Toward a Molecular Understanding of Adaptive Immunity: A Chronology, Part III

La inmunología en Antioquia: una historia con futuro. I. La creación de una Escuela

Mundialmente la inmunología es una de las ciencias biomédicas con mayor desarrollo en la segunda parte del siglo xx y principios del siglo xxi, además ha tenido un desarrollo muy importante en Antioquia a partir de los años sesenta del siglo xx. En la presente reseña histórica, el autor, quien ha participado activamente durante cincuenta años como estudiante y profesor de inmunología en la Universidad de Antioquia, relata los momentos más significativos y el papel que han desempeñado algunos distinguidos profesores en el desarrollo de la investigación y la docencia de pregrado y posgrado en esta disciplina. En esta primera parte se relatan los antecedentes y los eventos que en las décadas de 1960 y 1970 permitieron establecer la inmunología como una disciplina biomédica independiente en la Universidad de Antioquia.

Vaccination with trifunctional nanoparticles that address CD8+ dendritic cells inhibits growth of established melanoma

AIM

We wanted to assess the potency of a trifunctional nanoparticle (NP) that targeted and activated CD8⁺ dendritic cells (DC) and delivered an antigen to induce antitumor responses.

MATERIALS & METHODS

The DC targeting and activating properties of ferrous NPs conjugated with immunostimulatory CpG-oligonucleotides, anti-DEC205 antibody and ovalbumin (OVA) as a model antigen to induce antigen-specific T-cell responses and antitumor responses were analyzed.

RESULTS

OVA-loaded NP conjugated with immunostimulatory CpG-oligonucleotides and anti-DEC205 antibody efficiently targeted and activated CD8⁺ DC in vivo, and induced strong OVA-specific T-cell activation. Vaccination of B16/OVA tumor-burdened mice with this NP formulation resulted in tumor growth arrest.

CONCLUSION

CD8⁺ DC-targeting trifunctional nanocarriers bear significant potential for antitumor immunotherapy.

Human Memory CD4+ T Cell Immune Responses against Giardia lamblia

The intestinal protozoan parasite Giardia lamblia may cause severe prolonged diarrheal disease or pass unnoticed as an asymptomatic infection. T cells seem to play an important role in the immune response to Giardia infection, and memory responses may last years. Recently, TH17 responses have been found in three animal studies of Giardia infection. The aim of this study was to characterize the human CD4(+) T cell responses to Giardia. Peripheral blood mononuclear cells (PBMCs) were obtained from 21 returning travelers with recent or ongoing giardiasis and 12 low-risk healthy controls and stimulated in vitro with Giardia lamblia proteins. Production of tumor necrosis factor alpha (TNF-α), gamma interferon, interleukin-17A (IL-17A), IL-10, and IL-4 was measured in CD4(+) effector memory (EM) T cells after 24 h by flow cytometry. After 6 days of culture, activation and proliferation were measured by flow cytometry, while an array of inflammatory cytokine levels in supernatants were measured with multiplex assays. We found the number of IL-17A-producing CD4(+) EM T cells, as well as that of cells simultaneously producing both IL-17A and TNF-α, to be significantly elevated in the Giardia-exposed individuals after 24 h of antigen stimulation. In supernatants of PBMCs stimulated with Giardia antigens for 6 days, we found inflammation-associated cytokines, including 1L-17A, as well as CD4(+) T cell activation and proliferation, to be significantly elevated in the Giardia-exposed individuals. We conclude that symptomatic Giardia infection in humans induces a CD4(+) EM T cell response of which IL-17A production seems to be an important component.

Granulocyte-Colony Stimulating Factor related pathways tested on an endometrial ex-vivo model

INTRODUCTION

Recombinant human Granulocyte-Colony Stimulating Factor (rhG-CSF) supplementation seems to be a promising innovative therapy in reproductive medicine, used in case of recurrent miscarriage, embryo implantation failure or thin endometrium, although its mechanisms of action remain unknown. Our aim was to identify possible endometrial pathways influenced by rhG-CSF.

MATERIALS AND METHODS

Hypothetical molecular interactions regulated by G-CSF were designed through a previous large scale endometrial microarray study. The variation of endometrial expression of selected target genes was confirmed in control and infertile patients. G-CSF supplementation influence on these targets was tested on an endometrial ex-vivo culture. Middle luteal phase endometrial biopsies were cultured on collagen sponge with or without rhG-CSF supplementation during 3 consecutive days. Variations of endometrial mRNA expression for the selected targets were studied by RT-PCR.

RESULTS

At the highest dose of rhG-CSF stimulation, the mRNA expression of these selected target genes was significantly increased if compared with their expression without addition of rhG-CSF. The selected targets were G-CSF Receptor (G-CSFR), Integrin alpha-V/beta-3 (ITGB3) implicated in cell migration and embryo implantation, Plasminogen Activator Urokinase Receptor (PLAUR) described as interacting with integrins and implicated in cell migration, Thymidine Phosphorylase (TYMP) implicated in local angiogenesis, CD40 and its ligand CD40L involved in cell proliferation control.

CONCLUSION

RhG-CSF seems able to influence endometrial expressions crucial for implantation process involving endometrial vascular remodelling, local immune modulation and cellular adhesion pathways. These variations observed in an ex-vivo model should be tested in-vivo. The strict indications or counter indication of rhG-CSF supplementation in reproductive field are not yet established, while the safety of its administration in early pregnancy on early embryogenesis still needs to be demonstrated. Nevertheless, rhG-CSF appears as a promising therapy in some difficult and unsolved cases of reproductive failure. Indications of pre-conceptual rhG-CSF supplementation may derive from a diagnosed lack of endometrial expression of some target genes.

Roles of ligands from the TNF superfamily in B cell development, function, and regulation

Most ligands from the tumour necrosis factor (TNF) superfamily play very important roles in the immune system, and particularly so in B lymphocyte biology. TNF ligands are essential to many aspects of normal B cell biology from development in the bone marrow to maturation in the periphery as well as for activation and differentiation into germinal centre, memory or plasma cells. TNF ligands also influence other aspects of B cell biology such as their ability to present antigens or regulate immune responses. Importantly, inadequate regulation of many TNF ligands is associated with B cell disorders including autoimmunity and cancers. As a result, inhibitors of a number of TNF ligands have been tested in the clinic, with some becoming very successful approved treatments alleviating B cell-mediated pathologies.