Organization of Lymphocyte Receptor Genes Defintions

Germ-line theory: Suggests that genetic information for each antibody is encoded, in its entirety, within the germ-line genome.

After revaluations and calculations the germ-line theory was not accurate because there simply was not enough DNA to fit the size of antibody repertoire.  

 

Recombination Signal Sequences (RSS): Specific DNA sequence motifs that ensure one of each type of segment (V & J for the light chain OR V, D & J for the heavy chain) is included in the recombined variable region gene.

The RSS for the V region must be 3’, while the RSS for the J region must be 5’ in order to be compatible for joining.

Terminal deoxynucleotidyl Transferase (TdT): Enzyme responsible for the generation of additional diversity in the CDR3 region of the antibody heavy chain

TdT, RAG1 and RAG2 are the three proteins implicated in V(D)J recombination that are unique to lymphocytes.

Specific Antibody Deficiency (SAD) Investigation

           In class we have been discussing the structure and function of the different classes of anitbodies we find in our immune system. Our body contains five classes on immunoglobulins which include IgA, IgG, IgD, IgE, and IgM. Out of these five IgG is the immunoglobulin who has the main role in protection against infections, as it protects us from bacteria and viruses. SAD is a disorder in which a person has normal levels of all immunoglobulins except IgG. Due to the fact that IgG having a main role in protecting against infection, it is common for patients with SAD to experience recurrent infections. Particularly it has been found that IgG acts against the sugar coat of illnesses such as Streptococcus pneumoniae, Moraxella catarrhalis and Haemophilus influenza. This is because IgG produces molecules against the pathogens that cause upper and lower respiratory infections.

            However, as crucial as IgG is to our immune system, our bodies are equipped with other components that also help in fighting off infections such as T cells, complements proteins, other WBCs and IgA. This explains why some patients diagnosed with SAD rarely get sick. This means that their other components are working well together and compensating for the deficiency of IgG. In general, the infections suffered by patients with SAD are not as severe as those suffered by patients who have combined deficiencies of IgG, IgA and IgM. For example diseases such as X-linked Agammaglobulinemia (XLA) or Common Variable Immune Deficiency. Although, often patients with SAD will come to the physician’s office with a single severe pneumonia or other infection.

          Although recurrent infections in the ears, sinuses, bronchi or lungs is usually a pretty good indicator of SAD, to diagnose precisely diagnose one must measure the total amount of immunoglobulins. Treatment for SAD usually can be treated with antibiotics, unless the infection has taken a severe course. In this case Ig replacement therapy is considered. Children are more likely to outgrow SAD through close monitoring and immunizations such as pneumococcal vaccines. If diagnosed as a teenager or adult it is less likely that the deficiency will be resolved on its own. In both scenarios close monitoring of the Ig levels is crucial.

 

 

 

"Specific Antibody Deficiency." Immune Deficiency Foundation. N.p., 2013.

        Web. 19 Oct. 2016. <http://primaryimmune.org/about-primary-

         immunodeficiencies/specific-disease-types/specific-antibody-         deficiency/>.                                                  

Post Exam 1 Reflection

My immunology learning has expanded more and more as the semester goes by both inside and outside of the classroom. In class lectures I am enriched with a lot of content and information as I do my best to keep up with the professor by taking notes and looking at the slides. Taking notes is definitely a method that works for me, because the act of writing the most important portion of what was said helps me make connections in my brain that are more likely to stay. Even if the professor is talking really fast and I feel as though I will not be able to keep up with my notes I still am convinced my “chicken scratch” is better than nothing. Another learning technique that I have found to be helpful outside of the classroom has been to make 3x5 color-coded notecards based on the slides and my notes. I used this notecards not only to study the material but also to make connections by grouping notecards in a kinetic manner. For this last exam that we had I made a large amount of notecards which was time consuming, but definitely worth it at the end because as I was answering the questions on the test I felt confident in knowing the material. Another study habit that helped me was encountering the material in different settings. For example, over the weekend I attempted to explain the core concepts of immunology to my mother in the most simplified way I could (in Spanish) so that she could understand. This method forced my mind to work extra hard in making connections both with the content and then translating them into Spanish. Surely the concepts I explained to her have been ingrained in my memory. I love immunology because it is a class that is extremely relevant to my future as I aspire to become a health professional. This class is surely preparing me for graduate school where I am sure to encounter the material again. Even more importantly it is preparing me to be able to diagnose my patients and educate them on how a particular disease is affecting their body, down to the cells and their mechanisms. I believe the two most important things I have learned in class thus far is the interaction between MHC class 1 and 2 and how the body uses these cell surface proteins to recognize self from non-self. The second most important thing I’ve learned is the process of inflammation and what is happening internally on the cellular level when the tissue is damaged.

Innate Immunity Definitions

 

1. Pathogen-associated molecular patterns (PAMPs): Conserved motifs, usually present many copies on the surface of a bacterium, fungal cell, parasite, or virus particle.

“Scavenger receptors recognize PAMPs such as LPS, lipoteichoic acid (LTA) or β-glucans and trigger phagocytosis.”

 

 

2. Opsonization: Deposition of opsonins on an antigen, thereby promoting a stable adhesive contact with an appropriate phagocytic cell.

 “Antibodies and complement components aid in opsonization by coating  a dangerous MRSA pathogen, making it "tasty” for phagocytic cells.

3. Toll-like receptors (TLRs): A family of cell-surface receptors found in invertebrates and vertebrates that recognize conserved molecules from many pathogens.

“Unique to among TLRs, TLR4 has been found to move from the plasma membrane where it binds to PAMPs and also in endosomes and lysosomes where it recognizes degradation of endocytosed pathogens.”