HIV/AIDS is raging and causing millions of deaths around the world. The major challenge in treating HIV/AIDS is the establishment of HIV reservoirs where the viruse escapes both drug and immune system attempts at eradication. Throughout the course of HIV/AIDS, productive HIV infection occurs primarily in the lymphoid follicles or germinal centers (GC) surrounding follicular dendritic cells (FDC). In the GCs, FDCs trap and maintain infectious HIV for years and provide these infectious viruses to the host cells. FDCs also attract B and T cells into the GCs and increase the ability of CD4+ T cells to be infected. Additionally, FDCs also mediate the increase of HIV replication in HIV-infected CD4+ T cells. Recently, several clinical cases and in vitro studies suggest that alpha-1-antitrypsin (AAT) might inhibit HIV infection and replication. Therefore, I hypothesized that AAT inhibited both the infection and replication of HIV in primary CD4+ T cells. I also postulated that AAT inhibited the FDC-mediated contributions that potentiate HIV infection and replication. To test whether AAT inhibited HIV infection in lymphocytes, CD4+ T cells were pretreated with AAT and then incubated with HIV to detect HIV infection. To exam whether AAT inhibited HIV replication, infected CD4+ T cells were cultured with AAT to detect the replication of HIV. To determine whether AAT blocked the FDC-mediated contributions to HIV pathogenesis, activated or resting FDCs were treated with AAT to detect the trapping and maintenance of HIV. The results suggested that AAT inhibited HIV entry into CD4+ T cells by directly interacting with gp41 and thereby inhibiting the interaction between HIV and CD4+ T cells. AAT also inhibited HIV replication in infected CD4+ T cells. Further study revealed that AAT interacted with low-density lipoprotein-receptor related protein to mediate the internalization of AAT through a clathrin-dependent endocytic process in CD4+ T cells. Subsequently, internalized AAT was transported from the endosome to the lysosome and then released into the cytosol. In the cytosol, AAT directly interacted with IκBα to block its polyubiquitinylation at lysine residue 48, which resulted in the accumulation of phosphorylated/ubiqutinylated IκBα in the cytosol. In turn, the dissociation of IκBα from NF-κB was blocked, which thereby inhibited the nuclear translocation and activation of NF-κB. Additionally, AAT also down-regulated FDC-CD32 and FDC-CD21 expression, which are regulated by NF-kB, thereby inhibiting the trapping and maintenance of HIV on FDCs. Hence, AAT not only suppresses HIV replication, but also blocks HIV replication in CD4+ T cells. Moreover, AAT also inhibits the activation of FDCs thereby affecting the trapping and maintenance of HIV.

Activation of the immune system during photodynamic therapy (PDT) and improvement of the effector functions of mAbs - these are the ways to use and enhance the potential of the immune system to fight cancer. Tumor cells lack β-glucan as a surface compo¬nent and can‘t trigger complement receptor 3-dependent cellular cytoto¬xicity and initiate tumor-killing activity during PDT. So, it gave rise to the hypothesis that β-glucan in combination with PDT will produce more effective killing of by iC3b fragment opsonized tumor cells. The human Fc portion is essential for the recruiting of human effector immune cells to produce antitumor effect. Therefore, connection of Fv portion of murine anti-CD7 antibody with Fc portion of human IgG1 can be helpful for such protein to obtain ideal feathers. However, each modification of the monoclonal antibody can cause the lost or decrease in the rate of protein expression and antigen-binding properties. Monoclonal antibody products are unique in their molecules. Because of post-translational modifications that often occur during the fermentation process, the final product is heterogeneous. Therefore, careful characterization of monoclonal antibodies is required in order to assess their identity, purity, potency and safety. Response of Lewis lung carcinoma tumor to PDT modulated by β-glucan was assessed in mice and functional characteristics of novel purified chimeric anti-CD7 antibody was tested in this study. / Imuninės sistemos aktyvinimas taikant fotosensibilizacinę terapiją (FNT) ir monokloninių antikūnų efektorinių funkcijų gerinimas yra vienas iš būdų, kaip naudoti ir sustiprinti organizmo imuninės sistemos veiksnių potencialą kovai su naviku. Navikinės ląstelės membranos paviršiuje nėra β-gliukano, todėl FNT metu negali būti aktyvinamas nuo komplemento receptoriaus 3 priklausomas ląstelės citotoksiškumo mechanizmas bei sukeliama navikinės ląstelės žūtis. Todėl galima tikėtis, kad β-gliukanas ir FNT, taikomi kartu, gali aktyvinti iC3b frag¬mento opsonizuotų navikinių ląstelių žūtį. Norint aktyvinti žmogaus imunines ląsteles priešnavikiniam poveikiui sukelti, pelės monokloniniam antikūnui būtina žmogaus imunoglobulino Fc dalis. Todėl pelės antikūno prieš CD7 vienos grandinės Fv fragmento sujungimas su žmogaus imunoglobulino G1 Fc dalimi baltymui gali suteikti idealias savybes. Tačiau, bet kokia monokloninio antikūno modifikacija gali keisti jo savybes ir, išskiriant baltymą, dėl daugiapakopio proceso ji gali keistis. Todėl, norint įvertinti chimerinio CD7-Fc antikūno identiškumą, grynumą, veiksmingumą bei saugumą, būtina atlikti tyrimus, kuriais būtų galima nustatyti, ar antikūnas išlaiko specifiškumą antigenui, kaip aktyviai jungiasi prie jo, ar aktyvina imuninius mechanizmus. Šio tyrimo metu buvo vertintas pelėms įskiepytos Luiso plaučių karcinomos atsakas į FNT moduliaciją β-gliukanu ir išgrynintas chimerinis antikūnas prieš CD7 bei ištirtos jo funkcinės savybės in vitro.