The crustacean hyperglycemic hormone (CHH) peptides regulate diverse physiological processes from reproduction to metabolism and molting in arthropods. In insects, the ion transport peptides (ITP), also members of the CHH family, have only been implicated in ion transport. In this study, we sequenced a nucleotide fragment spanning the conserved A1/A2 region of the putative CHH/ITP gene. This fragment was amplified from larval cDNA of the tobacco hornworm, Manduca sexta and showed a high degree of sequence conservation with the same region from other insects and, to a lesser degree, with that of crustacean species, suggesting the presence of a Manduca-specific CHH/ITP mRNA (MasITP mRNA). CHH-like immunocytochemical analyses with two crustacean antisera (from Carcinus maenas and Cancer pagurus) identified the presence of CHH-like immunoreactivity in nervous tissue of all developmental stages, but not in the gut of M. sexta. Specifically, CHH-like peptides localized to paired type IA(2) neurosecretory cells of the pars lateralis of the brain (projecting ipsilaterallly to the corpora cardiaca-allata complex) and to neurosecretory cells and transverse nerves of the ventral nerve cord in larvae, pupae, and adults. The distribution of the putative MasITP peptide shifted during development in a manner consistent with metamorphic reorganization. A comparison of hemolymph equivalents of CHH detected by enzyme-linked immunosorbent assay with CHH-like immunoreactivity in transverse nerves provided evidence for the release of MasITP from the transverse nerves into the hemolymph at insect ecdysis. These data suggest the presence of an insect ITP in M. sexta and a role for this hormone during ecdysis.

Mother-to-child-transmission of HIV by breast-feeding remains a major obstacle in the eradication of HIV infection. Compared to adults, HIV-infected infants have more rapid disease and show higher susceptibility to co-infections like tuberculosis (TB). Although the Bacille Calmette-Guérin vaccine can be administered at birth to protect against TB, BCG can disseminate in HIV-infected infants and increase mortality. Thus, a pediatric combination vaccine to stop both HIV and TB infection in infants is urgently needed. Towards the goal of developing a pediatric combination HIV-TB vaccine to prevent both oral HIV acquisition by breast-feeding and TB infection, we tested and optimized an immunization regimen using a novel live attenuated Mycobacterium tuberculosis vaccine engineered to express simian immunodeficiency (SIV) antigens followed by heterologous MVA-SIV boosting in the infant macaque model. A single oral dose of the attenuated Mtb-SIV vaccine strain mc26435 during the first week of life was sufficient to induce persistent TB-specific immune responses. SIV-specific immunity was induced at low but comparable magnitudes after oral or intradermal priming, and was enhanced following MVA-SIV boosts. T cell responses were most pronounced in intestinal tissues and oral lymph nodes. Importantly, in addition to plasma SIV-specific IgG and IgA antibodies, infant macaques developed mucosal SIV-specific IgA in saliva and intestinal IgA and IgG. While future SIV and Mtb challenge studies will be needed to determine the protective efficacy of the Mtb-SIV / MVA-SIV vaccine, infants at high risk for oral HIV acquisition by breast-feeding and TB infection could profoundly benefit from an effective combination vaccine.

Congenital human cytomegalovirus (HCMV) infection can result in lifelong neurological deficits. Seronegative pregnant woman often acquire primary HCMV from clinically asymptomatic, but HCMV-shedding children. Potential age-related differences in viral and immune parameters of primary RhCMV infection were examined in an oral rhesus CMV infection model in specific pathogen free macaques.

Infants compared to adults exhibit reduced immune responsiveness and are biased towards a T helper 2 (Th2) response. We hypothesized that this is due to the presence of intrinsic differences in cytokine receptor signaling in CD4+ T cells. We utilized human adult and cord blood (CB) samples to determine whether age-related differences exist in (i) Th1 and Th2 cytokine receptor (R) expression, (ii) STAT phosphorylation, and/or (iii) JAK/STAT signaling. Our data show that a lower percentage of CB compared to adult CD4+ T cells expresses IFNγR1 (P=0.0053). However, absolute numbers of IFNγR1 are higher on CB compared to CD4+ T cells (P=0.0305). In contrast, we did not detect differences in the levels of IL4Rα expression. Consistent with this data, CB CD4+ T cells show lower phosphorylation levels of STAT1, but not STAT6 in response to IFNγ or IL4 stimulation. Furthermore, several genes of the JAK/STAT signaling pathway (e.g. jak1, ifng, stam, isg15 and oas1) were induced at higher magnitude and with faster kinetics in adult compared to CB PBMC after in vitro stimulation with IFNγ. Thus, our data demonstrate that unique age-related differences exist in CD4+ T cell cytokine receptor signaling that may underlie the reduced immune responsiveness and Th2-biased response of infants. Unraveling these molecular mechanisms may aid in pediatric vaccine and therapeutics design.

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