, and interferon-γ upon antigen stimulation. The increase of ICOS+CXCR3+CXCR5+CD4+ T cells in blood correlated with the increase of preexisting antibody titers, but not with the induction of primary antibody responses. Consistently, purified ICOS+CXCR3+CXCR5+CD4+ T cells efficiently induced memory B cells, but not naïve B cells, to differentiate into plasma cells that produce influenza-specific antibodies ex vivo. Thus, the emergence of blood ICOS+CXCR3+CXCR5+CD4+ T cells correlates with the development of protective antibody responses generated by memory B cells upon seasonal influenza vaccination.

Japanese mortality due to colorectal cancer is on the rise, surpassing 49,000 in 2015. Many new treatment methods have been developed during recent decades. The Japanese Society for Cancer of the Colon and Rectum Guidelines 2016 for the treatment of colorectal cancer (JSCCR Guidelines 2016) were prepared to show standard treatment strategies for colorectal cancer, to eliminate disparities among institutions in terms of treatment, to eliminate unnecessary treatment and insufficient treatment, and to deepen mutual understanding between health-care professionals and patients by making these Guidelines available to the general public. These Guidelines were prepared by consensus reached by the JSCCR Guideline Committee, based on a careful review of the evidence retrieved by literature searches, and in view of the medical health insurance system and actual clinical practice settings in Japan. Therefore, these Guidelines can be used as a tool for treating colorectal cancer in actual clinical practice settings. More specifically, they can be used as a guide to obtaining informed consent from patients and choosing the method of treatment for each patient. As a result of the discussions held by the Guideline Committee, controversial issues were selected as Clinical Questions, and recommendations were made. Each recommendation is accompanied by a classification of the evidence and a classification of recommendation categories based on the consensus reached by the Guideline Committee members. Here we present the English version of the JSCCR Guidelines 2016.

Our understanding of the origin and functions of human blood CXCR5+ CD4+ T cells found in human blood has changed dramatically in the past years. These cells are currently considered to represent a circulating memory compartment of T follicular helper (Tfh)-lineage cells. Recent studies have shown that blood memory Tfh cells are composed of phenotypically and functionally distinct subsets. Here we review the current understanding of human blood memory Tfh cells and the subsets within this compartment. We present a strategy to define these subsets based on cell surface profiles. Finally, we discuss how increased understanding of the biology of blood memory Tfh cells may contribute insight into the pathogenesis of autoimmune diseases and the mode of action of vaccines.